Vacuum Leaks Delay Launch of NASA's InSight Mars Mission

Vacuum Leaks Delay Launch of NASA's InSight Mars Mission

NASA’s next mission to Mars was scheduled to launch in March 2016, but the agency and its French counterpart, CNES, announced today that it will not be ready.  Spacecraft can be launched to Mars only every 26 months because of planetary alignments, so another opportunity is not available until the spring of 2018.  The cost impact of the delay and what that means for other planetary science missions is not yet known.

The Interior Exploration using Seismic Investigations Geodesy and Heat Transport (InSight) mission is part of NASA’s Discovery program.  NASA planetary science division director Jim Green said during a NASA teleconference this afternoon that the total cost of the mission, including the launch vehicle and all phases from design to data analysis, is $675 million.  Of that amount, $525 million has been spent already, including purchase of the Atlas V rocket that is already at Vandenberg Air Force Base (VAFB) in preparation for the March launch.

One of the two science instruments for the InSight lander is being provided by CNES.  The Seismic Experiment for Interior Structure (SEIS) is a highly sensitive seismometer package designed to detect ground movement on Mars.  The seismometers are inside a sphere.  Air must be evacuated from the sphere to create a vacuum.   Over the past several months, leaks have been detected during tests conducted by CNES at two facilities in Paris.

NASA Associate Administrator for the Science Mission Directorate, John Grunsfeld, said that as recently as yesterday morning he was “confident” the problems were solved.  At about 1:00 pm Eastern Standard Time (EST), however, he was informed that another leak had been detected.  NASA and CNES determined that insufficient time remained before the instrument needed to be shipped to the United States and integrated into the spacecraft to make the March 2016 launch date.

InSight Principal Investigator Bruce Banerdt from the Jet Propulsion Laboratory (JPL) said during the telecon that he was disappointed, but “I am a patient man” who has been waiting for 25 years to get this kind of data about Mars.  He optimistically sees it “as a minor setback, not a disaster…A hiccup on our path” to learn about the seismology of Mars.  The only other Mars spacecraft outfitted with seismometers were Viking 1 and 2, which landed in 1976.  Grunsfeld said NASA had learned a lesson from Viking — do not put seismometers on the spacecraft legs where they are affected by wind noise.

For InSight, the seismometers are inside a sphere and a “very deep vacuum” needs to be created inside that sphere according to CNES’s director of the Toulouse Space Centre, Marc Pircher.   A leak was discovered in August.  It was fixed, but then another developed.  That was fixed and until yesterday, it appeared that the instrument was good to go.  Then this new leak, of unknown origin, was detected. 

There really was no decision for NASA and CNES officials to make, Grunsfeld said:  “The decision was made by the leak. We didn’t have to scratch our heads and say should we go or not go,” because at the leak rate observed the instrument “would not have worked at all.”

The 3 kilogram SEIS sphere contains three Very Broad Band (VBB) seismic probes and their temperature sensors, three Short Period (SP) seismic probes and their temperature sensors, electronics and other hardware and software.  All of that is working.  The issue is only with leakage from the sphere itself.  The problems also do not affect InSight’s other science instrument, the Heat Flow and Physical Properties Package, provided by Germany’s space agency, DLR.

Seismic Experiment for Interior Structure (SEIS).  Image credit:  CNES

Grunsfeld and Green repeatedly indicated that the path forward is still being determined.  The spacecraft is already at the launch site and the first order of business is to return it to its manufacturer, Lockheed Martin, for storage.  NASA does not yet know how much that will cost.  NASA also will work with the United Launch Alliance to determine how to utilize the Atlas V rocket.

The next launch opportunity is not for 26 months, so there is no urgency in making other decisions, Grunsfeld said.  He would not commit to launching InSight in 2018, but conveyed that he hopes that will be the case.

In a NASA press release this afternoon, Green referenced the fact that NASA made a decision in 2008 to delay the planned 2009 launch of the Mars Science Lander (MSL) and its Curiosity rover for two years because of readiness concerns. The subsequent success of that mission has “vastly outweighed any disappointment about that delay.”  JPL Director Charles Elachi added that it “is more important to do it right than take an unacceptable risk.”

From a science standpoint, that is obviously correct, but a key concern is the cost impact on other NASA science missions. The life cycle cost of MSL/Curiosity grew to $2.5 billion, $881 million above its 2008 baseline cost according to a 2012 Government Accountability Office (GAO) report.  NASA often must pay for cost overruns on one program by not initiating new projects.  The Discovery program is intended to support the launch of a new mid-sized planetary mission every other year, but funding constraints have stretched that cadence.  In September, NASA selected five semi-finalists for the next launch opportunity in 2020, a four-year wait after InSight was expected to launch.  If InSight’s costs grow substantially, the 2020 launch date or the next Discovery mission could be delayed.

Congress is very supportive of NASA’s planetary science program, however, as evidenced by the significant increase it received in the final FY2016 budget.   The Discovery program was one of those singled out in the appropriation bill’s explanatory statement, providing $189 million “to support the current selection as well as funds to enable a 2017 announcement of opportunity” for the next.

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