EscaPADE: Twin Spacecraft Take an Unprecedented Winding Route to Mars

NASA’s EscaPADE twin spacecraft will take a novel, winding route to Mars

Twin spacecraft are set to launch on an unprecedented, indirect route to Mars to study why the once-active planet lost much of its atmosphere billions of years ago. The mission, called EscaPADE (Escape and Plasma Acceleration Dynamics Explorers), is led by the University of California, Berkeley and supported by Advanced Space and Rocket Lab as part of NASA’s SIMPLEx (Small, Innovative Missions for Planetary Exploration) program.

Unlike a conventional direct transfer, the two small orbiters will follow a “launch-and-loiter” plan that lets them fly almost any time and wait for the ideal planetary alignment. After liftoff, the spacecraft will travel to the Sun–Earth Lagrange Point 2 (L2), about 1.5 million kilometers (930,000 miles) from Earth, where they will loiter in a kidney bean–shaped orbit for roughly a year.

Why L2? Lagrange points are locations where the gravitational pull of the Sun and Earth balance, allowing spacecraft to remain with minimal fuel use. The L2 region also offers a relatively benign radiation environment outside Earth’s Van Allen belts, making it an attractive holding area while mission planners wait for the next Mars transfer window.

The mission was originally planned for a direct launch during the late-2024 transfer window, but schedule changes and launch delays left EscaPADE without a ride. Rather than wait until the next prime window in 2026, mission designers adopted the launch-and-loiter approach: the spacecraft will wait at L2, perform a brief Earth gravity-assist swing in November 2026, and then depart for Mars. Both vehicles are expected to enter Martian orbit in September 2027 regardless of the exact launch date.

Launch and partners

The twin spacecraft are slated to launch on Blue Origin’s New Glenn rocket — the first time this new launcher will carry valuable payloads — from Cape Canaveral Space Force Station in Florida. The launch window includes a planned liftoff time as early as 2:45 p.m. ET on Sunday. Blue Origin has said it is coordinating with the FAA to keep the New Glenn launch on schedule; operations could be affected if a government shutdown delays the countdown beyond the weekend.

Low cost, higher risk

EscaPADE is one of SIMPLEx’s most ambitious missions. With a total cost under $100 million, it aims to deliver scientific returns comparable to much more expensive missions while accepting greater programmatic and technical risk. “We don’t use the word ‘cheap.’ We say, ‘high value,’” said Jeff Parker, chief technology officer at Advanced Space. “We’re providing science that is at the level of missions that cost hundreds of millions of dollars, but with a low budget.”

The unusual loiter adds wear-and-tear risk to components and introduces mission uncertainty. Past SIMPLEx missions have experienced failures or setbacks — for example, Lunar Trailblazer ended after communications problems, and LunaH-Map was hampered by launch delays. Still, EscaPADE’s backers argue that accepting some added risk is worthwhile if the program can produce high scientific value at dramatically lower cost: even a single success can validate the approach.

“The idea is launch anytime, loiter until the planets are just perfectly aligned, and then to depart on your interplanetary cruise to Mars,”

— Jeff Parker, Advanced Space

What the mission will study

Once in Martian orbit, the twin spacecraft will investigate the processes that stripped Mars of much of its atmosphere and transformed it from a warmer, wetter world into the cold, thin-atmosphere planet we see today. Studying plasma interactions and atmospheric escape will help scientists better understand planetary evolution — both for Mars and for terrestrial planets beyond our solar system.

Outlook

EscaPADE is a test of both an innovative trajectory and the SIMPLEx philosophy: achieve high-value science with smaller, more affordable spacecraft. If successful, the mission could expand options for future planetary exploration by demonstrating a flexible, cost-conscious way to reach distant targets.