NASA’s MAVEN Mars mission has been successfully launched aboard an Atlas V by United Launch Alliance.  The Atlas V first stage uses a Russian-built RD-180 engine burning kerosene and liquid oxygen (the world’s most powerful liquid fuel engine, based on the RD-170 designed and built by the Soviet Union) for its first stage and an American-built RL10 engine burning liquid hydrogen and liquid oxygen for its Centaur second stage. (The RL10 was the first liquid hydrogen rocket engine to be built in the United States with the first successful mission occurring in 1963.)

MAVEN has a 10 month trip to Mars.  The spacecraft has three sets of instruments. The Particles and Fields Package is six individual instruments that measure different aspects of  the solar wind and ionosphere of the planet. The Remote Sensing Package will measure properties of the upper atmosphere and ionosphere. The Neutral Gas and Ion Mass Spectrometer will measure the composition and isotopes of thermal neutrals (uncharged molecules) and ions in the Martian atmosphere.

It is thought that Mars had a thick atmosphere 4 billion years ago that was similar in composition to Earth’s atmosphere as well as liquid surface water. The current theory of what happened to these is that the molten metal at the core of Mars solidified.  Mars’ magnetic field weakened dramatically so that the planet was no longer protected from solar winds.  Subsequently Mars lost its atmosphere and its liquid water leaving Mars a desert.  MAVEN’s instruments are designed to measure the solar wind hitting Mars and the remnants of Mars’ atmosphere to attempt to confirm or refute this theory.