Nasa wants to measure 'Marsquakes'
"Does Mars have fault lines like the Earth does? How extensive are those? What kinds of 'marsquakes' are there?"
These, Nasa official Lindley Johnson told reporters on a conference call, are some of the important questions the project hopes to answer.
The InSight mission, which aims to launch in March 2016, will send a device to Earth's next-door neighbour to measure seismic activity and a subsurface heat probe to measure the flow of heat from the interior.
"Seismology is the standard method by which we've learned to understand the interior of the Earth," explained John Grunsfeld, associate administrator for the Science Mission Directorate at Nasa Headquarters.
"And we have no such knowledge for Mars."
InSight was selected from a pool of three finalists to be sponsored by the low-budget Discovery series.
The other two – one to explore a comet and another to take a closer look at Saturn moon Titan – were equally compelling, Grunsfeld said.
Artist rendition of the proposed InSight Lander. (JPL/Nasa)
"All of these missions had top science," he said, adding that the proposals also all seemed equally realistic, in terms of their ability to actually get answers.
But InSight won out because it seemed the most likely to come in on schedule and on budget, under the $425-million cap set for the projects. That cap does not include the cost of the launch vehicle.
Insight saved money by adopting a seismic monitor developed by the French space agency and a heat-flow probe developed by the German aerospace centre.
The project also incorporated into its design "proven systems" from Nasa's highly successful Phoenix lander mission, which helped convince the selection committee it was a low-risk endeavour.
James Green, director of Nasa's Planetary Science Division, said they anticipate it will take six months for InSight to reach Mars, and then a full Martian year – about 680 Earth days – to gather the data it is looking for.
Grunsfeld added that because the device is intended to land in the relatively benign equatorial region of the planet, the device may continue to provide data beyond that first year.
Measuring seismic activity
Unlike an earlier Nasa attempt to measure seismic activity that placed the device on the legs of the lander, leading to interference from wind, the agency said InSight plans to use a robotic arm to pull the seismometer package from the platform and place it on the ground.
The final budget for the project, the 12th to get sponsorship under Discovery, will be set after a confirmation review next year.
The Discovery series is separate from other Mars-specific programming at Nasa, and the agency said this project was chosen on its own merits and with no relation to the ongoing Curiosity mission.
As for Curiosity, Nasa announced Monday that the Mars rover flexed its robotic arm for the first time since before its launch in November.
"We have had to sit tight for the first two weeks since landing, while other parts of the rover were checked out, so to see the arm extended ... is a huge moment for us," Nasa engineer Matt Robinson said in a statement.
Curiosity has also fired its laser to zap a Martian rock called Coronation, Nasa said Sunday. – Sapa-AFP