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"It's basically wishful thinking in a lot of ways — that there's a suitable target, that you can find it in time, that you can actually catch it if you go there and bring it back." Al Harris retired NASA planetary scientist WASHINGTON—NASA is looking for a rock. It has to be out there somewhere — a small asteroid circling the sun and passing close to Earth. It can't be too big or too small. Something six to nine metres in diameter would work. It can't be spinning too rapidly, or tumbling knees over elbows. It can't be a speed demon. And it shouldn't be a heap of loose material, like a rubble pile. The rock, if it can be found, would be the target for what NASA calls the Asteroid Redirect Mission. Almost out of nowhere it has emerged as a central element of NASA's human space flight strategy for the next decade. Rarely has the agency proposed an idea so controversial among lawmakers, so fraught with technical and scientific uncertainties, and so hard to explain to ordinary people. The mission, which could cost upward of $2 billion, would use a robotic spacecraft to snag the small rock and haul it into a stable orbit around the moon. Then, according to NASA's plan, astronauts would blast off in a new space capsule atop a new jumbo rocket, fly toward the moon, go into lunar orbit and rendezvous with the robotic spacecraft and the captured rock. They would put on spacewalking suits, clamber out of the capsule and examine the rock in its bag, taking samples. This would ideally happen, NASA has said, in 2021. "That's our plan," said Michael Gazarik, NASA's top official for space technology. "We have to merge it with reality." Plans, goals, dreams and technological realities are difficult to sort through these days at NASA. Apart from the asteroid mission, the human space flight program has few attainable destinations in the near term. Astronauts in 2021 may simply orbit the moon and come home, a significant feat, but one the agency first achieved in December 1968. Or they could fly to a gravitationally stable point in space beyond the moon, a potential base for future operations. NASA has what might be called middle-age problems. Founded 55 years ago, America's civilian space agency had its greatest glory in its youth, with the moon shots, and it retains much engineering talent and lofty aspirations. But even as the agency talks of expanding civilization throughout the solar system, it has been forced to recognize its limitations. Flat budgets have become declining budgets. The joke among agency officials is that, when it comes to budgets, flat is the new up. NASA lacks the money and the technology to do what it has long dreamed of doing, which is to send astronauts to Mars and bring them safely back to Earth. It has resorted to fallback plans, and to fallbacks to the fallbacks. Thus was born this improbable Asteroid Redirect Mission. The human space flight program has long been searching for a mission beyond Low Earth Orbit (LEO). That's where NASA has been sending astronauts since the 1970s, and where the underappreciated international space station circles the planet, currently occupied by two Americans, three Russians and an Italian. The asteroid mission not only goes beyond LEO, it scratches many other itches at the agency. NASA has marketed this as planetary defence — a way to get the upper hand on asteroids that could potentially smash into Earth. The agency also has said this could boost the commercial mining of asteroids for their minerals, thus expanding humanity's economic zone. And the robotic part of the proposal involves new propulsion technology that NASA thinks could be crucial for an eventual human mission to Mars. There are also political factors. President Barack Obama vowed in 2010 to send humans to an asteroid. NASA officials have said this mission meets that goal. Most important, the ensnared asteroid would provide a destination beyond LEO for new, expensive hardware that NASA is already building: the big rocket called the Space Launch System and the Orion crew capsule. The mission could deflect accusations that the government is building rocket ships to nowhere. "It is really an elegant bringing together of our exciting human space flight plan, scientific interest, being able to protect our planet, and utilizing the technology we had invested in and were already investing in," said Lori Garver, NASA's deputy administrator. But the mission is viewed skeptically by many in the space community. At a July gathering of engineers and scientists at the National Academy of Sciences, veteran engineer Gentry Lee expressed doubt that the complicated elements of the mission could come together by 2021 and said the many uncertainties would boost costs. "I'm trying very, very hard to look at the positive side of this, or what I would call the possible positive side," he said. "It's basically wishful thinking in a lot of ways — that there's a suitable target, that you can find it in time, that you can actually catch it if you go there and bring it back," said Al Harris, a retired NASA planetary scientist who specializes in asteroids. "Of course, there's always luck. But how much money do you want to spend on a chance discovery that might have a very low probability?" said Mark Sykes, a planetary scientist who chairs a NASA advisory group on asteroids. If the target rock isn't scoped out well in advance, it could even turn out, on close inspection, to be something other than a small asteroid — say, a spent Russian rocket casing that's footloose around the sun. NASA officials understand this and have recently been floating a different scenario, a Plan B. Instead of the robotic spacecraft trying to nab a small, little-understood and potentially unruly rock, the spacecraft could travel to a much larger, already-discovered asteroid and break off a chunk to bring back to lunar orbit, where astronauts would visit it. That would eliminate a lot of unknowns. In space missions, unknowns ratchet up costs and create delays. But under Plan B, the target might be an underwhelming boulder the size of, say, a washing machine. Presumably that's not what Obama meant in 2010 when he vowed to send humans to an asteroid. NASA's turmoil dates to Feb. 1, 2003, when the space shuttle Columbia disintegrated over Texas, killing the seven astronauts on board. The grieving space community decided to rethink the enterprise of human space flight, from the architecture of rockets to the fundamental purpose of launching people off the planet. Many people inside and outside of NASA wanted to get back to exploration, which would mean sending humans beyond Low Earth Orbit for the first time since the late 1960s and early 1970s. President George W. Bush proposed a plan to return astronauts to the moon by 2020 as part of a sustained lunar presence. The new NASA program, Constellation, included plans for two rockets, a crew capsule called Orion and a lunar lander. But at NASA there's a saying: "Budget is mission-critical." Constellation's funding fell short of what top NASA officials expected. The program fell behind schedule. A new rocket, Ares I, had some delays and technical problems (then-NASA administrator Michael Griffin would point out that only the PowerPoint rockets always work perfectly). Barack Obama won the presidency, and Griffin was soon gone, along with Bush's Constellation program. Obama's pick to run his NASA transition team, Lori Garver, never liked the back-to-the-moon strategy. "If your goal is Mars, that is certainly a detour," she said recently. In killing Constellation, Obama and his team adopted what the Augustine Committee dubbed the "flexible path" strategy. The concept is arguably a sign of institutional maturity: NASA would focus less on destinations and more on creating new technologies. The idea was to advance space flight capabilities, with the long-term goal of sending people to Mars. Commercial companies could take over the routine taxi rides to orbit, and NASA would tackle harder missions. But there's a problem with the harder stuff: Often it's just too hard. Just about everyone in the space community wants to go to Mars. Rovers are great, but they're sluggish, and scientists fantasize about a human geologist being able to decide where to dig into the Martian soil for clues about the planet's history and possible signs of life. Many people feel strongly that societies that don't explore the frontier will invariably go into decline. The fourth rock from the sun haunts the imagination of people from the third rock. Mars has as much land area as the Earth. Someone like Elon Musk, the visionary founder of SpaceX, isn't necessarily going to wait for a NASA mission; he talks of establishing a Mars colony, and says he wants to die there — just not while attempting to land. A private venture called Inspiration Mars hopes to send two astronauts on a flyby mission of Mars in 2018. And a Dutch reality show, Mars One, is lining up thousands of volunteers for a Mars colony that supposedly — and implausibly — will begin with landings in 2023. NASA, however, is not an entrepreneurial outfit. Its plans have to pass multiple layers of technical, political and budgetary review. A fundamental presumption of NASA missions is that the astronauts will come back alive. A journey to Mars would take about two years and expose astronauts to extremely high levels of radiation. The Martian atmosphere is a nightmare, just thick enough to cause problems but too thin to be of much use in braking a speeding spacecraft. NASA last year landed a one-ton rover on Mars, but to put humans there, engineers think they would need to land a 40-ton payload, including a habitat, fuel and food. To scale up by a factor of 40 is not as simple as, for example, making a parachute 40 times as big, because physics and aerodynamics don't work that way. More doable is a human mission that orbits Mars. Astronauts could essentially telecommute to work, operating rovers and other instruments from orbit. Indeed, a Mars orbit in the 2030s is an official NASA goal, direct from Obama. On April 15, 2010, in a closely watched speech at the Kennedy Space Center, the president said that by 2025, NASA will begin missions to "deep space," starting by "sending astronauts to an asteroid for the first time in history." Then would come a Mars orbital mission in the mid-2030s, he said. "And a landing on Mars will follow," he said, without giving a certain date. He added: "I understand that some believe that we should attempt a return to the surface of the moon first, as previously planned. But I just have to say pretty bluntly here: We've been there before." NASA missions historically have received bipartisan support. Not this time. House Republicans have treated the asteroid initiative — which would cost $105 million in 2014 under the president's budget request — as though it were an effigy of the Obama administration. In July, House Republicans on the Science Committee passed a bill that would take the unusual step of prohibiting NASA from proceeding with the asteroid mission without first supplying Congress with more information about it. Senate Democrats are protecting the initiative for now. Many times in recent months, NASA officials have cited planetary defence as a reason for the mission. But the target rock would not be nearly big enough to pose a threat to human civilization should it hit the Earth, and the methods used in the mission would not be applicable to the deflection of a large asteroid. In recent days, Gen. Charles Bolden Jr., a four-time shuttle astronaut appointed by Obama as NASA administrator position, has backed off the save-the-Earth rhetoric. Meanwhile, Garver, the NASA deputy administrator who has been a driving force behind the mission, is headed for the door. She announced in August that she's leaving the agency for a position with the Air Line Pilots Association. Although NASA has publicly talked of an asteroid rendezvous in 2021, the idea has a fundamental problem. That is the first scheduled mission with a crew in the new Orion capsule. Officials in charge of getting astronauts home safely do not sound eager to conduct a shakedown cruise that involves complicated spacewalking and an interaction with a bagged asteroid in orbit around the moon. Mark Geyer, the Orion program manager, said: "I think it's clear that there's more risk in doing the asteroid mission on the first flight with people. In general, you'd rather activate the systems and test them first." NASA officials have suggested they could delay the asteroid mission until later flights of the Orion capsule. The transition to the post-shuttle era is nowhere more obvious and more poignant than at the Kennedy Space Center. Officials at Cape Canaveral say they're optimistic and talk about creating a 21st-century spaceport. They point to the fact that the Orion capsule is under construction on the centre's grounds. But the space centre is looking rough around the edges, like a historical site. The cafeteria draws a sparse crowd at lunchtime. The media centre is quiet. Two launch pads, 39A and 39B, await the arrival, someday, of the SLS, or some other rocket needing to go somewhere. One pad still has a massive space shuttle gantry, as if hoping a shuttle will materialize. The dominant structure on the Cape, soaring 160 metres, is the Vehicle Assembly Building. It's a mega-hangar built in the 1960s, the height of the Cold War space race, when NASA had a blank cheque and needed a structure large enough to hold a vertical Saturn V moon rocket. There's not much left inside. Up top, vultures perch on the edge of the roof, and then jump — soaring on the updrafts as the Florida wind slams into the great, empty building.  via Science - Google News http://news.google.com/news/url?sa=t&fd=R&usg=AFQjCNHVHjZO5JEH2EXMwxbquuTZQOBifQ&url=http://www.thestar.com/news/world/2013/09/01/inside_nasas_mission_improbable_catching_an_asteroid.html | |||
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