* This weblog provides an "online notebook" to provide comments on current events, interesting items I run across, and the occasional musing. It promotes no particular ideology. Remarks may be left on the site comment board; all sensible feedback is welcome.
* WINGS & WEAPONS: The idea of submarines launching surface-to-air missiles (SAM) to defend themselves from antisubmarine warfare (ASW) helicopters is not new, but the idea has never caught on. Now, according to an article from IHS JANE'S Online ("IDAS Partners Look To Re-plan Submarine Development Firing" by Richard Scott, 27 June 2017), Diehl Defence and Thyssenkrupp Marine Systems are now collaborating on an "Interactive Defence & Attack System for Submarines (IDAS)" self-defense SAM system, with a test launch to take place before the end of the year.
IDAS is built around the Diehl IRIS-T air-to-air missile. Range is given as 10 kilometers (6.2 miles), with the weapon also capable of attacking small surface craft or other targets. IDAS is fired out of a torpedo tube; since IRIS-T is an infrared heat-seeking missile, IDAS adds a fiber-optic link to give active control of the weapon until it can acquire a target. If the link with the operator on the submarine is broken, the missile will continue with its attack autonomously.
The IDAS Consortium was established in 2012. Diehl Defence is responsible for the IDAS missile itself, the fiber-optic system, and the missile control system, while Thyssenkrupp is performing submarine integration and the ejection container system. Each container stores four missiles, with a piston system used to shoot each missile individually out of the torpedo tube.
* As discussed by an article from WIRED Online ("Airbus' New Black Boxes Will Eject From Crashing Planes" by Jack Stewart, 4 July 2017), the disappearance of Malaysian Airlines Flight 370 on 8 March 2014 led to a massive search for the missing aircraft that came up zero. That leaves as an ongoing issue how to make sure an airliner won't simply disappear again.
After the loss of MH370, the International Civil Aviation Authority adopted a new standard requiring a plane to be capable of reporting its position at least every 15 minutes -- going to once a minute in an emergency. There's talk of continuous data relay through satellite, but it's not very practical for an airliner to relay much more than its position and flight path once a minute. An airliner "black box", or flight data recorder, monitors almost a hundred sensors, computer inputs, switch positions, and flap locations, as well as a continuous recording of voices through the pilots' headsets and a cockpit microphone. It simply wouldn't be practical to send such a stream of data on a near-continuous basis.
European aircraft giant Airbus has a compromise proposal, in the form of deployable flight data recorders. On large planes that frequently fly over water or remote areas, Airbus will install a second, redundant black box near the rear of the fuselage, with a mechanical ejection system. If an airliner crashes into the sea, the black box -- which will actually be fluorescent orange -- will be popped out, to float on the surface of the water using an emergency locator signal.
The black box will be ejected only if the aircraft undergoes major structural deformation, or if it is submerged in more than about two meters of water. That will prevent it from being deployed on false alarms. Unlike the current generation of black boxes, the new Airbus black boxes will store 25 hours of voice and data, not just two. Airbus plans to introduce the ejectable black boxes in 2019, first on the A350, then across the Airbus product line.
* As discussed by an article from JANES' IHS 360 Online ("Anglo-French Anti-Ship Missile Completes First Test" by Craig Hoyle, 5 July 2017) European defense giant MBDA has now test-fired the company's next-generation light antiship missile, being developed for a joint UK-France requirement. The weapon, named the "Sea Venom" AKA "Anti-Navire Legere (ANL / anti-ship light)", is to replace the current British Sea Skua and French AS-15TT helicopter-launched light antiship missiles.
Sea Venom / ANL has a maximum range of 20 kilometers (12.4 miles). The weapon has a launch weight of 100 kilograms (220 pounds), including a 30-kilogram (66-pound) warhead. It has an imaging infrared seeker and a two-way datalink, allowing an operator to view the seeker image and provide course updates, including retargeting. Primary targets are fast patrol boats, corvettes, and other small warships. The Royal Navy plans to carry the missile on the Leonardo AW159 Wildcat helicopter, while the French Navy plans to carry them on the AS565 Dauphin and NH90 helicopters. Adapting the Sea Venom / ANL to launch platforms, such as the AW159, that already carry light antiship missiles is seen as easy.COMMENT ON ARTICLE
* PRINTED BONES: As discussed by an article from AAAS SCIENCE NOW Online ("Print-On-Demand Bone Could Quickly Mend Major Injuries" by Jessica Boddy, 28 September 2016), researchers have now created what they call "hyperelastic bone" that can be manufactured on demand, and works almost as well as the real thing -- at least as shown by tests using monkeys and rats. ranging from bones wracked by cancer to broken skulls.
Surgeons currently replace shattered or missing bones using a number of techniques. The most common option is an "autograft", where a piece of bone is taken from a patient's own body, usually from a hip or a rib, and implanted where it's needed elsewhere. Surgeons prefer autografts because they're real bone, complete with stem cells that give rise to cartilage and bone cells to provide extra support for the new graft. Humans can't regrow entire skeletons from scratch with stem cells, but existing bone can signal stem cells where to grow and what to grow into. There's also no risk of immune rejection. The problem is there's only so much bone that can be shuttled around a person's body, and doing so requires added surgery.
Another bone replacement option is creating a scaffold for bone to grow on. Such scaffolds, made of both natural and synthetic materials, provide a substrate for stem cells that then build bone -- in principle, at least. The problem is that stem cells can be choosy about what substrate materials they like to grow on. Researchers have persuaded stem cells to grow on a ceramic material named "calcium phosphate (CaP)", but a CaP scaffold is stiff and brittle, making it difficult to implant into patients. Worse, sometimes the body will reject the scaffolds. There's also the problem of fabricating them, particularly for replicating many small bones, as in facial surgery.
Researchers at Northwestern University in Evanston, Illinois, think they can address all these problems. Their hyperelastic bone is a 3D-printed scaffold made up of "hydroxyapatite", a naturally occurring mineral that exists in our bones and teeth; a biocompatible polymer called "polycaprolactone"; and a solvent -- with the roles:
The mixture is printed layer-by-layer, computer-controlled to produce a specific bone. If, for example, a patient came in with a broken jaw, the patient can be x-rayed, with the data fed into a design system that generates the appropriate scaffold configuration. The scaffold can then be immediately printed in preparation for implantation. Of course, the scaffold design system would require a lot of effort, in particular since the x-ray imagery it obtained would be for a broken bone; it would have to be able to extrapolate back to an unbroken bone.
The research team originally tried the scheme to fuse spinal vertebrae in rats, as a step towards use in spinal surgery in humans. Eight weeks after the Northwestern researchers implanted the hyperelastic bone, they found that new blood vessels had grown into their scaffold, and calcified bone started to form from the rats' existing stem cells.
The researchers also used hyperelastic bone to repair a macaque monkey's damaged skull. After four 4 weeks with a hyperelastic bone implant, the scaffold was infiltrated with blood vessels and some calcified bone. The macaque also didn't suffer from any adverse biological effects, such as inflammation or infection -- which are often problems with synthetic implants.
The ink materials -- hydroxyapatite, polymer, and solvent -- are commonly used in biomedical engineering labs, and are not particularly expensive. A custom bone could be printed in five hours or less; sheets could also be pre-printed, which surgeons could cut and paste into the shape they want. That's all a future, however; the technique has not been trialed in humans yet, and an operational system will require a lot of work. Nonetheless, the medical research community feels the scheme has ground-breaking potential.COMMENT ON ARTICLE
* FLOODED OUT: In October 2012, Hurricane Sandy descended on the US Northeast, destroying or damaging 650,000 homes and killing some 159 people. Rising seas made the storm surge that much more disastrous, and since that time there has been a push to persuade those living in vulnerable coastal areas to move inland.
As discussed here earlier in 2017, not everyone has been willing to go, preferring to remain and take their chances. According to an article from REUTERS ("New York Lets Neighborhood Return To Nature To Guard Against Storms" by Peter Szekely, 27 October 2017), the effort's has done well on Staten Island, one of the boroughs of New York City.
When New York State officials offered to buy up properties on Staten Island to set up an uninhabited buffer zone, Frank and Mary Lettieri were reluctant to leave their neighborhood of Oakwood Beach. They'd lived in their home since 1987, raised five kids there, and had spent a small fortune rebuilding the house after Sandy. However, the offer wasn't something they could ignore, either: they'd also been flooded out in 1992, while Sandy had drowned a father and son in the house next door. The Lettieris took the offer, and moved to higher ground farther inland. Frank said: "The writing was on the wall. We had to go."
According to a recent study from Rutgers University, sea level rise will dramatically increase the average number of storms that flood New York City with surges of at least 2.3 meters (7.4 feet). The researchers traced the history of flooding in the area by examining sediment cores going back to 850 CE. They found that, before 1800, such surges only took place about once every 500 years; but from the 1970s, they picked up to once in 25 years on the average. Using computer modeling, they estimated the rate would be once every five years by 2030. By 2100, this "once in 500 years" event will have surges of 5.1 meters (16.7 feet). According to Lisa Bova-Hiatt, executive director of the Governor's Office of Storm Recovery: "To say that extreme weather is not our new normal would just be incredibly short-sighted."
Using money from the US Department of Housing & Urban Development, New York has spent $255 million USD to buy 654 properties, mostly on Staten Island, with dozens more in the pipeline. According to Bova-Hiatt: "The program is voluntary. However, at some point it would be fantastic to have the entire area as a buffer zone."
About 80% of the Staten Islanders offered the deal took it. As for the die-hards, Bova-Hiatt says the state has no intention of using the power of "eminent domain" to force them to move. However, the buyout program is not certain to persist indefinitely and, in the face of future Sandys, they stand to lose everything.
Two of them stay-behinds in Oakwood Beech are Gregory and Olga Epshteyn. They feel along at times, most of the other homes having been torn down to allow the area to return to its natural state. Gregory says that the city still diligently provides services, such as garbage pickup and street lights. Olga adds: "We love it here, but we miss our neighbors."COMMENT ON ARTICLE
* DRONES FOR AFRICA (2): The Zipline system is only now going into service, but everyone involved is optimistic, believing that other undeveloped countries in Africa and elsewhere will see drones as an enabling technology for development. The Rwandan government is now looking beyond the Zipline system, building the first of a network of "droneports" as a pilot project. The facility was award-winning British architect Norman Foster. Foster's design for the initial droneport focused on a low-cost structure, based on using local earth mixed with additives to construct a set of vaults -- each resembling a tarpaulin held down at four corners, blown to a domelike configuration, being left open-air or given walls as need be. They are not only cheap, but seem entirely African in their style.
The droneports will support a "Redline" network, which will transport medical and emergency supplies, presumably as an extension of the Zipline scheme, and a "Blueline" network, which will make larger commercial deliveries and subsidize the medical supply chain. Jonathan Ledgard -- founder of Redline and a former Africa correspondent for THE ECONOMIST -- sees the initial droneport as an experiment: "Aerospace companies are looking to move down in size, while robotics startups are looking to move up in size."
Africa's road network is too rickety to support robust growth. The Redline team believes drones can help bypass the ground transport bottleneck. Ledgard says: "We aim to have up to 18 ports on the national network for Rwanda, but there are much bigger opportunities in bigger countries, including beyond Africa. We're talking about a supplementary transport system -- not replacing rail, lorries, bikes, adding another system that doesn't exist, but that does make sense."
Rwanda's government is very enthusiastic about drones, but some other African countries are nervous. Drone projects in Kenya were put on hold for a time due to security concerns. South Africa, in contrast, likes drones as much as Rwanda. Working with South African National Parks, Peace Parks Foundation and other groups, UAV [Unmanned Aerial Vehicle] & Drone Solutions (UDS) has been testing aerial anti-poaching schemes in Kruger national park and KwaZulu-Natal province.
Otto Werdmuller von Elgg, director of UDS, says: "We've clocked about 4,000 hours of flying, 99% of that at night and almost 100% of it beyond the line of sight, two things that are usually forbidden under many drone regulations. The parks use conventional tactics during the day to locate and track, but without the drone and thermal imaging, they couldn't operate so well at night."
Drones have been tested in other parks and reserves on the continent, but some conservationists are sceptical, arguing that rangers' boots on the ground are cheaper and more important. But UDS insists its method helps to cover large areas and keeps rangers safer, especially at night. Von Elgg says: "Poachers used to be able to operate freely at night, but they quickly hear that we're in the area. We've seen a direct correlation between our presence and poaching numbers declining."
Drone enthusiasts see other applications for Africa, from delivery of product to infrastructure inspection. High-flying solar-powered drones may be able to provide wireless service over large areas at low cost. Some voices are calling for caution, however. Josiah Mugambi, executive director of the iHub, a technology and innovation space in Nairobi, says: "There is some potential in drones, but we need to not get overly focused on the technology and rather look at the problem you're trying to solve. If it's for niche uses, it may not be very scalable as a business. One of the obstacles has been security considerations -- people are worried about how they might be used, and that has put the brakes on it a bit."
The cautions are taken seriously, but the outlook is upbeat. Mbwana Alliy -- founder and managing partner of Savannah Fund, an early-stage seed fund focused on emerging tech companies in Africa -- says: "I think drones are the next big thing. There are big possibilities beyond the obvious delivery and logistics potential (from medical supplies to retail) -- around agriculture in helping farmers understand their land, yields better, around mapping, in construction and mining, even in market research. Drones may well bring the most exciting potential to marry the real and vast physical challenges of Africa with the digital revolution." [END OF SERIES]COMMENT ON ARTICLE
* ONCE & FUTURE EARTH (15): The Earth's early peridodite crust was temporary, being displaced by less dense basalt. Black basalt is widely found on all the large rocky worlds of the Solar System. The surfaces of Mercury, Venus, and Mars are mostly basalt; the dark low-lying "maria" of the Moon are basalt as well, contrasting with the anorthosite lunar highlands. 70% of the Earth's surface, including all the ocean floors, is basalt. There are variants of basalt, but they all have two major ingredients in common:
Basalt was derived from the peridotite crust as it sank into the Earth and was heated. Different components of the peridotite melted at different temperatures; at the lowest melting temperature, about 1,100C (2,000F), the melt was, relative to the body of the peridotite, substantially enriched in calcium and aluminum, slightly enriched in iron and silicon, and notably deficient in magnesium.
This magna was light enough to rise towards the surface, sometimes breaking through as volcanic eruptions, resulting in widespread deposits of black basalt. Sometimes it didn't break through, resulting in big underground deposits of gabbro. In any case, the Earth now had a permanent crust, one that was substantial enough to bear the weight of mountain ranges.
From space, the Earth would have had a dark surface, with red fissures and dotted with volcanoes. Eruptions, along with meteor impacts, were common, resulting in a hellish atmosphere -- the composition of which is not completely known, but it clearly had no free oxygen. The nearby Moon's tides helped keep the crust unstable, while the rapid rotation of the Earth meant storms beyond all human experience.
The effusions from the Earth and the objects from the sky often included quantities of water -- and so in time, oceans began to form. The atmosphere and the oceans are only a small portion of the Earth's total mass, with the atmosphere being about a millionth of the total, and the oceans only about a five-thousandths of the total. However, humans primarily know about and deal with the surface of the planet, which has been shaped by the influence of wind and water.
Water has a number of idiosyncratic properties that reinforce its importance to the planet. It is an electrically polarized molecule, which makes it a great solvent. The polarization also means that, atypically, water becomes less dense when it freezes, and so ice floats on water. If ice were more dense, it would sink -- and eventually the oceans would frozen to their depths, turning the planet into an "icebox".
Of course, for at least most of the Earth's history, the oceans have been largely ice-free. The warmth of the Sun at tropical latitudes generates massive currents in them, circulating around the ocean basins, carrying warmth towards the polar regions. Variations in such circulations can have dramatic climatic effects. The Sun's heat also evaporates the ocean's waters, with clouds carrying the water over seas and continents, with rainfall creating bodies of fresh water on the land, as well as underground aquifers -- though fresh water is a minority of the water on Earth, less than 3% today.
On top of this surface water cycle, there is also a water cycle extending down into the mantle. Some rocks, like olivene, are dry, containing only a trace of water. However, in the upper mantle, under heat and pressure, it becomes wadsleyite, which is about 3% water. The upper mantle may contain about nine times the water of the Earth's oceans. The rocks at lower depths are not as "wet", but the total amount of water in the deep Earth is estimated at 80 times that of the oceans. [TO BE CONTINUED]COMMENT ON ARTICLE
* Space launches for October included:
-- 09 OCT 17 / VRSS 2 -- A Chinese Long March 2D booster was launched from Jiuquan at 0413 UTC (local time - 8) to put the second "Venezuelan Remote Sensing Satellite (VRSS) 2" into orbit. The satellite had a launch mass of about a tonne (1.1 tons), and a design life of five years. It was built by DFH Satellite Company, a subsidiary of the state-owned China Aerospace Science and Technology Corporation. VRSS 2 carries a high-resolution camera with a maximum resolution of around a meter, as well as a medium resolution infrared camera. The satellite was to collect imagery of Earth for the Venezuelan government for scientific research, national security and disaster response applications.
-- 09 OCT 17 / IRIDIUM NEXT 21:30 -- A SpaceX Falcon 9 Full Thrust booster was launched from Vandenberg AFB at 1237 UTC (local time + 7) to put ten "Iridium Next" low-orbit comsats satellites into space. Each satellite had a launch mass of 860 kilograms (1,896 pounds) and a design lifetime of 15 years. This launch brought the number of Iridium Next satellites in orbit to 30, on the way to a baseline constellation of 66. The booster first stage performed a soft landing on the SpaceX recovery barge. This was the 17th intact recovery of a Falcon 9 first stage.
-- 09 OCT 17 / MICHIBIKI 4 -- An H-2A booster was launched from Tanegashima at 2201 UTC (next day local time - 9) to put the "Michibiki (Guiding) 4" navigation satellite into orbit. It was the fourth and final spacecraft in the Japanese "Quasi-Zenith Satellite System" -- which provides GPS augmentation for Japan and neighboring countries, ensuring that GPS works in mountain valleys and cities with towering buildings.
-- 11 OCT 17 / SES 11 (ECHOSTAR 105) -- A SpaceX Falcon 9 Full Thrust booster was launched from Cape Canaveral at 2253 UTC (local time + 4), carrying the "SES 11" AKA "EchoStar 105" geostationary comsat. It was shared by SES of Luxembourg and EchoStar of Colorado in a "condosat" arrangement, hence the two names.
SES 11 was built by Boeing Satellite Systems (BSS), being based on the BSS 702HP platform; it had a launch mass of 5.2 tonnes (5.7 tons), a payload of 24 C-band transponders for SES and 24 Ku-band transponders for EchoStar, and a design life of 15 years. It was placed in the geostationary slot at 105 degrees west longitude to provide TV broadcast, video relay for cable networks, and data services to the Americas. The Falcon first stage performed a successful soft-landing on the SpaceX recovery barge; that first stage had been previously launched in February, this being the third recycling of a Falcon 9 first stage.
-- 13 OCT 17 / SENTINEL 5P -- A Rokot booster was launched from Plesetsk Northern Cosmodrome in Russia at 0927 UTC (local time - 4) to put the "Sentinel 5 Precursor (5P)" Earth observation satellite into Sun-synchronous orbit, for the European Space Agency and the European Commission. Sentinel 5P was built by Airbus Defense & Space. The satellite had a launch mass of about 820 kilograms (1,800 pounds) and a design lifetime of seven years. Its primary payload was the Tropomi spectrometer, designed to detect the levels of trace gases in Earth's atmosphere, such as methane, ozone, formaldehyde, carbon monoxide, sulfur dioxide, nitrogen dioxide, and aerosols. Sentinel 5P was the sixth satellite in the European Copernicus Earth-monitoring constellation since launches began in 2014.
-- 14 OCT 17 / PROGRESS 68P (ISS) -- A Soyuz 2-1a booster was launched from Baikonur at 0846 UTC (local time - 6) to put a Progress tanker-freighter spacecraft into orbit on an International Space Station (ISS) supply mission. It docked with the ISS Pirs module two days after launch. It was the 68th Progress mission to the ISS.
-- 15 OCT 17 / NROL-52 (USA 279) -- An Atlas 5 booster was launched from Cape Canaveral at 0728 UTC (local time + 4) to put a classified spacecraft payload for the US National Reconnaissance Office into orbit, the mission being designated "NROL-52". The payload was suspected to be a QUASAR / Satellite Data System (SDS) geostationary data-relay platform. The booster was in the "421" configuration, with a 4-meter (13.1-foot) diameter payload fairing, two solid-rocket boosters, and a single Centaur engine on the upper stage.
-- 30 OCT 17 / KOREASAT 5A -- A SpaceX Falcon 9 Full Thrust booster was launched from Cape Canaveral at 1934 GMT (local time + 4) to put the "Koreasat 5A" geostationary comsat into space, for KTsat of South Korea. The satellite was built by Thales Alenia Space, being based on the SpaceBus-4000B2 platform. It had a launch mass of 3,500 kilograms (7,700 pounds), a payload of 36 Ku-band transponders, and a design life of 15 years.
It was placed in the geostationary slot at 113 degrees east to support direct-to-home television broadcast plus other communications services to Korea, Japan, the Philippines, Guam, Indochina, and South Asia. KoreaSat 5A also supported maritime communications. The Falcon 9 first stage performed a soft landing on the SpaceX drone barge in the Atlantic.
-- 31 OCT 17 / SKYSAT x 6, DOVE x 4 -- An Orbital Sciences Minotaur-C booster was launched from Vandenberg AFB in California at 2137 UTC (local time + 7) to put six "SkySat" and four "Dove" Earth imaging satellites into orbit for Terra Bella Imaging and Planet Labs respectively.
* MORE SPACE NEWS: The Minotaur-C launch from Vandenberg AFB on 31 October deserves to be described in more detail. The primary payload consisted of six SkySat high-resolution imaging spacecraft for Terra Bella -- previously Skybox Imaging, which Google sold to Planet Labs in April 2017. The other four Dove satellites were three-unit Cubesats, launched as the "Flock-3m" mission, adding to Planet Lab's constellation.
Both companies are based in the US. SkyBox Imaging was formed in 2009, being bought by Google in 2014 at a cost of half billion USD. The company's initial prototype satellite, "SkySat-1", was launched by a Russian Dnepr rocket in November 2013. A second prototype, "SkySat-2", flew in July 2014 aboard a Russian Soyuz-2-1b/Fregat rocket, as a secondary payload in the launch of a Russian Meteor-M weather satellite. The first operational SkySat spacecraft were launched in 2016, wkith "SkySat-3" lofted an Indian PSLV rocket in June 2016, while "SkySat-4 / -5 / -6 / -7" was launched by a European Vega rocket in September 2016.
Planet Labs announced in February 2017 that it had entered an agreement with Google to acquire Terra Bella, the purchase being completed on 14 April. As part of the deal, Google bought a stake in Planet Labs and agreed to buy images back from the company.
The six satellites on this launch were "SkySat-8 / -9 / -10 / -11 / -12 / -13", AKA "SkySat-C6" to "SkySat-C11". Each SkySat satellite had a mass of about 120 kilograms (260 pounds). The prototype satellites were built by SkyBox, which then licensed the design to Space Systems / Loral and contracted them to build the operational spacecraft. The prototypes were slightly smaller than the operational satellites, and lacked propulsion systems. The operational satellites used "High-Performance Green Propulsion (HPGP)" thrusters developed by ECAPS, a subsidiary of the Swedish Space Corporation.
SkyBox initially ordered thirteen satellites from SS/L, in addition to the two prototypes it had built itself. In January 2016, six more satellites were ordered from SS/L, with Terra Bella holding options for further satellites.
The imaging system aboard each SkySat consisted a Cassegrain reflecting telescope using CMOS imaging sensors, with half of each satellite's sensor suite being used for panchromatic imaging; and the other half divided into four bands -- near-infrared, red, green and blue -- for multispectral imaging. The imager could provide panchromatic images at resolutions of up to 86 centimeters (2.8 feet) and multispectral images at resolutions of one meter (3.3 feet). As well as taking still images, the SkySat spacecraft could also record short high-definition videos from orbit.
For this launch, two of the SkySats attached directly to Minotaur-C's payload adaptor, the remaining four being attached to an "upper bulkhead" -- a multi-satellite adapter allowing two levels of payloads. The Flock-3m CubeSats were carried on the lower level, along with the two SkySats.
Each Flock mission consists of a set of three-unit CubeSats, which can image the Earth at resolutions of up to three meters (ten feet), depending on their orbit. Planet Lab's goal is to obtain real-time imagery of the whole planet.
The company was founded in December 2010, being originally named "Cosmogia Incorporated". The firm launched its first prototype satellite -- "Dove-2" -- on a Soyuz-2-1a booster in April 2013. "Dove-1" was launched two days later aboard the maiden flight of Orbital Sciences Corporation's Antares booster. Two more prototypes were launched by a Dnepr booster in November 2013: one was deployed from the rocket itself and the other was to have been released from another satellite, UniSat-5, but failed to deploy it.
The first set of operational Dove satellites, "Flock-1", were deployed from the International Space Station following launch as cargo aboard the OA-1 Cygnus mission, carried to orbit by an Antares rocket in January 2014. More than three hundred Doves have been launched since that time, using Antares, Atlas V, Dnepr, Falcon 9, H-IIB, PSLV, and Soyuz boosters.
Two Flocks were lost in separate launch failures: the twenty-six satellites of "Flock-1d" were destroyed in the October 2014 Antares launch failure, shortly after the booster lifted off with the OA-3 Cygnus mission aboard; while the eight-satellite "Flock-1f" was lost with SpaceX's CRS-7 Dragon mission when its Falcon 9 booster failed in June 2015.
Minotaur-C is a four-stage booster, all four stages being solid-fuel. It is effectively a three-stage Pegasus air-launched booster without wings, using a first stage with a Peacekeeper ICBM or Castor 120 rocket motor -- the first stage being "stage 0", the three Pegasus stages remaining "stage 1", "stage 2", and "stage 3".
This launch used the Minotaur-C "3210" configuration, the numeric code being defined as follows:
* SURVIVOR: As discussed by an article from SCIENCEMAG.org ("What Can Science Learn From A Child Who Has Controlled HIV Without Drugs For More Than 8 Years? by Jon Cohen, 26 July 2017), much progress has been made in controlling the AIDS epidemic -- but there's much more to be done. Now researchers are paying close attention to a South African child, born to an HIV-positive mother, who is managing to keep the virus under control without use of anti-retroviral (ARV) drugs.
The child was given ARVs starting at eight weeks of age, with the treatment halted at 40 weeks as part of a clinical trial. Now, going on nine years later, the child is doing fine. Researchers working on the case are careful to add that the child is still HIV-positive; the viral load is so low that standard tests don't pick it up, but it can be detected with the most sensitive tests.
However, the case does provide clues on what makes long-term remission from an HIV infection possible. In most HIV-positive people who stop taking ARVs, the virus comes roaring back within weeks. Merely extending the remission time would have substantial benefits: patients would have more pleasant lives, the cost of treatment would be slashed proportionally to the extension of the interval, and long-term side effects would be reduced as well. Any means of extending the remission period also might be a step to a full cure.
There have been only two other reports of children in which the HIV load remains almost invisible for years after stopping treatment. Researchers suspect that chances of long-term remission are better if a patient starts treatment very soon after infection, as the South African child did.
The new case offers a unique study opportunity because it was part of a major clinical trial for which blood samples were stored at regular intervals. However, with so few examples, some researchers aren't getting their hopes up. They remember the case of the "Mississippi baby", who had a similar history, receiving intense attention from scientists and the public, until the virus bounded back after 27 months off treatment. Sharon Lewin -- a leading HIV cure researcher and director of the Peter Doherty Institute for Infection and Immunity in Melbourne, Australia -- suggests caution: "Single-case reports have limited value now. We know it happens and we need to understand why. But I'm surprised there's so much interest in this."
There are a few, very few, people who can control HIV without ARVs. These "elite controllers" -- discussed here in 2010 -- typically have genetic factors that cause the immune system to react very strongly to HIV. For those not so lucky, ARVs do a good job of keeping the virus under control. However, the virus doesn't go away, lying dormant in long-lived immune system memory cells, to bounce back when treatment stops. Nobody has yet figured out how to suppress these reservoirs.
Treating people shortly after they become infected still might help reduce the size of the initial reservoir, making it easier to destroy later. Even if it can't be destroyed, it might be reduced to such a small size that the immune system can handle the viral load without use of drugs. Asier Saez-Cirion, a viral immunologist at the Pasteur Institute in Paris, followed a group of 23 patients in France, named the VISCONTI cohort, who started treatment shortly after becoming infected, and continued treatment for an average of three years. In this group, the virus remained undetectable by ordinary tests for an average of seven years. None of the patients had the genetic markers of elite controllers.
The VISCONTI data was a set of case reports, not a controlled study, and so it was widely discounted. However, controlled studies then gave similar results -- though other studies have shown that, while early treatment can result in remission, the virus can bounce back later. The thinking is that if early treatment can be continued long enough to allow the host to establish a robust immune response, it may be able to keep the virus under control indefinitely. Nobody thinks they're close to a cure; but they have hopes they are on the right track.COMMENT ON ARTICLE
* MEGATURBINES: As discussed by an article from REUTERS ("Wind Power's Big Bet: Turbines Taller Than Skyscrapers" by Stine Jacobsen and Vera Eckert, 27 June 2017), European wind farm operators, having got off the ground thanks to government subsidies, now have to face the fact that the subsidies are being phased out. One solution to the problem: build giant wind turbines. These machines will each stand 300 meters (980 feet) tall -- almost as high as London's Shard, Western Europe's tallest building -- with 200-meter (656-foot) rotor spans.
The world's three biggest offshore wind operators -- DONG Energy, EnBW, and Vattenfall -- are all investigating "megaturbines". At least one manufacturer, Siemens Gamesa, plans to have a prototype in in operation in 2018, with the first wind farms using megaturbines in operation in the first half of the 2020s.
The European countries that have invested the most into the offshore wind industry -- Denmark, Germany, the Netherlands, and Britain -- are planning to gradually drop subsidies during the next decade. That presents a challenge to wind operators; only a few years ago, subsidies still accounted for around half of European wind project income. With the writing on the wall, DONG and EnBW submitted bids, with no subsidies factored in, in response to a request in April 2017 for a German project planned for 2024.
That was a first, raising the question of how wind operators will stay economically afloat. The answer, the companies believe, is scale, employing giant wind turbines that dramatically cut costs per megawatt. Each turbine generate between 10 and 15 megawatts (MW) of power -- as compared to the biggest turbines currently in operation, made by MHI Vestas, which are 195 meters (640 feet) tall and generate 8 MW.
Going to megaturbines is a big leap, however. Michael Guldbrandtsen, an offshore wind consultant, said megaturbines present financial and technical risks, but the elimination of subsidies presented no alternative: "Without a significant increase in the size of turbines, it would not be possible to ensure a reasonable return."
Building such huge turbines is technically challenging, since they must be relatively cheap and light, but able to stand up to storm winds. Some industry observers are skeptical that, even if megaturbines can be built, they will make money -- saying that operators will have to run leaner businesses, and electricity prices will have to rise.
Operators are pushing ahead regardless. Michael Simmelsgaard, head of offshore business at Swedish utility Vattenfall, said the industry would cross the 10 MW turbine threshold "faster than many expect now." A 10 MW turbine could power about 9,000 homes. He added: "We will definitely see these big turbines." Other operators are as or more enthusiastic.
The biggest technical challenge is building rotor blades that can handle the stresses, and a pylon structure that can handle the rotor blades. The blades of the megaturbines will be about 50 meters (164 feet) longer than any now available. Fabricating rotor blades is not trivial; they are built of layers of carbon or glass fiber, laminated with adhesives that have to be dried at exactly the right temperatures to ensure strength.
Denmark's state research institute DTU Wind Energy, which has driven much of the innovation in wind power, is working on keeping down the weight of these super-long blades by increasing the carbon fiber content. They have designed blade features like the flaps on aircraft wings to control and reduce load variations, so turbulence does not break the blades. It demands substantial computer power to validate blade designs. New manufacturing facilities will be needed to turn out the blades.
Even with the megaturbines, operators will have to change the way they do business to stay alive. A study by Bernstein Research showed that, using a current power price forecast and current wind turbine technology, operators would need to reduce their capital expenditure by around 60% percent for zero-subsidy projects to break even. Megaturbines would mean a 40% capital-expenditure reduction. The study suggested that power prices would have to increase by at least 5 euros per megawatt-hour (MWh), relative to current prices of 30 euros per MWh, for there to be any possibility of survival.
* In related news, as reported by an article from SCIENCEMAG.org (" Offshore wind Farms Have Powerful Advantage Over Land-Based Turbines, Study Finds" by Eli Kintisch, 9 October 2017), a study of wind turbines conducted by the Carnegie Institution for Science in Palo Alto, California, showed that land-based wind turbines have a scaling problem: make arrays of them too dense, and one turbine will rob the wind energy from another downwind of it, a phenomenon known as "wind shadow". This is why land-based wind turbines are preferably set up in a line on a ridge.
The researchers got to wondering if wind turbines installed in the open ocean -- where air currents are 70% stronger than on land -- would also suffer from wind shadow. Using a digital model, they determined that turbines placed in the North Atlantic could generate three times as much power as an existing wind farm in Kansas of similar size.
Wintertime low-pressure systems, which occur more frequently at sea than land, mix energy from fast, upper level winds down to the surface of the ocean, speeding surface winds. Wind shadow would not be a major problem because the upper level winds would recharge the surface winds in the shadow of a turbine. Of course, the engineering issues in building, connecting, and sustaining a wind turbine farm in the remote Atlantic are staggering -- but the Carnegie researchers say the potential is enormous, that such oceanic wind farms could provide "civilization-scale power".COMMENT ON ARTICLE
* DRONES FOR AFRICA (1): As discussed by an article from THE GUARDIAN ("From Killing Machines To Agents Of Hope: The Future Of Drones In Africa" by Zoe Flood, 27 July 2016), in the 21st century, drones have become established as a military technology -- but they are increasingly being used for civil applications. They have particular promise in Africa, which is noted for its poor infrastructure; drones promise to literally fly over the bottlenecks to support medical supply chains and commercial deliveries, or combat poaching; or generally provide cost-effective services that were difficult before.
For example in Rwanda, as in many other African countries, the rainy season makes already difficult roads between smaller towns and villages all but impassable. Trucks struggle through the mud, and in some cases even more agile motorbikes and foot traffic are unable get through. According to Jean Philbert Nsengimana, Rwanda's technology minister:
Rwanda is essentially a rural country. Lots of blood products cannot be stocked at every health center. At best it can take four to six hours to get supplies through. For mothers giving birth, post-partum haemorrhaging, or bleeding post-delivery, happens quite often. It may not be possible to prevent. Then what is needed is a quick and rapid intervention.
Enter Zipline, a California startup that plans to use small drone aircraft for humanitarian assistance. Zipline is working with UPS and vaccine distributer Gavi to deploy a fleet of drones in Rwanda, where the machines will deliver medical supplies. The goal is to have 15 autonomous aircraft flying out of a centralized hub make 150 deliveries each day to 21 medical stations throughout the western half of the country. The Rwandan government is providing assistance to set up the drone network.
Zipline designs, builds, and tests its drones in northern California. The drones, which have a span of about two meters, are built to be simple and rugged, to reduce cost and improve availability. The payload carrier and parachute are made in-house for 50 cents and designed to be used once, then discarded. The drones are of fixed-wing configuration, not quadcopters, since quadcopters are essentially fair-weather flying machines, and also not so reliable.
In operation, a doctor or nurse will request supplies -- blood, vaccines, or medicine -- via text message using a smartphone or tablet. A drone operator will retrieve the supplies from a central warehouse, stuff them into a padded cardboard box, and place the payload in the belly of a drone. Clip a charged battery to the nose, upload the flight plan from an iPad, and the drone will be ready to fly.
The drone will be launched by pneumatic catapult, to then fly autonomously to the GPS coordinates of the destination. It will have an operational radius of about 70 kilometers (45 miles), which is plenty for a small country like Rwanda. The drone will cruise at an altitude of about 100 meters (330 feet), to then descend to the target area, where it will drop its payload. It will be able to drop it into an area about the size of four parking spaces. The drone-port that will deploy the autonomous aircraft fits in a shipping container, making it easily deployed after, say, a natural disaster. [TO BE CONTINUED]COMMENT ON ARTICLE
* ONCE & FUTURE EARTH (14): 98% of the Earth consists of the "Big Six" elements: oxygen, silicon, aluminum, magnesium, calcium, and iron. Oxygen plays a central role -- not merely because we'd suffocate without it, but because it is reactive, and easily combines with most other elements. Indeed, in the Hadean Era, its was effectively only present in combination with other elements, there being little or no free oxygen in the atmosphere. Any free oxygen that did make its way into the atmosphere would have quickly reacted with something else, and ceased to exist as free oxygen.
Silicon has a high affinity for oxygen, the consequence being the widespread presence of quartz, SiO2 -- as well as more elaborate silicates, in the form of feldspar, green olivine, red garnet, asbestos, and mica. Aluminum, magnesium, and calcium are not as common as silicon, but they are nonetheless significant in the Earth's crust. Oxides of them include calcium oxide, or lime; magnesium oxide, which is rare; and aluminum oxide which, given traces of chromium or titanium, become the gemstones ruby and sapphire accordingly.
It is iron which is the most common element on the Earth, though it's mostly concentrated in the planet's core. However, even in the crust, one out of every ten atoms is iron. Its bonding behavior is promiscuous; while it can be found in relatively pure deposits of metal, it may bond with other elements in a confusing set of ratios. One of the most common forms is hematite, or Fe2O3.
In any case, after the formation of the Earth-Moon system in the Big Thwack, the temperature of the Earth and Moon was on the order of 5,500 degrees Celsius (10,000 degrees Fahrenheit). It wasn't until it cooled to about 1,650C (3,000F) that crystals began to form out of the magma. The first was olivene, which being generally denser than the melt out of which it originated, tended to sink -- forming deep-underground deposits of a pretty green rock named "dunite". It is only found on the surface of the Earth today if driven by the deep uplift of mountains.
Since olivene contains magnesium, the melt became depleted in magnesium, with aluminum and calcium becoming more significant in the melt. On the Moon, a feldspar named "anorthite" began to emerge from the melt; and since it was lighter than the melt, it tended to rise. They formed feldspar mountains, now observed as the Lunar Highlands. Apollo samples of anorthites show they range from about 4.5 to 3.9 billion years old.
On Earth -- wetter, with deeper magma oceans -- a somewhat different scenario unfolded. Although some anorthite crystallized out of the melt, the predominant crystalline material was magnesium-rich pyroxene, which combined with olivene to form a hard, greenish-black rock named "peridotite". The peridotite may have formed an early crust over the Earth; but in any case, once it hardened, it became denser than the magma, to sink into the Earth. Over hundreds of millions of years, the Earth's mantle hardened, its upper regions being formed of peridotite rock.
In the meantime, the lower layers of the mantle were solidifying as well. The mantle became three distinct regions: an upper mantle, a transition zone, and an inner mantle. The upper mantle extends to a depth of about 400 kilometers (250 miles). The transition zone is about 240 kilometers thick, being mostly composed of "wadsleyite", a stone derived from olivene under pressure. The inner mantle, which extends to the core, is mostly composed of magnesium silicates.
While the boundaries between the layers to the core are relatively distinct, if variable in depth, the interface between inner mantle and core is, as revealed by seismic probes, very irregular -- with what are referred to as "mountains" of various materials disrupting the boundary. The core itself is, again, mostly iron and some nickel, under massive pressure and with very high temperatures. In the early days of the Earth, it was completely liquid; today, it has a crystallized core, surrounded by liquid metal. It is the movements of this liquid metal that generate the Earth's magnetic field. The hot core also drives geological activity in the upper layers. [TO BE CONTINUED]COMMENT ON ARTICLE
* GIMMICKS & GADGETS: An article from THE GUARDIAN Online ("Forest Cities" by Tom Phillips, 17 February 2017) focused on Italian architect Stefano Boeri. The notion of "vertical farms", or skyscrapers devoted to growing crops, has been discussed here, last in 2010; Boeri has come up with an interesting variation on the idea, the "skyscraper forest", essentially a skyscraper decked out in trees. He has already realized the concept in the "Bosco Verticale (Vertical Forest)" skyscraper complex in his hometown of Milan. He has now unveiled plans for a similar exercise in the eastern Chinese city of Nanjing.
The Chinese effort will feature two neighboring towers, covered with 23 species of tree and more than 2,500 cascading shrubs. The structures will house offices, a 247-room luxury hotel, a museum, and a green architecture school. They are now under construction, to be completed in 2018.
His office claims the two towers will draw suck 25 tonnes of carbon dioxide from Nanjing's air each year, and generate about 60 kilograms of oxygen every day. They also soak up dust generated by urban road traffic. However, Boeri says this is only the first step in China, the architect telling THE GUARDIAN:
We have been asked to design an entire city where you don't only have one tall building but you have 100 or 200 buildings of different sizes, all with trees and plants on the facades. We are working very seriously on designing all the different buildings. I think they will start to build at the end of this year. By 2020, we could imagine having the first forest city in China.
A city built around skyscraper forests would be a big help towards getting China's notorious urban air-pollution problem under control. Boeri sees a number of such cities springing up -- the first to be located in Luizhou, a mid-sized Chinese city of about 1.5 million residents in the mountainous southern province of Guangxi. Boeri says that China needs to "imagine a new model of city" that doesn't mean urban sprawl, instead embracing "a system of small, green cities."
He adds that he hopes the "idea of vertical forests can be replicated everywhere." He doesn't have any problem with people copying his idea -- it's not like the notion of growing plants on skyscrapers could realistically be patented -- and in fact, wants to see what others can do, believing his work may be "useful for other kinds of experiments."
* As discussed by an article from AAAS SCIENCE NOW Online ("These Tiny Camera Lenses Can See Like An Eagle" by Rachel Lallensack, 15 February 2017), a team of researchers at the University of Stuttgart in Germany has used 3D printing to fabricate a "microlens" system that imitates the "foveated" vision of eagles and other raptors.
The microlens system starts with a CMOS solid-state imaging sensor, with four different imaging arrays arranged in a 2x2 matrix on one chip. Four microlenses featuring different focal lengths, are fabricated directly onto the chip. All the lenses have the same center of view, with the four images merged to give an image 70 degrees wide, with resolution low at the edge and increasingly sharp towards the center.
This is like an eagle eye, in that eagles have high concentrations of visual receptors at the center of their field of vision, meaning they see things at the center of their field of vision with extreme clarity. The microlens is just a lab demo right now; the imager doesn't have enough resolution, and it takes hours to precision-print the lenses. Once a production version is available, the researchers believe their microlens imaging system could have applications such as insect-sized flying "microdrones", or even drones that can be used to inspect the human body from the inside.
* As discussed by an article from WIRED Online ("Want Efficient Energy? Try Carbon Dioxide-Powered Turbines" by Nick Stockton, 26 May 2017), carbon dioxide has acquired a dirty reputation in recent years -- but it's just a common molecule with certain properties, some of which are convenient, some of which aren't so convenient.
One convenient property that isn't so obvious is that it could make electrical power generation more efficient. Most electricity is generated by steam turbines, using what is called the "Rankine cycle": water is heated into steam, which flows through a turbine, spinning the turbine to generate power. The steam loses energy through the turbine, to then condense back into water, and be turned back into steam again. In principle, any heat source -- coal, gas, nuclear, solar -- can provide the heat.
This works well enough, but it does have a difficulty -- in that it takes considerable energy to turn water into steam, and then to "superheat" it for driving through a turbine. CO2, in contrast, can't be a liquid except under high pressures, and it takes deeper cold than found naturally on this planet to turn it into a solid.
A recent paper in the science press by Levi Irwin, a contractor at the Department of Energy (DOE), points out that these properties of CO2 -- as well as its ability to be highly compressed -- make it a better "working fluid" for a power generation system than steam. Operating in a "Brayton cycle", meaning it's never liquefied, extremely hot and compressed "supercritical" CO2 improves gas turbine energy efficiency by 30%. Brayton cycle systems, not needing to handle two different phases of the working fluid, are also simpler and more compact than Rankine cycle systems.
The difficulties with a CO2-based Brayton cycle turbogenerator system is that it works at higher temperatures than a steam-based Rankine cycle system, which particularly stresses the turbine. The turbine blades also have to be designed specifically to handle the hot CO2 working fluid; blades designed for a steam turbine aren't optimum to the task. The DOE announced last October that it was starting work on a prototype CO2-based turbogenerator system, capable of providing ten megawatts, which is slated to come online in about six years.COMMENT ON ARTICLE
* SYNTHETIC FRAUD: As discussed by an article from BLOOMBERG BUSINESSWEEK Online "Scammers Are Constructing Fake People to Get Real Credit Cards" by Jennifer Surane, 12 September 2017), in May 2017 agents of the US Federal Bureau of Investigation (FBI) and US Postal Service (USPS) descended on the home of Charles Whitlock JR, a South Carolina disk jockey. He was believed to have obtained 558 credit cards from Capital One Financial Corporation using fake identities.
The investigators found a small fleet of shiny new cars -- plus two ledgers listing names, Social Security numbers, birth dates, and addresses. They were all fakes, Whitlock having been patiently creating them since 2013. Prosecutors believe Whitlock had pulled in at least $340,000 USD with his scams. He says he's innocent.
This new frontier in charge card scams is known as "synthetic identity theft": instead of stealing someone's identity, the trick is to fabricate an identity. It was almost unknown half a decade ago, but now it is estimated to account for as much as a fifth of bogus credit card charges. Ironically, synthetic identity theft has been growing because of improved charge card security, thanks to "smart cards". Since now it's harder to rip off a somebody else's charge card, it becomes more attractive to fabricate a charge-card user wholesale.
Synthetic fraudsters buy stolen Social Security Numbers (SSN) or try to find SSNs that haven't been assigned, then use them as the foundation of a fake identity. The scammers begin by applying for a credit card, using the SSN and somebody else's address. These initial contacts are usually discarded, but bank inquiries generate placeholder profiles with a credit bureau. Eventually, a lender grants a scammer an account.
That's when the long con begins. The scammer faithfully pays off charges to the card, using a PO box as a mailing address, building up a credit history. Once an identity is established, the scammer can sign up for more cards. The process may go on for years; but in the end, the scammer will then "bust out", making false charges to the cards, and then going off the radar. When a synthetic account goes bad, lenders are inclined to believe a good customer just had some troubles. A collections department may go in circles for months until they realize they've been had.
The best SSNs for synthetic fraud are those of people who don't use credit, including infants and children, since they provide a blank slate to work from. Using a child's SSN used to be a non-starter, because the birthdate was woven into the numbers; but from 2011, the Social Security Administration (SSA) began fully randomizing the numbers. The holder of the stolen SSN isn't responsible for the losses; the banks are the ones that get ripped off.
The SSA does run a database that lenders fan use to confirm applicant's name, birth date, and SSN. Banks pay a one-time $5,000 USD enrollment charge plus a fee every time they look someone up, which requires handwritten consent from the customer. There's an overwhelming need for a robust electronic ID scheme, but nobody sees it as happening in the USA any time soon.
Card issuers try to screen out synthetic fraud by noting which computers and tablets customers use to file credit applications. However, Whitlock submitted 90% of his 750 applications by phone. Capital One eventually detected his activity with fraud analytics software, discovering that a variety of cardholders happened to be making transactions with the same cluster of merchants and PayPal accounts. Prosecutors say they obtained surveillance videos of the Whitlock using a variety of cards, and that he also marketed himself on social media as a credit-repair specialist.
Lenders are getting wise to synthetic fraud, but one of the effects of that wisdom is that it is becoming harder for youngsters and new immigrants to get a credit card. The problem seems likely to get worse before it gets better. Never underestimate the resourcefulness of crooks.COMMENT ON ARTICLE
* QUANTUM LEAP FOR QSS: On 15 August 2016, China put the "Quantum Science Satellite (QSS)" into orbit. The space platform -- named "Micius" after a classic Chinese scholar -- was intended to validate long-range datalinks protected through a "quantum entanglement" encryption technique. Such an encryption scheme had been demonstrated over fiber-optic links, but was limited in range; QSS was flown to show that longer ranges could be obtained using space optical links.
As discussed by an article from AAAS SCIENCE Online ("China's Quantum Satellite Achieves 'Spooky Action' At Record Distance" by Gabriel Popkin, 15 June 2017), Chinese researchers have announced that QSS has demonstrated quantum entanglement of particles over a distance of 1,200 kilometers (745 miles), several times farther than has been achieved on the ground.
In quantum physics, a particle that can exist in multiple states may be said to exist, in potential, as all of them at once, until it is observed and a particular state obtained. In quantum entanglement, two particles -- in the case of QSS, photons -- are generated with complementary properties, the two "entangled" particles being sent to distant locations, and the properties not established until the two are received. If the state of one is obtained, the other is necessarily known; it almost appears there is some instantaneous communications between the two particles, but that is demonstrably not true. Albert Einstein thought it was a ridiculous idea, calling it "spooky action at a distance."
Einstein didn't live to see this ridiculous idea proven true. From the 1970s, physicists conducted experiments to show that this "spooky action at a distance" was for real, and were able to demonstrate it over increasing distances. Although quantum entanglement might seem like it a technique for faster-than-light communications, it can't be used in that way, even in principle. However, it can potentially be used for strongly encrypted communications. Long strings of entangled photons, shared between distant locations, can be used to construct "quantum keys" to provide secure communications. Attempts to intercept the creation of such quantum keys would break the entanglement and give away the eavesdropping.
Efforts to make use of this effect ran into the problem that it was difficult to maintain an entanglement with photons sent through the air or via fiber-optic cable; the longest distance over which a quantum key was established was, until now, a few hundred kilometers. Sending the photons through the vacuum of space seemed a good way to get much more range. QSS was launched to see if the scheme was at all workable. The mission is the foundation of the $100 million USD Quantum Experiments at Space Scale program, one of a set missions that China hopes will make it a space science power.
In the first experiment conducted by the QSS research team, they sent a laser beam into a light-altering crystal on the space platform. The crystal emitted pairs of photons entangled with polarization states at right angles to each other. The pairs were split, with photons sent to separate receiving stations in Delingha and Lijiang, 1,200 kilometers apart. Both stations are in the mountains of Tibet, reducing the amount of air the finicky entangled photons had to traverse. The researchers have now announced that they had simultaneously measured more than 1,000 entangled photons, with the two photons of an entangled pair proving to be at 90 degrees far more often than could have been expected by chance.
However, the observations were difficult; they had to be performed at night, and the researchers only recovered about one photon pair for every six million photons sent to the space platform. The head of the research team, Pan Jian-Wei -- a physicist at the University of Science and Technology of China in Shanghai -- expects that improved satellites will be launched with more powerful and cleaner lasers that will allow entangled pairs to be observed in daylight. Pan says: "In the next 5 years we plan to launch some really practical quantum satellites."
Following up the initial tests, the researchers are using QSS to distribute quantum keys to Chinese ground stations, which will require longer strings of photons and additional steps. The next step will be to perform quantum key distribution between China and Australia -- which will require storing one of the entangled photons on the satellite, until it comes into view of an Australian ground station.
Other nations are working on quantum-encrypted communications satellites. The ultimate goal is a global secure communications network. The Chinese have obtained a head start in the race, but nobody's close to a practical system just yet, and it may end up being a collaborative effort.COMMENT ON ARTICLE
* SOUTH AFRICA AGAINST AIDS (2): Another problem with South Africa's program to control AIDS is data collection and analysis. The data center of the Southern Africa International Epidemiological Database to Evaluate AIDS at the University of Cape Town has tracked treatment enrolment and retention since the initiative was established in 2006. However, officials say even that simple data have been hard to collect and interpret.
Sometimes the same person turns up in several different records; for example, sometimes a patient moves and starts going to a different clinic. Many others are enrolled, but then disappear from the radar. For a long time, the center's HIV-clinic data showed a low number of AIDS deaths and a high rate of drop-outs -- but when the data were integrated with the country's death register in the late 2000s, it emerged that more than 30% of those reported as lost were actually dead.
The system is moving towards unique patient identifiers that will reduce confusion. Researchers would like to see much more detailed clinical data collected, so that they can find out what happens when large populations take ARVs in the long term. There is considerable research on the health effects of the drugs, but much of it comes from Europe or North America, where patient populations are much smaller, and the medical resources are much greater.
Yet another issue is drug resistance. In rich countries, HIV patients are routinely checked to see if HIV is acquiring resistance to their medications, and switched to other medications if so. In South Africa, only a few of the available ARV drugs are provided free through the country's health system, and resistance tends to be poorly managed.
The Durban-based Centre for the AIDS Program of Research has more than 15 years of data, gathered from a community of about 100,000 households in the rural district of uMkhanyakhude, about 2 hours' drive north of Durban, in KwaZulu-Natal. The data show that resistance is a growing problem. Between 2010 and 2012, the proportion of new HIV cases that were already drug resistant rose by 7%, and its likely to get worse.
While ARVs have proven highly successful at extending the lives of HIV patients, that very extension poses challenges of its own, which will become more evident as the many South Africans on ARVs grow older. The fraction of HIV-infected people who are older than 50 is predicted to triple in the next 30 years. Some studies have found that certain cancers are more common in people taking ARVs, and long-term use of the drugs has been linked to increased risk of hypertension, diabetes, and obesity -- although it's hard to show whether such problems are caused by the ARVs, or by HIV itself. Researchers are now looking at the possible effects of ARVs on metabolism. The life-saving benefits of the drugs outweigh these potential risks, but public-health researchers still need to know what the future holds for such a large population on ARVs.
In Europe and the United States, people aging with HIV tend unsurprisingly to be less healthy than do those who do not have the virus. However, Janet Seeley -- a social scientist based at the London School of Hygiene and Tropical Medicine -- and her colleagues got a surprise when they inspected the data for several hundred people over the age of 50 in Uganda and South Africa. They found that people with HIV who were taking ARVs had better quality of life, and were more able to perform daily activities than were their HIV-negative peers.
Seeley first thought: "This must be wrong." -- but then realized: "It's logical, really." Care for people with HIV isn't always great, but at least they see a health practitioner on a regular basis. In South Africa, older people who received HIV therapy were more likely to be on treatment for other chronic conditions than were people in the comparison group who were HIV-negative.
Researchers are also investigating the histories of children who are born to mothers with the virus, but not infected themselves. Some studies show these "uninfected exposed" children tend to have poorer health, such as lower birth weight and bone density, than do those born to mothers without the virus. However, a recent review shows that other studies show no evidence of a difference. Still, since about a third of the children born in South Africa are uninfected exposed, the issue is taken very seriously.
Clive Gray, an immunologist at the University of Cape Town, is investigating the possible effects of in utero HIV and ARV exposure on the developing fetus, and on an uninfected child's long-term health. He and some colleagues are investigating 500 mother–baby pairs, including mothers both with and without the virus, in Nigeria and South Africa. Although the study is still progress, the researchers have already noticed that that HIV-negative children born to infected mothers have impaired immunity in their first year of life. It is not clear that HIV or the ARVs are the cause, though the problem remains significant in either case.
Possibly the most important question is how South Africa's massive rollout of ARVs will affect infection rates. Victims with a suppressed viral load are less likely to transmit HIV to others -- a fact that has led the WHO to recommending that all people who test positive for HIV go on ARVs as soon as possible, instead of waiting for symptoms to become evident. The South African health ministry has accepted that recommendation, and is also pushing prophylactic use of ARVs for sex workers.
Even patchy ARV coverage can slash infection rates. A study by the Africa Centre found that someone living in a community where 30%:40% of HIV-infected people are on treatment is 38% less likely to get infected than is someone living in a community where fewer than 10% are on treatment. However, nobody really expects ARV use to ramp up very quickly, both because of the difficulty in getting people tested in the first place, and also to get them to use the ARVs -- they have unpleasant side-effects, why would anyone who felt well be inclined to bother?
The research community is very interested in the South Africa experiment with widespread ARV use, and sees the country as a testing ground for new weapons in the fight against AIDS -- therapies and particularly vaccines that could render ARVs largely obsolete. Among those involved with the effort against HIV in South Africa, there is satisfaction in how far they've come, along with a realization of just how much farther they will have to go. The war is not remotely over yet. [END OF SERIES]COMMENT ON ARTICLE
* ONCE & FUTURE EARTH (13): As understood now, in its early days, the Solar System consisted of multitudes of small bodies that had a tendency to accumulate into larger ones. Eventually, there were two planets in the orbit that the Earth now follows -- a "proto-Earth", and a smaller body named "Theia" about a third of the mass of the modern Earth. Eventually, they were likely to collide, and they did so about 4.5 billion years ago.
The collision was off-center; the proto-Earth was badly damaged, while Theta was simply obliterated. Some of the debris from the collision was cast off into deep space, but most of it remained as an incandescent cloud around the battered proto-Earth. As the system cooled, however, it formed into twin nuclei, both accumulating material from the cloud. Most of it fell into the proto-Earth, but some of the material fell into the other nucleus, forming a "proto-Moon". Soon they were Earth and Moon, of the size and broad geological composition that they have now.
Had the collision been more head-on, the end result would likely have been a single world, of the combined mass of the proto-Earth and Theia. Had the collision been more glancing, the Earth might have ended up with multiple moons. Had the two worlds performed a close encounter but not collided, it would have disrupted their orbits in some unpredictable way. In any case, the Big Thwack theory seemed to account neatly for all the observed properties of the Earth-Moon system:
Models show that the Moon formed very close to Earth, only about 24,000 kilometers (15,000 miles) away -- about a sixteenth of its present distance. It was enormous in the night sky, spanning 8 degrees of arc, about 16 times the diameter of the Sun. When the lunar nearside was facing the Sun, the illumination on Earth was so bright as to flood out the stars. Eclipses were commonplace. The Moon has receded since then, and continues to do so. The laser retroreflectors placed on the lunar surface by the Apollo program show the recession rate to be currently about four centimeters (an inch and a half) a year.
The Earth was spinning rapidly after its emergence from Theia and proto-Earth, with the day being about five hours long -- though the year was the same length of time as it is now. We don't actually have any way of clocking the day length in that era, but there's no doubt that the Earth's rotation is continuing to slow down, as the Moon moves farther away. Corals show lines defining daily growth; about 400 million years ago, they had 400 lines of growth per year, not 365 lines as today, and extrapolating from that suggests the five-hour day of 4.5 billion years ago.
At that time, the Moon went around the Earth once every 84 hours -- with enormous tides created by the force of gravity between the two bodies, helping them stay molten for longer than they would have, had they being independent. However, within a few million years, they had cooled to form surfaces of hard black rock, though their interiors remained molten, the molten state being maintained to a degree by the decay of radioactive isotopes in the interior.
The first few hundred million years of the Earth's existence are known as the "Hadean Eon", reflecting the hellish conditions of the world: widespread volcanic activity, seas of lava, and occasional impacts of asteroids or comets. Some of the impacts were no doubt massive, though none on the order of the Big Thwack. However, since the Earth has been transformed since the Hadean Eon, the only evidences for exactly what conditions on Earth were like are inferential. [TO BE CONTINUED]COMMENT ON ARTICLE
* SCIENCE NOTES: As discussed by an article from BBC WORLD Online ("Record Surge In Atmospheric CO2 Seen In 2016" by Matt McGrath, 30 October 2017), concentrations of atmospheric carbon dioxide surged to a record high in 2016, according to the World Meteorological Organization (WMO). 2016's increase was 50% more than the average of the past decade.
2016 saw average concentrations of CO2 hit 403.3 parts per million, up from 400 PPM in 2015. Researchers believe the surge was due to a combination of human activities and the El Nino weather phenomenon. El Nino affects the amount of carbon in the atmosphere by causing droughts that cut down the uptake of CO2 by plants and trees. Emissions from human sources have slowed down in the last few of years, but CO2 concentrations continue to grow.
The last time the Earth experienced a comparable concentration of CO2 was three to five million years ago, in the mid-Pliocene era. The climate then was two to three degrees Celsius warmer, and sea levels were ten to twenty meters higher due to the melting of Greenland and the West Antarctic ice sheets.
Another concern in the WMO report is the continuing, mysterious rise of methane levels in the atmosphere, which were also larger than the average over the past ten years. Climatologists worry that increased heat leads, in a vicious cycle, to increased methane emissions, which further increase the heat. The report was issued ahead of the next installment of UN climate talks, in Bonn. Negotiators will be pushing to take further action on climate change -- an effort complicated by the US government's indifference to the issue.
* As discussed by an article from INTERNATIONAL BUSINESS TIMES ("Giant Exploding Methane Bubbles Left Craters 1km Wide In The Barents Sea 12,000 Years Ago" by Martha Henriques, 1 June 2017), scores of huge craters have been found in the floor of the Barents Sea, being the remains of ancient explosions of methane pockets at the end of the last ice age.
The methane in the pockets formed under the ice sheets that extended to the floor of the Barents Sea.. The slow movements of the ice, which was up to 2.7 kilometers (1.7 miles) thick in places, over millennia, gradually collected methane seeping up from deep underground reservoirs to collect in pockets underneath the seafloor surface. When the ice sheets went on the face about 12,000 years ago, the pressure on the methane pockets was greatly reduced, with the seafloor above pockets rising in mounds until they burst in violent eruptions, leaving craters as big as a kilometer across.
About a hundred kilometer-sized craters were mapped in a 440-square-kilometer (170 square miles) survey area, with thousands of craters just a few hundred meters across found as well. Methane pockets still do occur in Siberia, as the permafrost melts and the gas accumulates below the surface; but most are only about a tenth of the size of the ancient pockets. However, as ice sheets retreat, we can expect more large pockets to occur. Many will simply vent slowly without leaving a big crater. Nobody knows how many pockets there are, the seafloor of the polar regions being poorly mapped.
* As discussed by an article from NATURE.com ("Solar System Survey Casts Doubt On Mysterious Planet Nine" by Gabriel Popkin, 22 June 2017), studies of the orbits of some of the far-ranging planetoids of the Kuiper Belt on the outskirts of the Solar System have suggested there may be an unseen "Planet IX" lurking in orbit far from the Sun. Now another study of the orbits of these "Kuiper Belt Objects (KBO)" suggests there's no Planet IX.
The KBOs in question were discovered in the course of the "Outer Solar System Origins Survey (OSSOS)", which is investigating the region of space beyond Neptune. Using the 3.6-meter (11.8-foot) Canada-France-Hawaii telescope on Mauna Kea, Hawaii, the team found four bodies that orbit the Sun in enormous ellipses at least 250 astronomical units (AU) wide. An AU is the average About a dozen such large-orbit bodies have been spotted so far, including the four found by OSSOS.
The case for Planet IX has been made because six of those KBOs were clustered into two groups instead of being randomly arranged. Two groups of researchers suggested was that an unseen planet, possibly ten times Earth's mass, had "shepherded" the objects into those two groups. All involved acknowledged the data was sketchy and incomplete; they had a hint of the existence of a Planet IX, but not much more than that.
The OSSOS team claims the sources of potential error drowned out the hint. Astronomer Samantha Lawler -- of the National Research Council Canada in Victoria, BC -- commented: "They were building this entire argument around six objects with unknown biases in how they were detected, which is a very dangerous game to play."
Three of the objects found by OSSOS appeared to be in the two previously identified clusters -- but when the OSSOS authors compensated for the fact that their survey preferentially spotted bodies in certain parts of the sky at certain times of year, the evidence for clustering vanished. Advocates for Planet IX still believe the hint is worth following up, and say they have other reasons for believing it might be there.
Konstantin Batygin -- an astronomer at the California Institute of Technology in Pasadena and a member of one of the teams that proposed the existence of Planet IX -- says that discoveries of KBOs that aren't coupled to Neptune, and others with orbits nearly perpendicular to those of most Solar System objects, are most easily explained by the presence of a large planet in the outer Solar System. The matter will be resolved by further observations, though it will likely take a generation and use of more powerful telescopes.COMMENT ON ARTICLE
* ANOTHER MONTH: I took my yearly photoshoot trip from Loveland CO to the Denver Zoo on Wednesday, 4 October. As far as the catch of animals, it was meager, the most interesting thing being peahens with chicks walking the grounds. I also got some nice shots of a painted lady butterfly -- these insects being all over the landscape at the time, with weather radar picking up huge clouds of them.
However, the trip did have a good payoff, since the zoo was hosting the DINOSAURS LIVE! exhibit, with various mechanized dinosaur replicas scattered around the grounds. Of course, the kids visiting the zoo absolutely loved them -- kids and dinosaurs, they're a match. Another plus was finally noticing the underground parking garage, which I'd never spotted in the decades I'd been going to that zoo; nothing much in itself, but it did have some nice decor.
I also took note of the bike-sharing station there, which I also hadn't spotted before -- though it's a fairly recent addition. The map of the Denver B-Cycle system gives dozens of stations all over downtown, though nothing in the suburbs. Daily fees are stiff, but a year pass is only $95 USD.
* As for the RFN (real fake news) for October goes, things got off to a ghastly start on the 1st, when a lunatic named Stephen Paddock opened fire on a country music festival in Las Vegas, shooting from his hotel room with semi-automatic weapons rigged to full automatic operation. 58 people were killed, plus 546 injured. Paddock shot and killed himself. Nobody knows why he did it. The result was that discussions of everything else faded into the background for a few days -- and then the matter was effectively forgotten. The debate over gun control has become so gridlocked that few find it worth their time to bother to raise the issue.
Attention then turned back to what passes for normal these days. Also at the first of the month, in response to a complaint from US plane-maker Boeing, the US government proposed to slap a punitive tariff on the new CSeries small jetliners from Bombardier of Canada. The provocation for the exercise was the sale of a big batch of CSeries jetliners to Delta Airlines, with Boeing claiming that Bombardier had been unfairly subsidized in the development of the aircraft. Given the protectionist inclinations of the Trump Administration, Boeing was able to successfully make a case for tariffs to the government.
This bold move of course immediately ran into complications. It turns out that the Bombardier group includes Short Aircraft of Belfast, Northern Ireland, with the Belfast plant producing assemblies for the CSeries. British Prime Minister Theresa May quickly objected to the tariff -- and presumably also got a hint that hopes for a great trade deal with the US in the wake of Brexit might be resting on sand. More substantially, Canada was working towards the purchase of a batch of Boeing Super Hornet fighters, while Britain was acquiring the Boeing P-8 Poseidon ocean patrol aircraft, based on the Boeing 727 jetliner. If Boeing persists in the assault on Bombardier, kiss those deals good-bye. Delta officials also said they refused to pay the penalty.
Then the other shoe dropped with a boom: European aircraft giant Airbus, Boeing's arch-enemy, was simply given, didn't buy but was given, a majority stake in Bombardier. The direct entrance of Airbus into the fray shifted the political landscape drastically -- in particular because Airbus has a plant in Mobile, Alabama, and could in principle make CSeries jetliners there, bypassing the tariff. Boeing officials insisted the tariff will still apply, but since made-in-America CSeries jetliners mean American jobs, that seemed a feeble protest.
Things are not looking good for Boeing, all the more so because review of the tariff of the US International Trade Commission, a nonpartisan office, is not complete yet. The only lesson so far is that trade protectionism is a concept that tends to sound much better in theory than it turns out to be in practice.
Other fusses were going on in parallel:
The noisiest fuss occurred in the wake of the deaths of four US servicemen in Niger. The White House said little or nothing about the issue for days -- and then, when confronted with the matter, Trump simply denounced Obama, saying Obama never called families of servicemen who were killed in action. That was false, and the following uproar was very loud, if vaporous.
The most substantial issue facing the Trump Administration is tax reform, Trump proposing a major tax cut. Given budget deficits, that is widely seen as irresponsible. The Trump Administration is playing the "supply-side economics" card, and claiming the tax cut will result in such an economic boom as to wipe out the deficit. However, everybody knows supply-side economics is a con job -- and the con job became more apparent when the details of the tax plan were released. They involve elimination of the inheritance tax and the "alternative minimum tax" mechanism, both of which only affect the very rich, while eliminating exemptions for the middle class to compensate for the cuts.
Indeed, it's such an obvious scam that it's hard to think it really cons anyone. On 26 October, the House of Representatives did pass the tax bill -- but by a vote of only 216:212, with all Democrats in the House voting against it, along with 20 Republicans, and three Republicans abstaining. Now it goes to the Senate, where the Republicans don't have such a comfortable majority; only three GOP have to break ranks to shoot down the tax bill. It is easy to identify at least four, the most visible being Bob Corker of Tennessee, who has flatly announced he won't vote for a bill that increases the deficit.
Corker is not going to run for re-election in 2018, and so he has been scathingly blunt about Trump, saying in an interview: "The president has great difficulty with the truth, on many issues." -- adding that world leaders know this, that Trump "debases the country", that he cannot "rise to the occasion as president". With less dignity, Corker also described the White House as an "adult daycare center".
Arizona Senator Jeff Flake, announcing his own retirement from politics, similarly denounced Trump in an eloquent speech: "We were not made great as a country by indulging or even exalting our worst impulses, turning against ourselves, glorying in the things which divide us, and calling fake things true and true things fake."
Arizona Senator John McCain and ex-President George W. Bush spoke out as well, with McCain saying America "will not thrive in a world where our leadership and ideals are absent." -- and Bush saying "our politics seems more vulnerable to conspiracy theories and outright fabrication."
Most Republicans in Congress of necessity turn a blind eye to Trump, though Corker says his own views are nothing unusual among his Congressional colleagues. However, subtle mockery does appear to be spreading; Senator Thom Tillis (R-NC) took a bag of popcorn to a Trump meeting. Symbolic? Yes; Tillis tweeted a shot of himself doing it. Will this become a custom? One hopes so.
Trump, to no surprise, has simply continued on his erratic course with the same old bluster and baloney. Being a theatrical person, he is unconcerned that he's not accomplishing much beyond jamming up the government -- which, since he's contemptuous of the government, is all for the good to him.
Shoes continue to drop. At the end of the month, a Federal judge blocked Trump's ban on transgenders in the military, US District Judge Colleen Kollar-Kotelly drily saying that the administration's arguments for the ban "do not appear to be supported by any facts."
More significantly, two aides to the Trump presidential campaign, Paul Manafort and Rick Gates, were indicted on charges including money-laundering by the Justice Department probe headed by Special Counsel Robert Mueller. Congressional Republicans are trying to shift focus by launching probes into a Canada-Russia uranium deal during the Obama Administration and Hillary Clinton's email fumble. Both seem acts of desperation, particularly the assault on Clinton: it was only too easy to manufacture controversy to cut Clinton to shreds during the presidential campaign -- but now the GOP only makes her look better, and themselves look worse.
Nobody knows what happens next. We only know about the future by extrapolation from the past; since we're in a situation that's not much like any we've been in before, who can say? One thing that can be said about the future is that there's no prospect of things settling down. Hang on, the roller-coaster is still building up speed.
* Thanks to two readers for donations to support the website last month. That is very much appreciated.COMMENT ON ARTICLE