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Technology for the Future: In-Space Technology Experiments Program, part 2

The purpose of the Office of Aeronautics and Space Technology (OAST) In-Space Technology Experiments Program In-STEP 1988 Workshop was to identify and prioritize technologies that are critical for future national space programs and require validation in the space environment, and review current NASA (In-Reach) and industry/ university (Out-Reach) experiments. A prioritized list of the critical technology needs was developed for the following eight disciplines: structures; environmental effects; power systems and thermal management; fluid management and propulsion systems; automation and robotics; sensors and information systems; in-space systems; and humans in space. This is part two of two parts and contains the critical technology presentations for the eight theme elements and a summary listing of critical space technology needs for each theme.

Breckenridge, Roger A.

Synerjet propulsion and the trimarket opportunity - Orbital, transglobal and lunar transportation services with one vehicle type

A proposed aerospace transporter for performing earth-to-orbit/return missions as well as transatmospheric and in-space high-energy missions is argued to be an effective and feasible alternative for development. The vehicles are based on the exploitation of 'synerjet' technologies that use airbreathing/rocket combined-cycle propulsion. The vehicle is shown to be capable of terrestrial-service intercontinental transglobal flight in an 'orbital cruise' mode as well as round trips from low orbits to high orbits and to the moon. The operational flexibility is linked to the development of synerjet propulsion, so directions are proposed for technology development and validation efforts. The development of the NASP X-30 by NASA is shown to be an important initial contribution to the R&D in this direction.

Escher, William J. D.

Large scale cryogenic fluid systems testing

NASA Lewis Research Center's Cryogenic Fluid Systems Branch (CFSB) within the Space Propulsion Technology Division (SPTD) has the ultimate goal of enabling the long term storage and in-space fueling/resupply operations for spacecraft and reusable vehicles in support of space exploration. Using analytical modeling, ground based testing, and on-orbit experimentation, the CFSB is studying three primary categories of fluid technology: storage, supply, and transfer. The CFSB is also investigating fluid handling, advanced instrumentation, and tank structures and materials. Ground based testing of large-scale systems is done using liquid hydrogen as a test fluid at the Cryogenic Propellant Tank Facility (K-site) at Lewis' Plum Brook Station in Sandusky, Ohio. A general overview of tests involving liquid transfer, thermal control, pressure control, and pressurization is given.

Source record

Impact of low gravity on water electrolysis operation

Advanced space missions will require oxygen and hydrogen utilities for several important operations including the following: (1) propulsion; (2) electrical power generation and storage; (3) environmental control and life support; (4) extravehicular activity; (5) in-space manufacturing and (6) in-space science activities. An experiment suited to a Space Shuttle standard middeck payload has been designed for the Static Feed Water Electrolysis technology which has been viewed as being capable of efficient, reliable oxygen and hydrogen generation with few subsystem components. The program included: end use design requirements, phenomena to be studied, Space Shuttle Orbiter experiment constraints, experiment design and data requirements, and test hardware requirements. The objectives are to obtain scientific and engineering data for future research and development and to focus on demonstrating and monitoring for safety of a standard middeck payload.

Powell, F. T.

OTV fluid mangement systems

Design, performance, and technology issues associated with reduced gravity propellant management for orbital transfer vehicles (OTV's) are reviewed. The in-space cryogenic management state-of-technology significantly affects the overall confidence level associated with a resupply mission and propulsion performance. Cryogen resupply sequences, timelines, controls, and associated crew involvement are all affected by the technology state. Additionally, OTV propellant tankage configurations, tankage thermodynamic conditions, acceleration environment, propulsion interfaces, and instrumentation are significant factors. Basic propellant transfer phases examined that drive orbital servicing requirements include: (1) tankage preconditioning; (2) tankage chilldown; and (3) propellant fill. Propellant management support of the OTV propulsion phases includes engine restart requirements and orbital coast between engine burns. Technology activities in support of identified technology issues are reviewed.

Hastings, L.

Status Report on Nuclear Stage Definition

This status report on nuclear stage definition should convey the message that a comprehensive analysis is underway, embracing many vehicle concepts and the full range of expected RNS operations. Flexible use in the future space program is one objective; economy and ease of operations are also major goals. Not until details unfold in the several mission areas and in definitions of interrelated systems can the RNS studies be narrowed down to fewer alternatives. Consequently, the current phase of the NSSD study is emphasizing (1) in-space operations, especially as they are affected by aftercooling and the radiation environment of the stage, and (2) RNS concepts in which the unique features of nuclear propulsion are utilized or designed around. Studies to date indicate that significant benefits can be realized through use of an RNS in the missions of the 1980's. Tn the broader context of technology advancement and foundation-building for later decades, the development of a reusable nuclear stage is highly desirable. The next year's efforts will, we trust, bring us much nearer to a full understanding of the RNS and its role in the future space program.

Johnson, Paul G.

In-space fabrication of thin-film structures

A conceptual study of physical vapor-deposition processes for in-space fabrication of thin-film structures is presented. Potential advantages of in-space fabrication are improved structural integrity and surface reflectivity of free-standing ultra-thin films and coatings. Free-standing thin-film structures can find use as photon propulsion devices (solar sails). Other applications of the concept involve free-standing shadow shields, or thermal control coatings of spacecraft surfaces. Use of expendables (such as booster and interstage structures) as source material for the physical vapor deposition process is considered. The practicability of producing thin, textured, aluminum films by physical vapor deposition and subsequent separation from a revolving substrate is demonstrated by laboratory experiments. Heating power requirement for the evaporation process is estimated for a specific mission.

Lippman, M. E.

Spacecraft Conceptual Design for Returning Entire Near-Earth Asteroids

In situ resource utilization (ISRU) in general, and asteroid mining in particular are ideas that have been around for a long time, and for good reason. It is clear that ultimately human exploration beyond low-Earth orbit will have to utilize the material resources available in space. Historically, the lack of sufficiently capable in-space transportation has been one of the key impediments to the harvesting of near-Earth asteroid resources. With the advent of high-power (or order 40 kW) solar electric propulsion systems, that impediment is being removed. High-power solar electric propulsion (SEP) would be enabling for the exploitation of asteroid resources. The design of a 40-kW end-of-life SEP system is presented that could rendezvous with, capture, and subsequently transport a 1,000-metric-ton near-Earth asteroid back to cislunar space. The conceptual spacecraft design was developed by the Collaborative Modeling for Parametric Assessment of Space Systems (COMPASS) team at the Glenn Research Center in collaboration with the Keck Institute for Space Studies (KISS) team assembled to investigate the feasibility of an asteroid retrieval mission. Returning such an object to cislunar space would enable astronaut crews to inspect, sample, dissect, and ultimately determine how to extract the desired materials from the asteroid. This process could jump-start the entire ISRU industry.

asteroid retrieval

The manned maneuvering unit flight controller arm

The Manned Maneuvering Unit (MMU) and its support equipment provide an extravehicular astronaut mobility, and the ability to work outside the confines of the Shuttle Orbiter payload bay. The MMU design requirements are based on the highly successful Skylab M-509 maneuvering unit. Design of the MMU was started as an R&D effort in April 1975 and Flight Hardware design was started in August 1979 to support a possible requirement for in-space inspection and repair of Orbiter thermal protection tiles. Subsequently, the qualification test and production activities were slowed, and the current projected earliest first flight is now STS-11 in January, 1984. The MMU propulsion subsystem provides complete redundancy with two identical "system". Each system contains a high pressure gaseous nitrogen tank, an isolation valve, a regulator, and twelve 1.7 lbf (7.5 N) thrusters. The thrusters are packaged to provide the crew member six-degree-of-freedom control in response to commands from translational and rotational hand controllers. This paper discusses the MMU control arm requirements, design, and developmental history.

Falkner, K. E.

Design of a water electrolysis flight experiment

Supply of oxygen (O2) and hydrogen (H2) by electolyzing water in space will play an important role in meeting the National Aeronautics and Space Administration's (NASA's) needs and goals for future space missios. Both O2 and H2 are envisioned to be used in a variety of processes including crew life support, spacecraft propulsion, extravehicular activity, electrical power generation/storage as well as in scientific experiment and manufacturing processes. The Electrolysis Performance Improvement Concept Study (EPICS) flight experiment described herein is sponsored by NASA Headquarters as a part of the In-Space Technology Experiment Program (IN-STEP). The objective of the EPICS is to further contribute to the improvement of the SEF technology, specifially by demonstrating and validating the SFE electromechanical process in microgravity as well as investigating perrformance improvements projected possible in a microgravity environment. This paper defines the experiment objective and presents the results of the preliminary design of the EPICS. The experiment will include testing three subscale self-contained SFE units: one containing baseline components, and two units having variations in key component materials. Tests will be conducted at varying current and thermal condition.

Lee, M. Gene

Modular Assembled Radiators for Nuclear Electric Propulsion (NEP) VehicLes (MARVL) Project Thermal Technology Development

Nuclear Electric Propulsion (NEP) has been considered for crew and cargo class missions to Mars for more than six decades. The Primary Heat Rejection Subsystem (PHRS) of an NEP vehicle expels the megawatts of waste heat generated by the Power Conversion Subsystem (PCS). In previous studies, integrating the majority of the NEP vehicle within a single launch fairing required the use of complex deployable elements and resulted in reduced PCS efficiency. To achieve the necessary radiating area, past design studies have utilized massive multi-wing folding radiators resulting in conceptual PHRS designs that have been widely acknowledged as non-optimal. The Modular Assembled Radiators for NEP VehicLes (MARVL) project is incorporating in-Space Assembly (iSA) into the design process to realize lightweight, modular, and more capable PHRS radiators. Since the project’s Authority to Proceed (ATP) date of October 2024, the project team has been developing a modular design for the PHRS radiators that will be suitable for both the Mars mission environments and iSA commissioning operations. This document captures the current progress of the incremental technology development for the thermal components of the MARVL System of Interest (SOI).

Modular Radiator

The COLD-SAT Experiment for Cryogenic Fluid Management Technology

Future national space transportation missions will depend on the use of cryogenic fluid management technology development needs for these missions. In-space testing will be conducted in order to show low gravity cryogenic fluid management concepts and to acquire a technical data base. Liquid H2 is the preferred test fluid due to its propellant use. The design of COLD-SAT (Cryogenic On-orbit Liquid Depot Storage, Acquisition, and Transfer Satellite), an Expendable Launch Vehicle (ELV) launched orbital spacecraft that will perform subcritical liquid H2 storage and transfer experiments under low gravity conditions is studied. An Atlas launch vehicle will place COLD-SAT into a circular orbit, and the 3-axis controlled spacecraft bus will provide electric power, experiment control, and data management, attitude control, and propulsive accelerations for the experiments. Low levels of acceleration will provide data on the effects that low gravity might have on the heat and mass transfer processes used. The experiment module will contain 3 liquid H2 tanks; fluid transfer, pressurization and venting equipment; and instrumentation.

Schuster, J. R.

Electric propulsion interactive effects with spacecraft science payloads.

Interactive effects between electric thruster units and a Solar Electric Pioneer (SEP) spacecraft science payload are investigated. Studied effects include magnetic contamination (steady state), electric contamination (steady state and time varying) and particle contamination of regions in and around the spacecraft. Conducted electromagnetic interference is measured for thrusters powered with prototype power processing units and radio frequency interference effects between the thruster and the omnidirectional low gain antenna are determined. Material deposition and transport of thruster propellant ions and atoms and charge exchange metal ions and atoms are also experimentally determined. Large scale environmental effects between the plasma thrust beam and the particles and fields in interplanetary space are discussed. Contaminant reduction techniques are proposed, and both laboratory and in-space interactive effects tests are suggested.

Sellen, J. M., Jr.

The LeRC rail accelerators: Test designs and diagnostic techniques

The feasibility of using rail accelerators for various in-space and to-space propulsion applications was investigated. A 1 meter, 24 sq mm bore accelerator was designed with the goal of demonstrating projectile velocities of 15 km/sec using a peak current of 200 kA. A second rail accelerator, 1 meter long with a 156.25 sq mm bore, was designed with clear polycarbonate sidewalls to permit visual observation of the plasma arc. A study of available diagnostic techniques and their application to the rail accelerator is presented. Specific topics of discussion include the use of interferometry and spectroscopy to examine the plasma armature as well as the use of optical sensors to measure rail displacement during acceleration. Standard diagnostics such as current and voltage measurements are also discussed.

Zana, L. M.

LeRC rail accelerators - Test designs and diagnostic techniques

The feasibility of using rail accelerators for various in-space and to-space propulsion applications was investigated. A 1 meter, 24 sq mm bore accelerator was designed with the goal of demonstrating projectile velocities of 15 km/sec using a peak current of 200 kA. A second rail accelerator, 1 meter long with a 156.25 sq mm bore, was designed with clear polycarbonate sidewalls to permit visual observation of the plasma arc. A study of available diagnostic techniques and their application to the rail accelerator is presented. Specific topics of discussion include the use of interferometry and spectroscopy to examine the plasma armature as well as the use of optical sensors to measure rail displacement during acceleration. Standard diagnostics such as current and voltage measurements are also discussed. Previously announced in STAR as N83-35053

Zana, L. M.

Pathfinder: Surface exploration, in-space operations and space transfer

Viewgraphs on the Pathfinder program are presented. Information is given on technology needs, a planetary rover, program management, an autonomous lander, mission applications, orbital assembly, cryogenics, space nuclear reactors, space manufacturing, optical communications, spacecraft propulsion, aerobraking, and orbital transfer vehicles.

Mankins, John

NASA's Chemical Transfer Propulsion Program for Pathfinder

Pathfinder is a research and technology project, with specific deliverables, initiated by the National Aeronautics and Space Administration (NASA) which will strengthen the technology base of the United States civil space program in preparation for future space exploration missions. Pathfinder begins in Fiscal Year 1989, and is to advance a collection of critical technologies for these missions and ensure technology readiness for future national decisions regarding exploration of the solar system. The four major thrusts of Pathfinder are: surface exploration, in-space operations, humans-in-space, and space transfer. The space transfer thrust will provide the critical technologies needed for transportation to, and return from, the Moon, Mars, and other planets in the solar system, as well as for reliable and cost-effective Earth-orbit operations. A key element of this thrust is the Chemical Transfer Propulsion program which will provide the propulsion technology for high performance, liquid oxygen/liquid hydrogen expander cycle engines which may be operated and maintained in space. Described here are the program overview including the goals and objectives, management, technical plan, and technology transfer for the Chemical Transfer Propulsion element of Pathfinder.

Hannum, Ned P.

Mixed fleet assessment for on-orbit consumables resupply

Significant increases in the cost effectiveness and operational flexibility of in-space systems can be realized when the capability to replenish consumable fluids and propellants is incorporated into the designs of spacecraft, satellites, and orbiting platforms and laboratories. Reusable tankers are currently being designed for transporting fluids to space. A number of options exist for transporting the fluids and propellants to the space-based user systems. The fluids can be transported to space either in the Shuttle cargo bay or using Expendable Launch Vehicles (ELVs). Resupply can thus be accomplished either from the Shuttle bay, or the tanker can be removed from an ELV and attached to a carrier such as the Orbital Maneuvering Vehicle (OMV) or Orbital Transfer Vehicle (OTV) for transport to the user to be serviced. A third option involves locating the tanker at the Space Station or an unmanned platform as a quasi-permanent servicing facility which returns to the ground for recycling once its tanks have been depleted. This paper documents the impacts of a mixed fleet approach to consumables logistics to orbit. Both storable fluids and propellants, and superfluid helium, are considered. Current modular tanker designs for monopropellants, bipropellants and water for Space Station propulsion are discussed. Trade-offs in superfluid helium tanker sizes, shapes to fit the range of ELVs currently available, and boil-off losses associated with longer-term (greater than 6 months) space-basing, are addressed.

Eberhardt, Ralph N.