Waterbuffalo
05-21-2008, 09:56 AM
Now I know that Chief and I have SUCH an affliction for nasa..
Well here is another article and it looks like they're readying to land on Mars.
I only copied part 1 of this, please go to the link for the fine pictures AND page 2.
http://www.nytimes.com/2008/05/20/science/space/20mars.html?em&ex=1211428800&en=ab3c8134cf38de86&ei=5087%0A
"A spacecraft now completing a nine-month journey from Earth to Mars must survive a fiery, risky descent to the Red Planet to have a chance to scoop up water ice believed buried under an arctic plain.
After traveling 422 million miles since its launching last Aug. 4, NASA’s Phoenix Mars Lander is aiming for a touchdown on Sunday in the unexplored northern regions of Mars. But first, it must survive what its developers call the final “seven minutes of terror” to reach the surface.
“There are many, many risks and uncertainties,” said Dr. Edward Weiler, associate administrator of the National Aeronautics and Space Administration science division. Since the start of planetary exploration, 55 percent of spacecraft sent to land on Mars have failed, he said.
Although the Phoenix lander, a conglomeration of parts from two earlier failed missions, has been tested and rechecked to correct all known design flaws and potential errors, Dr. Weiler said, “there are always the unknown unknowns.”
If all goes as planned, the lander is to set down on Vastitas Borealis, the arctic planes of Mars roughly equivalent to northern Canada on Earth, about 15 minutes before mission control receives confirmation at 7:53 p.m. Eastern time. The first picture from the spacecraft, expected to be an image of its deployed solar power panels, should arrive about two hours later, mission managers said.
Barry Goldstein, Phoenix project manager from NASA’s Jet Propulsion Laboratory in Pasadena, Calif., said that for him the most hair-raising part of the journey will begin about 14 minutes before touchdown, when the spacecraft reaches the beginnings of the thin Mars atmosphere, jettisons the cruise stage that has nurtured it since leaving Earth and experiences three minutes of radio silence as it turns its heat shield toward Mars.
Then, with seven minutes remaining, Phoenix is to plunge into the atmosphere at 12,750 miles an hour, where friction will slow it, heating the shield to 2,600 degrees Fahrenheit. At 8 miles in altitude and 1,000 miles an hour, the spacecraft will deploy its parachute for the next three minutes of descent, when it is to jettison the heat shield, extend its three landing legs and begin using its radar to gather readings on its speed and distance from the surface.
At six-tenths of a mile above the surface and 125 miles an hour, Phoenix is to separate from its parachute and the back shell that holds it and begin the sequential firing of 12 rocket thrusters that slow it to landing at 5 1/2 miles an hour 40 seconds later.
It has been 32 years since NASA, with the twin Viking landers in 1976, has put a craft on the Martian surface using rockets to slow the descent. The last previous attempt was the 1999 Mars Polar Lander, which crashed when its engines cut off prematurely.
The later Mars Pathfinder and the two robot rovers, the Opportunity and the Spirit, which have operated for three years in the equatorial region, landed using air bags to cushion the impact. Mr. Goldstein said air bags were not practical for heavier craft like the Phoenix because the added weight of bigger bags would severely cut into the scientific payload.
Unlike the wheeled rovers, the Mars Phoenix Lander is to stay in one spot and dig for evidence of water and other conditions that could have supported primitive life.
Although there are ample indications that Mars had surface water billions of years ago — in some cases, evidence suggests that water may have flowed in some gullies and channels within the last few millions of years or later — conditions today, including an atmosphere 1 percent as dense as Earth’s, do not allow for liquid water, scientists said. But, instruments on the Mars Odyssey orbiter discovered in 2002 that plentiful water ice lay just beneath the surface throughout much of high-latitude Mars.
The target landing area for the Phoenix, surveyed in detail by the high-resolution camera aboard the Mars Reconnaissance Orbiter spacecraft, is a permafrost region with few rocks or deep slopes that could threaten the lander, said Dr. Ray Arvidson of Washington University in St. Louis, chairman of the landing-site working group. “This is one of the least rocky areas on all of Mars,” he said.
Dr. Peter Smith of the University of Arizona, the principal scientist for the $420 million mission, said that the area was covered with polar ice in winter, but that the Phoenix was to land in early summer, when the frozen surface is mostly clear and the soil is exposed for study. The 770-pound lander, with a 121-pound science payload, is to spend at least three months examining the surface with a trench-digging robot arm.
The Phoenix is named after the mythical bird that rose from its ashes, because the spacecraft is made up of parts from two earlier attempts to explore Mars. The spacecraft has the skeleton and some instruments from the 2001 Mars Surveyor lander, which remained grounded because of cost overruns, as well as instruments that are based on those aboard the unsuccessful Mars Polar Lander."
Well here is another article and it looks like they're readying to land on Mars.
I only copied part 1 of this, please go to the link for the fine pictures AND page 2.
http://www.nytimes.com/2008/05/20/science/space/20mars.html?em&ex=1211428800&en=ab3c8134cf38de86&ei=5087%0A
"A spacecraft now completing a nine-month journey from Earth to Mars must survive a fiery, risky descent to the Red Planet to have a chance to scoop up water ice believed buried under an arctic plain.
After traveling 422 million miles since its launching last Aug. 4, NASA’s Phoenix Mars Lander is aiming for a touchdown on Sunday in the unexplored northern regions of Mars. But first, it must survive what its developers call the final “seven minutes of terror” to reach the surface.
“There are many, many risks and uncertainties,” said Dr. Edward Weiler, associate administrator of the National Aeronautics and Space Administration science division. Since the start of planetary exploration, 55 percent of spacecraft sent to land on Mars have failed, he said.
Although the Phoenix lander, a conglomeration of parts from two earlier failed missions, has been tested and rechecked to correct all known design flaws and potential errors, Dr. Weiler said, “there are always the unknown unknowns.”
If all goes as planned, the lander is to set down on Vastitas Borealis, the arctic planes of Mars roughly equivalent to northern Canada on Earth, about 15 minutes before mission control receives confirmation at 7:53 p.m. Eastern time. The first picture from the spacecraft, expected to be an image of its deployed solar power panels, should arrive about two hours later, mission managers said.
Barry Goldstein, Phoenix project manager from NASA’s Jet Propulsion Laboratory in Pasadena, Calif., said that for him the most hair-raising part of the journey will begin about 14 minutes before touchdown, when the spacecraft reaches the beginnings of the thin Mars atmosphere, jettisons the cruise stage that has nurtured it since leaving Earth and experiences three minutes of radio silence as it turns its heat shield toward Mars.
Then, with seven minutes remaining, Phoenix is to plunge into the atmosphere at 12,750 miles an hour, where friction will slow it, heating the shield to 2,600 degrees Fahrenheit. At 8 miles in altitude and 1,000 miles an hour, the spacecraft will deploy its parachute for the next three minutes of descent, when it is to jettison the heat shield, extend its three landing legs and begin using its radar to gather readings on its speed and distance from the surface.
At six-tenths of a mile above the surface and 125 miles an hour, Phoenix is to separate from its parachute and the back shell that holds it and begin the sequential firing of 12 rocket thrusters that slow it to landing at 5 1/2 miles an hour 40 seconds later.
It has been 32 years since NASA, with the twin Viking landers in 1976, has put a craft on the Martian surface using rockets to slow the descent. The last previous attempt was the 1999 Mars Polar Lander, which crashed when its engines cut off prematurely.
The later Mars Pathfinder and the two robot rovers, the Opportunity and the Spirit, which have operated for three years in the equatorial region, landed using air bags to cushion the impact. Mr. Goldstein said air bags were not practical for heavier craft like the Phoenix because the added weight of bigger bags would severely cut into the scientific payload.
Unlike the wheeled rovers, the Mars Phoenix Lander is to stay in one spot and dig for evidence of water and other conditions that could have supported primitive life.
Although there are ample indications that Mars had surface water billions of years ago — in some cases, evidence suggests that water may have flowed in some gullies and channels within the last few millions of years or later — conditions today, including an atmosphere 1 percent as dense as Earth’s, do not allow for liquid water, scientists said. But, instruments on the Mars Odyssey orbiter discovered in 2002 that plentiful water ice lay just beneath the surface throughout much of high-latitude Mars.
The target landing area for the Phoenix, surveyed in detail by the high-resolution camera aboard the Mars Reconnaissance Orbiter spacecraft, is a permafrost region with few rocks or deep slopes that could threaten the lander, said Dr. Ray Arvidson of Washington University in St. Louis, chairman of the landing-site working group. “This is one of the least rocky areas on all of Mars,” he said.
Dr. Peter Smith of the University of Arizona, the principal scientist for the $420 million mission, said that the area was covered with polar ice in winter, but that the Phoenix was to land in early summer, when the frozen surface is mostly clear and the soil is exposed for study. The 770-pound lander, with a 121-pound science payload, is to spend at least three months examining the surface with a trench-digging robot arm.
The Phoenix is named after the mythical bird that rose from its ashes, because the spacecraft is made up of parts from two earlier attempts to explore Mars. The spacecraft has the skeleton and some instruments from the 2001 Mars Surveyor lander, which remained grounded because of cost overruns, as well as instruments that are based on those aboard the unsuccessful Mars Polar Lander."