While it is unclear what if any implications the recent successful landing of the first stage of the Falcon 9 first stage means for the future of space travel, planetary scientist and space commentator Paul Spudis suggested on Friday that the feat and the similar one performed earlier by Blue Origin could have some benefit for a return to the moon. In the meantime, a test of the engines in the recovered first stage had mixed results. The engines fired alright, but SpaceX CEO Elon Musk reported, “thrust fluctuations” that might have been caused by “debris ingestion.” Does that mean the rocket could or could not have been reused? The answer is not yet forthcoming.
Spudis, for his part, suggest that reusable rockets have good implications for a return to the moon.
“With the Falcon 9 first stage recovery, SpaceX developed the capability to safely soft-land a throttleable, cryogenic engine system—a key technical development needed for the creation of a permanent space-based transportation system. Although there are differences between landing the Falcon 9 stage and a lunar soft-lander, if one can be done, so can the other. All lunar landers to date, both robotic and manned, have used storable propellants (usually hydrazine and nitrogen tetroxide) and then, after a single use, were discarded. To return to the Moon permanently, we must develop reusable propulsion systems that use the propellants that we are able to manufacture on the Moon (cryogenic liquid oxygen and liquid hydrogen and/or liquid methane).”
It should be noted that NASA has already experimented with reusable lander prototypes along those lines, in its Morpheus and Mighty Eagle programs. Before that, both NASA and the Defense Department conducted tests on the DC-X single stage to orbit prototype.
The idea is that a lunar base or, as the Europeans prefer, a Moon Village would be kept resupplied by reusable lander that would be refueled and refurbished on the lunar surface. Such a vehicle would be a critical component in an Earth to moon transportation infrastructure moving people and cargo between the home planet and our nearest neighbor. Such a system would, for example, ship fuel created from lunar ice to space-based depots where spacecraft headed for deep space would top off.
SpaceX is thinking more along the lines of reusable rockets taking payloads to low Earth orbit. The ability to recover a rocket is just the first step in developing such a capability. Musk also has to demonstrate that the Falcon 9 first stage can be refurbished and reused relatively cheaply and quickly. SpaceX will likely need years of experimentation and refinement of its technology before it achieves that capability.