Showing posts with label nasa. Show all posts
Showing posts with label nasa. Show all posts

Tuesday, October 23, 2007

Fueling starts for space shuttle launch try Tuesday


CAPE CANAVERAL, Fla. Oct 23 (Reuters) - Technicians began filling shuttle Discovery's fuel tank for a launch attempt at 11:38 a.m. EDT 1538 GMT on Tuesday, officials said.

Loading the ship's external fuel tank with 500,000 gallons of liquid oxygen and liquid hydrogen began at 2:13 a.m. EDT 0613 GMT. The process was expected to take about three hours.

Discovery carries a new module for the International Space Station, which is a little more than 60 percent complete. NASA has 11 construction missions to the outpost remaining and two resupply flights before the $100 billion station is finished.

NASA needs to have the work completed within three years when the shuttle fleet is due to be retired.

The new module, called Harmony, will be the first expansion to the station's living space since 2001. It will serve as a connecting point for new laboratories owned by Europe and Japan, which are scheduled for launch in December and in 2008.

Once Discovery's fuel tank is full, a specially trained team of inspectors will head to the launch pad to scrutinize the tank for ice buildups and cracks in its foam insulation. Both ice and foam pose a serious risk to the shuttle if pieces should break off and hit the ship during liftoff.

NASA has been tweaking its launch procedures and shuttle equipment to avoid repeating the kind of damage shuttle Columbia sustained during its launch in 2003, which ended in the shuttle's breakup and the deaths of seven astronauts.

The shuttle's heat shield had been damaged by a chunk of falling tank insulation during liftoff and it failed as it flew through the atmosphere prior to landing.

For Discovery's flight, NASA carved an hour off the amount of time the tank is filled before launch in hopes of minimizing ice buildups.

Thursday, September 27, 2007

YES -Asteroid Probe's Launched


NASA's Dawn spacecraft in fine health after rocketing into space just after sunrise today, ending a long wait for mission scientists even as the probe's own eight-year journey to two large asteroids is just beginning.

For Dawn principal investigator Chris Russell, the liftoff capped a 15-year effort to plunder the secrets of planetary formation from asteroids Vesta and Ceres. Russell and his mission team watched Dawn rise over its Cape Canaveral Air Force Station in Cape Canaveral, Florida from the spacecraft's Launch Control Center.

"They were very taken by today's launch," said Russell, of the University of California, Los Angeles, of his colleagues in launch control after liftoff. "In fact, my wife cried when she saw it."

NASA first approved Dawn's mission as part of its Discovery program for smaller, more affordable science expeditions in 2001. Russell added that he first envisioned the mission using its efficient ion drive in 1992.

Since then, the mission has survived solar array dings, weather delays, rocket booster and launch tracking issues, as well as cancellation in March 2006. The space agency set the mission's current cost at about $357.5 million, not counting the cost of Dawn's Delta 2 rocket.

Dawn is now headed for a February 2009 swing past Mars before reaching its first space rock target, the bright and rocky asteroid Vesta, in August 2011. The probe's novel Xenon ion propulsion system is expected to guide it into orbit around Vesta for almost a year, then send it off toward the icy dwarf planet Ceres -- the largest space rock in the asteroid belt -- for a February 2015 rendezvous.

"The spacecraft is safe, it is healthy and there's not a single [major] issue aboard," said Keyur Patel, Dawn project manager at NASA's Jet Propulsion Laboratory in Pasadena, Calif., after the successful launch.

He credited Dawn's experienced mission team with tackling the last-minute hurdle of a wayward ship that encroached within the launch range perimeter. The snag delayed the probe's liftoff by about 14 minutes, after which the ship moved clear of the launch range in time for a 7:34 a.m. EDT (1134 GMT) space shot.

Dawn's two expansive solar arrays, which measure about 65 feet (about 20 meters) from tip to tip, successfully unfurled after liftoff and its primary science instruments were found to be in good health, mission managers said. A few minor issues, such as a one amp difference in the current produced by the two solar arrays, have popped up, but none are considered serious enough to pose a problem, they added.

"They're all just fine tuning," Patel said.

By Friday morning, Dawn is expected to have flown beyond the orbit of the moon as it continues its outbound flight to the asteroid belt that sits between the orbits of Mars and Jupiter.

Mission managers plan to test its three ion engines within about five days. A series of instrument checks of Dawn's optical camera, mapping spectrometer and gamma ray and neutron detector will also be performed, though the tools won't be fully calibrated until after the Mars flyby, Patel said.

"Every time we launch a spacecraft, they all have their own personalities," Patel said. "And what we're about to discover is what kind of personality Dawn has; whether it's going to be a well-behaved child, or someone that's slightly naughty."

source http://www.msnbc.msn.com/id/21014201/
Spacecraft’s ion drive gets its day in the sun
Dawn asteroid probe puts high-tech propulsion system to toughest test.
After suffering its share of dark days, NASA's Dawn mission finally had its “day in the sun” with Thursday morning’s launch toward our solar system's main asteroid belt.

The sun nearly set on Dawn a year and a half ago, when NASA canceled the mission over concerns about its ion engine. After a review of the planned improvements for the spacecraft, the space agency resurrected the project — but that wasn't the end of the mission's setbacks. Its originally scheduled June launch date was ruined by a processing accident involving its booster rocket.

That delay might have been a blessing in disguise, said Dawn mission designer Mark Rayman of NASA’s Jet Propulsion Laboratory


more
from NASA
NASA's Dawn Spacecraft Enroute to Shed Light on Asteroid Belt

CAPE CANAVERAL, Fla. - NASA's Dawn spacecraft is on its way to study a pair of asteroids after lifting off Thursday from the Cape Canaveral Air Force Station at 7:34 a.m. EDT.

Mission controllers at NASA's Jet Propulsion Laboratory (JPL), Pasadena, Calif., received telemetry on schedule at 9:44 a.m. indicating Dawn had achieved proper orientation in space and its massive solar array was generating power from the sun.

"Dawn has risen, and the spacecraft is healthy," said the mission's project manager Keyur Patel of JPL. "About this time tomorrow [Friday morning], we will have passed the moon's orbit."

During the next 80 days, spacecraft controllers will test and calibrate the myriad of spacecraft systems and subsystems, ensuring Dawn is ready for the long journey ahead.

"Dawn will travel back in time by probing deep into the asteroid belt," said Dawn Principal Investigator Christopher Russell, University of California, Los Angeles. "This is a moment the space science community has been waiting for since interplanetary spaceflight became possible."

Dawn's 3-billion-mile odyssey includes exploration of asteroid Vesta in 2011 and the dwarf planet Ceres in 2015. These two icons of the asteroid belt have been witness to much of our solar system's history. By using Dawn's instruments to study both asteroids, scientists more accurately can compare and contrast the two. Dawn's science instrument suite will measure elemental and mineral composition, shape, surface topography, tectonic history, and it will seek water-bearing minerals. In addition, the Dawn spacecraft and how it orbits Vesta and Ceres will be used to measure the celestial bodies' masses and gravity fields.

The spacecraft's engines use a unique, hyper-efficient system called ion propulsion, which uses electricity to ionize xenon to generate thrust. The 12-inch-wide ion thrusters provide less power than conventional engines but can maintain thrust for months at a time.

The management of the Dawn launch was the responsibility of NASA's Kennedy Space Center, Fla. The Delta 2 launch vehicle was provided by United Launch Alliance, Denver.

The Dawn mission to Vesta and Ceres is managed by JPL, a division of the California Institute of Technology, Pasadena, for NASA's Science Mission Directorate, Washington.

The University of California, Los Angeles, is responsible for overall Dawn mission science. Other scientific partners include Los Alamos National Laboratory, N.M.; Max Planck Institute for Solar System Research, Katlenburg, Germany; DLR Institute for Planetary Research, Berlin; Italian National Institute for Astrophysics, Rome; and the Italian Space Agency. Orbital Sciences Corporation of Dulles, Va., designed and built the Dawn spacecraft.

To learn more about Dawn and its mission to the asteroid belt, visit:


http://www.nasa.gov/dawn

Sunday, September 23, 2007

The next frontier? MARS


Every night while he was away, Jerry Linenger would curl up in a corner of the ceiling and read a page or two of the journals of doomed Arctic explorer Ernest Shackleton – for comfort, of all things – as the Earth drifted lazily by, far, far below.

"Their ship was crushed by the ice," Linenger says. "They had to hunt walrus to survive the winter before months of darkness set in. I'd read that and when I closed it, I would think, `It's not so bad up here.'"

Zero gravity can offer these unlikely opportunities for repose – not to mention a unique sense of perspective. For five months on the International Space Station, Linenger, an American astronaut crewing with two Russians, took solace where he could.

"I've been on submarines in the Indian Ocean, in the middle of nowhere, and it was nothing, compared to this," he says. "It was a sense of being completely dislocated from humankind, and that is a profoundly different kind of isolation."

That was five months. Can you imagine two years?

That's the best guess for a manned mission to Mars: Nine months' travel each way, with a shortcut across the orbit of Venus along the way. Depending on how long you stick around, even a brief – say, two-month – visit puts you four months shy of two years – two years off the Earth in that "complete dislocation from humankind" of which Linenger speaks.

This is not idle chatter. For all the financial stresses such a mission would entail – in 1989 NASA offered a catastrophic estimate of $400 billion, causing the hypothetical program to be scrapped; more recently, a highly optimistic $30 billion by some independent Mars advocacy groups, while in 2004, President George W. Bush said it would be $40 billion to $80 billion – this is entirely possible.

In other words, while the "if" and "when" of the mission are speculative at best – Bush's 2004 address famously recommended, not committed to, a Mars mission – we've done a remarkably good job of the "how."

Make no mistake. NASA, the Russians, and very quickly, the Chinese, likely have the technological know-how to do this right now. ("Getting people up there is quite possible. Getting them back is the hard part," says York University professor Peter Taylor, who worked on Phoenix, NASA's robotic mission to Mars currently en route. "I wouldn't want to be on the first trip.")

Starting tonight, the Discovery Channel will be airing a multi-part series called The Race to Mars that, in its exhaustive, comprehensive dramatization of an eventual Mars mission, pushes that disturbing detail aside for the sake of the argument.

And the argument – do we need to send humans to Mars? – is among the most profound we face today. Which is to say, among the ifs, whens and hows, perhaps the most compelling question, simply, is why. And there is no end to the answers that flow from anyone – astronauts, scientists, enthusiasts – you care to ask.

But the most riveting among them, perhaps, has nothing to do with science at all.

"The question I ask is, do human beings exist to strive, or to simply relax?" says Robert Zubrin, an aerospace engineer and the director of the independent Mars advocacy and research group, the Mars Society.

"Are we here to try to do great things that have never been done, to advance the frontiers of human possibility, or are we here to simply enjoy the fruits of others who have thought that way?"

In his recent book Moon Dust, the British journalist Andre Wright set out to interview the surviving astronauts of the Apollo missions to the moon, all now well into their 70s.

He was struck by the fact that, in a decade or less, there could well be no one left alive who knew what it was to stand with ground under their feet not of this Earth and stare back at the big blue ball they called home.

It led Wright to describe the Apollo missions as the last optimistic act of humankind – a mission executed not for military or commercial purposes, or any other reason than it challenged the limits of human innovation and ambition. It embodied the spirit, simply, that anything was possible.

At NASA and other governmental space agencies, at least, that spirit has been on the wane for decades. "For the past thirty years, they've been going up and down to orbit, and carrying on for the sake of carrying on," Zubrin says.

When the space shuttle Columbia evaporated on re-entry in 2003, it sent NASA into deep self-examination. A presidential commission on the disaster came back with an indictment of the program as lacking direction and purpose.

"Essentially, they said, `If you're going to assume the costs and risks of human space flight, you need to have goals that are worthy of those costs and risks,'" Zubrin says.

NASA consulted widely to determine a goal; Zubrin's group was among the consultations. In the end, they came up with that goal: Until 2010, it's shuttle and station. And then – on to the moon, and Mars.

But there's that political will issue again. Bush passed the buck to the next administration, which, when elected, will have to decide whether an investment of potentially more than $100 billion in a Mars mission is the right choice in a nation in deep economic stagger and bleeding badly in all respects from a prolonged war in Iraq.

But then, there's that which is priceless. When John F. Kennedy committed (not "recommended") to have a manned mission to the moon, it was a source of global inspiration – achievement for its own sake.

"It created that optimisitc attitude that anything is possible – that the world does not have to be as it always has been, and change is possible," Zubrin says. "It was a banner of progress and human possibility to embrace this goal."

Let us not forget the science. Zubrin's group has conducted 72 earthbound "Martian missions," in the Canadian Arctic and the Utah desert, simulating Martian living conditions and field work. The rehearsals are taken seriously, with participation from NASA and universities around the world.

Since 1964, when NASA's Mariner 4 executed the first successful flyby of the red planet, we've been to Mars a couple of dozen times, either probes on the surface or satellites in orbit, either Russian, American, Japanese or British. But we've never been there.

"Every time we go there, it's to answer a question. And inevitably, every question brings forward 10 more," said Alain Berinstain, the director of the planetary exploration program at the Canadian Space Agency. "That's why we're going to send humans to Mars: Because we can't answer all these questions robotically."

These are big ones. "Are we alone in the universe?" says Brendan Quine, the director of space engineering at York University, the country's primary research facility into Martian exploration. "These are profound questions that have far-reaching consequences."

Quine is associated with a unit called Northern Light, a joint venture between the school and Thoth Technologies, a Canadian aerospace firm. They're exploring privately funded space exploration (they hope to launch their own, private Martian probe in 2009, for a fraction of the cost of NASA's $350 million Phoenix mission).

One of Northern Light's objectives is to search for life. (Phoenix, which for the first time ever will sample some of the planet's icy ground, may beat them to it, though it's not one of the mission's stated goals.)

Key to this, of course, is water – something most believe the planet has in abundance in some form below its dusty ochre surface (the daytime temperature at the Martian equator is 20 degrees Celsius, but drops to —80 at night, so it's likely ice).

A thick band of hydrogen around the equator indicates water in some form. "We think there are very large reserves of water on Mars, actually," Quine says.

"There are clear coastlines – multiple coastlines, actually. You can't say they are until we test them, but they appear to be coastlines. In fact, we think that if we melted all the waters on Mars, we would flood the ocean basins to a depth of 500 metres. Then you've got a planet a lot like Earth."

Not that this is possible, of course. "But maybe there are ways, without substantially damaging the ecosystem, to bring Mars alive again."

Ecosystem. Again. Which assumes there is an ecosystem, and that there was one before. Strictly theory, of course, but a good one, suggests the impact of a massive meteorite, 20 kilometres wide, which hit Mars at a speed of 20 kilometres a second (its impact zone is the massive Hellas Crater, 2,100 kilometres wide). In theory, the impact would have thrown up millions of tonnes of debris, forcing the planet to heat up dramatically and the atmosphere to escape.

More theory: The thin Martian atmosphere is largely carbon dioxide. Left on its own, in a short 10,000 years, UV radiation would break it down to carbon monoxide. But it hasn't. "That means something is artificially maintaining the carbon dioxide atmosphere." Such as? "Micro-biological life produces carbon dioxide," Quine says. "I suppose volcanoes do as well, but we haven't seen much evidence of that."

Aha. Which is why we need to get there. For Quine and many others, all the robotic probes are a dress rehearsal for the real thing. "Before we send people, we need to know what the environment's like," he says.

He speaks as though it's an inevitable. He's not alone.

"We shouldn't think of it as a fairytale," Berinstain says. "The simple fact is, human beings go places they haven't been before, and as soon as they can. I don't know if it'll happen in 20, 30 or 100 years from now, but it will happen. There's no doubt in my mind about that."

For Zubrin, it's not we will, but we must. "To say we cannot accept the risks of humans to Mars would be to turn our backs not only on Apollo, but on Lewis and Clark, on Colombus, and everyone who took a chance to open up new possibilities to create the world we currently have," he says.

"For us to not accept that risk is for us to say we've become less than the people who got us to where we are today.

"And to me, that is something our society cannot afford."