This evening (20:45 PM Italian time), two identical twin spacecraft will leave Earth. And they won't be coming back. Blue and Gold (the colors of the University of California) are two probes built to do what no satellite has ever done: observe Mars simultaneously from two different angles, map its fragmented magnetosphere in 3D, and finally understand why the Red Planet transformed from a potentially habitable world to a barren, frozen desert. The mission GETAWAY (Escape and Plasma Acceleration and Dynamics Explorers) starts with a shoestring budget, a never-before-attempted trajectory, and a question worth billions: where did the Martian atmosphere go? And above all, could it happen to Earth?
The perfect theft of the solar wind
Four billion years ago, Mars had rivers. Maybe lakes. Maybe oceans. geological evidence They speak clearly: there was liquid water on the surface, and to maintain it, an atmosphere dense enough to prevent it from evaporating immediately was needed. Then something went wrong. The planet's magnetic field collapsed, leaving it without a shield against the solar wind. That constant stream of charged particles shooting out of the Sun at a million and a half kilometers an hour has begun to tear the air apart, particle by particle. Today, less than 1% of Earth's atmospheric pressure remains.
Probe MAVEN, in orbit around Mars since 2014, has demonstrated that the solar wind continues to this day eroding the Martian atmosphere. During solar storms, the rate of loss increases tenfold. But MAVEN can only measure from one point at a time. ESCAPADE changes the rules of the game.
ESCAPADE: Two probes for stereo vision
The launch is scheduled for today, Sunday, November 9 from Cape Canaveral, aboard the rocket New glenn by Blue Origin. This is the second flight of this launcher, and the first with such a valuable scientific payload. The two probes, the size of a photocopier and weighing about 250 kilos each, were built by Rocket Lab and managed by theUniversity of California, Berkeley.
The real innovation lies in the stereoscopic measurement. He explains it Robert Lillis, principal investigator of the mission:
"A single satellite can measure what's happening at a point, but it can't distinguish whether a change has occurred over time or whether it's simply passing through a different region. With two probes flying just minutes apart, we can separate temporal variations from spatial ones."
Blue and Gold will arrive on Mars in September 2027, after an anything-but-conventional journey. Instead of heading straight for the Red Planet, the probes will first reach a Lagrangian point (where the Sun and Earth's gravities balance), stay there for about a year studying space weather, then use Earth as a gravitational slingshot to launch themselves toward Mars. This flexible trajectory, designed by Advanced Space, could become the standard for future fleets of vehicles headed to Mars.
Radiation, communications and astronauts
Beyond the scientific mystery, ESCAPADE has immediate practical implications. Without a global magnetic field like Earth's, Mars is constantly bombarded by high-energy solar radiation. In 2024, the rover Curiosity recorded a solar storm that generated the equivalent of 100 days of cosmic microwave background radiation in a single day. For anyone hoping to set foot on Mars, knowing how to predict these storms is a matter of survival.
"We're making the necessary measurements to understand the system well enough to predict solar storms whose radiation could harm astronauts on the surface or in orbit," Lillis explained. Mars's fragmented magnetosphere also distorts radio waves, making communications and navigation difficult. The 3D maps that ESCAPADE will produce will be essential for designing reliable communications systems for future human missions.
ESCAPADE, a low-cost mission that aims high
With a total cost of approximately 80 million dollars, ESCAPADE is part of the program SIMPLEx (Small, Innovative Missions for Planetary Exploration) program, which focuses on cheaper, faster, and more risk-tolerant missions. For comparison, MAVEN cost over $670 million.
The actual scientific mission will last 11 months, from June 2028 to May 2029. During this time, the two probes will fly in formation about 160 kilometers above the Martian surface, collecting data on plasma, charged particles, and magnetic fields.
Casey Dreier of the Planetary Society emphasizes the importance of understanding what went wrong on Mars:
"From everything we know about the history of Mars through robotic exploration, it had very similar chemistry to Earth. It had fresh water. All the things Earth had. So what went wrong? This kind of knowledge helps us put Earth into context and makes us appreciate our own planet as a result of that understanding."
Mars didn't lose its atmosphere in a day. It took millions of years. But the process continues today, and studying it means understanding the mechanisms that protect (or not) rocky planets from stellar erosion. Earth has a robust magnetic field that will last for at least another billion years. Mars doesn't. And that difference made all the difference between a living world and a dead one.
Blue and Gold will launch tonight. They'll arrive in two years. And perhaps, when the data comes back, we'll finally understand why a planet that once resembled our own has turned into a frozen wasteland.
