NASA’s ESCAPADE: Twin Probes Take a Novel Route to Reveal How Mars Lost Its Atmosphere

Mars today is a cold, dry world, but geological and chemical evidence shows that billions of years ago it had a thicker atmosphere that allowed liquid water to flow on its surface. Scientists want to know what changed — and whether lessons from Mars can help us better understand and protect Earth's climate and atmosphere.

What ESCAPADE will study

NASA and the University of California, Berkeley's Space Sciences Laboratory are launching ESCAPADE (Escape and Plasma Acceleration and Dynamics Explorers), a pair of identical orbiters nicknamed Gold and Blue. The twin spacecraft will fly in formation to produce the first coordinated, three-dimensional view of Mars' magnetosphere and upper atmosphere, measuring how charged particles and electromagnetic fields accelerate atmospheric gas into space.

"From everything we know about the history of Mars through robotic exploration, it had very similar chemistry [to Earth]. It had very similar periods of time and development. It had that thicker atmosphere, had standing water, fresh water. All the things that Earth had," said Casey Dreier, chief of space policy at the Planetary Society.

A unique trajectory

The twin probes are scheduled to launch on Sunday at 2:45 p.m. ET from Kennedy Space Center aboard Blue Origin's New Glenn rocket. Rather than taking the direct cruise used by many past missions, ESCAPADE will first travel to an Earth–Sun Lagrange point — a region where the gravitational pulls of Earth and the sun are balanced — and loop near that point for about a year before using a slingshot back toward Earth and onward to Mars. Mission planners say this flexible route could enable launches spread over months, an advantage for future campaigns that may send multiple spacecraft or crews.

Spacecraft and timeline

Each probe is roughly the size of a mini-fridge and weighs about 250 pounds. The pair are expected to arrive at Mars in 2027 and operate together to capture complementary, real-time measurements of space weather effects and atmospheric escape. ESCAPADE builds on discoveries from NASA’s MAVEN mission, which has been studying Mars' upper atmosphere since 2014.

Why it matters for Earth and future explorers

Dreier and mission scientists stress that understanding how Mars lost most of its atmosphere helps put Earth in context: planetary environments can change dramatically over long timescales. One key difference is that Mars lacks a global magnetic field like Earth’s, leaving its upper atmosphere vulnerable to erosion by the solar wind.

"The interaction between the sun's particles and the atmosphere of Mars is thought to be one of the driving reasons that Mars no longer has a dense and protective atmosphere," Dreier said. "Understanding that relationship helps us understand the history and processes that have stripped away Mars's atmosphere over time."

Robert Lillis, ESCAPADE's principal investigator at UC Berkeley's Space Sciences Laboratory, highlighted another practical benefit: better space-weather measurements will improve forecasts of solar storms that could endanger astronauts on the surface or in orbit around Mars. ESCAPADE's data can inform shielding strategies and operational rules for future human missions.

Cost and context

ESCAPADE is a focused, cost-conscious science mission, with an estimated cost in the range of $70–$80 million. Dreier notes that such lower-cost missions can demonstrate scientific value efficiently, but he also warned that budget cuts and the retirement of spacecraft could impede long-term planetary science efforts that help us understand climate evolution across the solar system.

In short, ESCAPADE aims to answer fundamental questions about how planets lose atmospheres and how that process shapes habitability — knowledge that is directly relevant to protecting Earth and preparing humans to explore Mars safely.