NASA Keeps Mars Odyssey and MRO Running 25 Years On

NASA's 2001 Mars Odyssey reached Martian orbit on 24 October 2001 and is still working 25 years later. Together with the Mars Reconnaissance Orbiter (MRO), active since 2006 and run by the Jet Propulsion Laboratory in Pasadena, California, it forms the backbone of Mars research and communications.

According to Lockheed Martin, Odyssey has circled the planet more than 100,000 times and taken over a million images with its infrared camera. Rovers on the surface cannot transmit large amounts of data directly across roughly 225 million kilometers to Earth, so both orbiters relay their signals in the ultra-high-frequency band. Odyssey is controlled by a radiation-hardened RAD6000 processor, a 1990s design running at a maximum of 20 megahertz.

Lessons from 1999 and tricks from the ground

The longevity traces back to 1999, when NASA lost the Mars Climate Orbiter to a mix-up between imperial and metric units and the Mars Polar Lander to a software error during engine shutdown. JPL project manager Glen Havens says those failures were very present for the Odyssey team, which duplicated critical components such as the onboard computer and power supply and added reserves of batteries and fuel.

Age brings its own problems. MRO orients itself with star trackers that compare the sky to a stored star map. Chief engineer Paul Fieseler explains that some stars have moved slightly in the night sky, so engineers uploaded a corrected star map last year.

Odyssey's biggest risk is running out of hydrazine propellant, and it has no conventional fuel gauge. Ground teams switch on the tank heaters and measure how quickly the temperature rises: a fuller tank heats more slowly. That lets them calculate the remainder and limit consumption to a few drops per maneuver.

Succession worries

How fast things can go wrong was shown by MAVEN, only eleven years old, which NASA gave up on in June 2026 after it lost contact in December 2025 and began tumbling uncontrollably. To secure the relay link, NASA commissioned Blue Origin in September 2026 to build a communications-only Mars satellite by 2028, without science instruments.

Planned science missions such as the two Escapade probes and the three small Skyfall helicopters will be smaller and cheaper. Escapade lead Rob Lillis says his mission is near the limit of being too small for good science, and planetary scientist Briony Horgan sees a return to the cost and time pressure behind the 1999 losses.