NASA Engineer Ravi Prakash Discusses 2012 Curiosity Mission To Mars
When NASA’s Curiosity rover touches down on Mars on August 6, an Indian engineer will be helping to maneuver its complex entry, descent, and landing on the Red Planet’s Gale Crater.
AsianScientist (Jul. 9, 2012) - When NASA's 900 kg Mars rover Curiosity touches down on the Red Planet's Gale Crater at 11 a.m. (IST) on August 6, space buffs in India will have reason to celebrate.
The reason: one of the key figures behind the complex entry, descent, and landing of the Curiosity rover is of Indian origin.
He is thirty-year-old P. Ravi Prakash, who received a B.S. in aerospace engineering from the University of Texas at Austin and a M.S. in aerospace engineering from the Georgia Institute of Technology.
Prakash joined NASA's Jet Propulsion Laboratory (JPL) in 2005 and has been working at the Mars Science Laboratory ever since. Though he was born in Texas, he has deep connections with India – his mother was born and raised in Varanasi, UP, and his father is from Gaya, Bihar. He has visited India several times.
In an interview with Asian Scientist Magazine, Prakash describes the US$2.5 billion Curiosity mission, which was launched on November 26, 2011 to assess whether Mars has an environment that can support microbial life. The mission, which has a life span of one Martian year or 98 weeks, will also characterize the climate of Mars and prepare for future human landings.
What are you currently working on in the Mars Science Laboratory?
I've had really great jobs in the past like testing the Mars Science Laboratory's landing radar in the desert. Currently I'm the systems engineer for the MSL entry descent and landing instrumentation which we call MEDLI. MEDLI will make the most extensive set of engineering measurements on the heatshield ever.
In your recent interview to the Planetary Society you said that your job is to get Curiosity through the atmosphere at 13,000 mph to the ground in seven minutes. Is there any particular aspect of the entry, descent, and landing which is really worrying you most?
Landing Curiosity is no easy feat. Thousands of events have to happen successfully in a matter of minutes. The Mars Science Laboratory (MSL) entry, descent, and landing team has to make sure that the largest heat shield NASA has ever built keeps temperatures of 1,600 ˚C, caused by the deceleration from 13,000 mph, from burning up the spacecraft.
The team has to make sure the parachute, the largest one ever flown on Mars at 21.5 meters across, inflates properly. The team has to make sure that the Sky Crane maneuver, a clever lowering technique being usedkfor the first time, operates flawlessly.
No one part worries the team much more than the next because each part has to work just right.
Why has it been called Seven Minutes of Terror?
It takes only seven minutes for the spacecraft to go from the top of the atmosphere, going five times as fast as a speeding bullet, to a screeching halt on the surface of Mars.
During those seven minutes, the spacecraft is on its own, automatically deciding when to perform each of the thousands of actions that are required to land Curiosity on Mars.
The nerve-wrecking part of all this is that while Curiosity is already sitting on the surface of Mars, we will not know if it was dead or alive, if it had survived the unforgiving atmosphere of Mars, for 14 minutes, while that signal is hurtling through space headed towards Earth, 250 million kilometers away.
You have described the entry, descent and landing as "amazingly complicated, but incredibly elegant." Please comment.
Thousands of events have to happen with perfect timing in a handful of minutes, and coordinating all this is a daunting task.
Over the last few years, the team ran literally millions of simulations of the landing to make sure the entry, descent, and landing were properly choreographed and tried to find out what conditions would cause the mission to fail.
Having said that, what we do is very difficult and success can't be guaranteed. If it is successful, it can be likened to the accomplishment of the first landing of humans on the Moon.
In your paper which you have written about the entry, descent, and landing you have said that the Curiosity mission has a lot of technological firsts. Could you describe some of them?
The Mars Science Laboratory entry, descent, and landing sequence was the result of setting out to do what no other mission had accomplished before.
The Jet Propulsion Laboratory employed several technological firsts such as guided entry and precision landing on another planet, as well as the entire sky crane maneuver, to land the largest rover yet on the surface of Mars. For the first time, NASA chose a landing site based on scientific merit alone.
The sky crane landing system is being used for the first time. Why was this chosen despite the fact that it is fraught with risks?
It has several advantages over the Mars Exploration Rover airbag system and even the Viking and Phoenix lander systems that used rockets all the way to the ground. The sky crane landing system eliminates the need for bulky airbags or blockage of a ramp by placing the rover directly on its wheels.
(August 7, 2012) NASA’s Mars Curiosity Rover Lands On The Red Planet, Sends Photos To Earth
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