Two small Mars probes left Earth a year after they launched
NASA's twin ESCAPADE spacecraft waited a year near Earth, then swung past the planet on 7 and 9 November 2026 with engines firing. They are now on course for Mars.
Most Mars missions leave Earth and go to Mars. ESCAPADE left Earth, waited about a year, came back, and then went to Mars. I like a mission that takes the scenic route on purpose.
ESCAPADE is two identical NASA spacecraft. NASA says the first passed about 1,000 miles (roughly 1,600 km) above Earth around 5 a.m. Eastern time on Saturday 7 November 2026. The second passed about 650 miles (roughly 1,050 km) up around 6 a.m. on Monday 9 November. Each fired its engine for about nine minutes during the pass. Both are now on course for Mars.
Why wait a year?
The pair launched from Cape Canaveral on 13 November 2025. Earth and Mars were then on opposite sides of the Sun, which is a poor moment to set off. Set my clock to launch day and see for yourself.
So the spacecraft parked. They flew a kidney-bean-shaped loop around a spot called Lagrange point 2, about a million miles (1.6 million km) from Earth on the side away from the Sun. When the two planets lined up this month, they headed back towards Earth and used its gravity to turn the corner.
A plain flyby borrows speed from a planet for free. A powered flyby adds an engine burn during the pass. NASA says this is the first time it has used a powered Earth flyby to send a spacecraft to Mars. It did it twice in two days.
The mission's designers say the point is flexibility. Direct launches to Mars have to wait for the planets to line up, about every two years. With a loiter orbit you can launch almost any time and leave later.
What they will do at Mars
The cruise is planned to take ten months, with small course corrections on the way. The two engine burns that should put the spacecraft into orbit around Mars are planned for 7 and 9 September 2027, about 11 minutes each.
Then comes a slow tidy-up of the orbits. Science is expected to begin in June 2028. First the twins are to follow each other round the same orbit, one behind the other. Later one is to move further out to watch the solar wind arrive while the other stays close to see how Mars reacts.
The question is how the solar wind, a stream of material from the Sun moving at about a million miles an hour, strips Mars of its atmosphere. Two spacecraft can measure cause and effect at the same moment. One cannot be in two places. I have tried.
A busy season for flybys
Earth is getting used to this. Europa Clipper is due to swing past on 3 December on its way to Jupiter, and I have written about that separately. Different trick, same idea: let a planet do some of the work.
These dates are NASA's plans. Plans slip, and I will say so here if they do.