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Results for “SPACECRAFT GUIDANCE”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 127 records · Page 7

Lidar for Guidance of a Spacecraft or Exploratory Robot

A report describes the Laser Mapper (LAMP) -- a lightweight, compact, low-power lidar system under development for guidance of a spacecraft or exploratory robotic vehicle (rover) at Mars or another planet. The LAMP is intended especially for use during rendezvous of two spacecraft in orbit, for mapping terrain during descent and landing of a spacecraft, for capturing a sample that has been launched into orbit, or navigation and avoidance of obstacles by a rover traversing terrain. The LAMP includes a laser that emits high-power, short light pulses. The laser beam is aimed in azimuth and elevation by use of a mirror on a two-axis gimbal, which scans the beam across a field of regard. Light reflected by a target is collected by a telescope, and the distance to the target is determined by measuring the round-trip travel time for reflected light pulses. The distance information is combined with directional information to construct a three-dimensional map of targets in the field of regard.

Liebe, Carl Christian↗

Control and Guidance of Electrically Propelled Spacecraft

Some of the conditions and methods of control and guidance for a nuclear-electric spacecraft are discussed in general terms. The type of spacecraft considered is propelled by an ion motor. The broad aspects of the flight trajectory peculiar to this type of propulsion are examined. Some equipment limitations are reviewed.

NUCLEAR-ELECTRIC PROPULSION↗

Fracture Control and Structural Certification Guidance for Additive Manufactured Spacecraft Structures

This paper offers a NASA perspective on guidance for fracture control and structural certification of "fracture critical" additive manufactured spacecraft structures. Results of a recent industry survey on the need for maturing NASA guidance for AM certification are presented for the first time. The survey results are placed in the context of a description of what NASA standards in this area already exist, where the gaps are, and what work to address the gaps is underway.

McElroy, Mark↗

Iterative explicit guidance for low thrust spacecraft.

A retargeting procedure is developed for use as a nonlinear low thrust guidance scheme. The selection of a control program composed of a sequence of inertially fixed thrust-acceleration vectors permits all trajectory computations to be made with closed form expressions, and allows the controls to be represented by constant parameters, thrust-acceleration vectors and thrusting times. By requiring each trajectory to be time optimal, the guidance problem is transformed into a parameter optimization problem which is solved by the conjugate gradient method. The scheme is applied to a low thrust capture mission, and the results of computer simulations are presented.

Jacobson, R. A.↗