November 4, 2004

Scientists Continue Mars Rover Project

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Members of the Cornell team involved with the Mars Exploration Rovers mission have reported that their day-to-day operations are running quite effectively, despite the fact that other collaborators are located all over the nation and in Europe.

Up until four months into the mission, the people involved lived entirely on Mars time, and all of them worked at the Jet Propulsion Laboratory located in Pasadena, California. The mission was split into the science team and the engineering team. This schedule, said Miles Johnson ’02, a member of the engineering team, was “weird,” citing that they lived with Mars time wristwatches and the like.

He pointed out that one Mars day, called a “sol,” is 39 minutes longer than the length of an Earth day, and frequently this factor presented problems. Every few weeks, the teams would have to work in the middle of the Earth night because on Mars it was daytime. Furthermore, Johnson added, the Mars schedule made it difficult for the staff to keep in contact with family and friends.

Fortunately, the members of the mission came up with a solution.

“Since September 1 … all the scientists have returned to their home institutions. The science team still does what it did before, and the engineering team still does what it did before. And the engineers are still all at JPL. The scientists are distributed across the country and in Europe now, and we do all our operations work from our home institutions,” said Prof. Steven Squyres, astronomy, the principal investigator of the mission.

This new setup ushered in a different schedule, where operations would begin no earlier than 7 a.m. PST and end no later than 10 p.m. PST. The average workday is now six or seven hours long. Squyres explained that over the course of a month, the operations would begin and end early in the day, while a few weeks later, operations would be starting as late as 4 in the afternoon. On the old Mars time based schedule, the average workday might have lasted as long as 17 hours, which was done in shifts.

When asked how they achieved this efficiency, Squyres said, “We’ve simply gotten much better at our jobs. When we first landed, we really didn’t know how to operate these things very well. We managed, but it was very difficult. … Nobody had ever done anything like this before, and we were still learning how to do it. But when you’re doing something for the 300th time, it’s a lot easier than when you’re doing it for the third time, and it goes a lot faster.”

While this new schedule does present a few small issues, members of the science team at Cornell seem to agree that now operations are running far more effectively than they did at the beginning of the mission.

“We’ve been moving pretty smoothly since we went remote … in fact, it’s been going really well,” said Zoe Learner grad, an Athena science team student collaborator who gets to work with both the engineering team located in Pasadena and the science team.

The main issue that they brought up was that every few weeks, the team would have to plan on what was called a “restrictive sol” schedule, where the day’s activities would have to be planned and sent to the rovers before the collected data of the previous sol could be received or fully analyzed. This meant, according to Learner, that on that particular sol, the rovers would not be able to drive anywhere until the data was analyzed. Fortunately, Learner added, it is a small issue that the science and engineering teams have been able to deal with.

“We’ve gotten so good at operating the rovers that this has become far less of a problem,” Johnson said.

The staff of the mission, scattered throughout the nation and in Europe, now keeps in daily contact with each other largely through video-conferencing and frequent phone calls.

The MER mission has no apparent end in sight. NASA had predicted both rovers would last 90 days at most; according to Johnson, Squyres had even said that in the best case scenario, the rovers would last 120 days. What is most surprising is that as of yesterday afternoon, both Spirit and Opportunity have been operating for over 280 days.

“We built them well,” Squyres said, “At this point, we’re just going to drive ’em til they drop.”

Until that happens, the purpose of the mission remains to collect “geological and chemical evidence of the historical presence of water on Mars,” Johnson said. He points out that in the coming weeks, it will be even easier to operate the rovers; Mars is approaching springtime, meaning the solar-powered rovers will be able to draw on and use more solar energy.