The solar probe Ulysses has circled the sun for more than 18 years–almost as long as the Greek hero Odysseus, also called Ulysses, was absent from home due to the Trojan War and his prolonged journey home–but the space probe doesn’t have a homecoming in its future. Ulysses will receive its final transmission tomorrow, as researchers say the scientific findings sent home by the failing spacecraft no longer justify the mission’s costs. After shut-off, Ulysses will continue to orbit the Sun, becoming in effect a man-made ‘comet’. “Whenever any of us look up in the years to come, Ulysses will be there, silently orbiting our star, which it studied so successfully during its long and active life” [SPACE.com], says mission manager Richard Marsden.
The craft has already exceeded expectations. In February 2008, mission engineers announced with great solemnity and with heaps of praise for the orbiter that the craft would fall silent within a few months. Its power supply had grown too weak to keep the craft’s fuel lines from freezing. Not so fast: Engineers figured out that they could keep the lines warm by firing the craft’s thrusters in short bursts every couple of hours [The Christian Science Monitor]. Using that clever fix, Ulysses soldiered on for another year.
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As the second man to ever walk on the moon (he stepped out of the lunar module about 15 minutes after Neil Armstrong), Buzz Aldrin knows a little something about space exploration, about bold ambitions and great risks. Now, Aldrin is speaking out about NASA, and declaring loudly that the space agency has lost its boldness. The next step in humanity’s exploration of space must be a bootprint on Mars, he says.
Says Aldrin: “As I approach my 80th birthday, I’m in no mood to keep my mouth shut any longer when I see NASA heading down the wrong path. And that’s exactly what I see today. The agency’s current Vision for Space Exploration will waste decades and hundreds of billions of dollars trying to reach the moon by 2020—a glorified rehash of what we did 40 years ago. Instead of a steppingstone to Mars, NASA’s current lunar plan is a detour” [Popular Mechanics].
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Saturn’s moon Enceladus got humanity’s attention in 2005 when surprised astronomers detected jets of ice and gas spraying out from the moon’s icy surface, and since then researchers have eagerly investigated the possibility that the jets might emanate from liquid oceans beneath the frozen crust. A moon with liquid water would be of great interest, because it would be more likely to host extraterrestrial microbes. Now, two new studies with somewhat contradictory results have deepened the mystery of what lies beneath Enceladus’s shell of ice.
Both groups of researchers were looking for sodium near Enceladus; one found it, the other didn’t. Sodium is interesting because it indicates that deep under the ice, liquid water has been in contact with rocks, which leach salts [ScienceNOW Daily News]. The dissolved sodium, along with water, would be shot into space in the geysers, and some of the sodium would be trapped in ice crystals as they formed. The first research group found sodium traces in Saturn’s E ring, a wide band of ice particles that is believed to be replenished by Enceladus’s jets. “Those salty grains provide our current best smoking (or steaming) gun pointing to present-day liquid water near the surface of Enceladus” [Wired.com], wrote space scientist John Spencer in an essay accompanying the findings.
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Five days after their launch, NASA’s two new lunar probes have successfully rendezvoused with their target. The Lunar Reconnaissance Orbiter fired its thrusters this morning to settle into orbit around the moon, while the Lunar Crater Observation and Sensing Satellite (LCROSS) swung past the moon, streaming live video all the while. (NASA promises to put the video playback online soon.)
The paired satellites will spend the next year mapping the moon and searching for traces of water ice, culminating in a dramatic crash when LCROSS plunges into a crater. But for now, NASA is busy celebrating the successful first steps. The $504 million LRO is the first NASA vessel to orbit the moon since 1998. “LRO has returned NASA to the moon,” a flight controller said as NASA’s LRO mission control center erupted in applause. The probe’s lunar arrival comes just under one month ahead of the 40th anniversary of NASA’s first moon landing by Apollo 11 astronauts on July 20, 1969 [SPACE.com].
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NASA is turning its attention back on a familiar target–the moon–but in service of a unprecedented goal. Two new spacecraft are expected to launch this week on a robotic mission aimed at finding the best site for Earth’s first off-world colony, the centuries-old dream of science fiction writers and utopians…. “We’re going to provide NASA with what is needed to get human beings back to the moon and to stay there for an extended duration” [Los Angeles Times], explains NASA’s Craig Tooley. However, whether such a lunar outpost will ever be built is still an open question.
The spacecraft duo comprises an orbiter and a crash-lander; the two spacecraft will take off for the moon aboard a single Atlas V rocket, but once in space they’ll separate and take different routes. The Lunar Reconnaissance Orbiter (LRO) will make a four-day journey to the moon’s orbit where it will begin mapping the moon’s surface, looking for potential moon base sites in polar locations that are bathed in near-constant sunlight (which would be useful for solar panels). The orbiter will also carry pieces of plastic designed to simulate the density and chemical proportions of human skin and muscle…. The LRO’s particle detectors will measure how this plastic interacts with cosmic rays - a form of space radiation made up of particles such as protons that can lead to cancer by damaging DNA [New Scientist].
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For two years, the Mars rover Opportunity explored the Victoria crater and dutifully sent back reports on the sedimentary rock layers on display in the crater walls and the scattering of pebbles on the sunken floor. Now, the results of that comprehensive survey have been compiled and compared to data gleaned from Opportunity’s exploration of two smaller craters several miles away. The study shows that shifting sand dunes on ancient Mars once concealed a network of underground water spread across an area the size of Oklahoma…. “Given that we’ve seen the same stuff at places that are miles apart, it is a reasonable conjecture that those processes operated over most of this region” [National Geographic News], says lead researcher Steve Squyres.
The rover had previously explored the Eagle and Endurance craters, about 3.7 miles (6 kilometers) away from Victoria. Mission scientists chose Victoria as the next crater to explore because “it was the biggest crater we could possibly find,” said Steve Squyres…. The science team hoped that Victoria’s depth — of about 400 feet (125 meters) — might shed more light on the geology of the Meridiani Planum region [LiveScience]. Like a child in a fairy tale following a trail of pebbles, Opportunity also studied the small, round rocks made of the mineral hematite as it trundled towards the Victoria crater in 2006.
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The man tasked with steering NASA through difficult transitions and pointing the space agency boldly towards the stars will be a former astronaut who has piloted the space shuttle. On Saturday, President Barack Obama announced his long-awaited nomination for NASA administrator: Charles F. Bolden Jr. If confirmed by the Senate, the former astronaut and retired Marine Corps general will be the first African-American to head the space agency.
The pick has been celebrated by NASA insiders, and is viewed as a signal that, after some signs of ambivalence, President Obama is now embracing the expensive manned spaceflight program. “Clearly Charlie Bolden would not have taken the job if he were being asked to shut down human spaceflight,” said John Logsdon, a space policy expert in Washington…. He added that a recent announcement of the administration’s plans to review the Ares 1 rocket and Orion spacecraft, which are to replace the space shuttle by 2015, is not a shot across the bow of NASA’s human spaceflight program. He said it would be a review of the hardware, not the destination or goals [Los Angeles Times].
However, it is not clear whether the new leadership will adopt all of the goals for human exploration of the solar system that were laid out by the Bush administration: namely, returning to the moon by 2020 and then working towards landing humans on Mars.
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The U.S. government has announced increasing concern over the quality of its Global Positioning System (GPS), which could begin to deteriorate as early as next year, resulting in regular blackouts and failures – or even dishing out inaccurate directions to millions of people worldwide [The Guardian]. The possibility that new satellites would not be launched in time was announced in late April, but the warning was stepped up this week in a government statement that recognized cost over-runs of defence department space programmes [Nature] as part of the problem.
The functioning of GPS relies on a network of satellites that constantly orbit the planet and beam signals back to the ground that help pinpoint your position on the Earth’s surface [The Guardian]. GPS service cannot maintain its level of precision if old satellites wear out before new satellites are launched as replacements, and the ability of the system to provide full coverage could dip below 95% between 2010 and 2014, when the Air Force plans to begin replacing the current block of satellites with a newer generation [Nature], warned the report by the Government Accountability Office.
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Yesterday, about 350 miles above western Australia, two massively expensive pieces of space hardware rendezvoused in a delicate orbital dance. The space shuttle Atlantis arrived at the Hubble Space Telescope for the telescope’s fifth and final upgrade, and met the telescope in orbit as it circled the Earth at 17,200 miles per hour. With mission commander Scott Altman at the controls, Atlantis eased up within 30 feet of NASA’s flagship observatory, bringing the ship close enough for a capture attempt. Mission specialist Megan McArthur limbered up the shuttle’s robot arm and used snares at its end to latch on to a pin-like grapple fixture on the side of the gleaming telescope. “Houston, Atlantis. Hubble has arrived onboard Atlantis,” said Altman [Florida Today blog].
The astronauts audibly gasped as they drew up to the 12-ton telescope. “Just looking out the window here, and it’s an unbelievably beautiful sight,” said John M. Grunsfeld, a veteran astronaut. “Amazingly, the exterior of Hubble, an old man of 19 years in space, still looks in fantastic shape.” Dr. Grunsfeld, who is on his third Hubble repair trip, was one of the last humans to see the telescope in March 2002 and arguably knows it better than anyone on or above Earth [The New York Times].
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To explore the dark reaches of the solar system, NASA is going to need a lot more plutonium-238, the space agency has told the Department of Energy. NASA’s deep space probes are powered by pellets of the plutonium isotope: The electricity that powers onboard instruments comes from devices called radioisotope power generators. The RPGs make electricity with the heat from the radioactive decay of small amounts of plutonium-238 carried on board [Los Angeles Times]. Such devices are the only option for probes that voyage far from the sun and can’t absorb enough solar energy to power their operations.
But a new report from the National Research Council notes that the world’s stockpile of Pu-238 is rapidly dwindling, and explains that NASA only has enough left for a couple more missions. The isotope isn’t found in nature, and its production is at a dead halt all around the world. The United States stopped making Pu-238 at the end of the Cold War; although the isotope cannot be used in nuclear weapons, it’s a byproduct of the production of weapons-grade Pu-239. For the past few years NASA has been buying its supply from Russia, but Russia’s plutonium-making reactors were also shut down years ago. NASA will soon receive its last shipment of the isotope from Russia, after which the space agency will be looking for a new supplier.
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The Mars rover Spirit has driven almost 5 miles across the Martian surface, has climbed a hill as tall as the Statue of Liberty, and has generally kept on trucking for the five years since it landed on the planet, even though its mission was originally scheduled to last only 90 days. But its roving days could be over, unless its controllers at NASA’s Jet Propulsion Laboratory can extricate it from a sticky situation: Spirit is stuck in the Martian sand.
The rover was navigating around a low plateau en route to two volcanic features, Von Braun and Goddard, when it started rolling across the soft sand, and began to sink in. NASA controllers have tried a variety of maneuvers over the past few days in an attempt to extricate Spirit, but the rovers’ wheels have only sunk deeper, and are now partially buried in the sand. “This is quite serious,” said JPL’s John Callas, the project manager for Spirit and its twin, Opportunity. “Spirit is in a very difficult situation. We are proceeding methodically and cautiously. It may be weeks before we try moving Spirit again” [Los Angeles Times].
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While NASA’s central mission is the same as it always was–to send astronauts up, up, and away!–the details of how it will send bold explorers into the space frontier are suddenly, well, up in the air. After months of signaling displeasure with NASA’s operations, the Obama administration has ordered a 90-day review of the human space flight program. In a letter to NASA Acting Administrator Christopher Scolese, the president’s science adviser, John Holdren, wrote that “it would be only prudent” to review NASA’s human space flight program given the magnitude of its ambitions and “the significant investment of both funds and scientific capital” [Washington Post].
The crux of the matter is the Constellation program, which aims to replace the aging space shuttles with the newly designed Ares rockets and Orion crew capsule. But during the past several months, watchdog agencies have questioned whether NASA can deliver the Constellation program on time and within budget. Its estimated costs through 2015 have risen from $28 billion in 2006 to more than $40 billion today, and engineers still are wrestling with design flaws that would cause Ares I to shake violently during ascent and also possibly drift into its launch tower [Orlando Sentinel]. Back in December, Obama’s transition team reportedly asked NASA officials if military rockets used to launch satellites could be reconfigured to boost astronauts to the International Space Station and on to the moon.
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NASA hopes to send a “nano-satellite” the size of a bread loaf into orbit tomorrow, where it will conduct experiments on yeast to determine how the microorganisms behave in space. Weighing only 10 pounds, the tiny satellite called PharmaSat is scheduled to lift off on board a U.S. Air Force four-stage Minotaur 1 rocket late on May 5. Once aloft and free of the rocket, the satellite will circle the Earth at 17,000 mph while carrying a micro-laboratory packed with sensors and optical systems [ComputerWorld].
The satellite’s lab will autonomously conduct drug testing in orbit, treating the yeast with anti-fungal drugs to see if the yeast responds differently to treatment when it’s free of the Earth’s gravity. “There’s data that’s coming back from shuttle and space station missions that indicates something is changing microorganisms in a microgravity environment making them more varied,” said Bruce Yost, PharmaSat mission manager…. Those genetic changes could make bacteria more resistant to antibiotics and medical treatment — something scientists are hoping to learn more about before attempting longer jaunts into space such as to the moon and beyond [The Register]. One recent study found that salmonella become more virulent after just 83 hours of growing in space.
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When the Messenger spacecraft swooped low past the planet Mercury on October 6 2008, it gathered up a wealth of data that will have planetary scientists puzzling for years. As researchers sort through findings regarding Mercury’s volcanic past, meteor impacts, and the effect of the solar wind on the innermost planet’s magnetosphere, one broad conclusion stands out: Mercury isn’t just a boring chunk of rock. Marilyn Lindstrom, a NASA program scientist, said the Messenger findings show that Mercury is “just an amazingly dynamic planet, both in the past and in the present” [Baltimore Sun].
Superficially, Mercury looks a lot like the moon: small, grayish-brown and pockmarked with craters. Some scientists assumed that Mercury’s surface formed the same way the moon’s did, with lighter rocks rising to the surface of a magma ocean and congealing into a brittle crust early on. But the new observations reveal that 40 percent of the surface was formed by volcanoes. “Up until before Messenger’s arrival, we weren’t even sure that volcanism existed on Mercury” [Wired], says researcher Brett Denevi. The presence of titanium oxide also suggests that the planet was hot enough in its first 100 million years to be covered in magma oceans.
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NASA astronauts may not be assigned to a stint at a lunar base anytime soon. A statement by a NASA official suggested that the space agency is likely to scrap the idea of a permanent moon base, but could instead try to speed up other, more ambitious manned missions to explore our solar system.
NASA has been working towards returning astronauts to the moon by 2020 and building a permanent base there. But some space analysts and advocacy groups like the Planetary Society have urged the agency to cancel plans for a permanent moon base, carry out shorter moon missions instead, and focus on getting astronauts to Mars [New Scientist]. When the agency’s acting administrator, Chris Scolese, testified before a congressional subcommittee yesterday, he said that the agency probably won’t aim to build an outpost on the moon, suggesting that the agency may be following those advocates’ advice.
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