Keyword: Attitude control

Briefs: Software
Observation Scheduling System

Software has been designed to schedule remote sensing with the Earth Observing One spacecraft. The software attempts to satisfy as many observation requests as possible considering each against spacecraft operation constraints such as data volume, thermal, pointing maneuvers, and others. More complex constraints...

Briefs: Manufacturing & Prototyping
Propulsion Design With Freeform Fabrication (PDFF)

The nation is challenged to decrease the cost and schedule to develop new space transportation propulsion systems for commercial, scientific, and military purposes. Better design criteria and manufacturing techniques for small thrusters are needed to meet current applications in missile defense,...

Briefs: Software
ISS Solar Array Management

The International Space Station (ISS) Solar Array Management (SAM) software toolset provides the capabilities necessary to operate a spacecraft with complex solar array constraints. It monitors spacecraft telemetry and provides interpretations of solar array constraint data in an intuitive manner. The toolset provides...

Briefs: Mechanical & Fluid Systems
Ultra-Large Solar Sail

UltraSail is a next- generation ultra-large (km2 class) sail system. Analysis of the launch, deployment, stabilization, and control of these sails shows that high-payload-mass fractions for interplanetary and deep-space missions are possible. UltraSail combines propulsion and control systems developed for...

Briefs: Mechanical & Fluid Systems
Attitude and Translation Control of a Solar Sail Vehicle

A report discusses the ability to control the attitude and translation degrees-of-freedom of a solar sail vehicle by changing its center of gravity. A movement of the spacecraft's center of mass causes solar- pressure force to apply a torque to the vehicle. At the compact core of the...

Books & Reports: Physical Sciences
Spin-Stabilized Microsatellites With Solar Concentrators

A document proposes the development of spin-stabilized microsatellites powered by solar photovoltaic cells aided by solar concentrators. Each such satellite would have a cylindrical or other axisymmetric main body with solar cells mounted in a circumferential beltlike array on its exterior...

Briefs: Information Technology
Estimating the Inertia Matrix of a Spacecraft

A paper presents a method of utilizing some flight data, aboard a spacecraft that includes reaction wheels for attitude control, to estimate the inertia matrix of the spacecraft. The required data are digitized samples of (1) the spacecraft attitude in an inertial reference frame as measured, for...

Briefs: Software
Solar Sail Spaceflight Simulation

The Solar Sail Spaceflight Simulation Software (S5) toolkit provides solar-sail designers with an integrated environment for designing optimal solar-sail trajectories, and then studying the attitude dynamics/ control, navigation, and trajectory control/ correction of sails during realistic mission simulations....

Briefs: Mechanical & Fluid Systems
Staggering Inflation To Stabilize Attitude of a Solar Sail

A document presents computational simulation studies of a concept for stabilizing the attitude of a spacecraft during deployment of such structures as a solar sail or other structures supported by inflatable booms. Specifically, the solar sail considered in this paper is a square sail...

Briefs: Mechanical & Fluid Systems
Spacecraft Escape Capsule

A report discusses the Gumdrop capsule — a conceptual spacecraft that would enable the crew to escape safely in the event of a major equipment failure at any time from launch through atmospheric re-entry. The scaleable Gumdrop capsule would comprise a command module (CM), a service module (SM), and a crew escape...

Briefs: Mechanical & Fluid Systems

Biomorphic flyers have recently been demonstrated that utilize the approach described earlier in "Bio-Inspired Engineering of Exploration Systems" (NPO-21142), NASA Tech Briefs ,Vol.27, No.5 (May 2003), page...

Briefs: Photonics/Optics

Linear arrays of thermopile infrared detectors made of high-performance thermoelectric materials have been fabricated on silicon substrates by micromachining processes. Such...

Briefs: Software
Software Models Spacecraft Dynamics and Space Environment

The Spacecraft Control Toolbox (SCT) helps design control systems and attitude estimators, analyze station-keeping requirements, generate fuel and pointing budgets, and analyze spacecraft dynamics. The SCT provides a comprehensive set of over five hundred functions including:

Briefs: Physical Sciences
Using Rayleigh Scattering To Measure Spacecraft Attitude

Two reports describe a Rayleigh-scattering attitude sensor (RSAS) - an optoelectronic instrument for determining the orientation of a spacecraft. An RSAS comprises a telescope/video-camera/image-digitizer combination that is mounted on the spacecraft and that captures images of the limb of...

Briefs: Information Technology
Development of Flight Software for Small Explorer Spacecraft

A report describes a continuing program of development of flight software for the attitude-control system (ACS) and the command-and-data-handling (C&DH) system of a prototype standard spacecraft of the Small Explorer (SMEX)-Lite class. Both the C&DH and ACS parts of the...

Briefs: Mechanical & Fluid Systems
Model-Based Monitoring for Spacecraft Thruster Leakage

A report describes a method of detecting leakage in one of the 16 thrusters of the Cassini spacecraft. The detection method, implemented as part of the spacecraft flight software, is based on the fact that the three-axis rotational motion of a spacecraft is governed by the Euler's equation....

Briefs: Software
Program for Conceptual Design of an Attitude-Control System

A report describes the ACS Design Tool - a Macintosh- and PC-based computer program for evaluating conceptual designs of a spacecraft attitude-control system (ACS) within a computation time of about 15 minutes. Services provided by the program include computation of ACS performance and...

Briefs: Mechanical & Fluid Systems

The Spacecraft Autonomous Navigation System using GPS for Earth Orbiters (SANS-GEO) computer program is designed to perform the navigation calculations that will enable the New...

Briefs: Electronics & Computers
Estimating Attitude From GPS Measurements on One Antenna

A technique for estimating the boresight direction of a Global Positioning System (GPS) receiver antenna involves utilization of the relationship between the strengths of received signals and the direction-dependent antenna gain pattern. The technique is fundamentally different from, and...