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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 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2017

Results of the Apogee-Raising Campaign of the Magnetospheric Multiscale Mission

This paper describes the apogee-raising campaign of the Magnetospheric Multiscale mission, where the spacecraft increased their apogee radii from 12 to 25 Earth radii in a total of 98 maneuvers. These maneuvers included an initial formation resize set to spread the spacecraft apart for safety, 32 apogee-raise delta-v maneuvers, their associated slews, four perigee-raise maneuvers and the associated slews, and finally a set of maneuvers to get back into formation. These activities were all accomplished successfully and on schedule with no anomalies, and at a fuel consumption somewhat less than predicted. As a result, MMS was set up ready to carry out in situ studies of magnetic reconnection in the magnetotail, with sufficient fuel remaining for a significant extended mission.

Mission Design↗
NASA NTRS1974

Apogee motor rocketry reliability improvements

Since 1963, solid-propellant apogee motors have been placing satellites into geosynchronous orbits. Major technological breakthroughs are not required to satisfy future mission requirements; however, there is a need to improve reliability to enhance cost effectiveness. A summary of results and conclusions derived from a review of missions, where failure of a solid motor was inferred, and from a correlation of system factors with failures are reported. Highlights of a solid motor diagnostic instrumentation study are presented. Finally, recommendations are provided for areas of future apogee motor upgrade, which will increase project cost effectiveness by reducing the potential for future flight failures.

Behm, J.↗
NASA NTRS1974

Apogee motor rocketry reliability improvements

Since 1963, solid propellant apogee motors have been placing satellites into geosynchronous orbits. Major technological breakthroughs are not required to satisfy future mission requirements; however, there is a need to improve reliability to enhance cost effectiveness. Several management test options are discussed. A summary of results and conclusions derived from review of missions, where failure of a solid motor was inferred, and correlation of system factors with failures are reported. Highlights of a solid motor diagnostic instrumentation study are presented. Finally, recommendations are provided for areas of future apogee motor upgrade, which will increase project cost effectiveness by reducing the potential for future flight failures.

Behm, J.↗
NASA NTRS1973

Design assurance test of the Thiokol Te-M-521-5 apogee kick motor tested in the spin mode at simulated altitude conditions

One Thiokol Chemical Corporation TE-M-521-5 solid-propellant apogee rocket motor was successfully fired at an average simulated altitude of about 108,000 ft while spinning at 46 rpm. The general program objectives were to verify compliance of motor performance with the manufacturer's specifications. Specific primary objectives were to determine vacuum ballistic performance of the motor after prefire vibration conditioning and temperature conditioning at 40F, altitude ignition characteristics, motor structural integrity, and motor temperature-time history during and after motor operation. Additional objectives were to measure the lateral (nonaxial) thrust component during motor operation and to measure radiation heat flux in the vicinity of the nozzle exit plane.

Cimino, A. A.↗
NASA NTRS1977

Estimation of outgassing from an expended apogee motor and its effects on spacecraft surfaces

An experimental and theoretical investigation was carried out to evaluate the degradation of the solar cells and other sensitive surfaces of a spacecraft, resulting from the molecular outgassing of an expended solid propellant apogee motor. The motor, following its burnout, is retained by the spacecraft and is a source of gases and particulates which will be released mainly by the unburned propellant-to-casing insulation. The deployment of the solar array within a few minutes after the motor burn results in the interception and reflection to the surfaces of the spacecraft of the molecular outgassing and particulates. Various methods, based on some experimental data, were used to analytically assess the magnitude of the outgassing from the engine.

Scialdone, J. J.↗
NASA NTRS1993

Kalman filtering applied to real-time monitoring of apogee maneuvers

Part of the Space Mathematics Division in CNES, the Flight Dynamics Center provides attitude and orbit determinations and maneuvers during the Launch and Early Operation Phase (LEOP) of geostationary satellites. Orbit determination is based on a Kalman filter method; when the 2 GHz CNES/NASA network is used, Doppler measurements are available and allow orbit determination during the apogee maneuvers. This method was used for TELE-X and TDF 2 LEOP (3-axis controlled satellites) and also for TELECOM 2 and HISPASAT (spun satellites): it enables us to follow the evolution of the maneuver and gives out a quite accurate estimation of the reached orbit. In this paper, we briefly describe the dynamic models of the orbit evolution in both cases, '3-axis' and 'inertial' thrust. Then, we present the results obtained for each case. Afterwards, we present some cases to show the robustness of the filter.

Deboer, Frederic↗
NASA NTRS2017

Magnetospheric Multiscale Mission Navigation Performance During Apogee-Raising and Beyond

The primary objective of the Magnetospheric Multiscale (MMS) Mission is to study the magnetic reconnection phenomena in the Earths magnetosphere. The MMS mission consists of four identical spinning spacecraft with the science objectives requiring a tetrahedral formation in highly elliptical orbits. The MMS spacecraft are equipped with onboard orbit and time determination software, provided by a weak-signal Global Positioning System (GPS) Navigator receiver hosting the Goddard Enhanced Onboard Navigation System (GEONS). This paper presents the results of MMS navigation performance analysis during the Phase 2a apogee-raising campaign and Phase 2b science segment of the mission.

Farahmand, Mitra↗