NASA closes communications with Mars due to conjunction with the Sun

NASA has stopped sending commands for its missions to Mars because Earth and the red planet are on opposite sides of the sun, and this period, called solar conjunction of Mars, occurs every two years.

The Sun expels hot ionized gas from its corona that extends into space. During solar conjunction, when Earth and Mars can’t “see” each other, this gas can interfere with radio signals if engineers try to communicate with spacecraft on Mars. This could mess up commands and lead to unexpected behavior from deep space explorers.

To be safe, NASA engineers send Mars missions a list of simple commands that must be carried out for a few weeks. This year, most ships stop sending orders between November 12 and 25.

This doesn’t mean these robotic explorers will go dormant. NASA’s Perseverance and Curiosity rovers will monitor changes in surface conditions, climate and radiation while they remain parked. Although temporarily on Earth, the Ingenuity helicopter will use its color camera to study the movement of sand, a perpetual challenge for missions to Mars. The Mars Reconnaissance Orbiter, MRO, and Odyssey space probes will continue to take images of the surface. MAVEN will continue to collect data on interactions between the atmosphere and the Sun.

While NASA usually receives updates on the status of the Mars fleet throughout the conjunction, there will be a couple of days when the agency won’t hear anything because the red planet will be just behind the sun’s disk.

Once the moratorium (as the communications pause is known) ends, the orbiters will transmit all outstanding science data back to Earth, and the spacecraft can begin receiving instructions again.

“Our mission teams have spent months preparing mission lists for all of our Mars spacecraft,” Roy Gladden, director of the Mars Relay Network at NASA’s Jet Propulsion Laboratory in Southern California, said in a statement. “We will still be able to listen to them and check on their health in the coming weeks.”