Abstract: Omnivorous solar thermal thrusters and adjustable cooling structures are disclosed. In one aspect, a solar thermal rocket engine includes a solar thermal thruster configured to receive solar energy and one or more propellants, and heat the one or more propellants using the solar energy to generate thrust. The solar thermal thruster is further configured to use a plurality of different propellant types, either singly or in combination simultaneously. The solar thermal thruster is further configured to use the one or more propellants in both liquid and gaseous states. Related structures can include valves and variable-geometry cooling channels in thermal contact with a thruster wall.

Abstract: Pneumatically supported towers for low gravity applications are disclosed herein. In one aspect, an inflatable tower for use in vacuum environments can have a membrane configured to support a load when inflated with an inflation gas to a pressures less than 100,000 pascals and greater than 0.01 pascal. The inflation gas can be chosen to have a sufficiently low boiling temperature at the inflation pressure of the membrane that the gas will not condense to a liquid or solid within a defined range of temperatures in which the tower is designed to operate. The membrane can be configured to be packaged for transport in deflated condition and rolled onto cylinders from which the membrane can be later unfurled and inflated as part of the tower inflation process. The membrane can be further configured to progressively inflate beginning at a bottom or lowest level of the membrane during the tower inflation process.

Abstract: Omnivorous solar thermal thrusters and adjustable cooling structures are disclosed. In one aspect, a solar thermal rocket engine includes a solar thermal thruster configured to receive solar energy and one or more propellants, and heat the one or more propellants using the solar energy to generate thrust. The solar thermal thruster is further configured to use a plurality of different propellant types, either singly or in combination simultaneously. The solar thermal thruster is further configured to use the one or more propellants in both liquid and gaseous states. Related structures can include valves and variable-geometry cooling channels in thermal contact with a thruster wall.

Abstract: Omnivorous solar thermal thrusters and adjustable cooling structures are disclosed. In one aspect, a solar thermal rocket engine includes a solar thermal thruster configured to receive solar energy and one or more propellants, and heat the one or more propellants using the solar energy to generate thrust. The solar thermal thruster is further configured to use a plurality of different propellant types, either singly or in combination simultaneously. The solar thermal thruster is further configured to use the one or more propellants in both liquid and gaseous states. Related structures can include valves and variable-geometry cooling channels in thermal contact with a thruster wall.