Rover team relives a high time

NASA’s Jet Propulsion Libratory in Pasadena was buzzing Monday over the one-year anniversary of Curiosity’s touchdown on Mars to explore the 3-mile-high Mt. Sharp and to look for signs of past life.

To celebrate the rover’s landmark, JPL held a party, kicked off by a panel discussion in an auditorium full of enthusiastic employees.

Emceed by Chief Scientist Dan McCleese, the presentation recapped the harrowing “7 Minutes of Terror,” the name given to a video that described the seven minutes from Curiosity’s initial penetration of the Martian atmosphere to its landing.

In only seven minutes, the rover had to slow its 13,000 mph speed, release its heat shield, unfurl a giant parachute, use rockets as brakes once the parachute was cut loose, and finally be deposited gently by cables dangling from a “stage” that would then fly off to avoid colliding with the rover.

That’s a lot that can go wrong, especially when it’s all happening on autopilot.

“At that point, you know it’s out of your hands. You can’t send any commands to the rover,” said Bobak “Mohawk Man” Ferdowsi, whose hairstyle became an Internet meme during the control room broadcast of the landing.

Allen Chen, who led the control room team during those tense seven minutes and acted as play-by-play announcer for the viewing public, confessed during the panel discussion that for a moment, he thought the mission was doomed.

During Curiosity’s descent, the rover sent signals, or “tones,” every 10 seconds to update mission control on its status, which Chen listened to and decoded. Shortly after hitting the atmosphere, Curiosity chirped a tone that almost made Chen’s heart stop -- it translated to “catastrophic,” implying that the rover was about to fall apart.

“I bet if you go back and rewatch the video, you can see me seize up,” Chen said. “I’m a terrible poker player.”

But Chen wondered if the message, rather than the rover, was in error: “I thought, ‘Let me sit on this for a minute.’ If we’re about to lose the vehicle, it’s going to become pretty obvious in a minute or two.”

Chen’s calm paid off. Curiosity continued its descent without incident, and it turned out that the warning tone was the result of a calibration error.

In the year since, Curiosity has been busy. Although it landed in the middle of Gale Crater in order to climb the foothills of nearby Mt. Sharp, after touchdown the science team decided to direct its $2.5-billion, six-wheeled space wagon toward Yellowknife Bay, where the rover dug “the drill hole that made history,” said John Grotzinger, one of the team’s project scientists.

After seven months of preparation and deliberation at just the right spot, Curiosity “drilled, looked and Mars turned from red to gray,” Grotzinger said.

The gray color of the soil deep beneath the surface meant the planet’s iron was reduced -- the opposite, oxidized iron, gives Mars its red hue -- long ago. Reduced iron means there is a good chance certain microorganisms could have thrived on Mars in the past.

In addition, Curiosity has traversed ancient streambeds, evidence of Mars’ wet past. Although all of its water is locked up in ice, the planet had liquid water in flood channels and river systems 2 billion years ago, team scientist Ashwin Vasavada said.

So what happened to create the cold, red desert of today?

The leading theory, according to Vasavada, is that Mars lost its atmosphere over time. “Mars’ magnetic field went away and made its atmosphere vulnerable to being stripped away by solar wind,” he said.

Following the discussion, JPL employees filed into the Mall, a bright, open area near the visitors’ gate, where a band played and everyone received free ice cream and models of the rover.

“When we explore, we are asking questions about ourselves,” Adam Steltzner said of the reason more than 1.2 million people watched the landing live online and why the buzz over Curiosity hasn’t died down.

“I think one of the reasons this sticks is that this act of exploration is so important to us,” he said. “Through it, we dream a little bigger.”

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brad.balukjian@latimes.com