NASA is preparing to land their Phoenix lander on Mars – a procedure they call the ‘7 minutes of terror’.
With the successful rover missions, Spirit and Opportunity behind them, you would think they would be more optimistic about this upcoming landing.
“I do not feel confident. But in my heart I’m an optimist, and I think this is going to be a very successful mission,” said Peter Smith, principal investigator and optical scientist with the University of Arizona. “The thrill of victory is so much more exciting than the agony of defeat.”
Sunday night will be the big night, when the Phoenix lander will hit the Martian atmosphere traveling at nearly 13 thousand miles per hour. It’s on-board computers will be working at speed to deploy it’s parachute, jettison the heat shield, extend its three legs, release the parachute and finally fire its thrusters to slow its descent to hopefully make a soft landing.
The Mars Phoenix Lander team will be biting their nails as they watch the event unfold from computer monitors at the Jet Propulsion Laboratory In Pasadena, California.
“Everything has to go right,” said Ed Weiler, NASA Associate Administrator. “You can’t afford any failures.”
One of the worries for the Phoenix team, is the landing system itself. Since the Viking missions in the late 1970’s, NASA has not successfully landed a probe on Mars using stabilising thrusters and landing legs. The successful Pathfinder, Spirit and Opportunity rovers used massive airbags to cushion the impact on landing.
The Phoenix Lander was simply too big and heavy to use this method of landing and with plans to launch larger spacecraft in the future, NASA will need to learn to reliably land with thrusters and landing legs.
“We landed on Mars with rockets and legs twice with Viking. It’s not impossible by definition, we have proof of it,” said Weiler. “Humans will have to land on landing legs. Eventually we want to send humans there, obviously.”
The landing site for Phoenix is near the northern polar ice cap on the Northern plains of Mars. There it will dig and scoop with its robotic arm and look for organic chemical evidence of life past or present.
The Phoenix Lander was launched towards Mars last August.
Photo credit: NASA