Concept art of InSight Lander drilling beneath Mars' surface. Credit: NASA

WASHINGTON — A small lander that will study the geological composition of Mars beat out a comet-hopping probe and a vessel designed to sail the hydrocarbon seas of Saturn’s moon Titan to become NASA’s 12th Discovery-class mission, the space agency announced Aug. 20.

Dubbed InSight, the Mars lander will be managed by principal investigator W. Bruce Banerdt at the Jet Propulsion Laboratory (JPL) in Pasadena, Calif. Mission costs are capped at $425 million in 2010 dollars, excluding the launch, which is scheduled for March 2016, NASA said in a press release.

The stationary InSight lander, slated to arrive on the red planet in September 2016, will carry four instruments to the martian surface and “investigate whether the core of Mars is solid or liquid like Earth’s and why Mars’ crust is not divided into tectonic plates that drift like Earth’s,” NASA said.

Lockheed Martin Space Systems of Denver will build and operate the InSight spacecraft from the Mission Support Area (MSA) at the company’s Waterton Canyon facility near Denver, spokesman Gary Napier said in an Aug. 20 email. Lockheed did not disclose the financial terms of its arrangement with JPL.

Lockheed has worked on six of the 11 Discovery missions launched to date and is still operating the twin Gravity Recovery and Interior Laboratory probes, which in late May completed their primary mission to map the Moon’s gravitational field.

The InSight spacecraft will host four instruments, including two built by European space agencies.

The French space agency, CNES, will contribute an instrument to measure seismic waves travelling through Mars’ interior. The German Aerospace Center, DLR, is building a subsurface heat probe that will measure the flow of heat from the martian interior, NASA said.

JPL will provide an instrument that tracks Mars’ rotation axis, a robotic arm to move the European instruments from the spacecraft to the ground, and two black-and-white cameras.

The other finalists for the Discovery flight opportunity were the Comet Hopper mission proposed by the University of Maryland and the Goddard Space Flight Center in Greenbelt, Md.; and the Titan Maritime Explorer, a boat-like lander proposed by the Johns Hopkins University Applied Physics Laboratory in Laurel, Md., to explore Saturn’s largest moon.

John Grunsfeld, NASA’s associate administrator for science, said the InSight proposal had an edge on its competitors because review teams determined it was the likeliest to come in on time and on budget.

“[T]he InSight mission had the highest probability by enough margin that it distinguished itself,” Grunsfeld said in an Aug. 20 telephone briefing with the press.

Jim Green, who heads NASA’s Planetary Science Division, said InSight’s common heritage with another Mars lander, the Lockheed Martin-built Phoenix, lent further strength to the JPL proposal.

“[T]he heritage is important, and the Phoenix mission does indeed provide some of that heritage, giving us the confidence necessary for us to understand its cost implications,” Green said in the Aug. 20 telephone conference.

Phoenix launched in 2007. Operators lost communication with the spacecraft in November 2008, about five months after its mission to study the martian north pole began.

Meanwhile, members of the two teams whose Discovery mission proposals were not selected said via email Aug. 20 that they had not yet been debriefed by NASA.

“That will happen in the next month or so,” said Michael A’Hearn, a University of Maryland astronomy professor who was the deputy principal investigator for the Comet Hopper project.

“It is very, very disappointing, as we feel this mission was so exciting and so doable,” said Ellen Stofan, principal  investigator for the Titan Maritime Explorer proposal. “I am also very disappointed not to see an [Advanced Stirling Radioisotope Generator] mission selected as they are a critical technology for future planetary exploration,” added Stofan, a former JPL researcher who is now vice president Proxemy Research, Gaithersburg, Md.

Stofan was referring to a nuclear power source that allows robotic craft to operate in places where direct sunlight is not available to be absorbed by power-generating solar arrays. The Advanced Stirling Radioisotope Generator is expected to be more efficient than the radioisotope thermoelectric generator-type nuclear batteries that have powered previous deep-space probes. NASA plans to have two such generators ready for flight by 2016 and will provide a generator to qualified missions that request one, Green said.

Green added that Advanced Stirling Radioisotope Generators may still be available in 2015, when NASA will solicit proposals for the next Discovery mission. However, he said the generators are not reserved exclusively for Discovery missions, or even exclusively for science missions. Human exploration missions and space technology demonstrations could also lay claim to the generators, Green said.

InSight is now the last Mars surface mission in NASA’s budget. The U.S. space agency currently is planning two other Mars missions but both are orbiters.

The Mars Atmosphere and Volatile Evolution, or Maven, mission, managed by Goddard, is scheduled to launch late next year. Then, no sooner than 2018, NASA will look to launch its Mars Next Decade mission. The orbiter, which has yet to be designed, is intended to fill a void created by NASA’s withdrawal from the European-led Mars sample-collection  campaign known as ExoMars.

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.