Peering Into The Interior of Mars – The Mars InSight Mission

In about 70 days the Mars InSight lander will launch on an Atlas V-401 from Vandenberg Air Force Base sometime during a launch window from 5 May to 8 June. It’s planned to land in the Elysium Planitia region of Mars on 26 November, later this year, with a mission duration of 728 days (or 708 Mars days, or just over a Mars year). The aim of the mission is to explore the interior of Mars. The lander will measure three main attributes on the planet, seismology, temperature and movement. All of this aims to find out what is going on in the centre of Mars.

The science goals for the Mars InSight mission are to understand formation and evolution of Mars and to determine the level of tectonic activity on the planet. Mars is an amazing place to study as, unlike Earth and Venus, it hasn’t destroyed the record of it’s own development over the last 4.5 billion years so offers scientists a kind of time capsule to look back into a period close to the formation of the solar system. This will help us understand what conditions were like and maybe learn a bit about how the Earth might have once been. Mars has preserved the record of it’s own formation very well due to very low geological activity. We know a lot about the surface of Mars but very little about the inner goings on of the planet and the Mars InSight lander seeks to uncover some of those mysteries.

The Lander and Instruments

The lander is about 6 metres long, once it’s solar panels are spread out, and about 1.56 metres wide. It has a robotic arm that will place instruments in ideal positions once it lands. This robotic arm has a reach of around 2.4 metres. The whole thing weighs about 360 kilograms. On board there are three main instruments.

Seismometer

One is a seismometer called the Seismic Experiment for Interior Structure (SEIS). This will be lifted into place by the robotic arm on to the Martian surface and there it will sit patiently feeling for when the Martian surface moves, caused by marsquakes or meteorite impacts.

Temperature Probe

The second instrument is the Heat Flow and Physical Properties Probe. This will drill down about 5 metres into the Martian ground to measure the heat coming up from the Mars interior. The aim of this instrument is to understand how heat flows inside Mars and see if it is made from the same stuff that the Earth and Moon are made of, to compare them. Scientists think that Mars used to be a lot more active (as evidenced by it’s now dormant massive volcanoes) and are interested to find out just how much heat the planet is now generating.

RISE Instrument

The final instrument is the Rotation and Interior Structure Experiment (RISE). This instrument will fix the position of the lander and then monitor it to see how much the planet wobbles and deforms as it whizzes around the Sun and gets influenced by its gravity. These measurements will uncover important information about the deep core of Mars such as at what depth the core becomes solid. It will also help to determine what the core might be made of.

Getting to the surface

To get to the surface of Mars the lander wil fly through space in a protective shell that will act as a heat shield when the spacecraft starts to enter the Martian atmosphere at about 130km above the surface. It will be hurtling along at about 6.3 km per second and given the Mars atmosphere is considerably thinner than the Earths, it takes quite a bit of effort to slow something down going at this speed. As it gets lower and slower, being controlled by a bunch of small rockets, the spacecraft will deploy a parachute to slow down for the last bit of the descent. It has three big shock absorbing legs that also extend. In the final stages, the spacecraft, ditches the parachute and protective cover and continues the descent uses 12 little rocket engines. All of this happens in 6 minutes!

So watch out for the launch in May and then for the landing in November this year. It will be a very interesting mission to watch as it uncovers more about the red planet.