
On Saturday, May 5th, 2018, NASA commenced the latest in its ongoing robot exploration missions to Mars, with the launch of the InSight lander mission.
The Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) mission is the first designed to carry out a detailed examination of the Red Planet’s interior – its crust, mantle and core.
Studying Mars’ interior structure can answer key questions about the early formation of the rocky planets in our inner solar system – Mercury, Venus, Earth, and Mars – more than 4 billion years ago. In addition, the data gathered may also help us to understand how rocky exoplanets orbiting other stars in our galaxy may have formed.
As well as potentially being a ground-breaking mission, InSight’s departure from Earth marked the first time any US interplanetary mission had been launched from the West Coast, rather than the more familiar Kennedy Space Centre in Florida. InSight started its six-month journey to Mars atop a United Launch Alliance Atlas V 401 launch vehicle from Space Launch Complex 3-East at Vandenberg Air Force Base, California, lifting-off at 04:05 PDT (07:05 EDT; 11:05 UTC) on May 5th, marking the end of a 2-year delay for the mission.
That delay had been caused by the repeated failure of a vacuum sphere forming a part of a set of seismometers called the Seismic Experiment for Interior Structure (SEIS) package, a crucial part of the mission’s science. Attempts to correct the issue with the French-developed package consistently led to further problems until, in December 2015, NASA was forced to call off InSight’s planned March 2016 launch while the unit was France for further repairs – a move that gave rise to fears the entire mission would be cancelled if a solution could not be found in time for InSight to meet the next launch opportunity in 2018 – such launch windows occurring every 26 months.

The mission was saved in March 2016 – a week after its original launch date in fact – when NASA’s Jet Propulsion Laboratory (JPL) reached an agreement with the French space agency CNES. This allowed JPL to design, build and test a new vacuum enclosure, with CNES taking responsibility for integrating it with the SEIS package, and testing the completed unit in readiness for integration with the lander in time for a May 2018 launch.
On May 5th 2018, the launch itself proceeded smoothly, with the Atlas V booster quickly obscured by pre-dawn fog shortly after clearing the launch complex. however, it was caught at altitude by a NAA observation aircraft, as it rose above the cloud tops. As well as InSight, the rocket carried within its payload fairings two “cubesats”, each roughly the size of a briefcase, called MarCO A and MarCO B.
Together, these tiny, self-contained satellites for the Mars Cube One (MarCO) technology demonstrator. Sent on their way to Mars alongside InSight, they both operate independently of the lander, carrying their own communications and navigation experiments. Their mission is designed to provide NASA with a temporary communications relay system during InSight’s entry, descent and landing (EDL) mission phase, as it heads towards a (hopefully) soft-landing on Mars.
Currently, surface missions to Mars are generally monitored by the Mars Reconnaissance Orbiter, which monitors transmissions from a vehicle descending towards a landing on Mars. However, it cannot simultaneously transmit that information to Earth. This means that it can be as much as an hour before the data gathered during the critical EDL phase of a surface mission can be received on Earth. MarCO will be able to simultaneously receive and transmit EDL data sent by InSight to Earth, allowing mission engineers and scientists to have a more complete picture of this critical phase of the mission that much sooner. If successful, MarCO cover pave the way to a greater use of cubesats in the exploration of Mars.
