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Results for “ORBITAL RENDEZVOUS”

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 55 records · Page 3

Trajectory Design Considerations for Lunar Surface to Near Rectilinear Halo Orbit Rendezvous

NASA’s Artemis program plans to use a 9:2 resonant southward Near-Rectilinear Halo Orbit (NRHO) at the Earth-Moon’s L2 libration point to stage assets for a sustained lunar exploration campaign. This architecture includes the use of the Gateway space station positioned in this orbit. While the proximity operations in the NRHO are similar to field-free space dynamics, the far-field rendezvous aspect of the problem is more complicated. We analyze the key drivers of the ΔV performance of the far-field rendezvous problem from low lunar orbit to the Gateway. We find that lunar latitudinal libration is a driving factor to ΔV performance for surface ascent missions that rendezvous with the NRHO, and that transfer time from low lunar orbit to NRHO affects more aspects of the geometry and performance than expected from rendezvous in Keplerian orbits.

NRHO↗

Mars Sample Return: Launch and Detection Strategies for Orbital Rendezvous

This study sets forth conceptual mission design strategies for the ascent and rendezvous phase of the proposed NASA/ESA joint Mars Sample Return Campaign. The current notional mission architecture calls for the launch of an acquisition/ caching rover in 2018, an Earth return orbiter in 2022, and a fetch rover with ascent vehicle in 2024. Strategies are presented to launch the sample into a nearly coplanar orbit with the Orbiter which would facilitate robust optical detection, orbit determination, and rendezvous. Repeating ground track orbits existat 457 and 572 km which would provide multiple launch opportunities with similar geometries for detection and rendezvous.

transfer scenario↗

Low Earth Orbit Rendezvous Strategy for Lunar Missions

On January 14, 2004 President George W. Bush announced a new Vision for Space Exploration calling for NASA to return humans to the moon. In 2005 NASA decided to use a Low Earth Orbit (LEO) rendezvous strategy for the lunar missions. A Discrete Event Simulation (DES) based model of this strategy was constructed. Results of the model were then used for subsequent analysis to explore the ramifications of the LEO rendezvous strategy.

Cates, Grant R.↗

Optimal orbital rendezvous using high and low thrust

Optimal control theory is used to examine a specific class of spacecraft trajectory problems where high- and low-thrust propulsion systems are utilized. These problems assume a spacecraft is in an established orbit about a planet. It is desired to execute an intercept of a pre-determined position in space in a specified amount of time using an optimal high-thrust program. The spacecraft then returns to the original orbit station using the low-thrust propulsion system in an optimal fashion. A minimum fuel solution is sought using the linearized equations of motion, known as the CW equations, which simplify the necessary computations. Solutions are obtained for problems with a fixed final time. However, for the time-open case, the optimal solution is for the final time to be infinite. With a weighted function of the final time in the performance index, a limited range of optimal single impulse solutions for the time -open case can also be found.

Prussing, John E.↗

Apollo-Lunar Orbital Rendezvous Technique

The film shows artists rendition of the spacecrafts, boosters, and flight of the Apollo lunar missions. The Apollo spacecraft will consist of three modules: the manned Command Module; the Service Module, which contains propulsion systems; and the Lunar Excursion Module (LEM) to carry astronauts to the moon and back to the Command and Service Modules. The spacecraft will be launched via a three-stage Saturn booster. The first stage will provide 7.5 million pounds of thrust from five F-1 engines for liftoff and initial powered flight. The second stage will develop 1 million pounds of thrust from five J-2 engines to boost the spacecraft almost into Earth orbit. Immediately after ignition of the second stage, the Launch Escape System will be jettisoned. A single J-2 engine in the S4B stage will provide 200,000 pounds of thrust to place the spacecraft in an earth parking orbit. It also will be used to propel the spacecraft into a translunar trajectory, then it will separate from the Apollo Modules. Onboard propulsion systems will be used to insert the spacecraft into lunar orbit. Two astronauts will enter the LEM, which will separate from the command and service modules. The LEM will go into elliptical orbit and prepare for landing. The LEM will lift off of the Moon's surface to return to the Command and Service Modules, and most likely be left in lunar orbit. After leaving the Moon's orbit, and shortly before entering Earth's orbit, the Service Module will be ejected. The Command Module will be oriented for reentry into the Earth's atmosphere. A drogue parachute will deploy at approximately 50,000 feet, followed by the main parachute system for touchdown.

Source record↗

Earth orbit rendezvous evaluation program

Study program written in FORTRAN 4 developes an oribital rendezvous guidance scheme for large, constant thrust launch vehicles. It concentrates on /1/ an investigation of the direct extension of the present Saturn Iterative Guidance Mode /IGM/ scheme and /2/ a scheme formulated in a reference frame moving with the target satellite.

Bennett, A. G.↗

Automated orbital rendezvous considerations

The control of the rendezvous vehicle during proximity operations is considered. It is shown how fuzzy sets can be used for autonomous vehicle control to model the human capability of common sense reasoning. Such models are integrated with expert systems and engineering control systems technology to create a system that performs comparably to a manned system.

Lea, Robert N.↗

Co-apsidal autonomous terminal rendezvous in Mars orbit

The autonomous (or unmanned) Mars Orbit Rendezvous may be divided into four phases: approach, terminal, station-keeping, and docking. The paper outlines a feasible concept for the terminal rendezvous phase. A co-apsidal terminal rendezvous technique is described which utilizes the advantages of aligning the lines of apsides of two coplanar elliptic orbits of slightly different periods but of the same apoapsis distance. An initial maneuver nulling the inclination between the orbits is followed by another maneuver to align the two lines of apsides. A proper phasing maneuver is then executed at the coapsidal point, and the final rendezvous maneuver is performed at the same coapsidal point to complete the terminal rendezvous transfer. Cases are formulated in order of complexity with a view to illustrate the basic ideas of this technique. Pertinent calculations are also presented.

Tang, C. C. H.↗

Space Shuttle Orbiter onboard rendezvous navigation

Much of the work that the Space Shuttle will perform requires a capability to rendezvous with other orbiting objects. The formulation and design philosophy behind the Space Shuttle Orbiter rendezvous navigation system are the subjects of this paper. The current rendezvous navigation design incorporates a Kalman filter to estimate the relative position and velocity. The filter is augmented with state elements for the estimation of colored measurement noise and acceleration modeling errors. Several measurement types are available to the filter: a manual optical sighting device, an automatic optical tracking instrument, and a rendezvous radar which provides range and range rate measurements as well as the line of sight direction. The filter also includes a technique for detecting highly improbable measurements and excluding them from Kalman processing.

Little, M. J.↗