The US space agency, the National Aeronautics and Space Administration (Nasa), has reported that one of its future Mars scientific investigation projects has passed a key mission review, known as Key Decision Point C. The project is designated Escape and Plasma Acceleration and Dynamics Explorers (‘Escapade’ for short), which will involve sending two satellites to the Red Planet.

Having passed the review, Escapade now enters its Phase C, which will include the final mission design and the construction of the required instruments, which will include devices to measure magnetic fields, ions and electrons. The mission will be composed of two spacecraft and now has a target launch date of October 2024.

“We are thrilled to pass this critical milestone, the culmination of two years of science and engineering work from a talented and dedicated team at UC [University of California] Berkeley and our partners,” affirmed UC Berkeley space physicist and Escapade principal investigator Rob Lillis. “We’re very excited to now move towards final designs, assembly, test, launch and get on our way to Mars.”

Escapade has two main missions. One is to investigate how the Martian magnetosphere interacts with the solar wind (the magnetosphere is the magnetised volume of space around the planet). The other is to investigate the processes that drive the ‘escape’ of the Martian atmosphere into space. (A previous Nasa Mars orbiter mission, Maven, had determined that the Red Planet once had a much thicker atmosphere but that most of it was lost into space, and that this process was still continuing today.)

“This constellation of two satellites at Mars will answer big questions about the atmosphere and the solar wind in real time,” explained UC Berkeley Escapade mission scientist Shannon Curry. “With simultaneous two-point observations, Escapade will bring us the first ‘stereo’ picture of this highly dynamic environment,” elucidated Lillis.

Escapade will employ two identical spacecraft, based on the Photon design developed by US private sector space company Rocket Lab. Each will be the size of a mini-fridge and have a mass of 120 kg, excluding fuel. After launch, the two spacecraft will take 11 months to voyage to Mars. When they reach the Red Planet, they will enter a highly elliptical orbit. Then, over a six-month period, they will slowly drop into the same science orbit. This orbit will take them, at closest approach, to only 160 km above the Martian surface.