NASA’s robotic Mars Exploration Program is on a troubling path of decline—and decisions must be made now in order to stop it.

This is the conclusion my colleague Jason Callahan and I reached as we prepared a new report for The Planetary Society: Mars in Retrograde: A Pathway to Restoring NASA’s Mars Exploration Program (pdf). I urge you to download it and read it yourself.

Since its formation in the year 2000, the Mars Exploration Program has systematically worked to understand the Red Planet through robotic missions of exploration. It realized a revolution in humanity’s knowledge of Mars, and methodically worked toward the top goal of Mars science—sample return to Earth—a goal which could advance our search for life and reveal untold secrets into Mars’ ancient past.

The robotic program also provided precious information to support human exploration, collecting radiation measurements, landing data, resource characterization, and surface mapping for future missions.

But we found a fundamental contradiction in NASA’s extant Mars plans: there is not much of a program within the Mars Exploration Program.

Currently, NASA has a single mission development—the Mars 2020 rover (InSight, which launches in 2018, is part of the Discovery program). There have been no new mission starts for Mars since 2013, one of the longest droughts in recent history.

But the existing Mars missions are aging and won’t last forever. A new orbiter is badly needed to relay high-speed communications with ground missions and to provide high resolution mapping of the surface to support landing attempts by NASA and others (not to mention provide important science). Yet the latest budget release for 2018 contained no new start for this critical mission.