RETURN TO SENDER | Lockheed Martin delivered NASA’s InSight spacecraft to its California launch site just last week. The spacecraft will return to Lockheed Martin's Denver facility, where it will be placed in storage. Credit: Lockheed Martin

WASHINGTON — If it isn’t canceled altogether, NASA’s Mars InSight lander will now launch more than two years later than planned, thanks to a balky seismometer, the agency’s top science official told reporters Dec. 22.

“We’re looking at some time in the May 2018 timeframe,” John Gunsfeld, NASA associate administrator for science, said during a Dec. 22 conference call.

InSight was supposed to launch in March, but a series of leaks in a mission-critical instrument, the Seismic Experiment for Interior Structure (SEIS) provided by the French space agency, CNES, will keep the mission grounded well past a 26-day Mars launch window that opens March 4, Grunsfeld said.

When CNES discovered the latest leak during environmental testing Dec. 21, the French and U.S. space agencies were left with no choice but to suspend the March launch campaign, Grunsfeld told reporters.

InSight Mars lander undergoing a solar array deployment test in the MTF clean room at Lockheed Martin. Credit: Lockheed Martin
InSight Mars lander undergoing a solar array deployment test in the MTF clean room at Lockheed Martin. Credit: Lockheed Martin

Technical concerns aside, InSight could still be canceled for budgetary reasons — a possibility Grunsfeld would not rule out, because InSight is a cost-capped mission in NASA’s Discovery line of competitively selected missions.

The critical variable for InSight will be the cost of fixing SEIS, and storing the craft at Lockheed Martin Space Systems in Denver — where it was built — for roughly two years. InSight was delivered to California’s Vandenberg Air Force Base launch site Dec. 16 and now must be sent  back to Colorado. SEIS was supposed to arrive at Vandenberg in January for integration with the lander.

Grunsfeld on Dec. 22 would not estimate the final storage and repair bill, but said NASA would appraise the costs in the coming months.

If InSight survives its pending review, it will be the agency’s first interplanetary mission to lift off from Vandenberg; such missions normally launch from Cape Canaveral Air Force Station in Florida.

NASA first confirmed defects with SEIS on Dec. 3, saying the instrument had suffered “a leak in the vacuum container carrying its main sensors.”

The leak disclosed Dec. 3 was caused by a defective weld on the instrument’s vacuum tank, CNES President Jean-Yves Le Gall told SpaceNews Dec. 8. At the time, Le Gall said CNES had performed a new weld that should have fixed the problem. Apparently, it did not.

NASA selected InSight as the 12th in its Discovery mission in 2012, setting a cost-cap of $425 million in 2010 dollars, excluding launch. The lander, based on the Mars Phoenix craft that touched down on the red planet in 2008, beat out a comet-hopping probe and a vessel designed to sail the hydrocarbon seas of Saturn’s moon Titan to win NASA funding.

Dan Leone is a SpaceNews staff writer, covering NASA, NOAA and a growing number of entrepreneurial space companies. He earned a bachelor’s degree in public communications from the American University in Washington.