LA CANADA-FLINTRIDGE, Calif. — NASA has dubbed the dizzyingly complex landing of its new Mars rover “seven minutes of terror” — a sequence of pyrotechnics, ropes and a “backpack” of engines that must work in meticulous choreography to give the mission a shot. Because of the distance, the sequence will be over by the time engineers receive a message that it has begun; Curiosity already will be on the ground, either ready to deliver groundbreaking science, or lying in a $2.5-billion wreck.
This weekend, as scientists were preparing their final push, Adam Steltzner — a leader of the landing team and a confident man with a booming voice and a skinny-Elvis pompadour — was asked which of the seven minutes was his favorite.
“Like any good parent,” he said, clutching his chest, “I love each of those minutes equally.” He has allotted himself an hour a day to think about it, he said — between 2:30 a.m. and 3:30 a.m., staring at the ceiling.
As Curiosity zeroed in on Mars at 8,000 mph Saturday, the Jet Propulsion Laboratory in La Canada-Flintridge, which is managing the mission for NASA, was a combustible blend of confidence and anxiety.
Scientists reported that Curiosity was on a near-perfect trajectory for its scheduled landing at 12:31 a.m. Monday, and was sending home a strong stream of data. The weather on Mars was cooperating; a pesky dust storm south of Curiosity’s landing site had dissipated. But scientists also conceded, in less guarded moments, that there were many ways the mission could go awry — and just one way to get it right.
Doug McCuistion, director of NASA’s Mars Exploration Program, began a briefing Saturday by putting up a half-serious slide showing a football-style scoreboard in space. It read: “Mars 24; Earth 15,” a reminder that Mars is a devilish place to land a spacecraft, and that more than half of the missions attempted in the last 50 years have failed.
That tally includes mere “flybys” — attempts to get a peek at Mars without landing. Now, scientists are attempting to land a roving, nuclear-powered geochemistry laboratory the size of a sedan, the largest and most ambitious machine ever dispatched to another planet.
“Can we do this? Yeah, I think we can do this,” McCuistion said. “But that risk still exists.” He adapted the lyrics of a Tom Petty song: “We’re learning to fly and we don’t have wings,” he said. “And getting down is the hardest thing.”
More than 300 years’ worth of work hours have been put into the landing sequence alone, officials said, and in some cases, the entire professional output of some engineers is on the line.
Devin Kipp, 30, graduated from Georgia Tech seven years ago and was hired immediately as an engineer at JPL. Ever since, he has had one assignment, effectively: to build the largest supersonic parachute ever deployed in space. The chute is designed to keep Curiosity from falling to its death, slowing it from 900 mph to a manageable 180 mph. Kipp’s seven years of work will be over in two minutes.
“Parachutes aren’t perfect,” Kipp said Saturday. Engineers pointed out that when paratroopers jump out of planes, they wear a second chute in case the first one fails. Curiosity couldn’t carry that much mass, and does not have that luxury. Still, Kipp said: “I have tremendous confidence.”
The discussion of the perils faced by Curiosity in recent weeks has focused largely on its landing sequence, which has never been attempted before and will require the spacecraft to change form five times in 10 minutes. But the machinery is hardly the only challenge the craft must overcome.
Curiosity, for instance, must avoid winding up on top of a boulder that is so tall that the rover’s wheels aren’t touching the ground - “a really bad day,” Kipp said in a recent interview.
Satellites have created a remarkably detailed map of the rocks inside Curiosity’s landing site; in 48 square miles, there are 13,287 rocks that are at least 21/2 feet high, roughly one for every football field. The risk of landing on one of them is less than a quarter of 1 percent - but it’s there.
“We’re reminding ourselves to breathe every so often,” said mission manager Arthur Amador.
McCuistion has programmed his cell phone to count down the hours, minutes and seconds until touchdown. As the numbers shrunk this weekend, emotions began swinging like a pendulum.
“We’re going to stick the landing,” McCuistion said at a briefing Friday. “We’re about to land a small compact car on Mars with a trunkload of instruments. It’s exciting. It’s daring — but it’s fantastic.”
And if it fails? On Saturday, less than 24 hours later, McCuistion mused about that possibility too, without prompting.
“If we’re not successful, we’re going to learn,” McCuistion said. “We’ll pick ourselves up and dust ourselves off. This will not be the end.”