Monday, August 6, 2012

Mars Science Laboratory Lands on Mars

First Picture from the Curiosity Explorer on Mars. One of the rover's wheels appears in the corner. The horizon is curved due to a fish-eye lens on the camera.

"Seven minutes of terror" was a good prediction! As the Mars Science Laboratory hurtled from space into the atmosphere of Mars, ground controllers at Jet Propulsion Laboratory (JPL) and NASA were biting their nails and anxiously awaiting signals from the sensors. Of course, since Mars is so far away, it takes about 15 minutes for the signals to reach Earth, and there is nothing the controllers can do; the landing (or crash!) had already happened! As the signals came in, though, each signal received showed each step in the landing proceeding as expected, and the rover Curiosity made a safe landing on Martian soil.

The JPL control room erupted in cheers.

You would have thought Neil Armstrong had just walked on Mars. But after all, it was just a robot. Then again, this was no ordinary robot! Unlike the tiny Sojourner, or the medium sized Spirit and Opportunity rovers, Curiosity is a big auto-sized robotic rover that will explore a good chunk of Martian territory over the next two or more years. Instead of using the inflatable bounce-landing balloon approach, NASA opted for a new risky landing due to the rover's size. When the re-entry shield dropped off, a large hypersonic parachute deployed to slow the craft's descent to the surface. Just before reaching the surface, the protective structure (Mars Science Laboratory) housing and protecting the rover (Curiosity) fired thrusters to hover above the surface. The rover was then lowered by cables below the MSL's structure. With the rover ready, the thrusters reduced power and the entire system moved down until Curiosity landed, and sensors on the cables indicated to the MSL that there was no weight on them anymore. With that signal, the cables released the rover and the MSL rocketed away from the rover site.

Curiosity experiment diagram.

The landing actually occurred at about 11:15 p.m. MDT, with the signals reaching us on Earth at about 11:32 p.m. MDT. Within minutes, as the cheering continued at JPL, the first pictures arrived as "thumbnails" (small in signal size) showing the shadow of the rover and the horizon of Mars. Over the next couple of days, color pictures and images with higher HD resolution will be plastered all over the Internet and television screens as Curiosity begins its exploration. The mission: a 2-year investigation of Gale Crater, 96 miles in diameter and what NASA thinks is the best chance so far to examine the geology of Mars searching for signs of past or present life.

The current Mars Scoreboard.

Lest anyone get the idea that this landing was easy, NASA published a "Scoreboard" showing our human success rate at sending probes to Mars. So far, only the USA and Russia have been sending probes at the red planet, and to show you how hard that really is, take a look at the score: 15 successful missions and 24 failures! Unfortunately for Russia, they have experienced nothing but failures. Rather than look at their efforts as cursed, however, it's valuable to realize how HARD it is to send a probe through 350 million + miles of radiation-filled space and land it or orbit it exactly where you want.

It's just that NASA is REALLY good, and they make it look easy.

No comments: