New study: SpaceX starship could cut travel time to Uranus by half

A mission to explore Uranus — long viewed as one of the most scientifically significant yet technically challenging destinations in the solar system — may come sooner than expected, thanks to recent progress in SpaceX’s Starship launch vehicle.

In a study led by researchers from MIT’s Engineering Systems Laboratory, scientists found that Starship could significantly reduce the travel time for a proposed Uranus Orbiter and Probe (UOP) mission. The study suggests Starship could enable a spacecraft to reach Uranus in just over six years, compared to the 13-year cruise time expected under current mission plans.

The findings and discussion were published by MIT News.

Uranus as a priority

The National Academy of Sciences’ Planetary Science Decadal Survey in 2022 identified a Uranus mission as the highest-priority flagship mission for planetary exploration. Uranus, an “ice giant” tilted dramatically on its side, hosts fast winds, a complex magnetic field, and several moons believed to possibly harbor subsurface oceans — making them candidates in the search for extraterrestrial life.

“What we know about Uranus largely dates back to Voyager 2’s brief flyby nearly 40 years ago,” said Chloe Gentgen, an MIT PhD student in aeronautics and astronautics and co-author of the study. “A mission to Uranus would therefore radically transform our understanding of ice giants, the solar system, and exoplanets.”

Earlier mission designs assumed the use of SpaceX’s Falcon Heavy, requiring planetary gravity assists and long cruise durations. But Starship — the largest rocket ever built, capable of carrying up to 150 tons to orbit — may allow direct flight to Uranus after on-orbit refueling.

“When refueled in orbit, Starship could launch a spacecraft directly to Uranus,” Gentgen said, potentially cutting travel time almost in half.

Researchers also evaluated aerocapture, a maneuver where the spacecraft slows down by dipping into Uranus’ atmosphere, reducing the need for large onboard propulsion systems. They found that Starship’s heat-shielding system could potentially support such an approach.

The study notes that Starship must still demonstrate reliable orbital refueling before it can be selected for the Uranus mission. While its recent test flight — entering orbit and surviving reentry over the Indian Ocean — marked major progress, development timelines remain uncertain.

Mission formulation for the Uranus Orbiter and Probe is expected to begin later this decade, with launch windows available throughout the 2030s.