MAVEN: NASA's Martian atmosphere quest

Somewhere over our heads, a small capsule is just starting its journey across the inner solar system. NASA’s latest mission to Mars, the Mars Atmosphere and Volatile Evolution Mission (MAVEN), was launched this week from Cape Canaverel and, according to the iron laws of orbital mechanics, will reach the Red Planet next September.

There, it will perform an extraordinary series of manoeuvres, diving deep into the Martian atmosphere and climbing high above the planet in an elliptical orbit to take samples of the sparse atmospheric gases to try to answer a question that’s been nagging away at planetary scientists for decades: what happened to turn a planet with a dense atmosphere, flowing water at the surface and possible conditions for life into a cold, barren desert?

MAVEN’s elliptical orbit, varying from from 150km to 6000km above the planet with five ‘deep dips’ down to 125km up, will allow it to sample the atmosphere from the the upper layers down to the top of the well-mixed lower atnosphere, for its on-board instruments to analyse the mixtures of molecules and ions present at various altitudes. While at its furthest points, it will use ultraviolet imaging of the entire planet to determine what’s happening to the planet’s atmosphere today, such as the rate of gas loss and which gases are being lost fastest.