A Quick Look at Curiosity's MEDLI Suite

As the American space agency is getting ready to launch the Mars Science Laboratory (MSL) mission, experts take one final look at some of the spacecraft's instruments. One of the most important among them is MSL Entry, Descent and Landing Instrumentation (MEDLI).

As the name suggests, it will only operate as the MSL aeroshell enters the Martian atmosphere, at a steep angle and very high speeds. This is the first time a rover or lander is sent on another planet on a course that sets it at such a steep angle of atmospheric descent.

Having access to real-time data will therefore be essential for the computer controlling the mission during those critical minutes, and this is where the MEDLI suite will step in. It includes numerous sensors, spread out all over the aeroshell, which provide live data to the spacecraft's computers.

In this sense, MEDLI will literally be the most important of all MSL components as the mission lands on Mars. In addition, the heat and atmospheric pressure data that it will record will be made available to researchers designing other similar space missions.

The NASA Science and Human Exploration (SHED), Operations Mission (OMD) and Aeronautics Research Mission (ARMD) Directorates supported the development and integration of MEDLI.

The instrument itself was built by a collaboration of researchers from the Hampton, Virginia-based Langley Research Center (LRC) and the Ames Research Center (ARC), in Moffett Field, California.

“This is the first time we've ever had sensors that will collect accurate, high fidelity data of atmospheric entry at another planet,” explains ARMD Fundamental Aeronautics Program Hypersonics Project leader, Jim Pittman.

“Having that knowledge is of great interest to the hypersonics community – especially when it comes to being able to design future Mars entry systems that are safer, more reliable and lighter weight,” the NASA official goes on to say.

MEDLI sensors will be spread out at 14 locations on the heatshield and backshell of the MSL aeroshell. The suite includes 7 sensors belonging to the Mars Entry Atmospheric Data System (MEADS) and another 7 from the MEDLI Integrated Sensor Plugs (MISP).

“This isn't the first time we have drilled tiny holes in a spacecraft. In the 80s we installed pressure sensors in the nose cap of the space shuttle to study hypersonic flow. We have done extensive testing to make sure the MEADS pressure ports can withstand the heat of entry,” MEDLI principal investigator Neil Cheatwood concludes.