You may have noticed that Mars has been a bit quiet lately. We’ve not heard from the rovers and orbiters at Mars this week and wont send or receive data next week either. This is completely normal.



Every 2 years the orbits of Earth and Mars place the sun directly between, a period called solar conjunction. For 2 weeks, the sun is so close to Mars from our perspective here on Earth that data cannot be safely sent or received. NASA and other space agencies leave their spacecraft on their own for a little while.



NASA’s two NASA rovers (Curiosity and Opportunity) and five orbiters (European Space Agency’s Mars Express, India’s Mars Orbiter Mission, along with NASA’s Mars Odyssey, Mars Reconnaissance Orbiter and Mars Atmosphere and Volatile EvolutioN mission) received their last set of commands prior to the beginning of the solar conjunction period on June 7.



A bit like a honey-do list, each craft was assigned safe tasks to accomplish over the following two weeks. Some instruments are turned off to better protect them. Many instruments continue to gather data but store it until Earth comes back into view. The team of humans controlling these robots is using the time to catch up on other work or to take a few days off.



No new commands will be sent to Mars before June 21. Any information sent while Mars is within 2º of the sun can be lost to interference form charged particles from the sun. During this time spacecraft are left on autopilot. NASA engineers have become skilled at letting spacecraft be on their own with 10+ years experience in the current operating fleet.



“Like parents who raise youngsters to be responsible and let them go on a short vacation with their friends, they've done all they can to ensure the voyagers will be healthy and safe.” according to NASA



The last weather report received from the Curiosity rover from June 3 showed a pressure of 8.42 hPA (RDU had 120 times the air pressure that day), and a temperature range of -101 F to 15º F (The high at RDU was 84º F and a low of 62º F). It will be interesting to see if temperatures change much during the few weeks of radio silence.

Tony Rice is a volunteer in the NASA/JPL Solar System Ambassador program and software engineer at Cisco Systems. You can follow him on twitter @rtphokie.