NASA’s Mars Odyssey and Mars Reconnaissance Orbiter (MRO) have operated at Mars far longer than expected, producing observations that transformed scientists’ understanding of the planet’s water and changing surface. Their longevity reflects careful engineering, persistent troubleshooting and some luck, but their aging systems also raise questions about whether they may be among the last long-lived orbiters supporting Mars exploration.
Odyssey arrived at Mars on October 24, 2001. Together with its 20-year-old sibling, MRO, it has remained in service far beyond the few years envisioned for the missions. Their decades of observations from orbit have helped rewrite the story of water on Mars, both in the planet’s past and today.
A lasting scientific legacy
“Both Odyssey and MRO are among the most productive spacecraft to ever exist,” said Bryony Hogan, a planetary scientist at Purdue University who was not affiliated with either mission. She described the orbiters as “critically important” to NASA’s overall Mars research program.
Odyssey’s observations of Martian ice and MRO’s ability to track surface features that change over time have given scientists an unprecedented view of Mars as a dynamic, active planet rather than a static block of rock. The orbiters also relay communications between Earth and NASA’s rovers, which cannot communicate directly with Earth. That is an impressive legacy for spacecraft designed to last only a few years.
Surviving decades at Mars
Space is a harsh environment, and surviving there for decades requires both resilience and good fortune. One persistent danger is the barrage of high-energy particles striking the spacecraft. A sufficiently powerful particle hit to sensitive equipment can be fatal.
Engineers can continuously monitor satellites orbiting Earth, but communication bandwidth at Mars is far more limited. Scientific probes may be able to check in only once or twice a week, said Rob Lillis, a planetary scientist and astrophysicist at the University of California, Berkeley, who has worked on several recent Mars-orbiting satellites.
“The Mars rover has to be able to manage itself,” he says.
Source: www.wired.com
