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Niehoff, J. C.

Publications and source records attributed to Niehoff, J. C..

At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1986

Circulating transportation orbits between earth and Mars

This paper describes the basic characteristics of circulating (cyclical) orbit design as applied to round-trip transportation of crew and materials between earth and Mars in support of a sustained manned Mars Surface Base. The two main types of nonstopover circulating trajectories are the socalled VISIT orbits and the Up/Down Escalator orbits. Access to the large transportation facilities placed in these orbits is by way of taxi vehicles using hyperbolic rendezvous techniques during the successive encounters with earth and Mars. Specific examples of real trajectory data are presented in explanation of flight times, encounter frequency, hyperbolic velocities, closest approach distances, and Delta V maneuver requirements in both interplanetary and planetocentric space.

Friedlander, A. L.↗
NASA NTRS1980

Outer planet satellite return missions using in situ propellant production

In situ production of oxygen and oxygen with hydrogen for utilization as return propellant from the Galilean satellites has been investigated. Europa has emerged as the preferred landing sight because of the availability of water ice and its surface temperature. When oxygen is used with methane transported from earth, a Europa sample return mission requires 4000 kg less estimated earth launch mass than a vehicle using space storable propellant. Neither methane nor oxygen require active refrigeration at Europa. When oxygen and hydrogen are both utilized to form the primary sample return propellant, the required processor mass increases, but the estimated earth launch mass requirement is reduced by an additional 550 kg.

Ash, R. L.↗
NASA NTRS1980

Cost reduction in space operations - Structuring a planetary program to minimize the annual funding requirement as opposed to minimizing the program runout cost

An approach is proposed for the structuring of a planetary mission set wherein the peak annual funding is minimized to meet the annual budget restraint. One aspect of the approach is to have a transportation capability that can launch a mission in any planetary opportunity; such capability can be provided by solar electric propulsion. Another cost reduction technique is to structure a mission test in a time sequenced fashion that could utilize essentially the same spacecraft for the implementation of several missions. A third technique would be to fulfill a scientific objective in several sequential missions rather than attempt to accomplish all of the objectives with one mission. The application of the approach is illustrated by an example involving the Solar Orbiter Dual Probe mission.

Herman, D. H.↗
NASA NTRS1980

In Situ Propellant Production for improved sample return mission performance

In Situ Propellant Production (ISPP) on the surface of a target body is evaluated as a potential way to relax sample return mass constraints and to improve mission performance. Utilization of an oxygen/methane bipropellant combination for primary outbound and return propulsion has a significant favorable impact upon Earth escape requirements. A small sample can be returned from Mars using a single Shuttle/IUS(Twin) launch. Performance and design data are presented for the Mars mission. For sample returns from selected Galilean satellites, launch requirements are reduced by fifteen to forty percent. An assessment is made of overall utility of ISPP to planetary missions.

Stancati, M. L.↗
NASA NTRS1979

In situ propellant production - A new potential for round-trip spacecraft

In situ propellant production (ISPP) greatly reduces the Earth escape requirements for some roundtrip missions, particularly Mars Sample Return. ISPP systems are described which produce oxygen or oxygen and methane from available atmospheric and surface materials. With ISPP, a 1 kg sample can be returned direct from Mars using a single Shuttle launch. Mars entry can be either direct or from orbit. Comet and asteroid sample return is also accomplished within a single Shuttle launch. Launch requirements for round-trip missions to Ganymede and Callisto are reduced by 15 to 40%.

Stancati, M. L.↗
NASA NTRS1978

Asteroid mission alternatives

The options for asteroid missions are evaluated within the constraints of existing or planned launch vehicles and low-thrust propulsion systems. A wide variety of missions is possible, including flyby, rendezvous, and even sample return. The multi-asteroid rendezvous concept requires an ion drive low-thrust propulsion system of the type being developed for a comet rendezvous. It is indicated that there are plentiful opportunities for such missions to visit four asteroids with stay times of 60-90 days each and with transit times between rendezvous of the order of a year.

Niehoff, J. C.↗
NASA NTRS1977

Round-trip mission requirements for Asteroids 1976 AA and 1973 EC

The feasibility of manned or unmanned missions to two recently discovered asteroids is assessed. Characteristics of a likely target for a round-trip exploratory excursion include: a period close to one year; and an orbit that is nearly circular and nearly coplanar with the ecliptic. Mass requirements and optimal times of launch are investigated for unmanned and manned missions to Asteroids 1976 AA and 1973 EC (recently numbered 1943); 365-day round-trip trajectories in the first half of the 1990s are proposed. However, since neither of the two targets considered entirely fulfills all the necessary orbital characteristics, neither can offer the opportunity for a fast low-energy round-trip mission; nevertheless, other minor planets crossing earth's orbit may be found to meet the requirements.

Niehoff, J. C.↗
NASA NTRS1976

Penetrator mission concepts for exploration of the Galilean satellites

Penetrators are elongated missile-shaped objects designed to implant scientific instrumentation to depths of 1 to 15 meters in a wide variety of soil. A typical penetrator weighs 35 kg and impacts the surface at 150 m/sec oriented as close as possible to vertical. A spacecraft bus carries the penetrators to the target body, controls their deployment, and serves as a data communications relay. The analysis addresses the question of basic feasibility and covers such topics as trajectory requirements and delivered mass capability, deployment modes and penetrator retro sizing, impact site accessibility, guidance and control, and penetrator/bus communications. We conclude that such missions, while difficult in many respects, appear to be technically feasible in the context of Jovian system exploration in the post-1985 time period.

Friedlander, A. L.↗
NASA NTRS1974

Comparison of advanced propulsion capabilities for future planetary missions

This paper summarizes unmanned planetary performance (payload and trip time) of Shuttle-based advanced propulsion systems for 1980-90 missions analyzed as part of the recent NASA/AEC Advanced Propulsion Comparisons Studies. Propulsion system designs and condensed results from over 300 propulsion/mission combinations are discussed. Chemical rocket (CRP), solar electric (SEP), nuclear rocket (NRP), and nuclear electric (NEP) propulsion systems are all considered. In terms of missions flown, total flight time, and number of Shuttle launches required, NEP provides the best performance. Relative to NEP, it is shown that NRP, SEP, and CRP degrade mission performance by 20%, 40%, and 50%, respectively, at nominal payloads.

Niehoff, J. C.↗
NASA NTRS1974

Pioneer Mars 1979 mission options

Two mission concepts utilizing modified Pioneer Venus hardware are presented as relatively low-cost alternatives for scientific exploration of Mars in 1979. Mission A would perform in situ aeronomy measurements in the Martian ionosphere and include several remote sensing instruments capable of geological surface mapping at low altitudes. The initial high eccentricity orbit would be allowed to decay in an adaptive mode. Mission B would sequentially deploy (from an orbiter bus), four, nondestructing surface penetrometers carrying instrumentation to investigate soil density, composition and chemistry, subsurface water, and perhaps seismology. Mission B is more expensive than mission A, since it requires more extensive hardware modifications and systems development.

Niehoff, J. C.↗
NASA NTRS1974

Pioneer Mars 1979 mission options

A preliminary investigation of lower cost Mars missions which perform useful exploration objectives after the Viking/75 mission was conducted. As a study guideline, it was assumed that significant cost savings would be realized by utilizing Pioneer hardware currently being developed for a pair of 1978 Venus missions. This in turn led to the additional constraint of a 1979 launch with the Atlas/Centaur launch vehicle which has been designated for the Pioneer Venus missions. Two concepts, using an orbiter bus platform, were identified which have both good science potential and mission simplicity indicative of lower cost. These are: (1) an aeronomy/geology orbiter, and (2) a remote sensing orbiter with a number of deployable surface penetrometers.

Friedlander, A. L.↗
NASA NTRS1971

Jupiter orbiter missions

Jupiter orbiter missions, considering satellite emphasis and planetary environment and planetology missions

Niehoff, J. C.↗