NASA’s Mars Orbiter Appeared to Be Running Out of Fuel—Until It Wasn’t

In the summer of 2019, the trajectory of NASA’s Mars Orbiter spacecraft, dubbed MAVEN, sparked alarm. It appeared the spacecraft was running out of propellant, and without regular maneuvers to adjust its orbit, the mission would soon come to an abrupt end. Fortunately, the mission was saved in the nick of time, thanks to a flurry of creative solutions from the mission team and a healthy dose of luck.

In the fall of 2013, MAVEN was launched to explore the upper atmosphere of Mars, gathering invaluable data about the Red Planet’s past and present. As the spacecraft made its way to Mars, it fired its thrusters over 33 times to fine-tune its approach, using up a large amount of its available fuel.

The mission was expected to run for at least six years, but by June of 2019, the fuel aboard MAVEN was running dangerously low. Without the ability to fire its engines, MAVEN would slowly drift out of the atmosphere and eventually be lost in deep space.

The mission operators at MAVEN didn’t give up. By taking advantage of the spacecraft’s environment — the weak Martian gravity and the sun’s light — they came up with a workable plan. By slightly adjusting the angle at which the spacecraft was pointing towards the sun, light pressure from photons bouncing off the spacecraft’s solar panels would be just strong enough to push MAVEN back toward the atmosphere and avoid the deadly drift. This solution, though not ideal, would provide enough fuel to keep MAVEN in the atmosphere for an additional year or two.

But the mission team wanted to do better. When their calculations suggested that MAVEN might just have enough fuel left to fully correct its course and remain in orbit for its originally intended six-year mission, they did not hesitate to devise a creative solution. The team discovered that by fire a series of “mini-burns” over a longer period of time, they could actually get the spacecraft back onto its intended trajectory with less fuel than originally thought. After some last-minute test-firings, the team finalized the strategy—MAVEN would be adjusting its trajectory with just 0.06-percent of its remaining fuel.

The MAVEN mission was finally saved, thanks to the ingenuity of the mission team and a healthy dose of luck. The spacecraft returned to its expected trajectory without the need for any additional fuel tanks, and has since continued to provide the world with valuable data about the red planet’s atmosphere. It’s a rare victory for NASA, and a reminder that even in the harshest of environments, creative solutions can make amazing things happen.