NASA managers have just made the difficult but unavoidable decision to scrub the planned March 2016 launch of the InSight lander, the agency’s next mission to Mars, by at least two years because of a vacuum leak that was just detected in the probes flawed seismometer instrument which cannot be fixed in time.
The leak, if uncorrected, would render the probe useless to carry out the unprecedented scientific research foreseen to measure the planets seismic activity and sense for “Marsquakes” to determine the nature of the Red Planets’ deep interior.
John Grunsfeld, associate administrator for NASA’s Science Mission Directorate in Washington, announced the decision to suspend the InSight launch at a briefing for reporters on Tuesday, Dec. 22.
“We push the boundaries of space technology with our missions to enable science, but space exploration is unforgiving, and the bottom line is that we’re not ready to launch in the 2016 window,” said Grunsfeld.
Grunsfeld explained that there is simply insufficient time to locate and reliably repair the seismometer instrument leak in the short time span of barely over two months remaining until the opening of the Atlas rockets launch window to the Red Planet on March 4. The window only extends to March 30.
“We just haven’t had time to work through that because our focus was on getting ready to launch.”
The seismometer instrument is named Seismic Experiment for Interior Structure (SEIS) and was provided by the Centre National d’Études Spatiales (CNES) – the French national space agency equivalent to NASA. SEIS is one of the two primary science instruments aboard InSight. The other instrument measuring heat flow from the Martian interior is provided by the German Aerospace Center (DLR) and is named Heat Flow and Physical Properties Package (HP3).
The leak in the seismometer was initially discovered earlier this year. After several unsuccessful attempts to repair a leak in a section of instrument, engineers thought they had solved the problem until a new test was conducted on Monday, Dec. 21 and revealed another leak due to a faulty weld somewhere.
“A leak earlier this year that previously had prevented the seismometer from retaining vacuum conditions was repaired, and the mission team was hopeful the most recent fix also would be successful,” said NASA.
“However, during testing on Monday in extreme cold temperature (-49 degrees Fahrenheit/-45 degrees Celsius) the instrument again failed to hold a vacuum.”
It was at that point that NASA and CNES managers decided that the hoped for 2016 launch would have to be postponed.
“As of yesterday, we were still planning to go,” Grunsfeld elaborated during the briefing.
SEIS must hold a vacuum of at least one tenth of a millibar in order for the instrument to operate satisfactorily and conduct its research into the Red Planet’s seismic activity.
InSight is NASA’s next mission to Mars. It is a stationary lander based on the proven design of NASA’s Phoenix lander which touched down on the Red Planet in 2008.
The earliest opportunity to possibly launch Insight is now deferred to mid-2018, since launch windows to Mars only occur approximately every 26 months due to the positions of Earth and Mars in their orbits and the unavoidable physics of celestial mechanics.
However, due to the elusive nature of fixing the leak and unavoidable and unbudgeted costs to store the probe, it is not clear whether InSight will even be launched in 2018.
The decision on when and whether to launch InSight will not be conclusively decided for at least several months while NASA and CNES further investigate the nature of the leak.
“A decision on a path forward will be made in the coming months, but one thing is clear: NASA remains fully committed to the scientific discovery and exploration of Mars,” Grunsfeld noted.
SEIS is designed to “measure ground movements as small as the diameter of an atom and requires a vacuum seal around its three main sensors to withstand the harsh conditions of the Martian environment.”
The SEIS instrument measures about 9 inches wide. It was to be picked up from the lander deck and deployed to the surface using a robotic arm.
“It’s the first time ever that such a sensitive instrument has been built. We were very close to succeeding, but an anomaly has occurred, which requires further investigation. Our teams will find a solution to fix it, but it won’t be solved in time for a launch in 2016,” said Marc Pircher, Director of CNES’s Toulouse Space Centre.
“InSight’s investigation of the Red Planet’s interior is designed to increase understanding of how all rocky planets, including Earth, formed and evolved,” said Bruce Banerdt, InSight Principal Investigator at NASA’s Jet Propulsion Laboratory (JPL), Pasadena, California.
“Mars retains evidence about the rocky planets’ early development that has been erased on Earth by internal churning Mars lacks. Gaining information about the core, mantle and crust of Mars is a high priority for planetary science, and InSight was built to accomplish this.”
Until Monday, the teams had all been confident that the SEIS leak had been repaired. Indeed the probe just arrived at the launch site at Vandenberg Air Force Base in California for blastoff atop a United Launch Alliance Atlas V rocket.
InSight will most likely be shipped back to prime contractor Lockheed Martin in Denver for long term storage until a final decision on the future outcome is decided.
The total budgeted cost of the mission was cost capped at $675 million and about $525 million has already been spent, said Jim Green, director of the Planetary Science Division at NASA Headquarters, at the briefing.
NASA and the international collaborators will now have to evaluate the costs of repair and delay and determine if the cost cap will be breached and whether to continue forward with the InSight mission.
InSight is funded by NASA’s Discovery Program of low cost, focused science missions along with the science instrument funding contributions from France and Germany.
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