Scientists working on the Phoenix Mars Lander celebrate after the spacecraft landed successfully on Mars.
PASADENA, Calif. — NASA’s Phoenix spacecraft appeared Sunday to have made a safe, flawless landing on Mars.
Live Video of the LandingIn the mission support room during the final, tense minutes before the landing, long stretches of quiet were punctuated by cheers and clapping as confirmation of crucial events like the deployment of the parachute were confirmed.
Then, at 7:53 p.m. Eastern time, Richard Kornfeld, the lead communications officer for entry, descent and landing, announced: “Touchdown signal detected.” The mission controllers erupted in cheers and began hugging one another in congratulations.
Because the signal was relayed via the Mars Odyssey orbiter, the controllers would have to wait a couple of hours, until Odyssey’s next pass over the landing site, for additional word of the Phoenix’s condition, including whether it had successfully unfolded its solar panels, and possibly for the first photographs of its landing site in the frigid plains above the arctic circle of Mars.
If all is operating properly, the next few days will be spent checking out the lander’s instruments. Then it will begin the first up-close investigation of Mars’s northern polar regions. That area became a prime area of interest for planetary scientists after Odyssey discovered in 2002 vast quantities of water ice lying a few inches beneath the surface in Mars’s polar regions.
All of Mars’s surface is currently far too cold for life to exist, but in the past, the planet’s axis may have periodically tipped over so that its north pole pointed at the sun during summer. That could have warmed the ice into liquid water.
With liquid water comes the possibility of life.
On the spacecraft, a robotic arm with a scoop will dig into the permafrost terrain and into the ice. Instruments include a small oven that will heat the scooped-up dirt and ice to 1,800 degrees Fahrenheit. Analyzing the vapors will provide information on the minerals, and that will provide clues about whether the ice ever melted and whether this region was habitable.
“We see Phoenix as a stepping stone to future investigations of Mars,” said Peter H. Smith of the University of Arizona, the principal investigator of the mission.
But the spacecraft had to get to the surface first. Mission managers sent their last instructions to it around noon Eastern time on Sunday. From there, the spacecraft operated on autopilot all the way to the surface.
Barry Goldstein, the mission’s project manager, said the management team decided against a small tweak of the trajectory to move away from “a small, rather diffuse rock pile” within the intended landing area. But there was only a 1 percent chance of landing on the rock pile.
During the day Sunday, the pull of Mars’s gravity accelerated the spacecraft from 6,300 miles per hour to 12,700 m.p.h. when it entered the Martian atmosphere. The friction of the atmosphere slowed the craft down by 90 percent, then a parachute provided further drag. For the last kilometer down to the surface, 12 rocket engines slowed the spacecraft to a velocity of 5 m.p.h. as it bumped into the ground.
The landing held an extra measure of anxiety, because the spacecraft has the same basic design as NASA’s Mars Polar Lander, which crashed while landing near the south pole in 1999. The spacecraft was originally going to Mars’s equatorial region as Mars Surveyor 2001, but when investigations of the Polar Lander failure turned up major flaws in the design, that mission was canceled, and the almost complete Surveyor spacecraft was put into storage.
Dr. Smith then proposed using the body of Surveyor and resurrecting it as Phoenix for a different mission. Extensive testing identified more than a dozen flaws in the lander design, and mission managers believed they had fixed all of the known problems.
NASA is spending $420 million on the Phoenix mission, for testing and retrofitting the spacecraft, outfitting it with new instruments, launching and mission operations. The Canadian Space Agency contributed $37 million for one of the instruments, a weather station. In addition, the development and construction of the original Surveyor 2001 spacecraft cost $100 million.
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