A new spacecraft, known as MAVEN, will study the atmosphere of Mars.
Image courtesy of Lockheed Martin
Curiosity and other missions sent to Mars have discovered evidence that Mars was a wetter planet in the past, with a thick atmosphere.
This early environment may even have been able to support microbial life.
But today Mars is a cold and barren desert world.
One of the major reasons for this change in the Martian environment is the loss of almost all of its atmosphere.
To help answer the question of what happened to this thick atmosphere, Curiosity has instruments on board that monitor and analyze the Martian surface atmosphere, but their data don’t really answer the question.
Therefore, Curiosity is going to get some help from a new spacecraft: the Mars Atmosphere and Volatile Evolution, or MAVEN.
The solar wind is a constant flow of particles leaving the sun and flowing out through the solar system.
It is believed that as these particles pass Mars, they interact with its atmosphere and give gases such as nitrogen, carbon dioxide and water the energy to escape into space.
Over time this could erode the old atmosphere and leave the dry, desolate world we see today.
MAVEN is the first mission to Mars to study the upper atmosphere and collect data to test this theory of solar erosion.
Instruments on the spacecraft will sample the upper atmosphere and determine its current composition.
Collecting this data over the yearlong (in Earth time) primary mission will allow us to better understand how solar storms and other factors change the Martian atmosphere.
This information on how and at what rate atmospheric gases are being lost to space today will allow us to infer what happened in the past.
MAVEN is scheduled to launch on Nov. 18 from Cape Canaveral. Because of the orbits of the Earth and Mars, there is a 20-day period starting on that day in which the spacecraft must be launched. If bad weather or technical problems cause us to miss this window, we will have to wait 26 months for the next chance.
It will take 10 months to make the trip to Mars, so MAVEN should arrive in September 2014. After arriving at Mars it will take five weeks to get the spacecraft into the correct orbit, test the instruments and test the science-mapping sequence. MAVEN will then start its primary mission.
During the mission MAVEN will circle Mars in an elliptical orbit. Its closest point to the planet will be just 93 miles above the surface. Its highest point will be more than 3,700 miles above the surface.
This elliptical path will cause the spacecraft to pass through the upper atmosphere on each orbit, allowing it to directly sample the gas and ion composition.
At the high point of the orbit, MAVEN will carry out ultraviolet imaging of the entire planet. The combination of sample measurements and global imaging is a powerful way to understand the upper atmosphere.
To get a full profile of the upper atmosphere, the orbit will be adjusted five times during the primary mission to a lower altitude above the surface.
In these “deep-dip” orbits, MAVEN will collect data down to an altitude just 77 miles above the surface. These measurements will provide information down to the top of the well-mixed lower atmosphere, which Curiosity is measuring from the surface of Mars. We will then have a complete profile of the current Martian atmosphere.
MAVEN is now at Cape Canaveral being prepped for launch.
In August the components that were removed for shipment were reinstalled. These include the high-gain antenna and three instruments that mount to the spacecraft body.
Once the craft is completely assembled, engineers will test all the systems again.
This week the Deep Space Network communications system is being tested.
So hold on, Curiosity, reinforcements are coming!
Marty Scott is the astronomy instructor at Walla Walla University, and also builds telescopes and works with computer simulations. He can be reached at email@example.com.