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Results for “RENDEZVOUS TRAJECTORY”

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 145 records · Page 8
All sourcesNASA NTRSDOE OSTI
NASA NTRS1981

A mission to rendezvous with Anteros

A modest mission to rendezvous with the earth-approaching asteroid, Anteros, is studied. A 10-day launch window of May 16 to 25, 1985 is suggested. The times of flight range from 402 to 455 days and the launch energies per unit mass range from 32.9 to 37.3 km/sq sec. Rendezvous can be achieved with a postlaunch change in velocity of from 562 to 1001 m/sec. A mass of at least 615 kg can be delivered into orbit about the asteroid by the Titan 34D/IUS Two-Stage with 50 to 100 kg available for scientific instrumentation. The 1985 opportunity is compared to the 1987 trajectory identified by Niehoff (1977). Rendezvous opportunities are examined in the space of launch and arrival true anomalies.

Hulkower, N. D.↗
NASA NTRS1992

Mission options for rendezvous with the most accessible Near-Earth Asteroid - 1989 ML

The recent discovery of the Amor-class 1989 ML, the most accessible known asteroid for minimum-energy rendezvous missions, has expedited the search for frequent, low-cost Near-Earth Asteroid rendezvous and round-trip missions. This paper identifies trajectory characteristics and assesses mass performance for low Delta V ballistic rendezvous opportunities to 1989 ML during the period 1996-2010. This asteroid also offers occasional unique extended mission opportunities, such as the lowest known Delta V requirement for any asteroid sample return mission as well as pre-rendezvous asteroid flyby and post-rendezvous comet flyby opportunities requiring less than 5.25 km/sec total Delta V. This paper also briefly comments concerning mission opportunities for asteroid 1991 JW, which recently replaced other known asteroids as the most accessible Near-Earth Asteroid for fast rendezvous and round-trip missions.

Mcadams, Jim V.↗
NASA NTRS1991

The real-time operations of the Space Shuttle Orbiter during rendezvous and proximity operations

The Space Shuttle Orbiter is the only U.S. spacecraft in operation today that routinely performs an orbital rendezvous with another spacecraft. The trajectory planning and training of both flight crews and ground operations personnel required to achieve a 100 percent success rate is considerable. The preflight planning and training can be reduced through very simple design considerations of a new space vehicle.

Dougherty, Andrew↗
NASA NTRS2004

Analyses of the P/Wild 2 Images from STARDUST

This viewgraph presentation reviews the design of the Stardust spacecraft, and the trajectory that took it to rendezvous with the comet, Wild-2. Included are views of the comet, and comparisons with other astronomical bodies. Close up views show size, shape and orientation.

Wild 2 images↗
NASA NTRS1973

Viking type spacecraft rendezvous with the Martian moons.

The feasibility of a postlanding orbiter rendezvous with one or both of the Martian moons during a 1977 or 1979 follow-on Viking mission is investigated. Rendezvous is considered for two Viking trajectory options: landing from orbit and direct entry. Mission feasibility is demonstrated for launch by the Earth-to-orbit shuttle and by the Titan/Centaur booster. Required changes to the 1975 Viking hardware are outlined. Integrating the rendezvous into the ongoing Viking mission is shown to be a cost-effective approach.

Taylor, J. J.↗
NASA NTRSDate not supplied

Spacecraft Passive Safety Assessment Using Ellipse Constraints and Relative Orbital Elements

This paper presents necessary and sufficient conditions for validating spacecraft passive safety using relative orbital elements (ROE) centered around the far-field to near-field trajectory design of a hypothetical autonomous rendezvous and docking (AR&D) mission. The specific formulation of the ROEs used in this study are of quasi-nonsingular form based on elative eccentricity/inclination vectors. Current methodologies for ensuring passive safety apply keep-out volumes (KOV) to maintain appropriate separation between the Servicer and Client. Widely used techniques to assess the integrity of the KOV involve forward propagation of the relative Cartesian state to check for a potential KOV breach. In this study, an alternative approach to the propagation-based method is proposed using ROEs due to their valuable geometric insights of spacecraft relative motion. Modeling the relative trajectory and KOV ellipsoids as ellipses into the 2-D ROE sub-space simplifies the passive safety validation to a root-finding problem within the unit disk with high computational efficiency. Other approaches to intersection detection of the KOV are also evaluated in accuracy and run-time. Furthermore, a Monte Carlo simulation was employed to compare the ROE-based and relative Cartesian approaches in terms of maneuver error.

Bruce Barbour↗
NASA NTRS1962

Rendezvous Guidance Technology

The literature on rendezvous guidance technology is reviewed and a bibliography of about 160 documents is presented. The importance of the proper selection of the ascent trajectory and of the orbit for a manned space station or an orbiting launch complex is emphasized. The way the launch delay problem affects the selection of the ascent trajectory and the target orbit is discussed. A specific ascent trajectory and an orbit for a manned space station or an orbiting launch complex is recommended on the premise that launch delay problems will continue to outweigh most of the other orbit selection criteria. A new method for determining the velocity corrections required for mid-course guidance is proposed . The proposed methods consist of an "exact-numerical" solution of the relative equations of motion in the "Shell-coordinate system." The proposed "exact-numerical" method extends the applicability of the mid- course equations to a much greater range than that of the currently available linear methods .

Trajectory↗
NASA NTRS1983

Designing for a new era of launch vehicle operational efficiency

It is pointed out that early recognition of operational requirements and assessment of their effects provides the best chance of designing an economically viable future space transportation system (FSTS). Operational factors which may influence configuration design include fleet size, operation mode, refurbishment, and the resource requirements. FTST has a simplified operational role compared to the Space Shuttle, which, in addition to transportation, must perform experiments, support payloads, and stay long on orbit. In the future a space station will perform many of these tasks. The FSTS comprises a two-stage fully reusable launch vehicle designed to carry 150,000 lb to a space station, off-load, and return. It would always be launched fully loaded, and its cargo would be processed and redistributed at the space station. Attention is given to ground servicing, flight operations, rendezvous-compatible orbits, launch windows, standard trajectories, entry windows, operational costs, the mission model, and resource requirements.

Talay, T. A.↗
NASA NTRS1988

A software engineering approach to expert system design and verification

Software engineering design and verification methods for developing expert systems are not yet well defined. Integration of expert system technology into software production environments will require effective software engineering methodologies to support the entire life cycle of expert systems. The software engineering methods used to design and verify an expert system, RENEX, is discussed. RENEX demonstrates autonomous rendezvous and proximity operations, including replanning trajectory events and subsystem fault detection, onboard a space vehicle during flight. The RENEX designers utilized a number of software engineering methodologies to deal with the complex problems inherent in this system. An overview is presented of the methods utilized. Details of the verification process receive special emphasis. The benefits and weaknesses of the methods for supporting the development life cycle of expert systems are evaluated, and recommendations are made based on the overall experiences with the methods.

Bochsler, Daniel C.↗
NASA NTRS2012

Trajectory Options for a Potential Mars Mission Combining Orbiting Science, Relay and a Sample Return Rendezvous Demonstration

Mars sample return is a major scientific goal of the 2011 US National Research Council Decadal Survey for Planetary Science. Toward achievement of this goal, recent architecture studies have focused on several mission concept options for the 2018/2020 Mars launch opportunities. Mars orbiters play multiple roles in these architectures such as: relay, landing site identification/selection/certification, collection of on-going or new measurements to fill knowledge gaps, and in-orbit collection and transportation of samples from Mars to Earth. This paper reviews orbiter concepts that combine these roles and describes a novel family of relay orbits optimized for surface operations support. Additionally, these roles provide an intersection of objectives for long term NASA science, human exploration, technology development and international collaboration.

surface operations↗
NASA NTRS1983

Missions to the asteroid Anteros and the space of true anomalies

Three opportunities for missions to rendezvous ballistically with the earth-crossing asteroid Anteros are studied to illustrate the requirements for a trip to a near-earth minor planet. The rationale, sample payload, spacecraft requirements and trajectory characteristics of these opportunities are typical of a rendezvous mission to an accessible near-earth object. Round trip ballistic trajectories to return small samples of the asteroid with launch dates between 1985 and 2000 are also presented. Contours of minimum total delta drawn in the space of launch and arrival true anomalies, given the designation Prime Rib curves, are introduced as a useful tool for mission design.

Hulkower, N. D.↗
NASA NTRS1992

Trajectory design and navigation analysis for Cargo Transfer Vehicle proximity operations

The paper documents an investigation of alternative (or off-nominal) final approach trajectories and terminal guidance algorithms for Cargo Transfer Vehicle (CTV) automated rendezvous and proximity operation in the vicinity of Space Station Freedom (SSF). Ten candidate trajectory designs, representing a survey of all approaches that reasonably satisfy the mission constraints, are compared qualitatively and quantitatively. It is shown that several fundamentally different types of approach strategies are feasible in the CTV application and enjoy more favorable passive collision avoidance and plume impingement properties than the nominal. They are, however, generally more costly in propellant. The extent to which an alternative approach is more costly is determined largely by the abort (or specifically the 'hold' or 'wave-off') requirements. These approach techniques are verified in a software simulation using a parametrically defined candidate navigation system, and proximity sensor accuracy requirements are derived.

Marsh, S. M.↗
NASA NTRS1984

Ballistic comet exploration mission options

Trajectory options and mission opportunities of cometary rendezvous missions begining in 1990 are explored. The study is constrained to the capabilities of the Mariner Mark II multi-mission spacecraft, Shuttle launch and Centaur G-prime boost. The mission would be targeted at collecting an atomized sample, near the comet perihelion, and returning the sample for analysis. Mission trajectories, launch dates, payload masses and flight durations are provided for 13 comets. All missions would take from 4-8 yr and deliver a 600-2000 kg payload. A survey of mission opportunities involving Jupiter gravity assists is also presented.

Yen, C.-W. L.↗
NASA NTRS2019

Early Navigation Performance of the OSIRIS-REx Approach to Bennu

The New Frontiers-class OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer) mission is the first American endeavor to return a sample from an asteroid. In preparation for retrieving the sample, OSIRIS-REx is conducting a campaign of challenging proximity-operations maneuvers and scientific observations, bringing the spacecraft closer and closer to the surface of near-Earth asteroid (101955) Bennu. Ultimately, the spacecraft will enter a 900-meter-radius orbit about Bennu and conduct a series of reconnaissance flybys of candidate sample sites before being guided into contact with the surface for the Touch and Go sample collection event. Between August and December 2018, the OSIRIS-REx team acquired the first optical observations of Bennu and used them for navigation. We conducted a series of maneuvers with the main engine, Trajectory Correction Maneuver, and Attitude Control System thruster sets to slow the OSIRIS-REx approach to Bennu and achieve rendezvous on December 3, 2018. This paper describes the trajectory design, navigation conops, and key navigation results from the Approach phase of the OSIRIS-REx mission.

Antreasian, Peter G.↗
NASA NTRS1973

Antenna and propagation studies for spacecraft systems: Addendum to preflight SL-1/SL-3 Skylab VHF ranging coverage (early and late TPI)

A preflight assessment is presented of the expected Skylab VHF ranging coverage for the rendezvous portion of the SL-1/SL-3 mission, assuming a 28 July 1973 launch date, for the alternative trajectory cases characterized by either an early TPI or a late TPI. In this assessment early TPI and late TPI are used to indicate a TPI maneuver occurring 10 minutes prior to or after the nominally scheduled TPI maneuver, respectively. The Saturn workshop (SWS) maintains a solar inertial (SI) attitude throughout rendezvous for both trajectory cases. The results summarized concern VHF ranging function performance during that period most likely to be affected by off-nominal TPI conditions, i.e., NSR (5:56 g.e.t.) to station keeping. Curves are presented which show the variation in received power levels on both spacecraft-to-spacecraft links from about 100 n.mi. range to CSM and SWS station keeping. Appropriate threshold levels are shown on these received power curves to indicate zero circuit margins for the ranging function.

Eisenhauer, D. R.↗