NASA loses contact with MAVEN, which reached Mars with Mangalyaan

NASA has lost contact with its Mars Atmosphere and Volatile Evolution (MAVEN) spacecraftthe Mars orbiter that has worked for more than a decade to study how the planet’s atmosphere is escaping into space. The spacecraft went silent in early December and engineers are still trying to re-establish communication.

MAVEN’s job at Mars has been to measure the thin upper atmosphere and the ionosphere (charged particles high above the surface), and to watch how sunlight and the solar wind interact with them. Those measurements help scientists estimate how Mars went from a planet that once had flowing water to the cold, dry world we see today.

Beyond science, MAVEN also carries a relay radio that can pass messages between the earth and rovers on the ground, including NASA’s Curiosity and Perseverance.

On December 4, MAVEN sent its last full set of routine “health” data about its systems. Two days later it passed behind Mars from the earth’s point of view. This kind of temporary blackout is normal: when a planet blocks the line of sight, radio signals can’t get through. But after MAVEN was expected to reappear, NASA’s Deep Space Network didn’t detect its usual signal. NASA publicly described the problem on December 9 and said it was investigating.

In an update on December 15, NASA reported a small clue: during an ongoing radio science campaign, the team recovered a brief fragment of tracking data from December 6. From that fragment, NASA said MAVEN appeared to be rotating in an unexpected way when it emerged from behind Mars. The signal’s frequency also suggested MAVEN’s orbit may have changed. NASA hasn’t yet said what caused these changes.

MAVEN orbits Mars and repeatedly samples different heights above the planet, which is useful because the upper atmosphere changes with time of day, season, and solar activity. Its instruments measure gases and ions as well as the solar wind and magnetic environment around Mars. When it serves as a relay, MAVEN receives short UHF (ultra-high-frequency) transmissions from a rover, then sends the data back to the earth using a high power radio link.

With MAVEN having gone silent, NASA has shifted more relay work to other orbiters, including the Mars Reconnaissance Orbiter and Mars Odyssey, and has coordinated with European orbiters as needed as well.

NASA launched MAVEN in November 2013 from Cape Canaveral in Florida. After a months-long cruise through interplanetary space, it reached Mars and entered orbit in September 2014. MAVEN was designed for a two-year primary mission but has continued operating on an extended mission since, building a long record of how Mars’s upper atmosphere responds to the Sun.

India’s Mars Orbiter Mission (MOM), or Mangalyaanentered Mars orbit on September 24, 2014, days after MAVEN arrived. The Indian Space Research Organisation framed MOM as a technology demonstrator, with five instruments added for basic imaging and atmospheric studies.

Many in India often compared MOM to MAVEN at the time using their headline costs — about ₹450 crore for MOM v. $671 million for MAVEN — but the missions were built for different goals and payloads. MAVEN was also the more technically ambitious science mission.