Turbomolecular air-scoop for satellite air-breathing electric propulsion

A method comprising:

• collecting and compressing air with an air-scoop, wherein the air-scoop comprises:
• an air inlet that air molecules enter the air-scoop through at approximately an orbital speed when the air-scoop is moving through an atmosphere at approximately the orbital speed;
• and
• a rotor configured to be rotated by a motor at approximately a rotational speed, wherein:
• the rotor comprises a plurality of rotatable blade stages;
• each of the rotatable blade stages comprises a blade configuration that comprises a blade aspect ratio and a blade attack angle, wherein the blade aspect ratio is a quotient of blade width and blade separation in the rotatable blade stage;
• a first one of the rotatable blade stages is positioned closest among the rotatable blade stages to the air inlet, wherein the blade configuration of the first one of the rotatable blade stages substantially maximizes transparency of the first one of the rotatable blade stages to the air molecules entering the air-scoop through the air inlet at approximately the orbital speed when the rotor is rotating at approximately the rotational speed;
• a last one of the rotatable blade stages is positioned farthest among the rotatable blade stages from the air inlet, wherein the blade configuration of the last one of the rotatable blade stages substantially maximizes opacity of the last one of the rotatable blade stages to the air molecules in the air-scoop flowing directionally toward the air inlet when the rotor is rotating at approximately the rotational speed;
• and
• the blade configuration of the first one of the rotatable blade stages is different from the blade configuration of the last one of the rotatable blade stages;
• and
• supplying the collected and compressed air to a thruster as propellant;
• and
• generating thrust with the thruster using the collected and compressed air.

A method comprising:

• operating a spacecraft that comprises:
• a payload;
• and
• a spacecraft bus that comprises:
• a thruster operable to generate thrust;
• and
• an air-scoop operable to supply air to the thruster as propellant, wherein the air-scoop comprises:
• an air inlet that air molecules enter the air-scoop through at approximately an orbital speed when the spacecraft is moving through an atmosphere at approximately the orbital speed;
• and
• a rotor configured to be rotated by a motor at approximately a rotational speed, wherein:
• the rotor comprises a plurality of rotatable blade stages;
• each of the rotatable blade stages comprises a blade configuration that comprises a blade aspect ratio and a blade attack angle, wherein the blade aspect ratio is a quotient of blade width and blade separation in the rotatable blade stage;
• a first one of the rotatable blade stages is positioned closest among the rotatable blade stages to the air inlet, wherein the blade configuration of the first one of the rotatable blade stages substantially maximizes transparency of the first one of the rotatable blade stages to the air molecules entering the air-scoop through the air inlet at approximately the orbital speed when the rotor is rotating at approximately the rotational speed;
• a last one of the rotatable blade stages is positioned farthest among the rotatable blade stages from the air inlet, wherein the blade configuration of the last one of the rotatable stages substantially maximizes opacity of the last one of the rotatable blade stages to the air molecules in the air-scoop flowing directionally toward the air inlet when the rotor is rotating at approximately the rotational speed;
• and
• wherein the blade configuration of the first one of the rotatable blade stages is different from the blade configuration of the second one of the rotatable blade stages.