Pointing mechanism

Patent metadata

Field	Value
Publication number	US-11459129-B2
Application number	US-201616332288-A
Country	US
Kind code	B2
Filing date	Dec 6, 2016
Priority date	Sep 29, 2016
Publication date	Oct 4, 2022
Grant date	Oct 4, 2022

Abstract

An artificial satellite includes two pointing mechanisms. The pointing mechanisms respectively include main body side gimbals, deployed booms, thruster side gimbals, and thruster groups. The main body side gimbal connects the deployed boom to a satellite main body and adjusts a direction of the deployed boom. The thruster side gimbal connects the thruster to the deployed boom and adjusts the direction of the thruster. Each gimbal is a two-axis gimbal.

First claim

The invention claimed is:

1. A pointing mechanism comprising:
a deployed boom having a rod shape;
a main body side gimbal to connect the deployed boom to a satellite main body and adjust a direction of the deployed boom; and
a thruster side gimbal to connect a thruster to the deployed boom and adjust a direction of the thruster, wherein
the pointing mechanism includes a first pointing mechanism and a second pointing mechanism each mounted on an artificial satellite,
each of the main body side gimbal and the thruster side gimbal is a two-axis gimbal,
the first pointing mechanism includes a first attachment portion located at one corner out of four corners on a first anti-earth-oriented surface side, and
the second pointing mechanism includes a second attachment portion located at a diagonal corner of the first attachment portion out of the four corners on a second anti-earth-oriented surface side, opposite the first anti-earth-oriented surface side.

2. The pointing mechanism according to claim 1 , wherein
the thruster side gimbal connects a first thruster group comprising a plurality of thrusters to the deployed boom, and
during orbit raising, when a first operation number which is the number of activated thrusters out of the first thruster group of the first pointing mechanism and a second operation number which is the number of activated thrusters out of a second thruster group connected to the deployed boom of the second pointing mechanism are different from each other, the direction of the deployed boom to which the first thruster group is connected and the direction of the deployed boom to which the second thruster group is connected are adjusted, a satellite center of gravity, the first thruster group and the second thruster group are projected on a plane having a traveling direction as a normal line during orbit raising, and
the satellite center of gravity, the first thruster group and the second thruster group are arranged on a same common straight line, so that a ratio of a first distance from the satellite center of gravity to the first thruster group and a second distance from the satellite center of gravity to the second thruster group in the plane is an inverse ratio of the first operation number and the second operation number.

3. The pointing mechanism according to claim 1 , wherein when the artificial satellite is accommodated in a rocket fairing, the direction of the deployed boom is configured to be adjusted to be parallel to a surface to which the main body side gimbal is attached.

4. The pointing mechanism according to claim 1 , wherein
the deployed boom has the longest length in a length tolerance range, and
the length tolerance range is a range satisfied by a length of the deployed boom to accommodate an entire pointing mechanism in a fairing envelope region in a state in which the direction of the deployed boom is configured to be adjusted to be parallel to the surface to which the main body side gimbal is attached.

5. The pointing mechanism according to claim 1 , wherein
when station keeping is performed, the direction of the deployed boom and the direction of the thruster are adjusted so that a firing direction angle formed by a firing direction of the thruster and a north-south direction of the artificial satellite is the minimum angle in an angle tolerance range, and
the angle tolerance range is a range satisfied by the firing direction angle so that a solar cell paddle does not enter a firing range of the thruster.

6. A pointing mechanism comprising:
a deployed boom having a rod shape;
a main body side gimbal to connect the deployed boom to a satellite main body and adjust a direction of the deployed boom; and
a thruster side gimbal to connect a thruster to the deployed boom and adjust a direction of the thruster, wherein
the pointing mechanism is mounted in a pair on an artificial satellite,
a first attachment portion to which the main body side gimbal is attached and a second attachment portion to which the main body side gimbal of another pointing mechanism of the pair of pointing mechanisms is attached are in rotationally symmetric positions about a satellite center of gravity as seen from an earth-oriented surface side,
the first attachment portion is located at one corner out of four corners on a first anti-earth-oriented surface side, and
the second attachment portion is located at a diagonal corner of the first attachment portion out of the four corners on a second anti-earth-oriented surface side, opposite the first anti-earth-oriented surface side,
the thruster includes a thruster base, and
for each of the pair of pointing mechanisms, a length from the main body side gimbal to the thruster base is substantially equal to a width of the respective anti-earth-oriented surface side.

7. A pointing mechanism comprising:
a deployed boom having a rod shape;
a main body side gimbal to connect the deployed boom to a satellite main body and adjust a direction of the deployed boom; and
a thruster side gimbal to connect a thruster to the deployed boom and adjust a direction of the thruster, wherein
the pointing mechanism is mounted in a pair on an artificial satellite,
a first attachment portion to which the main body side gimbal is attached and a second attachment portion to which the main body side gimbal of another pointing mechanism of the pair of pointing mechanisms is attached are in rotationally symmetric positions about a satellite center of gravity as seen from an earth-oriented surface side,
the first attachment portion is located at one corner out of corners on an anti-earth-oriented surface side, the first attachment portion is located on one of a south surface facing the south when the artificial satellite orbits the earth and a north surface facing the north when the artificial satellite orbits the earth, and
the second attachment portion is located at a diagonal corner of the first attachment portion out of the corners on the anti-earth-oriented surface side in the other surface out of the south surface and the north surface,
the thruster includes a thruster base, and
for each of the pair of pointing mechanisms, a length from the main body side gimbal to the thruster base is substantially equal to a width of the respective anti-earth-oriented surface side.

8. The pointing mechanism according to claim 6 , wherein
the thruster side gimbal connects a first thruster group comprising a plurality of thrusters to the deployed boom, and
during orbit raising, when a first operation number which is the number of activated thrusters out of the first thruster group and a second operation number which is the number of activated thrusters out of a second thruster group connected to the deployed boom of the other pointing mechanism are different from each other, the direction of the deployed boom to which the first thruster group is connected and the direction of the deployed boom to which the second thruster group is connected are adjusted, the satellite center of gravity, the first thruster group and the second thruster group are projected on a plane having the traveling direction as a normal line during orbit raising, and the satellite center of gravity, the first thruster group and the second thruster group are arranged on the same straight line, so that a ratio of a first distance from the satellite center of gravity to the first thruster group and a second distance from the satellite center of gravity to the second thruster group in the plane is an inverse ratio of the first operation number and the second operation number.

9. The pointing mechanism according to claim 6 , wherein when the artificial satellite is accommodated in a rocket fairing, the direction of the de

Assignees

• Mitsubishi Electric Corp

Inventors

• Kawamura Shunichi

Classifications

• B64G1/24 Primary

  Guiding or controlling apparatus, e.g. for attitude control · CPC title

• B64G1/10

  Artificial satellites; Systems of such satellites; Interplanetary vehicles (space shuttles B64G1/14) · CPC title

• B64G1/222

  for deploying structures between a stowed and deployed state · CPC title

• B64G1/409

  Unconventional spacecraft propulsion systems · CPC title

• B64G1/242

  Orbits and trajectories · CPC title