What’s the News: City lights are more than a pretty sight from the air—they’re also a good way to tell how a country’s economy is doing, some economists say. Over the past decade, deducing a country’s gross domestic product from how much it glows in nighttime satellite images, a factor called luminosity, has become quite the econ fad. But as clever as it sounds, luminosity isn’t as helpful as you’d think, a new study says. Only in countries that are such a disaster that gathering reliable statistics is impossible is the glow a better approximation of GDP than you’d get with traditional measures.
The chip at the core of the Sprite
microsatellite is smaller than a dime.
What’s the News: Imagine a cloud of tiny satellites, each no larger than a postage stamp, sailing like dust on solar winds through a planet’s atmosphere and sending radio signals home, with no need for fuel. When a small patch of real estate opened up on an International Space Station experiment, researchers jumped at the chance to test the durability of such tiny “satellites on a chip,” which they hope to eventually deploy in atmospheres like Saturn’s, and three of the miniature objects are being delivered to the Space Station by Endeavor on its final flight (which was just scrubbed for today). They will allow researchers to see how well such microsatellites hold up to radiation and other rigors of space.
What’s the News: The many bits of space junk orbiting Earth, from foil scraps to lens caps to chunks of frozen urine, can damage satellites and spacecraft, which is why researchers have long sought methods to remove debris from orbit. Scientists at the U.S. Naval Research Laboratory have proposed a new way of taking out the trash (in two senses): They want to pump 20 tons of tungsten dust into Earth’s orbit; this dust would exert drag on the junk’s orbit, slowing it down and gradually lowering it until Earth’s atmosphere can burn it up. This bid to protect Earth’s 900 active satellites is controversial because the dust could potentially harm solar panels on satellites and obstruct astronomical measurements, but it’s a handy fix because it doesn’t require ambitious new technology.
Good news, solar sail enthusiasts: the NASA experimental spacecraft that was feared to be a dud sprang into life last week.
NanoSail-D was launched aboard a small satellite in December; once the satellite was in orbit the engineers back on Earth ordered the cargo door opened, and waited for NanoSail-D to pop out as planned. But the solar sail craft remained stubbornly inside the cargo bay. As weeks passed with no action, NASA’s hopes for the craft sunk.
But last Wednesday, NASA announced that NanoSail-D had spontaneously emerged.
“We knew that the door opened and it was possible that NanoSail-D could eject on its own,” Mark Boudreaux, FASTSAT project manager at the Marshall Center, said in a press release. “What a pleasant surprise this morning when our flight operations team confirmed that NanoSail-D is now a free flyer.” [CNN]
On December 6, NASA launched its Fast, Affordable, Science and Technology Satellite (FASTSAT), which, among other cargo, carried the test craft NanoSail-D. No bigger than a breadbox, NanoSail-D was supposed to blast free from FASTSAT and spend three days floating free before spreading a 100-square-foot solar sail—what would be NASA’s first successful solar sail project. But while all signs initially indicated the 8-pound box succeeded in ejecting from the satellite, now NASA is not so sure. The agency is having trouble communicating with NanoSail-D, and its whereabouts are unknown.
“We have not been able to locate or make contact with NanoSail-D,” says Kim Newton of NASA’s Marshall Space Flight Center in Huntsville, Alabama. The sail was scheduled to unfurl on 9 December, but NASA reports that the deployment of the sail cannot be confirmed, and it is not clear whether the sail was successfully ejected into space. [New Scientist]
Yesterday, the Russian space agency Roscosmos confirmed news from last week that they are pursuing plans to spend $2 billion cleaning up space debris. In a striking contrast to the secrecy that once cloaked space programs, the confirmation came via an announcement on Roscosmos’s official Facebook page:
Russia will build a special orbital pod that would sweep up satellite debris from space around the Earth.The cleaning satellite would work on nuclear power and would be capable to work up to 15 years. Energia said in a statement that the company would complete the cleaning satellite assembly by 2020 and test the device no later than in 2023.
For two years, the Chinese science satellite SJ-06F flew solo orbits around the Earth (or, as solo as a machine could be in the expanding haze of space junk in orbit). But now it has a partner: Last month China executed the delicate maneuver of aligning another satellite launched this year, SJ-12, with its older counterpart.
Only the United States had executed such a satellite rendezvous before this, and it shows off China’s advancement in satellite sophistication. Three years ago the country blew one of its satellites to smithereens in a practice test—a test that created thousands of additional chunks of debris in orbit. The satellite meet-up is a more elegant trick, and one whose implications could be sinister or benign. Let’s explore both possibilities.
Don’t Worry
China’s game of catch-up, which has its space program closing in on America’s abilities in orbit, strikes fear into the hearts of some politicos. But malfeasance need not be the aim of the satellite maneuver.
“This set of skills serves a whole lot of purposes,” says Dean Cheng, a Chinese policy expert with the Heritage Foundation, a think tank in Washington DC. The most immediate application, Cheng says, may be testing sensors and control systems to help pave the way for docking procedures to be used with China’s first space station module, Tiangong-1, which is set to launch in 2011. “This sort of thing may very well be consistent with wanting to test drive the hardware and software before you test it on your space laboratory,” Cheng says. [New Scientist]
It’s not just the sequoias—the towering firs, hemlocks, and other trees of the Pacific Northwest make its forests the tallest in the world, matched only by those in Southeast Asia. That’s according to a study by NASA, which has completed the first survey of the heights of forests throughout the world.
The map, created by NASA’s ICESat, Terra, and Aqua satellites, does more than give bragging rights to West Coast residents. For one thing, it could help scientists who are trying to predict while wildfires might strike, as well as those who want to determine what kind of forests make the best carbon sinks.
The map could also provide a means of monitoring the effects of climate change and deforestation on the world’s forests. Deforestation and land change use is responsible for 20 percent of the world’s emissions, and 48 percent of the world’s deforestation occurs in Brazil, according to a 2008 report by the World Resources Institute [The Independent].
Michael Lefsky and colleagues spent years compiling the data, which they describe in the journal Geophysical Research Letters.
For the better part of a decade, the Global Hawk unmanned aerial vehicle has coasted through the stratosphere, surveilling vast panoramas of land below for the U.S. Air Force and Navy. Now the plane’s broad reach will serve science. NASA announced this week that it had completed the first test flight of a Global Hawk retrofitted with monitoring equipment to help scientists study the the oceans, the atmosphere, and more.
“We can go to regions we couldn’t reach or go to previously explored regions and study them for extended periods that are impossible with conventional planes,” said David Fahey, co-mission scientist and research physicist [CNN]. From the comfort of their offices in Dryden Flight Research Center in the Mojave Desert, pilots flew the plane 14 hours up to the Arctic Ocean on this test run. Though this flight lasted about 14 hours, the Global Hawk can stay aloft for 30, and reach altitudes of 60,000, or twice as high as your last commercial airline flight attained.
Every time a space shuttle or the International Space Station has a near miss with a piece of space junk, we’re reminded just how much of the stuff litters the area around our planet—millions of total pieces amounting to more than 5,500 tons. The orbital debris includes everything from old rocket stages to shed paint flakes, and the situation worsened last year when two satellites collided, sending forth showers of debris. It’s a problem that grows steadily worse without an apparent solution, but now University of Surrey scientists say they’ve developed a possible solution: a tiny clean-up device with sails.
To help tidy up Earth’s orbit, the device could be attached to any piece of space-going technology. The CubeSail, which would measure more than 16 feet square when unfolded, is packed into a compartment that measures 4 inches wide and deep, and a foot long. When the sail is deployed, metal strips that are wound up inside the container straighten out and pull the sail flat. Despite its small size, the system could deorbit an object of up to 1,100 pounds, Surrey scientists say. CubeSail works by pulling against the small amounts of atmospheric gases present at orbital heights. Although the density of air molecules is low, it’s enough to make the sail act like a parachute, slowing it down, dragging the dead satellite to a fiery reentry much sooner than it would have done otherwise [Discovery News].
A lone wolf named Brutus is helping U.S. Geological Survey scientists study Arctic wolf migrations in remote regions of Canada. These migrations can traverse hundreds of miles in 24-hour winter darkness at temperatures that reach 70 degrees below zero Fahrenheit.
There’s no way humans can physically follow the wolves under these brutal conditions, so Brutus is sporting a GPS collar that beams his coordinates back to a satellite every 12 hours. As it turns out, the wolves are covering a lot of ground, as can be seen in the map above. Now, the fjords visible in the summer image above have frozen and can be crossed on foot. In one trip, the wolf and his pack traveled 80 miles from Ellesmere Island to Axel Heiberg Island and back in just 84 hours. Just through November 30, Brutus has traveled 1,683 miles [Wired.com].
Groundwater levels around the country have been sinking as wells for drinking water and irrigation pull water out of aquifers faster than they can naturally recharge. Now, using gravity-measuring satellites, NASA and California researchers have documented the extent of water loss in California’s Central Valley, and the results aren’t good.
The measurements show the amount of water lost in the two main Central Valley river basins within the past six years could almost fill the nation’s largest reservoir, Lake Mead in Nevada [AP]. The total is about 30 cubic kilometer; one cubic km contains more than 264 billion gallons of water.
Stars and other astronomical phenomena radiate across the electromagnetic spectrum, on both sides of the puny band of visible light that the human eye can pick up. NASA‘s newest toy, set for a Friday launch into space, will map the infrared portion of that radiation—and do it across the entire sky.
The Wide-Field Infrared Survey Explorer, or WISE, has been under construction since 2006. The satellite will spend six months mapping the entire sky in the infrared, after which it will make a second, three-month pass to further refine the mapping [Universe Today]. Stars, galaxies, comets, and other objects will fall under the explorer’s purview.
At least one start-up space company is finally getting off the ground. SpaceX, the company founded by Internet entrepreneur Elon Musk, had its first successful test launch last fall, and late last night it followed up with its first commercial space shot. The company’s Falcon 1 rocket took off from an atoll in the Marshall Islands and launched a Malaysian satellite into orbit. The spacecraft has black-and-white and color cameras to take high-resolution pictures of agricultural lands, forests, urban centers and other targets in Malaysia for commercial and government customers [Reuters].
The achievement is an important validation for SpaceX, which had three launch failures before getting its first test rocket into orbit in September 2008. Last year, SpaceX won a contract to supply the International Space Station after the shuttle retires, and this launch stands as the first physical proof that SpaceX can get the job done. To further develop their space delivery capability, SpaceX plans to follow this launch up later in the year with a launch of their larger rocket, Falcon 9 [Popular Science]. That rocket will be capable of carrying a cargo vehicle, called Dragon, to the low-Earth orbit where the space station resides.
80beats is DISCOVER's news aggregator, weaving together the choicest tidbits from the best articles on the day's most compelling topics.
80beats is written by Veronique Greenwood and Valerie Ross. This team darts through each day's science news faster than the ruby-throated hummingbird that beats its wings 80 times per second. Send ideas, tips, suggestions, and complaints to [azeeberg at discovermagazine dot com].
Not so helpful after all.
NanoSail-D, phone home.
For two years, the Chinese science satellite SJ-06F flew solo orbits around the Earth (or, as solo as a machine could be in the expanding 
It’s not just the sequoias—the towering firs, hemlocks, and other trees of the Pacific Northwest make its forests the tallest in the world, matched only by those in Southeast Asia. That’s according to a study by 
For the better part of a decade, the Global Hawk unmanned aerial vehicle has coasted through the stratosphere, surveilling vast panoramas of land below for the U.S. Air Force and Navy. Now the plane’s broad reach will serve science. NASA announced this week that it had completed the first test flight of a Global Hawk retrofitted with monitoring equipment to help scientists study the the oceans, the atmosphere, and more.
Every time a space shuttle or the 
A lone wolf named Brutus is helping U.S. Geological Survey scientists study 
Groundwater levels around the country 
Stars and other astronomical phenomena radiate across the electromagnetic spectrum, on both sides of the puny band of visible light that the human eye can pick up. 
