Maven stays silent after routine pass behind Mars

by Simon Mansfield
Sydney, Australia (SPX) Dec 14, 2025

NASA engineers are continuing efforts to restore contact with the Mars Atmosphere and Volatile EvolutioN (MAVEN) orbiter after the spacecraft fell silent during a routine pass behind Mars on December 6 2025. Before the loss of signal, telemetry from MAVEN indicated that the spacecraft and its subsystems were operating within expected parameters as it approached occultation by the planet.

As MAVEN moved behind Mars, communications with the Deep Space Network (DSN) cut off as expected, but controllers did not reacquire the downlink when the orbiter reappeared from the planet's shadow. The team declared a spacecraft emergency and began continuous DSN listening and commanding sessions in an attempt to re-establish at least a carrier signal from the orbiter.

Mission controllers are reviewing the last data packets received before occultation to narrow possible fault scenarios and identify any indications that the spacecraft may have entered a protective configuration. One working hypothesis is that MAVEN transitioned into a safe or degraded mode that altered its attitude or antenna pointing, leaving its high-gain antenna misaligned with Earth and preventing normal two-way communication.

Engineers are sending a sequence of contingency commands that target known safe-mode and attitude-control recovery paths, while keeping DSN antennas on standby to detect any response from the orbiter. The analysis includes checks on power generation, thermal conditions and attitude-control behavior inferred from pre-loss telemetry, as well as simulations of how various onboard failures would affect MAVEN's ability to point its antennas and solar arrays.

MAVEN has been in Mars orbit for more than a decade, studying how the solar wind and radiation strip gas from the Martian upper atmosphere and shape the planet's long-term climate evolution. The spacecraft's instruments have measured interactions between the ionosphere, exosphere and incoming space environment, providing constraints on escape rates of key atmospheric species and on how atmospheric loss varied over time.

In addition to its science mission, MAVEN has served as a key communications relay for surface missions including the Curiosity and Perseverance rovers, forwarding data between the Martian surface and Earth. With the orbiter currently offline, other spacecraft such as Mars Reconnaissance Orbiter, Odyssey and ESA's Trace Gas Orbiter are carrying a larger share of relay duties to maintain science return from ongoing missions on the ground.

If controllers cannot recover the spacecraft, Mars atmospheric science would lose a platform that has provided continuous upper-atmosphere and space-weather measurements through changing solar conditions and multiple dust seasons. The mission's long baseline of observations has been central to understanding how present-day escape processes connect to the thicker atmosphere Mars likely possessed billions of years ago.

NASA has not announced a timeline for declaring MAVEN unrecoverable and continues to treat the anomaly as an active recovery case. Future updates are expected once engineers either detect a signal from the orbiter or exhaust planned commanding and listening campaigns using the Deep Space Network.