NASA's InSight Mission to Mars Suspended Due to Vacuum Leak in Critical Seismometer Instrument

NASA officially announced at a media teleconference yesterday that the InSight mission to Mars has now been postponed, for at least two years, due to a leak in a seismometer instrument which cannot be repaired in time for the planned launch in March 2016. The lander had just been delivered to Vandenberg Air Force Base on Dec. 16 to be prepared for launch when the announcement was made.

“Learning about the interior structure of Mars has been a high priority objective for planetary scientists since the Viking era,” said John Grunsfeld, associate administrator for NASA’s Science Mission Directorate in Washington. “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. 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.”

“The JPL and CNES teams and their partners have made a heroic effort to prepare the InSight instrument, but have run out of time given the celestial mechanics of a launch to Mars,” said JPL Director Charles Elachi. “It is more important to do it right than take an unacceptable risk.”

“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.

As reported previously on AmericaSpace, the vacuum leak was being examined and tested, with the hope it could be repaired in time for launch. But now it seems that won’t happen.

The lander will now be returned to the Lockheed Martin facility in Denver.

The instrument, the Seismic Experiment for Interior Structure (SEIS), is a seismometer provided by France’s Centre National d’Études Spatiales (CNES). It 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.

While disappointing, the delay may work out for the best however, as it would be much better to launch later with all instruments working as they should be, rather than sooner but still have potentially faulty instruments. In this case, the seismometer is one of the most critical instruments on InSight, designed to examine the subsurface of Mars, the whole point of the mission.

“In 2008, we made a difficult, but correct decision to postpone the launch of the Mars Science Laboratory mission for two years to better ensure mission success,” said Jim Green, director of the Planetary Science Division in Washington. “The successes of that mission’s rover, Curiosity, have vastly outweighed any disappointment about that delay.”

Since the most favorable times for missions to Mars are every 26 months, due to the positions between the two planets, InSight won’t be able to launch again until at least 2018.

If it does launch later on, InSight will be the first mission to Mars to permanently place instruments into the ground using a robotic arm. The two instruments include the seismometer and a heat-flow probe. The seismometer will measure tiny marsquakes which cause microscopic movements of the ground, which will help scientists better understand the interior of Mars. The heat-flow probe measures heat coming from the planet’s interior and will hammer itself about 10 to 16 feet (3 to 5 meters) deep into the ground. Even the radio can be used to measure wobbles in the planet’s rotation and environmental instruments to monitor weather and changes in the magnetic field. And, of course, there will be cameras – two of them. InSight would also be the first Mars spacecraft ever launched from California.

Previous landers and rovers have focused on studying Mars’ surface and atmosphere, but InSight will look downward, examining the interior of Mars. Design-wise, it is similar to the Mars Phoenix Lander, which landed near the Martian north pole in 2007. InSight will study rocks deeper down, which will help scientists better understand the geological history of not only Mars, but other rocky planets as well, perhaps even rocky exoplanets. Instead of roving around, InSight will stay in one place and look deep underground.

“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) in 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.”

The instruments on InSight include:

Grapple – Mechanism at the end of the IDA that grips the instruments during deployment

Heat Flow Probe – Hammering mechanism that pulls the temperature sensors down into the regolith

HP3 – Heat Flow and Physical Properties Package, the heat flow experiment

IDC – Instrument Deployment Camera, pointable medium-resolution camera

IDA – Instrument Deployment Arm

ICC – Instrument Context Camera, fixed wide-angle camera

Pressure Inlet – Wind-shielded opening for pressure sensor

RISE Antenna – X-band radio antenna for the Rotation and Interior Structure Experiment

SEIS – Seismic Experiment for Interior Structure, the seismometer

Tethers – Cables carrying electrical power, commands and data between the lander and instruments

TWINS – Temperature and Winds for InSight, environmental sensors

UHF Antenna – Antenna used for communication with orbital relay spacecraft

WTS – Wind and Thermal Shield protecting the seismometer from the environment

Goals of the mission include:

Determine the size, composition, physical state (liquid/solid) of the Martian core

Determine the thickness and structure of the Martian crust

Determine the composition and structure of the Martian mantle

Determine the thermal state of Mars’ interior

Measure the magnitude, rate and geographical distribution of Mars’ internal seismic activity

Measure the rate of meteorite impacts on the surface of Mars

From the mission website:

“InSight’s primary objective will be to uncover how a rocky body forms and evolves to become a planet. Generally, a rocky body begins its formation through a process called accretion. As the body increases in size, its interior heats up and melts. As it subsequently cools and recrystallizes it evolves into what we know today as a terrestrial planet, containing a core, mantle and crust. While all of the terrestrial planets share similar structures and their bulk compositions are roughly the same as the meteoritic material from which they were formed, they are by no means uniform. Each of the terrestrial planets reached their current formation and structure through a process known as differentiation, which is poorly understood. InSight’s goal will be to solve the mystery of differentiation in planetary formation – and to bridge the gap of understanding that lies between accretion, and the final formation of a terrestrial planet’s core, mantle, and crust.”

Another addition to the spacecraft is a microchip which contains the names of about 827,000 people worldwide who participated in an online “send your name to Mars” last August and September.

The Curiosity rover, meanwhile, continues its close-up study of Martian sand dunes, the first time this has ever been done. Smaller sand drifts have been seen by all of the previous landers and rovers, but the much larger dunes are a spectacular sight when seen on the ground. The dune called Namib Dune, where Curiosity still is right now, is a massive wall of sand that reaches 13 feet (4 meters) tall. The dunes themselves are in turn covered by many finely-etched sand drifts.

According to Nathan Bridges of the Johns Hopkins University’s Applied Physics Laboratory, Laurel, Md., “These dunes have a different texture from dunes on Earth. The ripples on them are much larger than ripples on top of dunes on Earth, and we don’t know why. We have models based on the lower air pressure. It takes a higher wind speed to get a particle moving. But now we’ll have the first opportunity to make detailed observations.”

The darker-colored dunes stand out very noticeably against the surrounding terrain, especially when seen from orbit. While very similar to dunes on Earth, it is also a bit surprising how they can form as tall as they are, with such steep sides, in the thin Martian air.

After the dunes, Curiosity will continue heading towards the foothills of Mount Sharp, with their very scenic mesas and buttes. Almost like being in Arizona, except, of course, it’s Mars.

More information about the InSight mission is available here.

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