Three concrete shells lie dormant in the Nevada desert for more than half a century. These are not ordinary military bunkers: they are test stands built to roar nuclear-propelled rocket engines, intended one day to propel astronauts to Mars. No flame has been rekindled there since 1973.
Key takeaways
- Ultra-powerful nuclear rocket engines were successfully tested in the Nevada desert, but none ever flew
- The program was canceled not because of a technical failure, but because the missions it was designed for were never funded
- These facilities remain highly radioactive after more than 50 years and are only now beginning to be partially dismantled
A program born to reach Mars
It all begins in Jackass Flats, a remote sector of the Nevada Test Site, about 100 miles northeast of Las Vegas. The Nuclear Rocket Development Station was a NASA-AEC facility involved in researching nuclear-propulsion rocket engines like the KIWI series, intended for propulsion of upper-stage spacecraft. The project, initially named Project Rover and later NERVA, aimed at an ambitious goal for its era: to equip future crewed missions to Mars with an engine capable of drastically shortening the journey.
On this secluded site, the program consisted of test cells A and C, an ETS-1 engine test stand, reactor and engine maintenance and assembly facilities, a control complex, and a radioactive materials storage area. The most remarkable detail was arguably the way irradiated reactors were transported: the three test cells were linked by a railway, with a remotely controlled locomotive hauling the highly radioactive reactor, nicknamed the shortest and slowest railway in the world. A precaution that speaks volumes about the danger behind those reinforced-concrete walls.
Five minutes of firing for years of work
The contrast is stark between the scale of the infrastructure and the brevity of the tests they housed. The KIWI-A reactor was tested on July 1, 1959 for 5 minutes at 70 megawatts; KIWI-A1 followed on July 8, 1960 for 6 minutes at 85 megawatts, then KIWI-A3 on October 10, 1960 for 5 minutes at 100 megawatts. Five minutes, six minutes: that was all some of these technological behemoths endured before returning to radioactive dismantling.
Other tests lasted a little longer, never reaching the magnitude of a real flight. The Peewee test reactor operated in November-December 1968 in Test Cell C for 40 minutes at 500 megawatts, with performance close to predictions. Then came the XE’, the only engine tested in a configuration close to flight: it fired downward into a diffuser at the engine-test stand, delivering about 1100 megawatts and logging roughly 28 startups. The last reactor to run on the site, the NF-1, operated at 44 megawatts with several 90-minute tests during the summer of 1972. In total, across the program’s lifetime, the Space Nuclear Propulsion Office oversaw 23 reactor tests between 1959 and 1972. Twenty-three ignitions for a program that mobilized hundreds of engineers for nearly two decades.
An engine that worked, a mission that never existed
The most frustrating aspect of this story isn’t a technical failure. The engines ran. Then the program was shelved before any of them ever flew. The reason wasn’t a design flaw but simply a lack of mission: the craft wasn’t abandoned because it failed, but because the missions it was designed for—crewed flights to Mars and permanent bases beyond the Moon—were never funded; with the end of the Apollo program and the shuttle chosen as the next step, a powerful engine was left with nothing to propel. Project Rover was a technical success, but it was ultimately canceled. Nevada didn’t get its lunar or Martian launch; it got empty buildings that would rust in the open for decades.
Radioactive, dismantled, but not forgotten
This silence isn’t without consequence. The test cells left a lasting imprint in the soil and concrete. Various types of nuclear reactors were tested at Test Cell TCA from 1959 to 1969, contaminating the installation with fission products, neutron-activation products, and fuel particles; most contamination came from relatively short-lived isotopes, now gone, but some concerning isotopes remain, such as cesium-137, strontium-90, cobalt-60, and europium. An invisible heritage that explains why these structures could never be reused or even freely visited.
The landscape has finally shifted, but only recently and in a limited way. In 2023, the Nevada National Security Site completed the demolition of four buildings at the Test Cell C facility, a cleanup milestone led by EM Nevada’s environmental program teams. The rest of the site, meanwhile, remains dormant. And paradoxically, the idea that gave birth to it has never seemed more relevant: nuclear-thermal propulsion is being reconsidered by space agencies, driven by the promise of shortening a future journey to Mars, exactly the rationale that justified building these test stands more than sixty years ago. The difference this time is that no reinforced-concrete wall awaits in the desert to receive it: engineers are starting from scratch, at other sites, with different materials, hoping not to repeat the mistake of building a technology without a mission to accomplish.
Sources: vermotetassocies.com | tile.loc.gov
