The US Defense Advanced Research Projects Agency (Darpa) has recently commissioned three private companies, Blue Origin, Lockheed Martin and General Atomics, to develop nuclear fission thermal rockets for use in lunar orbit. Such a development, if flown, could usher in a new era of spaceflight. That said, it is only one of several exciting avenues in rocket … Continue reading A New Era of Spaceflight? Exciting Advances in Rocket Propulsion