Berkeley’s ESCAPADE spacecraft say goodbye to Earth. Next stop: Mars.

After loitering around Earth for nearly a year, NASA’s two ESCAPADE spacecraft — conceived, led, managed and operated by UC Berkeley — have now made their final pass by our planet and are on their way to Mars.

One of the identical spacecraft, dubbed Blue, burned its engines for more than 9 minutes starting at 5 a.m. EST on Saturday, Nov. 7, as it made a close approach to Earth. The burn and a slingshot effect provided by Earth’s gravity combined to propel it on a trajectory that intersects with Mars’s orbit, which it will enter on Sept. 9 of next year.

“Our fantastic operations team at the Berkeley Space Sciences Lab put 110% into this critical maneuver, getting the spacecraft ready and watching like hawks for potential issues. We’re excited to now focus on our interplanetary journey. Onward, to Mars!” said Rob Lillis, ESCAPADE’s principal investigator and associate director for planetary science at the Space Sciences Laboratory.

This was the first successful Earth-powered gravity assist for a deep space mission ever, requiring perfect timing after flying through Earth’s radiation belts, which can cause them to suddenly shut down. At the time of its engine burn, it was about 1,000 miles (1,700 kilometers) above the surface of our planet.

Blue’s twin, called Gold, successfully completed a similar maneuver at 6 a.m. EST today (Monday, Nov. 9), when it was about 650 miles (1,000 kilometers) above the surface. It will turn on its engines again on Sept. 7 to drop into orbit around Mars.

The ESCAPADE (Escape and Plasma Acceleration and Dynamics Explorers) spacecraft were launched from Cape Canaveral, Florida, on Nov. 13, 2025, when Earth and Mars were on opposite sides of the sun. Instead of heading straight for the Red Planet via a Holman transfer, as most other Mars missions have done, both spacecraft entered a “loiter” or “Earth-proximity” orbit, charting a first-of-its-kind, kidney-bean-shaped course around a place in space about a million miles from Earth called the Earth-Sun Lagrange point 2. Then they headed back toward Earth to perform a gravitational slingshot maneuver around our planet once Earth and Mars were favorably aligned, which happened this past weekend.

“It’s a standard Holman transfer, but nobody else has done it with a powered gravity assist — in other words, thrusting while doing a gravity assist,” said Mark Lewis, manager of SSL’s Mission Operations Center. “It would open up the possibility for people to launch in between transfer windows, loiter around, and then go when it’s convenient to do so.”

This method provides the flexibility to launch almost anytime, rather than waiting every two years to launch when the planets are aligned and the transit time is at a minimum.

Once in orbit around Mars, the two spacecraft will fly in formation to study how a million-mile-per-hour stream of material flowing from the sun, known as the solar wind, interacts with the Martian environment and how that drives atmospheric loss from the planet.

The twin ESCAPADE spacecraft have already taken some science observations during their loiter orbit as they flew multiple times through Earth’s magnetotail, a part of our planet’s magnetic environment that gets stretched away from Earth, opposite the sun, by the solar wind. During the 10-month trip to Mars, the spacecraft will also be able to study the dynamics of the solar wind between Earth and Mars.

When they reach Mars, two days apart, each spacecraft will fire its engine for about 11 minutes to slow down and enter orbit around the planet. The spacecraft will then take several months to maneuver into their first science formation, where they will follow one another in the same orbit to study how the planet’s environment changes with time and location. Science operations are expected to begin in June 2028.

Six months later, the two spacecraft will shift into different orbits, with one traveling farther from Mars to observe the incoming solar wind and the other staying closer to the planet to study how Mars responds to the solar wind in real time. That science campaign is scheduled to last for five months.

“This will be the first science mission to choreograph two orbiters around Mars, and the first time we will be able to make coordinated observations of the Martian environment from two different locations simultaneously,” Lillis said. “The formation flying will allow us to investigate how the dynamic Martian magnetosphere varies both spatially and temporally.”

“By better understanding how the solar wind affects the Martian environment, ESCAPADE’s findings could help us plan and prepare for future human exploration of the Red Planet,” said Michele Cash, ESCAPADE program scientist at NASA headquarters, in a NASA press release.

Funded by NASA’s Heliophysics Division, ESCAPADE is part of the agency’s SIMPLEx (Small Innovative Missions for Planetary Exploration) program, which supports missions that explore the solar system in innovative ways with smaller budgets.

Berkeley’s SSL leads the mission with key partners Rocket Lab, NASA’s Goddard Space Flight Center in Greenbelt, Maryland, Embry-Riddle Aeronautical University, Advanced Space and Blue Origin.