It’s been 10 months since NASA launched its MAVEN (Mars Atmosphere and Volatile Evolution) spacecraft, and scientists are eagerly waiting to see it finally arrive at Mars. The MAVEN won’t actually land on Mars. Instead, it will orbit the red planet and study its upper atmosphere, according to a statement on NASA’s website.

NASA's MAVEN Spacecraft Closes In On Mars

NASA reaches new milestone

The spacecraft travelled 442 million miles to reach Mars. When it arrives in the planet’s orbit, six thruster engines will fire to settle it. Then the six main engines will light up two at a time, burning for about a half hour at a time to slow down the MAVEN so that it can enter an elliptical orbit.

This weekend marks a major milestone after 11 years of developing the spacecraft. Upon arrival into Martian orbit, the project then enters the science phase, allowing NASA to investigate the planet in a way no past missions have enabled the agency to do.

Scientists will be studying Mars’ upper atmosphere to see “how it interacts with the sun and the solar wind,” according to MAVEN principal investigator Bruce Jakosky of the University of Colorado, Boulder. They will be watching to see how much gas from the planet’s atmosphere has been lost into space throughout its lifetime and what has caused that loss.

How MAVEN will enter Mars’ orbit

In order to get into orbit around Mars, onboard computers will control the spacecraft. NASA scientists will update insertion instructions after uploading the newest information about its location, orientation and velocity.

If everything goes according to plan, the MAVEN won’t need any more commands from Earth. Scientists will have to make final corrections for its trajectory, however, 24 to 6 hours before the spacecraft is inserted into orbit around Mars. NASA said this will only happen if the spacecraft’s navigation team thought it was entering orbit at an altitude that’s too low.

Other than that, scientists have already programmed the spacecraft to do what they want it to do. The MAVEN will then have to reorient itself to make sure the thrusters are pointed in the right direction for the burn. Communication with Earth will be limited during this time.

Then for the next 33 minutes, the MAVEN will burn up over half of the fuel it has left, entering an orbit of about 236 miles above Mars’ north pole. Then three minutes after the engines cut off, normal communications with Earth will be restored, and the spacecraft can send all of the data it collected during the insertion process back to Earth.