Berkeley-Led ESCAPADE Twins Complete Earth Slingshot, Set Course for Mars Arrival in 2027

At 5 a.m. Eastern on Saturday, Nov. 7, a spacecraft called Blue lit its engines and kept them burning for more than nine minutes as it swept about 1,000 miles (1,700 kilometers) above Earth. The burn, combined with the pull of Earth's gravity, bent its path toward Mars. Two days later, at 6 a.m. on Monday, Nov. 9, its twin, Gold, did the same thing from roughly 650 miles (1,000 kilometers) up.

Blue and Gold are NASA's ESCAPADE spacecraft, short for Escape and Plasma Acceleration and Dynamics Explorers. UC Berkeley conceived, leads, manages and operates the mission. The source describes the two maneuvers as the first successful Earth-powered gravity assist for a deep space mission. The timing had to be exact, and the craft had to come through Earth's radiation belts, which can cause them to shut down suddenly.

The route to this point was unusual. The twins launched from Cape Canaveral, Florida, on Nov. 13, 2025, when Earth and Mars sat on opposite sides of the sun. Rather than head straight for Mars on a Holman transfer, as most Mars missions have done, both craft entered a loiter orbit near Earth. They traced a kidney-bean-shaped course around Earth-Sun Lagrange point 2, a spot about a million miles from Earth, a path no mission had flown before. Then they looped back toward Earth to slingshot once the planets lined up, which happened this past weekend.

Mark Lewis, manager of the Mission Operations Center at Berkeley's Space Sciences Laboratory, put it plainly: it is a standard Holman transfer, but nobody had done it with a powered gravity assist, meaning thrusting during the flyby. He said the approach could let missions launch between transfer windows, wait in orbit, and depart when convenient. Mars launches have typically had to wait for planetary alignment roughly every two years, when transit time is shortest.

Rob Lillis, the principal investigator and associate director for planetary science at the lab, credited the operations team for putting 110% into the maneuver and watching for problems. His summary of the moment was short: onward, to Mars.

The trip will take about 10 months. Gold will fire its engine on Sept. 7 to drop into Mars orbit, and the two craft arrive two days apart, each burning for about 11 minutes to slow down. Blue's entry date is given as Sept. 9 of next year. Both have already collected some science, flying several times through Earth's magnetotail, the part of our planet's magnetic environment stretched away from the sun by the solar wind. On the way to Mars they will also study solar wind dynamics between the two planets.

At Mars, the spacecraft will spend several months maneuvering into a first science formation, following one another in the same orbit to see how the planet's environment changes with time and location. Science operations are expected to begin in June 2028. Six months later they will split into different orbits: one farther out to watch the incoming solar wind, the other closer to see how Mars responds in real time. That campaign is scheduled for five months.

The goal is to learn how the solar wind, a stream of material moving at about a million miles per hour, interacts with Mars and drives atmospheric loss. Lillis called it the first science mission to choreograph two orbiters around Mars, allowing simultaneous observations from two locations. Michele Cash, ESCAPADE program scientist at NASA headquarters, said the findings could help plan for future human exploration of Mars.

ESCAPADE is funded by NASA's Heliophysics Division and belongs to the SIMPLEx program, which backs smaller-budget missions. Berkeley's lab leads it with partners Rocket Lab, NASA's Goddard Space Flight Center in Greenbelt, Maryland, Embry-Riddle Aeronautical University, Advanced Space and Blue Origin. The next milestone is the pair of Mars orbit insertion burns in September 2027.