NASA’s Mars Odyssey Orbiter Captures Huge Volcano Approaching 100,000 Orbits

NASA’s longest-lived Mars rover is set to hit a new milestone on June 30: 100,000 trips around the Red Planet since launch 23 years ago. During this time, the 2001 Mars Odyssey orbiter mapped minerals and ice on the Martian surface, identified landing sites for future missions, and relayed data from NASA’s rovers and landers to Earth.

Scientists recently used the orbiter’s camera to capture a stunning new image of Olympus Mons, the tallest volcano in the solar system. The image is part of the Odyssey team’s ongoing effort to provide high-altitude views of the planet’s horizon. (The first of these views was released in late 2023.) Similar to Earth astronauts’ view aboard the International Space Station, this view allows scientists to learn more about the clouds and drifting dust on Mars.

The latest image of the horizon, taken on March 11, captures Olympus Mons in all its glory. With a base that stretches over 373 miles (600 kilometers), the shield volcano rises to a height of 17 miles (27 kilometers).

“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 just how big it is towering over the landscape,” said Odyssey project scientist Jeffrey Plaut of NASA’s Jet Propulsion Laboratory in the South. California, which runs the mission. “Not only is the image spectacular, but it also provides us with unique scientific data.”

In addition to offering a frozen snapshot of clouds and dust, these images, if taken over many seasons, can give scientists a more detailed understanding of the Martian atmosphere.

The blue-white band at the bottom of the atmosphere indicates how much dust was present at the site during early fall, when dust storms typically begin to blow through. The purple layer above it was probably caused by a mixture of the planet’s red dust with bluish clouds of water ice. Finally, a bluish-green layer can be seen at the top of the image where the water ice clouds reach about 50 kilometers into the sky.

How they photographed it

Named after Arthur C. Clarke’s classic science fiction novel “2001: A Space Odyssey,” the orbiter captured the scene using a heat-sensitive camera called the Thermal Emission Imaging System, or THEMIS, built and operated by Arizona State University in Tempe. But because the camera is designed to look down at the surface, taking a horizon shot requires some special planning.

By firing thrusters located around the spacecraft, Odyssey can point THEMIS at different parts of the surface or even slowly flip over to see Mars’ tiny moons, Phobos and Deimos.

Recent imaging of the horizon was conceived as an experiment many years ago during the landings of NASA’s Phoenix mission in 2008 and the Curiosity rover in 2012. As with other Mars landings before and after those missions, Odyssey played an important role in relaying data as a spacecraft. barrel towards the surface.

In order to transmit their vital technical data to Earth, the Odyssey antenna had to be pointed at the newly arriving spacecraft and its landing ellipses. Scientists were intrigued to note that the positioning of Odyssey’s antenna for this mission meant that THEMIS would be pointed toward the planet’s horizon.

“We just decided to turn on the camera and see what it looks like,” said Odyssey spacecraft engineer Steve Sanders of Lockheed Martin Space in Denver. Lockheed Martin built Odyssey and helps run day-to-day operations alongside mission managers at JPL. “Based on these experiments, we designed a sequence that keeps the field of view of THEMIS in the center of the horizon as we orbit the planet.”

The Secret of the Long Space Odyssey

What is Odyssey’s secret to being the longest continuously active mission in orbit around a planet other than Earth?

“Physics does a lot of the hard work for us,” Sanders said. “But they are subtleties that we have to master over and over again.

These variables include fuel, solar energy and temperature. To ensure that Odyssey uses its fuel (hydrazine) sparingly, engineers must calculate how much is left since the spacecraft does not have a fuel gauge. Odyssey relies on solar power to operate its instruments and electronics. This force changes when the spacecraft disappears behind Mars for about 15 minutes in orbit. And temperatures must remain balanced for all Odyssey devices to function properly.

“It takes careful monitoring to keep the mission running this long while maintaining a historic timeline of science planning and execution — and innovative engineering practices,” said JPL’s Odyssey project manager Joseph Hunt. “We look forward to collecting more great science in the coming years.”