SEARCH · Search NASA
Results for “Orbit Transfer”
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Efficient Computation of Optimal Low Thrust Perturbed Orbit Transfers
No abstract provided
Low-energy trajectories from geosynchronous transfer orbits to lunar libration orbits
No abstract provided
German telecommunications satellite (Deutscher fernmelde satellit) (DFS-1 and -2)
The German Telecommunications Satellite (DFS) Program is to provide telecommunications service for high data rate transmission of text and video data to the Federal Republic of Germany within the 11-14 GHz and 20-30 GHz bands. The space segment of this program is composed of three satellites, DFS-1, DFS-2, and DFS-3, which will be located at 23.5 degrees E longitude of the geostationary orbit. The DFS will be launched from the Center Spatial Guyanis in French Giana on an Ariane launch vehicle. The mission follows the typical injection sequence: parking orbit, transfer orbit, and earth orbit. Attitude maneuvers will be performed to orient the spacecraft prior to Apogee Kick Motor (AKM) firing. After AKM firing, drift phase orbital and attitude maneuvers will be performed to place the spacecraft in its final geostationary position. The Deep Space Network (DSN) will support the transfer and drift orbit mission phases. Information is presented in tabular form for the following areas: DSN support, compatibility testing, frequency assignments, telemetry, command, and tracking support responsibilities.
Orbital cargo transfer simulation
Orbital cargo transfer simulation techniques involving zero-g aircraft and water immersion
Practical aspects of transfer from GTO to lunar orbit
This paper is a presentation of some practical aspects of orbital transfer from Geosynchronous Transfer Orbit (GTO) to close, near-circular orbits of the Moon. The intent is to identify the important parameters affecting the problem and to bound (approximately) the range of required delta V for a spacecraft that has been placed in GTO. The basic geometric relationships are described and the dynamics are simulated by use of the Zero-Sphere-of Influence Patched Conic method. It is found that the inclination of the transfer orbit to the Earth-Moon plane is relatively unimportant while the position of the line of apsides with respect to the Moon's orbit is the main geometric parameter of interest. It is shown that this parameter can be controlled by selecting the time of day for launch and that two launch windows of approximately 45 minutes duration are available each day of the year if use is made of the recommended phasing orbit transfer. The phasing orbit transfer not only provides twice-daily launch windows, but also provides a mechanism for efficacious correction of GTO injection errors. Delta V penalties for out-of-plane transfer and for late launch are evaluated and the method is recommended for use as an affordable means of achieving lunar orbit.
Three-impulse transfer from lunar orbits.
Three-impulse orbital transfer from lunar orbits and earth reentry trajectory applications
Three-impulse transfer from lunar orbits.
Three-impulse orbital transfer from lunar orbits and earth reentry trajectory applications
Satellite Power Systems (SPS) concept definition study. Volume 5: Special emphasis studies
Satellite configurations based on the Satellite Power System baseline requirements were analyzed and a preferred concept selected. A satellite construction base was defined, precursor operations incident to establishment of orbital support facilities identified, and the satellite construction sequence and procedures developed. Rectenna construction requirement were also addressed. Mass flow to orbit requirements were revised and traffic models established based on construction of 60 instead of 120 satellites. Analyses were conducted to determine satellite control, resources, manufacturing, and propellant requirements. The impact of the laser beam used for space-to-Earth power transmission upon the intervening atmosphere was examined as well as the inverse effect. The significant space environments and their effects on spacecraft components were investigated to define the design and operational limits imposed by the environments on an orbit transfer vehicle. The results show that LEO altitude 300 nmi and transfer orbit duration 6 months are preferrable.
Launch vehicles for communications satellites
After giving brief development histories of the Delta and the Atlas Centaur launch vehicles, attention is given to the operational characteristics of the ascent, parking orbit, transfer orbit, and orbital insertion phases of the delivery of a communications satellite to a geostationary orbit by means of a Delta launch vehicle. NASA plans to employ Delta vehicles for as long as they are needed during the transition period to the Space Shuttle. NASA planning for Atlas Centaur includes launches through 1985 for INTELSAT-VA, and through 1986 for FLTSATCOM satellites.
Current systems: Upper stages
The United States orbital transfer vehicles are presented: PAM-D (Payload Assist Module); PAM-D2; IUS (Inertial Upper Stage); and TOS (Transfer Orbit Stage). This presentation is represented by viewgraphs.
Guidebook for analysis of tether applications
This guidebook is intended as a tool to facilitate initial analyses of proposed tether applications in space. Topics disscussed include: orbit and orbit transfer equations; orbital perturbations; aerodynamic drag; thermal balance; micrometeoroids; gravity gradient effects; tether control strategies; momentum transfer; orbit transfer by tethered release/rendezvous; impact hazards for tethers; electrodynamic tether principles; and electrodynamic libration control issues.
Quasilinearization program for determining optimum finite-thrust transfers between inclined orbits
Quasi-linearization program for boundary value problem of minimum fuel orbital transfer
The subscale orbital fluid transfer experiment
The Subscale Orbital Fluid Transfer Experiment (SOFTE) is a planned Shuttle Orbiter fluid transfer experiment. CASP (Center for Advanced Space Propulsion) performed certain aspects of the conceptual design of this experiment. The CASP work consisted of the conceptual design of the optical system, the search for alternative experimental fluids, the determination of the flow meter specifications and the examination of materials to use for a bladder that will empty one of the tanks in the experiment.
Manned Mars mission transfer from Mars parking orbit to Phobos or Deimos
This paper addresses the problem of orbit transfers from a Mars parking orbit with an inclination of 165 degrees to the Mars moons. The transfer can be accomplished using a three impulse transfer. The current 1999 baseline manned Mars mission requires a Mars parking orbit with an inclination of 165 degrees. This orbit inclination is necessary due to the direction of the Mars arrival and departure asymptotes of the interplanetary trajectory. The selection of this inclination for the parking orbit minimized the delta velocity requirements at Mars arrival and departure. This presents a problem In making transfers from this orbit to either Phobos or Deimos since it is a retrograde orbit. It is possible to make this transfer efficiently using a three impulse transfer and an intermediate transfer orbit with a very large apogee altitude. This paper will show how the intermediate transfer orbit apogee can be determined based on a preselected transfer time, the delta velocities required as a function of transfer time, and the propellant required as a function of mission module weight for a transfer time of 5 days. The data presented in this paper Is specifically for the 1999 opposition class mission but the methods outlined are applicable to any other mission which requires a high inclination parking orbit.
Optimal aeroassisted transfer between coplanar elliptical orbits
An attempt is made to solve the problem of orbital transfer between coplanar elliptical orbits. Pure propulsive transfer is analyzed with the restriction of two impulses for the transfer. The optimal switching conditions are reviewed, and it is shown that the solution is obtained by solving a set of three nonlinear equations for three unknowns. A semianalytical solution is obtained to the problem of planar rotation of an orbit for the pure propulsive maneuver, and it is shown that, for high eccentricity and rotation angle, aeroassisted transfer is a fuel-saving maneuver. It is demonstrated that complete circularization of the intermediate orbit is not necessary in the optimal aeroassisted transfer. An analytical proof is presented, giving an explicit condition for noncircularization. A complete numerical solution is presented for a case of optimal aeroassisted transfer from a low-energy orbit to a high-energy orbit.