Mars is set for a rare twin encounter this weekend as NASA prepares to launch the $80 million ESCAPADE mission — short for Escape and Plasma Acceleration and Dynamics Explorers — to study how the planet lost its once-dense atmosphere and surface water. As reported by Space.com, the mission involves two identical probes, nicknamed Blue and Gold, flying aboard Blue Origin’s New Glenn rocket from Cape Canaveral no earlier than November 9.

The spacecraft will orbit Mars together to produce a three-dimensional picture of how the solar wind — a stream of charged particles from the Sun — interacts with and strips away the Martian atmosphere. “To understand how the solar wind drives different kinds of atmospheric escape is a key piece of the puzzle of the climate evolution of Mars,” said Robert Lillis, principal investigator for ESCAPADE and associate director for planetary science at the University of California, Berkeley’s Space Sciences Laboratory.

Space.com notes that each probe carries identical instruments, including electrostatic analyzers from UC Berkeley to detect charged particles, a magnetometer from NASA’s Goddard Space Flight Center, and plasma sensors from Embry-Riddle Aeronautical University. Cameras from Northern Arizona University may even capture Mars’ faint green auroras.

After a year-long detour to a gravitational “sweet spot” between Earth and the Sun, the satellites will reach Mars in September 2027, eventually flying in formation just 160 kilometres above its surface. The data will reveal how energy and matter flow between the planet and solar wind — a process key to understanding why Mars turned from a once-habitable world into a frozen desert.