Mars Exploration Rovers Update: More On Mars
Posted by A.J.S. Rayl
25-01-2004 11:00 CST
Opportunity landed in Meridian Planum on Mars last night at 9:05 p.m. Pacific Standard Time (PST) -- and fours hours later sent its first postcards home!
As the second Mars Exploration Rover neared the point of entering the Martian atmosphere, all systems were 'go' and looking good.
"Sit back and enjoy, it's going to be an E-ticket ride," Wayne Lee, chief engineer for entry, descent and landing, calmly announced.
And what a ride it was.
California Governator Arnold Schwarzenegger and former Vice President Al Gore arrived at the Jet Propulsion Laboratory (JPL) in plenty of time to be on hand to witness the event up close at the MER Mission Control.
Opportunity entered the top the Martian atmosphere right on schedule at 8:59 p.m., Pacific Standard Time (PST), cruising through the ‘six minutes of terror’ seemingly effortlessly. The parachute deployed as programmed four minutes later, at 9:03, with the backshell/heat shield separating about a minute later at 9:04.
By 9:05 p.m., Opportunity was bouncing on the ground in Meridiani Planum, landing with a relatively light impact force of between 2 and 3 Gs.
"We're on Mars!" EDL Manager Rob Manning announced.
The flight team thought at first that they had temporarily lost Opportunity’s signal but that turned out to be wrong. The signal, as it turned out, was never lost. Roars of applause and cheers erupted in mission control and virtually everywhere else at the lab.
The flight team received two and a half minutes of communication as Opportunity rolled to a stop.
"Even though computer models say it's going to be easier, every time we do this it's another experiment," Manning had said earlier today. "Entry, descent, and landing is a controlled crash and it's as scary as it's even been."
One would be hard pressed, however, to find anyone on NASA's newest 'dream team' who didn't consider the terrifying six minutes of entry, descent, and landing worth the cost of wrangled nerves and sleepless nights.
"We've got the best party in town, which is saying something for Los Angeles," said Matt Wallace, MER mission manager.
"Everything went very well all the way into the atmosphere, except you could hear Wayne going through a timeline we guessed in advance," recounted Manning just minutes after the successful landing. "It turns out we were really behind it. We went down eastward, and flew past our target [landing site] because the atmosphere was a little uncooperative, which was not a bad thing. One of the challenges in getting to Mars is not our systems, but the challenge itself. We did see the signal all the way down -- Goldstone and Canberra [stations in the Deep Space Network] did a phenomenal job. We do tend to want to pretend this is a standard capability . . . but to listen to our spacecraft as it goes throughout the solar system is really phenomenal."
The lander roll to a stop on its rear petal, but, said Wallace, "that forward path [to egress] is beautifully clear for us."
The first impression from the signal after touchdown was that Opportunity was bouncing for several minutes. But Manning said, "I was wrong, it turned out we got two signals that interfered with each other . . . out truths are often temporary."
What wasn't temporary were the first images that came streaming in via orbiter Mars Odyssey just after 1 a.m.
"I am flabbergasted, astonished, blown away!" lead scientist Steve Squyres exclaimed. "Opportunity has touched down on a bizarre, alien landscape. I said three weeks ago when we landed at Gusev that I thought we hit the sweet spot. But I still can't find words to describe this beautiful, alien place."
At first glimpse Squyres said he thought Opportunity might have landed in a crater, because of the shape of the skyline. If that is the case, he added: "I don't expect any significant problem getting out. In terms of rover trackability, how could you beat this?"
The most striking thing to the scientists was the image of a distinct outcropping of bedrock. "This is the first bedrock outcrop we've ever seen on Mars, and I can say that unequivocally," declared Squyres. "It could be volcanic or it could be sedimentary -- who knows at this point?"
Of course, it is far too early to discern anything about the story of water at Meridiani Planum from these early images. "But we're going to have a heck of a story to tell," sighed Squyres. "Right now, I'm just in awe."