Mars Odyssey Marks 100,000 Orbits, Showcases Stunning View of Olympus Mons

NASA’s Odyssey spacecraft, the longest-running mission at Mars, has completed its 100,000th orbit around the Red Planet, the mission team announced today.

To commemorate this achievement, NASA released a detailed panorama of Olympus Mons, the tallest volcano in the solar system, captured by Odyssey in March. Olympus Mons is located near the Martian equator, with its base stretching 373 miles (600 kilometers) and its peak rising 17 miles (27 kilometers) into the thin Martian atmosphere. Earlier this month, astronomers discovered that a temporary morning frost forms on the volcano’s summit for a few hours each day, providing new insights into how ice from the poles moves across the dry Martian landscape.

In the latest image of Olympus Mons, a bluish-white band can be seen skimming the volcano, indicating the amount of dust in the Martian air at the time the photo was taken, according to NASA. A thin layer of purple above this band likely shows a mix of atmospheric dust and bluish water-ice clouds. The blue-green layer at the top edge of the image represents water-ice clouds reaching up to about 30 miles (48 kilometers) into the Martian sky, scientists say.

To capture this panorama, scientists instructed Odyssey to slowly rotate so its camera could point toward the Martian horizon, creating views similar to those taken by astronauts on the International Space Station looking at Earth.

“Normally, we see Olympus Mons in narrow strips from above, but by turning the spacecraft toward the horizon, we can see in a single image how large it looms over the landscape,” said Jeffrey Plaut, Odyssey’s project scientist at the Jet Propulsion Laboratory (JPL) in California. “Not only is the image spectacular, but it also provides us with unique scientific data.”

By taking similar images at different times of the year, scientists can study how the Martian atmosphere changes over the planet’s four seasons, which last from four to seven months each.

Scientists say the idea for the latest image began as early as 2008, when another NASA mission, Phoenix, landed on Mars. Odyssey, which served as a communication link between the lander and Earth, pointed its antenna at the lander, and scientists noticed its camera could view Mars’ horizon.

“We just decided to turn the camera on and see how it looked,” said Steve Sanders, Odyssey’s mission operations spacecraft engineer at Lockheed Martin Space in Denver, Colorado. “Based on those experiments, we designed a sequence that keeps the camera’s field-of-view centered on the horizon as we go around the planet.”

The Odyssey mission launched in April 2001 and is managed by JPL. It was NASA’s first successful mission to Mars after two failures in the previous two years. In 1998, the Mars Climate Orbiter reportedly burned up in Mars’ atmosphere due to a mix-up in measurement systems. A year later, the Mars Polar Lander crashed onto the Martian surface because its engine shut off too early. Odyssey was seen as a mission of redemption.

Odyssey entered orbit around Mars in October 2001 and has since discovered hidden water-ice reservoirs just beneath the planet’s surface, which could be accessible to future Mars astronauts. The spacecraft has also mapped large areas of the planet’s surface, including its craters, helping astronomers understand Mars’ history.

The recent milestone of 100,000 orbits means Odyssey has traveled over 1.4 billion miles (2.2 billion kilometers). The solar-powered spacecraft does not have a fuel gauge, so the mission team uses calculations to estimate the remaining fuel, keeping the 23-year-old mission operational. “Physics does a lot of the hard work for us,” said Sanders. “But it’s the subtleties we have to manage again and again.”

Recent estimates suggest Odyssey has about 9 pounds (4 kilograms) of propellant left, enough to keep the mission going until the end of 2025.

“It takes careful monitoring to keep a mission going this long while maintaining a historical timeline of scientific planning and execution — and innovative engineering practices,” said Joseph Hunt, Odyssey’s project manager at JPL. “We’re looking forward to collecting more great science in the years ahead.”