ESCAPADE's Twin Probes Slingshot Past Earth and Head for Mars

Just days before the first anniversary of its launch, NASA's ESCAPADE mission has done something the agency had never done on a trip to Mars. Both of its spacecraft have now completed a powered Earth flyby, swinging past with their engines firing, and both came out the other side pointed at Mars. The first flyby happened on 7 November and the second on 9 November, and according to NASA's announcement the pair is on course to reach the Red Planet in September 2027. Whatever your view of small missions, it is hard not to root for this one.

A year spent waiting in the wrong place

The odd thing about ESCAPADE is that it left Earth when Mars was on the far side of the Sun. A normal Mars mission would have waited for the next window, which opens roughly every two years. This one launched anyway, on 13 November 2025, riding a Blue Origin New Glenn from Cape Canaveral, and then it simply did not go to Mars. Both spacecraft settled into a looping "loiter" path around Lagrange point 2, a balance point about a million miles from Earth on the side facing away from the Sun. NASA describes the route as kidney-bean shaped.

We ran the numbers on our side to see how far the planets have moved in that year. When the spacecraft launched, Mars sat almost exactly opposite Earth on the other side of the Sun, about 205 degrees ahead of us in its orbit. This week it is only about 58 degrees ahead. Earth has gone round the Sun once, Mars has crept along behind it, and the geometry finally lines up. That is the whole idea. You park, you wait, and you go when the sky says so.

Nine minutes at the bottom of the swing

A gravity assist normally costs nothing but time. You fly close to a planet, borrow a little of its orbital motion and leave faster. The ESCAPADE powered Earth flyby added something extra: each spacecraft fired its engine during the closest approach. Per the NASA release, the first one, nicknamed Blue, began a burn of about nine minutes at roughly 5 a.m. EST on 7 November, which is 10:00 UTC, while passing about 1,000 miles (1,700 km) above Earth. Its twin, Gold, did the same at 6 a.m. EST (11:00 UTC) on 9 November from about 650 miles (1,000 km) up.

Why burn at the lowest point? Because that is where a rocket engine is most effective. The faster you are moving, the more a given push adds to your energy, and nothing moves faster than a spacecraft skimming the top of a planet's gravity well. Physicists call this the Oberth effect, and it is why a burn at closest approach beats the same burn made far from the planet.

Berkeley's own news report calls this the first successful powered Earth gravity assist for a deep space mission. Mark Lewis, who manages the operations centre there, put the novelty simply: a standard transfer, but "nobody else has done it with a powered gravity assist."

The part that kept the operations room awake

It is easy to read a headline like "completes flybys" and forget how much could have gone wrong. Berkeley's report points out that the spacecraft had to pass through Earth's radiation belts right before the burn, and that those belts can cause electronics to shut down suddenly. A shutdown at that moment would have wasted the whole window. Rob Lillis, the principal investigator, said the Berkeley operations team put everything into getting the spacecraft ready, and the crew gathered in the early hours to watch Gold's burn.

The mission has also had one earlier wobble. In December 2025, during trajectory correction burns on 8 and 12 December, engineers noticed low thrust on one of the two spacecraft. NASA delayed the next attempt, and the team completed the second correction for that spacecraft on 6 January. You can read that whole story, including the first "selfies" from the pair, on the mission's NASA blog archive. Looking back, the January success reads like a rehearsal for this week.

What happens between now and September 2027

The cruise to Mars will take about ten months, with a few small trajectory corrections along the way. Each spacecraft will then fire its engine for roughly 11 minutes to be captured by Mars. NASA lists those insertion burns for 7 September and 9 September 2027, and Berkeley says Gold goes first, with Blue following two days later.

Our calculation puts Mars about 204 million kilometres from Earth today, which is 11.3 light-minutes. By 7 September 2027 that grows to about 296 million kilometres, or 16.4 light-minutes. That means every command the team sends on arrival day takes more than a quarter of an hour to arrive, and the engineers will be watching a burn they cannot steer. If you want to play with that yourself, our light travel time calculator does the arithmetic, and the live solar system map shows where Earth and Mars are right now.

The science does not start straight away. The pair will spend several months moving into a first formation, flying one behind the other in the same orbit, and NASA expects science operations to begin in June 2028. Six months after that they will split into different orbits, one going farther out to watch the incoming solar wind and the other staying close to see how Mars reacts. That campaign is planned for five months. Lillis described it as the first time anyone will make coordinated measurements of Mars from two places at once.

Why this might matter more than the little spacecraft suggests

ESCAPADE is a small mission. It is funded by NASA's Heliophysics Division under the SIMPLEx programme, which exists for low-cost science, and the University of California, Berkeley leads it with partners including Rocket Lab, Goddard, Embry-Riddle, Advanced Space and Blue Origin. But Jeff Parker, the lead mission designer at Advanced Space, makes a point that deserves attention. A loiter orbit followed by an Earth flyby means a Mars-bound spacecraft can launch almost any time rather than only when the planets line up. You launch when your rocket is ready and use Earth's gravity to catch up with the planet later.

That kind of flexibility is valuable. It does not make Mars closer, and the trip still takes most of a year. Still, a trick that lets mission planners decouple "when the rocket is ready" from "when the planets align" could change how future Mars missions get scheduled. I would not be surprised to see other teams studying this week's data very carefully. If you like following new rockets as much as new trajectories, our rocket launch schedule and the Starship launch page keep track of the vehicles that might use ideas like this one. Starship's next test, by the way, is targeted for 13 November, and we covered it in our Flight 15 preview.

A busy week for deep space

ESCAPADE is not the only spacecraft with a date in the diary. ESA's BepiColombo is due to enter orbit around Mercury on 21 November, which we explained in our BepiColombo guide, and Mars has been in the news lately after gas was spotted above the Alba Mons fissures, as covered in our Mars volcano story. Our deep space tracker lists the probes we follow, and the planet parade guide tells you when Mars itself is up before sunrise. For ESCAPADE, the next thing to watch is quiet: small course corrections, a long cruise and then two engine burns in September 2027. The twins are on their way, and for now that is the best possible news.