A spacecraft including: an engine; a thrust vector control device controlling a thrust vector as a direction of a thrust acting on the spacecraft; and a main control device configured to acquire state quantities of the spacecraft in a powered descending in which the spacecraft is guided to a target point while the engine generates the thrust, and generate a throttling command by which combustion of the engine is controlled and an operation command by which the thrust vector control device is operated. The state quantities contain a first acceleration parameter and a second acceleration parameter. The first and second acceleration parameters are calculated as coefficients A and B obtained by fitting based on acceleration of the spacecraft previously detected, supposing the following equation is satisfied between a reciprocal number 1/a of the acceleration a of the spacecraft and time t:
1/a=−At+B  (1).

A microthruster for controlling small spacecraft and methods for manufacturing the same are disclosed. Embodiments of the microthruster include one or more nozzle throats with cross sectional areas of at most 20 μm.sup.2, and some with 6 μm.sup.2. Some embodiments include heaters that heat water in one or more reservoirs to increase pressure in the reservoirs and eject the water from the one or more nozzle throats. Some embodiments are manufactured by etching channels into one or more layers of material, and still further embodiments are manufactured by forming the nozzle throats and/or the reservoirs between two layers of material. Some microthruster embodiments are flat in shape with the nozzle throats ejecting water out the thin sides of the microthruster. Still further embodiments are formed by etching channels into one layer of material, printing a heater onto another layer of material, and bonding the two layers together.

A method (50) for orbit control of a satellite (10) in Earth orbit and for desaturation of an angular momentum storage device of the satellite, the satellite (10) including an articulated arm (21) suitable for moving a propulsion unit (31) within a motion volume included in a half-space delimited by an orbital plane when the satellite is in a mission attitude, the method (50) including a single-arm control mode using only the propulsion unit (31) carried by the articulated arm (21), the single-arm control mode using a maneuvering plan including only thrust maneuvers to be executed when the satellite (10) is located within an angular range of at most 180° centered on a target node in the orbit of the satellite (10), including two thrust maneuvers to be performed respectively upstream and downstream of the target node.

In a spacecraft for operating a thruster that includes a microwave source, a resonant cavity, and a source of propellant which the thruster converts to hot gas and directs via a nozzle to generate thrust, a method includes operating the thruster in an ignition mode in which the microwave source outputs power at a first rate, and operating the thruster in a propulsion mode in which the microwave source outputs power at a second rate higher than the first rate.

Systems and methods are described herein for mounting a thruster onto a vehicle. A thruster mounting structure may comprise a first, second, and third rotational joint, a boom, and thruster pallet, and a thruster attached to the thruster pallet. The first rotational joint may be attached to the vehicle and configured to rotate in a first axis. The first rotational joint may be connected to the boom and configured to pivot the boom about the first axis. The boom may be connected to the second rotational joint, which is connected to the third rotational joint and configured to rotate the third rotational joint in the first axis. The third rotational joint may be connected to the thruster pallet and configured to pivot the thruster pallet in a second axis that is perpendicular to the first axis.

Systems and methods are described herein for mounting a thruster onto a vehicle. A thruster mounting structure may comprise a first, second, and third rotational joint, a boom, and thruster pallet, and a thruster attached to the thruster pallet. The first rotational joint may be attached to the vehicle and configured to rotate in a first axis. The first rotational joint may be connected to the boom and configured to pivot the boom about the first axis. The boom may be connected to the second rotational joint, which is connected to the third rotational joint and configured to rotate the third rotational joint in the first axis. The third rotational joint may be connected to the thruster pallet and configured to pivot the thruster pallet in a second axis that is perpendicular to the first axis.

In an example, a method for deorbiting a spacecraft is described. The method includes selecting a target landing site for deorbiting the spacecraft. The method includes determining a range target and a velocity target for reaching a predicted atmospheric entry location. The method includes determining a back-propagated orbit state estimate of the spacecraft. The method includes comparing the back-propagated orbit state estimate to a known orbit state of the spacecraft to determine that the back-propagated orbit state estimate has converged with the known orbit state. The method includes calculating based on determining that the back-propagated orbit state estimate has converged with the known orbit state, (a) an estimated time of ignition for a propulsion system of the spacecraft and (b) an estimated burn velocity vector of the propulsion system using the range target and the velocity target. The method includes performing a burn pulse by the propulsion system.

In an example, a method for deorbiting a spacecraft is described. The method includes selecting a target landing site for deorbiting the spacecraft. The method includes determining a range target and a velocity target for reaching a predicted atmospheric entry location. The method includes determining a back-propagated orbit state estimate of the spacecraft. The method includes comparing the back-propagated orbit state estimate to a known orbit state of the spacecraft to determine that the back-propagated orbit state estimate has converged with the known orbit state. The method includes calculating based on determining that the back-propagated orbit state estimate has converged with the known orbit state, (a) an estimated time of ignition for a propulsion system of the spacecraft and (b) an estimated burn velocity vector of the propulsion system using the range target and the velocity target. The method includes performing a burn pulse by the propulsion system.

[Object] To provide a sheet-like structure capable of highly accurately estimating a sheet-like shape.

[Solving Means] A sheet-like structure includes a sheet-like member and a plurality of detection sensors. The sheet-like member extends along an in-plane direction orthogonal to a thickness direction and receives light incident on the sheet-like member. The plurality of detection sensors are dispersedly arranged on the sheet-like member along the in-plane direction and are for detecting an incident angle of the light with respect to the sheet-like member at each arrangement position of the plurality of detection sensors.

Systems and methods for describing, simulating and/or optimizing spaceborne systems and missions. Configurations for spaceborne systems are generated and validated based on simulation output.