A closer look at what happens in the conclusion of the mission as the spacecraft’s power supply continues to dwindle.
The day is approaching when NASA Mars InSight Lander will fall silent, ending its historic mission to reveal the secrets of the interior of the red planet. The spacecraft’s power output continues to dwindle as the windblown dust on its solar panels thickens, so the team has taken steps to continue as long as possible with the remaining power. The end should arrive in the next few weeks.
But even as the tight-knit 25-30-member operations team — a small group compared to other Mars missions — continues to make the most of InSight (short for Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) , they’ve also begun taking steps to slow down the mission.
Here’s a preview of what it looks like.
The most important of the InSight mission’s final steps is to store its wealth of data and make it accessible to researchers around the world. Lander data provided details about Mars inner layersits liquid core, the surprisingly variable remnants beneath the surface of its nearly extinct magnetic field, the weather on this part of Mars, and lots of seismic activity.
Knowledge seismometerprovided by France’s Center National d’Etudes Spatiales (CNES), has detected more than 1,300 marsquakes since the lander touched down in November 2018, the largest measuring a magnitude 5. He even recorded earthquakes of meteor impacts. Observing how the seismic waves from these earthquakes change as they pass through the planet provides invaluable insight into the interior of Mars, but also provides insight into how all rocky worlds form, including Earth and its Moon.
“Finally, we can see Mars as a planet with layers, with different thicknesses and compositions,” said Bruce Banerdt of NASA’s Jet Propulsion Laboratory in Southern California, the mission’s principal investigator. “We’re starting to really unravel the details. Now, it’s not just that conundrum; it is in fact a living, breathing planet.
The seismometer readings will join the only other set of extraterrestrial seismic data, from the Apollo lunar missions, in NASA’s Planetary Data System. They will also go to an international archive maintained by the Incorporated Research Institutions for Seismology, which houses “all of the Earth’s seismic network data locations,” said JPL’s Sue Smrekar, InSight’s deputy principal investigator. “Now we also have one on Mars.”
Smrekar said the data should continue to yield discoveries for decades.
Earlier this summer, the lander had so little energy left that the mission shut down all of InSight’s other science instruments to run the seismometer. They even disabled the fault protection system which would otherwise automatically shut down the seismometer if the system detects that the lander’s power output is dangerously low.
“We were down to less than 20% of the original production capacity,” Banerdt said. “That means we can’t afford to run the instruments 24 hours a day.”
Recently, after a regional dust storm added to the lander’s dust-covered solar panels, the team decided to shut down the seismometer completely to save power. Now that the storm is over, the seismometer is once again collecting data – even though the mission expects the lander to only have enough power for a few more weeks.
Of the seismometer’s array of sensors, only the most sensitive were still working, said Liz Barrett, who leads science and instrumental operations for the JPL team, adding, “We’re pushing it all the way.”
A silent member of the team is ForeSight, the life-size engineering model of InSight in JPL In situ instrument laboratory. Engineers used ForeSight to practice how InSight would place scientific instruments on the Martian surface with the lander’s robotic arm, test technique to bring the lander’s thermal probe into sticky martian soiland develop ways to Reduce noise captured by the seismometer.
ForeSight will be crated and stored. “We’re going to wrap it carefully,” Banerdt said. “It’s been a great tool, a great companion for us all this mission.”
Declare the end of the mission
NASA will declare the mission terminated when InSight misses two consecutive communication sessions with the spacecraft orbiting Mars, part of the Mars Relay Network – but only if the cause of the missed communication is the lander itself, said network manager Roy Gladden of JPL. After that, NASA Deep Space Network will listen for a while, just in case.
There will be no heroic steps to restore contact with InSight. While a mission-saving event – a strong gust of wind, for example, blowing the panels clean – is not out of the question, it is considered unlikely.
In the meantime, as long as InSight stays in touch, the team will continue to collect data. “We will continue to do scientific measurements as long as we can,” Banerdt said. “We are at the mercy of Mars. The weather on Mars is not rain and snow; the weather on Mars is dust and wind.
Learn more about the mission
JPL manages InSight for NASA’s Science Mission Directorate. InSight is part of NASA’s Discovery program, operated by the agency’s Marshall Space Flight Center in Huntsville, Alabama. Lockheed Martin Space in Denver built the InSight spacecraft, including its cruiser stage and lander, and is supporting spacecraft operations for the mission.
Several European partners, including the French National Center for Space Studies (CNES) and the German Aerospace Center (DLR), support the InSight mission. CNES has made available the Interior Structure Seismic Experiment (SEIS) instrument at NASA, with the principal investigator at the IPGP (Institut de Physique du Globe de Paris). Important contributions to SEIS have come from the IPGP; the Max Planck Institute for Solar System Research (MPS) in Germany; the Swiss Federal Institute of Technology Zurich (ETH Zurich) in Switzerland; Imperial College London and the University of Oxford in the UK; and JPL. DLR provided the heat flux and physical properties package (resume3) instrument, with major contributions from the Space Research Center (CBK) of the Polish Academy of Sciences and Astronika in Poland. The Spanish Centro de Astrobiología (CAB) provided the temperature and wind sensors, and the Italian Space Agency (ASI) provided a passive laser retroreflector.
Jet Propulsion Laboratory, Pasadena, California.
Written by Pat Brennan