Early Monday morning, August 6th NASA will experience what it has been calling seven seconds of terror. That is when the Mars Science Laboratory Curiosity lands on Mars. Curiosity is the latest in the Mars Rover series of vehicles and is the largest rover to be landed to date. Curiosity was launched on November 26, 2011 and will land at 12:31 am Central Daylight Time on August 6, 2012. Now you may be thinking big deal they are landing an unmanned vehicle on Mars.
Well the big deal is that it will approach Mars at about 13,000 mph; then comes the guided entry and deceleration with small rockets to about 1,000 mph; at 900mph a 100 pound parachute, that must withstand 65,000 pounds of force deploys; at 370 mph the heat shield separates, if this does not happen then the radar altimeters and cameras do not work; then comes a powered decent to about 70 mph, at 2 mph a sky crane will lower Curiosity to the Martin surface, at 0 mph from a height of 25 feet, then explosives cut the cables and the descent stage which flies away to crash landing away from Curiosity. At about 2 minutes before touchdown Curiosity's cameras will begin taking photographs at the rate of 5 frames per second.
Now for the seven minutes of terror. From the time Curiosity enters the Martin atmosphere it will take seven minutes for it to touchdown. Because of the distance that Mars is from Earth it takes 14 minutes for a radio signal from Mars to reach Earth. So when the signal is received on Earth that Curiosity has entered the Martin atmosphere it will have been on the surface for seven minutes and Curiosity will either be exploring or a pile of scrap on the Martin surface. As you can tell there are many things that can go wrong with this mission. I know I plan to be watching to hopefully see the first pictures of a spacecraft actually landing on another planet. NASA TV will have coverage as will www.nasa.gov .
For a NASA video of the Seven Minutes of Terror see:
For more information on Curiosity see: http://solarsystem.nasa.gov/news/msl_landing.cfm