A project is underway that would use nuclear power to take astronauts to Mars. NASA says nuclear thermal rocket engines would be more efficient than using conventional chemical propulsion for such deep space missions… or travel beyond the moon’s orbit. Now, NASA has earmarked $110 million of its annual budget for the development of the technology. It’s an idea that has been around for decades, but never was put to the test. The last time NASA conducted nuclear thermal rocket tests were more than 50 years ago, but now there are plans to try to launch a nuclear thermal rocket engine by 2027.