An MIT team has come up with two cost-efficient orbital fuel depot designs that do not require long-term commitment. Both designs take advantage of the fact that each lunar mission carries a supply of “contingency propellant” — fuel that’s meant to be used only in emergencies. In most cases, this backup fuel goes unused, and is either left on the moon or burned up as the crew re-enters the Earth’s atmosphere.
Instead, the MIT team proposes using contingency propellant from past missions to fuel future spacecraft. For instance, as a mission heads back to Earth, it may drop a tank of contingency propellant at a depot before heading home. The next mission can pick up the fuel tank on its way to the moon as its own emergency supply. If it ends up not needing the extra propellant, it can also drop it at the depot for the next mission — an arrangement that the team refers to as a “steady-state” approach.
A depot may also accumulate contingency propellant from multiple missions, part of an approach the researchers call “stockpiling.” Spacecraft heading to the moon would carry contingency propellant as they normally would, dropping the tank at a depot on the way back to Earth if it’s not needed; over time, the depot builds up a large fuel supply. This way, if a large lunar mission launches in the future, its rocket wouldn’t need a huge fuel supply to launch the heavier payload. Instead, it can stop at the depot to collect the stockpiled propellant to fuel its landing on the moon
Acta Astronautica - On-orbit depot architectures using contingency propellant
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Instead, the MIT team proposes using contingency propellant from past missions to fuel future spacecraft. For instance, as a mission heads back to Earth, it may drop a tank of contingency propellant at a depot before heading home. The next mission can pick up the fuel tank on its way to the moon as its own emergency supply. If it ends up not needing the extra propellant, it can also drop it at the depot for the next mission — an arrangement that the team refers to as a “steady-state” approach.
A depot may also accumulate contingency propellant from multiple missions, part of an approach the researchers call “stockpiling.” Spacecraft heading to the moon would carry contingency propellant as they normally would, dropping the tank at a depot on the way back to Earth if it’s not needed; over time, the depot builds up a large fuel supply. This way, if a large lunar mission launches in the future, its rocket wouldn’t need a huge fuel supply to launch the heavier payload. Instead, it can stop at the depot to collect the stockpiled propellant to fuel its landing on the moon
Acta Astronautica - On-orbit depot architectures using contingency propellant
Read more »