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

WASHINGTON — NASA announced Sept. 2 that it has approved plans to launch a delayed Mars lander mission in 2018, although at an additional cost that could affect plans for later planetary missions.

The InSight Mars lander, originally scheduled for launch in March, will now launch no earlier than May 5, 2018, after NASA’s Science Mission Directorate formally approved the revised mission plan this week. That launch will allow a landing on Mars in November 2018.

NASA postponed the launch in December 2015 after a series of problems with one of its primary instruments, the Seismic Experiment for Interior Structure (SEIS), provided by the French space agency CNES. The instrument suffered a series of vacuum leaks that NASA concluded could not be fixed in time to permit a launch during a window that lasted about a month.

Under the new mission plan, NASA’s Jet Propulsion Laboratory will take the lead in redesigning the chamber that contains SEIS. That chamber must maintain a very strong vacuum to measure seismic vibrations as small as half the radius of a hydrogen atom. CNES will focus on the instrument’s sensors and the final integration of the instrument on the spacecraft.

The redesign of SEIS, and other aspects of the mission’s two-year delay, will add $153.8 million to InSight’s original cost of $675 million. That cost is in line with previous estimates by project management earlier this year, who predicted the delay would cost roughly $150 million.

That additional money will come from plans for later missions. NASA said in its Sept. 2 statement that while no current missions would be affected, “there may be fewer opportunities for new missions in future years, from fiscal years 2017–2020.”

David Schurr, deputy director of NASA’s planetary science division, said Sept. 2 the additional cost is not covered by project reserves already applied to the mission. “The plan is for planetary science to cover these costs over the next four years,” he said.

One area that could be affected is NASA’s Discovery program of low-cost planet science missions. NASA selected five proposals for study last year, and has suggested it might choose two of them for development when it makes a final selection late this year. The additional costs of an InSight delay have worried some in the planetary science committee that NASA might be able to afford only one mission.

Jim Green, director of NASA’s planetary science division, has long advocated selecting two missions in the ongoing Discovery competition. “I’m going to do everything humanly possible to make it difficult for the selection official not to pick two,” he said at a July 25 meeting of the NASA Advisory Council’s science committee in Cleveland.

He added, though, that this choice will depend on the estimated costs of the missions included in their updated studies and the available budget. “My approach is to look at the budget, see what we can support and then fill that budget within our selection opportunity,” 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...