The Boeing Company

Sadek W Mansour

Hanching Grant Wang

Jeffrey Scott Noel

Umesh Ketkar

Gary E Lemke

Grant Wang

Jason D Flathom

Andrew I Mactavish

Douglas Bender

John D Haskell

Rainier Pio Roda

Sheng N Sun

Albert A Munoz

Carl J Iii Hahn

Systems and methods for launching a plurality of spacecraft, provided in a stack of spacecraft, from a launch vehicle traveling along an in-track path include releasing, in a first separation event occurring at a first time, a first spacecraft from the stack of spacecraft using a first separation force having a first separation force in-track component along the in-track path. Subsequently, in a second separation event occurring at a second time, a second spacecraft is released from the stack of spacecraft using a second separation force having a second separation force in-track component along the in-track path, wherein the second time occurs a first time delay after the first time. The first and second separation in-track components may be different, such as by varying a magnitude of the separation force or an angle at which the spacecraft is launched.

Systems and methods for launching a plurality of spacecraft

A method for autonomously controlling electric power supplied to a thruster of a spacecraft during electric orbit raising includes determining a state of charge of a battery onboard the spacecraft at an entry into an eclipse during each orbit of a plurality of orbits during the electric orbit raising of the spacecraft. The method also includes determining an electric power level used to fire each thruster of a plurality of thrusters during each orbit beginning after the eclipse, based at least on the state of charge of the battery, and that will provide a shortest electric orbit raising duration and minimize thruster propellant usage during electric orbit raising.

Autonomous control of electric power supplied to a thruster during electric orbit raising

A system for managing momentum accumulation of a spacecraft in orbit may include a reaction wheel assembly for controlling an attitude of a body of a spacecraft, the body defining at least one face, and absorbing momentum, a plurality of arcjet thrusters coupled to the face to generate thrust, and a control processor coupled to the plurality of arcjet thrusters for controlling the thrust, wherein actuation of each arcjet thruster of the plurality of arcjet thrusters is configured to produce a net momentum accumulation in the reaction wheel assembly that is below a momentum saturation point of the reaction wheel assembly.

System and method for managing momentum accumulation

A method for spacecraft power acquisition is provided using single-axis slit sun sensors for both wing-stowed and wing-deployed spacecraft configurations. The method for wing-deployed spacecraft includes initializing a solar wing of the spacecraft to search for sun; rotating the spacecraft about a search axis substantially parallel to a slit sun sensor field of view; monitoring the slit sun sensor for a time of arrival signal; and wherein, if the time of arrival signal occurs, the spacecraft is rotated along the search axis to an orientation where the time of arrival signal occurred and the spacecraft is placed in stable rotation about an axis substantially parallel to a solar wing longitudinal axis; and for a non-occurrence of the time of arrival signal, the spacecraft is slewed about a keyhole axis substantially perpendicular to the search axis to move the sun away from a keyhole.

Method and system for spacecraft power acquisition using single-axis slit sun sensor

A simple, robust algorithm for power acquisition for power, thermal, and momentum safety for high heater-power spacecraft uses current sensors rather than sun sensors and includes a wing sun search phase, an xz slew phase, and a safe hold phase. Solar wing current is continuously monitored against a high current threshold and a low current threshold. Wing sun search phase transitions either to xz slew phase or safe hold phase. When current is too low, the xz slew phase is entered and slews the spacecraft about an axis in the xz plane until current is high enough. When current is high enough, the algorithm transitions or remains in safe hold phase and the spacecraft is spun about its wing axis. A low current persistence timer is longer than a high current persistence timer in order to bias the algorithm to prefer safe hold phase over xz slew phase.

Spacecraft power acquisition procedure and method for wing-deployed configuration

A spacecraft power/sun acquisition method includes a pitch search phase in which the spacecraft is rotated about a pitch axis, stopped, quaternions reset to remember position, and yaw search phase is entered when a first TOA occurs from a first slit sun sensor, and a keyhole slew is performed when the first TOA does not occur. The method also includes yaw search phase in which a keyhole slew is performed by rotating the spacecraft about a yaw axis, stopping the spacecraft, and entering pitch search phase when the first TOA does not occur, and in which the spacecraft is rotated about a yaw axis, stopped, quaternions reset, and sun hold phase is entered when a second TOA occurs from a second slit sun sensor. Lastly, the method includes a sun hold phase in which the spacecraft is oriented to the sun and placed in spin at power safe attitude.

Growing community of inventors

Torrance, CA, United States of America

Sadek W Mansour