Concept art of InSight Lander drilling beneath Mars' surface. Credit: NASA

WASHINGTON — NASA could make a decision within a week on the fate of a NASA Mars lander that is facing about $150 million in additional costs because of an instrument problem that caused it to miss its launch window this year.

In a presentation to a meeting of the Mars Exploration Program Analysis Group (MEPAG) here March 2, Bruce Banerdt, principal investigator of the InSight Mars lander mission, said the project has completed a revised plan for the mission that supports a launch in 2018, and presented that plan to NASA officials a day earlier.

“That presentation went very well,” he said of the NASA briefing. “We had a lot of probing questions and difficult conversations, but overall, I think that we got a positive response.”

InSight was scheduled to launch this month and land on Mars in September. The spacecraft, based on the Phoenix mission that landed on Mars in 2008, is designed to study the planet’s interior using a probe to measure heat flow below the surface and a seismometer provided by the French space agency CNES.

However, in December NASA announced it was postponing the launch because of problems with leaks in the seismometer, which requires a very strong vacuum to operate. The instrument suffered several leaks during its development, and NASA concluded the problems could not be fixed in time to allow a launch before the 2016 window closed at the end of March.

“That was going to take us about three or four weeks beyond our launch if everything went well, so that was not in the cards,” Banerdt said of plans to fix the seismometer after the latest leak. “We know what went wrong. We know how to go about fixing it.”

The revised plan, he said, would take advantage of the next Mars launch window in 2018. InSight would launch on May 5 of that year from Vandenberg Air Force Base in California, landing Nov. 26 on the Elysium Planitia region of Mars, the same landing site as previously planned. The spacecraft’s nominal mission would run though November 2020.

That revised plan, including modification and testing of the seismometer, would come at a price: “on the order” of about $150 million, he said. That additional cost means that a final decision on whether to spend that money for a 2018 launch, cancel the mission, or take another option rests with agency leadership.

“We’re well on our way” to making a decision on InSight, said Jim Green, the director of NASA’s planetary sciences division, in a talk earlier in the day at the MEPAG. “Perhaps we’ll be able to announce what our next steps are for InSight within this next week or so.”

If NASA decided to go ahead with InSight, it would need to find that money, most likely within the agency’s planetary sciences program. “It means less money to do something else,” Banerdt said. “Sorry about that.”

Banerdt said one option not under consideration was having CNES pay for at least part of the additional costs because its instrument caused the delay. “They will be spending money on the overrun” to correct the instrument problem, he said. “They won’t be giving us any money to do the things we need to do, and that’s because that’s the way international collaborations work: no money changes hands.”

One particular target for the additional funds could be the Discovery program of lower-cost science missions, of which InSight is a part. Some in the planetary science community have expressed concern that the additional cost for InSight could keep NASA from selecting two Discovery missions late this year in an ongoing competition, as some agency officials have suggested they might do.

Green, in his remarks, offered no hints about any effect additional InSight costs might have on the ongoing Discovery competition. “We’ll announce the mission or missions that will go forward in the December timeframe,” he said.

Jeff Foust writes about space policy, commercial space, and related topics for SpaceNews. He earned a Ph.D. in planetary sciences from the Massachusetts Institute of Technology and a bachelor’s degree with honors in geophysics and planetary science...