NASA is preparing to launch the MAVEN mission to Mars on November 18.

MAVEN stands for “Mars Atmosphere and Volatile Evolution”, and the mission will examine the upper portion of Mars’ thin, mostly carbon dioxide atmosphere in order to determine how the climate of the Red Planet has changed over time.

"The MAVEN mission is a significant step toward unraveling the planetary puzzle about Mars’ past and present environments," said John Grunsfeld, associate administrator for NASA’s Science Mission Directorate in Washington. "The knowledge we gain will build on past and current missions examining Mars and will help inform future missions to send humans to Mars."

Scientists think that Mars may have been habitable for at least microbial life billions of years ago. Surfaces features like dry river channels and minerals that typically form in water suggest that liquid water once existed on the planet’s surface, but such conditions require a denser atmosphere that allows water to remain liquid rather than freeze or sublimate (go directly from a solid to a gas) as it does today.

The launch window for MAVEN opens at 1:28 pm Eastern Standard Time and will last for 20 days. The mission will be sent into space with a United Launch Alliance Atlas V 401 rocket, launching from Cape Canaveral Air Force Station in Florida.

After a 10-month journey, MAVEN will arrive at Mars in September 2014. MAVEN will orbit Mars for one year, looking at all of Mars’ latitudes from different altitudes (orbiting between 78 to more than 3,800 miles above Mars’ surface).

MAVEN’s Particles and Fields Package is composed of six instruments that will characterize the solar wind that Mars receives in its average orbit of 1.5 AU from the Sun (or 228 million kilometers). These instruments also will look closely at the ionosphere of Mars, a region of ionized gas that marks the boundary between the lower atmosphere and the charged particles of the solar wind. Understanding the ionosphere can reveal the rate of atmospheric escape and the subsequent evolution of Mars’ climate and habitability.

MAVEN also has an Imaging Ultraviolet Spectrograph to study the upper atmosphere and ionosphere, and a Neutral Gas and Ion Mass Spectrometer to measure the molecules that make up the upper atmosphere. [For more information on the instruments, see http://lasp.colorado.edu/home/maven/science/instrument-package/

"Launch is an important event, but it’s only a step along the way to getting the science measurements," said Bruce Jakosky, principal investigator at the University of Colorado, Boulder’s Laboratory for Atmospheric and Space Physics (CU/LASP) in Boulder. "We’re excited about the science we’ll be doing, and are anxious now to get to Mars."

Artist’s conception of the Mars Atmosphere and Volatile Evolution Mission (MAVEN) spacecraft in low Mars orbit. Credit: NASAgovVideo