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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 109 records · Page 6
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NASA NTRS1961

Velocity Requirements for Abort From the Boost Trajectory of a Manned Lunar Mission

An investigation is made of the abort velocity requirements associated with failure of a propulsion system for a manned lunar mission. Two cases are considered: abort at less than satellite speed, which results in maximum decelerations in the following entry, and abort at greater than satellite speed with immediate return to earth. The velocity requirements associated with the latter problem are found to be substantial (several thousand feet per second) and are found to be even more severe if boost trajectories which lead to burnout at high altitudes or large flight-path angles are used. The velocity requirements associated with abort at less than satellite speed are found to be less severe than those for abort at greater than satellite speed except for nonlifting vehicles. It is found that abort rockets sufficient for abort at greater than satellite speed can be used to reduce maximum decelerations in entries following an abort at lower speeds. This reduction is accomplished by use of the abort rockets to decrease entry angle immediately prior to entry into the atmosphere.

Slye, Robert E.↗
NASA NTRSDate not supplied

Dust Mitigation Technology Development for Future Lunar Missions with the Dust Solution Testing Initiative (DuSTI) Project

The jagged, hard, and electro-statically-charged dust on the lunar surface is one of the most significant hazards to human exploration of the Moon. The safety of the crew members and sustainability of habitats, science, and supporting hardware depend on effective dust mitigation techniques and technologies. As NASA pursues a new generation of lunar missions with the Artemis program, the Dust Solution Testing Initiative (DuSTI) project is pursuing dust mitigation solutions by performing tests on promising commercial off the shelf (COTS) technologies over FY21.

dust↗
NASA NTRS1972

Apollo guidance, navigation and control: Guidance system operations plan for manned CM earth orbital and lunar missions using Program COLOSSUS 3. Section 3: Digital autopilots (revision 14)

Digital autopilots for the manned command module earth orbital and lunar missions using program COLOSSUS 3 are discussed. Subjects presented are: (1) reaction control system digital autopilot, (2) thrust vector control autopilot, (3) entry autopilot and mission control programs, (4) takeover of Saturn steering, and (5) coasting flight attitude maneuver routine.

Source record↗
NASA NTRSDate not supplied

Artemis Lunar Mission Availability & Design

The National Aeronautics and Space Administration’s (NASA) Artemis Program is leading international spaceexploration in a return to human lunar missions. The mission design underpinning this program is a critical aspect inthe integration of the multiple vehicles, processes, and capabilities to execute the most demanding human spaceflightmissions to date. Frequently mission design is characterized solely by its trajectory and the associated delta-velocityto achieve the end-to-end mission on a single day of flight. However, in practical terms for spaceflight missions,actual performance must characterize the translation delta-velocity demand, integrated power and thermal, crew dayoperations, commodities limitations, launch vehicle opportunities, and numerous additional factors across numerouslaunch day dependent variables. These factors together provide a unified set of mission design constraints that mustall be met in order to execute a fully integrated mission. The frequency of achieving all of the mission designconstraints is thus characterized as mission availability. The mission availability reflects the number of opportunitiesin any given period (month, year, etc.) for which an end-to-end mission could be launched. Ensuring adequatemission availability for the Artemis Program is necessary to support long term viability and sustainability of humanlunar exploration. This paper will characterize the driving factors in the Artemis mission availability includingvehicle specific effects from the Space Launch System (SLS), Orion Multi-Purpose Crew Vehicle, Gateway, HumanLanding System (HLS) and other contributing projects. This analysis will also summarize the relevant factors thatfuture vehicles and projects should consider for the integration and expansion of exploration capabilities with theArtemis Program.

Nujoud Fahoum Merancy↗
NASA NTRSDate not supplied

Ka-Band GaN-on-SiC MMIC Balanced High Power Amplifier for NASA's Lunar Missions

The feasibility of Ka-band GaN-on-SiC MMIC based balanced high power amplifier (HPA) for science data downlinks from NASA’s Lunar mission assets in space is investigated. The HPA combines the RF output power from two PAs using a rectangular waveguide based 3-dB hybrid coupler. The investigation includes characterizing the HPA for the overall RF output power, Gain, PAE, RMS EVM for offset-QPSK, 8PSK, 16APSK, and 32APSK waveforms, Spectrum, 3rd order IMD products, noise figure, phase noise, & group delay. The HPA has high Pout and good linearity and can support high data rate downlinks from the surface and vicinity of the Moon to Earth.

Rainee.N. Simons↗
NASA NTRS1971

Guidance system operations plan for manned cm earth orbital and lunar missions using program Colossus 3. Section 2: Data links

The data links for use with the guidance system operations plan for manned command module earth orbital and lunar missions using program Colossus 3 are presented. The subjects discussed are: (1) digital uplink to CMC, (2) command module contiguous block update, (3) CMC retrofire external data update, (4) CMC digital downlink, and (5) CMC entry update.

Hamilton, M. H.↗
NASA NTRS1961

Point Return from a Lunar Mission for a Vehicle that Maneuvers Within the Earth's Atmosphere

An investigation has been made of point return of a vehicle with a lift-to-drag ratio of 1/2, returning from a lunar mission. It was found that the available longitudinal and lateral range allowed considerable tolerances in entry conditions for a point return. Longitudinal range capability for a vehicle that was allowed to skip to an altitude not exceeding 400 miles was about 3-1/2 times greater than the range capability of a vehicle that was restricted to remain in the atmosphere after entry. Longitudinal range is very sensitive to changes in both velocity and flight-path angle at the bottom of the first pull-out and at exit. An investigation showed that after a skip a vehicle could be placed in a circular orbit for a relatively modest weight penalty. A skip maneuver was found to have no effect on lateral range when the roll was initiated at a velocity near satellite speed after the vehicle had re-entered the atmosphere. However, when the roll was initiated at the earliest possible time along the undershoot boundary, lateral range was increased by a factor of about 2-1/2. The tolerable errors in time of arrival and in inclination of the orbital plane at point of entry were greater for the skip trajectory than for the no-skip trajectory.

Sommer, Simon C.↗
NASA NTRS1991

A review of candidate multilayer insulation systems for potential use on wet-launched LH2 tankage for the Space Exploration Initiative lunar missions

The storage of cryogenic propellants such as liquid hydrogen (LH2) and liquid oxygen (LO2) for the future Space Exploration Initiative (SEI) will require lightweight, high performance thermal protection systems (TPSs). For the near-term lunar missions, the major weight element for most of the TPSs will be multilayer insulation (MLI) and/or the special structures/systems required to accommodate the MLI. Methods of applying MLI to LH2 tankage to avoid condensation or freezing of condensible gases such as nitrogen or oxygen while in the atmosphere are discussed. Because relatively thick layers of MLI will be required for storage times of a month or more, the transient performance from ground-hold to space-hold of the systems will become important in optimizing the TPSs for many of the missions. The ground-hold performance of several candidate systems are given as well as a qualitative assessment of the transient performance effects.

Knoll, Richard H.↗
NASA NTRS1991

A review of candidate multilayer insulation systems for potential use on wet-launched LH2 tankage for the space exploration initiative lunar missions

The storage of cryogenic propellants such as liquid hydrogen (LH2) and liquid oxygen (LO2) for the future Space Exploration Initiative (SEI) will require lightweight, high performance thermal protection systems (TPS's). For the near-term lunar missions, the major weight element for most of the TPS's will be multilayer insulation (MLI) and/or the special structures/systems required to accommodate the MLI. Methods of applying MLI to LH2 tankage to avoid condensation or freezing of condensible gases such as nitrogen or oxygen while in the atmosphere are discussed. Because relatively thick layers of MLI will be required for storage times of a month or more, the transient performance from ground-hold to space-hold of the systems will become important in optimizing the TPS's for many of the missions. The ground-hold performance of several candidate systems are given as well as a qualitative assessment of the transient performance effects.

Knoll, Richard H.↗
NASA NTRS2006

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.↗
NASA NTRS1991

Lunar mission design using Nuclear Thermal Rockets

The NERVA-class Nuclear Thermal Rocket (NTR), with performance nearly double that of advanced chemical engines, has long been considered an enabling technology for human missions to Mars. NTR engines address the demanding trip time and payload delivery needs of both cargo-only and piloted flights. But NTR can also reduce the Earth launch requirements for manned lunar missions. First use of NTR for the Moon would be less demanding and would provide a test-bed for early operations experience with this powerful technology. Study of application and design options indicates that NTR propulsion can be integrated with the Space Exploration Initiative scenarios to deliver performance gains while managing controlled, long-term disposal of spent reactors to highly stable orbits.

Stancati, Michael L.↗
NASA NTRS1972

On obtaining lunar mission launch opportunities

A general procedure for predicting launch opportunities for the RAE-B lunar orbiter mission is presented. It is shown that knowledge of the earth-moon distance and lunar phase and declination are sufficient to determine launch periods consistent with present mission constraints and to approximately predict launch, transfer, and arrival parameters such as park orbit coast time, the possiblity of shadows in all phases of the mission, arrival energy, and the amount of sunlit orbit time in the lunar orbit. Constraints on RAE-B include bounds on the spin axis-sun angle in the translunar trajectory, an upper limit on the arrival energy, and a minimum time for sunlight duration in lunar orbits are being considered for the mission. Comparisons are made of relevant parameters for the two cases. The general features of launch, transfer, and arrival parameters are discussed and are shown to be a function of lunar declination, flight time, and launch azimuth.

Swartwood, H., Jr.↗