MRO's 'Very Large Roll,' Animated

This animation depicts NASA's Mars Reconnaissance Orbiter (MRO) performing what's called a "very large roll": a 120-degree roll that can increase the capabilities of the spacecraft's subsurface radar instrument, called Shallow Radar, or SHARAD. Very large rolls boost SHARAD's signal by 10 times or more, giving scientists a clearer and deeper look below the Martian surface than MRO has ever had before. The orbiter was designed to roll up to 30 degrees in any direction so that it can point its instruments at surface targets. These standard rolls give cameras like the High-Resolution Imaging Science Experiment (HiRISE) prime viewing at the front of MRO at the expense of SHARAD, which has an antenna mounted at the back of the orbiter. While this setup helps the cameras, it also means that radio signals SHARAD pings onto the surface below encounter parts of the spacecraft, interfering with the signals and resulting in images that are less clear. In 2023, the team decided to try developing 120-degree rolls – the very large rolls – that rotate SHARAD's antenna toward the planet and provide the radio waves an unobstructed path to the surface. That lets the radar's signals reach deeper and get a clearer picture of rocks, sand, and geologic layers underground. It also helps SHARAD look for water ice in the near-subsurface that could be accessed by astronauts to produce rocket propellant for the trip home and is important for learning more about the climate, geology, and potential for life at Mars. Animation available at https://photojournal.jpl.nasa.gov/catalog/PIA26478