Engineering topics

Rummel, John D.

Publications and source records attributed to Rummel, John D..

At least 37 records · Page 2

NASA NTRS1992

Towards a Mars base - Critical steps for life support on the moon and beyond

In providing crew life support for future exploration missions, overall exploration objectives will drive the life support solutions selected. Crew size, mission tasking, and exploration strategy will determine the performance required from life support systems. Human performance requirements, for example, may be offset by the availability of robotic assistance. Once established, exploration requirements for life support will be weighed against the financial and technical risks of developing new technologies and systems. Other considerations will include the demands that a particular life support strategy will make on planetary surface site selection, and the availability of precursor mission data to support EVA and in situ resource recovery planning. As space exploration progresses, the diversity of life support solutions that are implemented is bound to increase.

Rummel, John D.↗

NASA NTRS1992

Early SEI milestones - Underwater habitats and Antarctic research outposts as analogs for long duration spaceflight and lunar and Mars outposts

The use of analog environments for space research is considered focusing on underwater habitats and Antarctic research sites as analogous settings to long-duration space flight. It is pointed out that the use of these earth analogs can provide engineers, scientists, and future crew members with critical 'mission' experience at a relatively low cost.

Rummel, John D.↗

NASA NTRS1992

Long-term effects of microgravity and possible countermeasures

The measures that can be taken to counteract the effect of long-term exposures to microgravity are discussed. It is noted that, although it was shown that specially designed exercise programs can counteract the effect of exposures of up to one year in space, is it questionable whether U.S. astronauts could or should have to maintain such regimes for extremely prolonged missions. The methods considered by NASA Life Sciences Division are to provide an artificial gravity environment by the generation of centrifugal forces by means of either the continuous rotation of the whole spacecraft or using a short-arm centrifuge on board a zero-g spacecraft. Results obtained in studies of these two methods are discussed, and the centrifuge research facility that is presently being developed by NASA is described.

Wolfe, James W.↗

NASA NTRS1992

Development of countermeasures for medical problems encountered in space flight

Past experience with piloted space missions is reviewed to develop potential countermeasures to the medical problems associated with a long-duration space flight. Particular attention is given to the Extended Duration Orbiter Medical Program, which is aimed at ensuring crew health and safety on Space Shuttle missions; Soviet experience with long-duration space flights; and a variety of countermeasures including physiological, psychological, environmental health, radiation protection, and artificial gravity countermeasures.

Nicogossian, Arnauld E.↗

NASA NTRS1992

Development of life support requirements for long-term space flight

Life support system requirements for future long-term space flights are discussed. These requirements include overall reliability in the space environment, providing maintenance and component replacement in space; reduced supply mass of consumables and spares; the ability to utilize local resources for increased self-sufficiency on planetary surfaces; and minimized mass power and volume requirements necessary for all space flight systems.

Rummel, John D.↗

NASA NTRS1992

Planetary protection policy (U.S.A.)

Through existing treaty obligations of the United States, NASA is committed to exploring space while avoiding biological contamination of the planets, and to the protection of the earth against harm from materials returned from space. Because of the similarities between Mars and earth, plans for the exploration of Mars evoke discussions of these Planetary Protection issues. U.S. Planetary Protection Policy will be focused on the preservation of these goals in an arena that will change with the growth of scientific knowledge about the Martian environment. Early opportunities to gain the appropriate data will be used to guide later policy implementation. Because human presence on Mars will result in the end of earth's separation from the Martian environment, it is expected that precursor robotic missions will address critical planetary protection concerns before humans arrive.

Rummel, John D.↗

NASA NTRS1991

Fourth Symposium on Chemical Evolution and the Origin and Evolution of Life

This symposium was held at the NASA Ames Research Center, Moffett Field, California, July 24-27, 1990. The NASA exobiology investigators reported their recent research findings. Scientific papers were presented in the following areas: cosmic evolution of biogenic compounds, prebiotic evolution (planetary and molecular), early evolution of life (biological and geochemical), evolution of advanced life, solar system exploration, and the Search for Extraterrestrial Intelligence (SETI).

Wharton, Robert A., Jr.↗

NASA NTRS1991

Bioregenerative life support - The initial CELSS reference configuration

The next major step in the development of an operational Controlled Ecological Life-Support System (CELSS) is the creation of a human-rated ground-based demonstrator able to constitute a CELSS's proof-of-concept. The reference configuration recently devised for such a ground facility by NASA will furnish a common reference to all investigators in the field, thereby facilitating performance comparisons among candidate subsystems and clarifying system-level modeling. A detailed NASA reference CELSS flowcharting is presented.

Rummel, John D.↗

NASA NTRS1990

Life sciences and Mars exploration

The major life science considerations for Mars exploration missions are discussed. Radiation protection and countermeasures for zero gravity are discussed. Considerations of crew psychological health considerations and life support systems are addressed. Scientific opportunities presented by manned Mars missions are examined.

Sulzman, Frank M.↗

NASA NTRS1990

Transpiration during life cycle in controlled wheat growth

A previously developed model of wheat growth, designed for convenient incorporation into system level models of advanced space life support systems is described. The model is applied to data from an experiment that grew wheat under controlled conditions and measured fresh biomass and cumulated transpiration as a function of time. The adequacy of modeling the transpiration as proportional to the inedible biomass and an age factor that varies during the life cycle are discussed.

Volk, Tyler↗

NASA NTRS1990

Long term life support for space exploration

A general strategy for the development of life-support systems is discussed in terms of present and future requirements for NASA exploration missions. A general life-support strategy is delineated for both intravehicular activity (IVA) and extravehicular activity (EVA) for lunar and Mars transfer vehicles, Mars habitats, and pressurized rovers. The baseline capability presented corresponds to the systems needs for the Space Station Freedom permanently manned capability and the Shuttle Extended Duration Orbiter. Design guidelines and system design goals are given for IVA life support with an emphasis on closed-loop systems, and the design prerogatives for EVA include a minimum time to transition between IVA and EVA, and minimum resitriction for human activity.

Rummel, John D.↗

NASA NTRS1989

Planetary protection policy overview and application to future missions

The current status of planetary protection (quarantine) policy within NASA is discussed, together with the issues of planetary protection and back-contamination as related to future missions. The policy adopted by COSPAR in 1984 (and recently reaffirmed by the NASA Administrator) for application to all unmanned missions to other solar system bodies and all manned and unmanned sample return missions is examined. Special attention is given to the implementation of the policy and to the specific quarantine-related constraints on spacecraft involved in solar system exploration that depend on the nature of the mission and the identity of the target body.

Rummel, John D.↗

NASA NTRS1989

Transpiration during life cycle in controlled wheat growth

A previously-developed model of wheat growth, designed for convenient incorporation into system-level models of advanced space life support systems is described. The model is applied to data from an experiment that grew wheat under controlled conditions and measured fresh biomass and cumulated transpiration as a function of time. The adequacy of modeling the transpiration as proportional to the inedible biomass, and an age factor which varies during the life cycle, are examined. Results indicate that during the main phase of vegetative growth in the first half of the life cycle, the rate of transpiration per unit mass of inedible biomass is more than double the rate during the phase of grain development and maturation during latter half of the life cycle.

Volk, Tyler↗

NASA NTRS1989

The case for cellulose production on Mars

From examining the consequences of not requiring that all wastes from life support be recycled back to the food plants, it is concluded that cellulose production on Mars could be an important input for many nonmetabolic material requirements on Mars. The fluxes of carbon in cellulose production would probably exceed those in food production, and therefore settlements on Mars could utilize cellulose farms in building a Mars infrastructure.

Volk, Tyler↗

NASA NTRS1989

Planetary protection and back contamination control for a Mars rover sample return mission

A commitment to avoid the harmful contamination of outer space and avoid adverse changes in the environment of the earth has been long reflected in NASA's Planetary Protection policy. Working under guidelines developed by the Committee on Space Research (COSPAR), NASA has implemented the policy in an interactive process that has included the recommendations of the U.S. National Academy of Sciences. Measures taken to prevent the contamination of earth during the Apollo missions were perhaps the most visible manifestations of this policy, and provided numerous lessons for future sample return opportunities. This paper presents the current status of planetary protection policy within NASA, and a prospectus on how planetary protection issues might be addressed in relation to a Mars Rover Sample Return mission.

Rummel, John D.↗

NASA NTRS1989

Life sciences interests in Mars missions

NASA's Space Life Sciences research permeates plans for Mars missions and the rationale for the exploration of the planet. The Space Life Sciences program has three major roles in Mars mission studies: providing enabling technology for piloted missions, conducting scientific exploration related to the origin and evolution of life, and protecting space crews from the adverse physiological effects of space flight. This paper presents a rationale for exploration and some of the issues, tradeoffs, and visions being addressed in the Space Life Sciences program in preparation for Mars missions.

Rummel, John D.↗

NASA NTRS1987

A modular BLSS simulation model

A bioregenerative life support system (BLSS) for extraterrestrial use will be faced with coordination problems more acute than those in any ecosystem found on Earth. A related problem in BLSS design is providing an interface between the various life support processors, one that will allow for their coordination while still allowing for system expansion. A modular model is presented of a BLSS that interfaces system processors only with the material storage reservoirs, allowing those reservoirs to act as the principal buffers in the system and thus minimizing difficulties with processor coordination. The modular nature of the model allows independent development of the detailed submodels that exist within the model framework. Using this model, BLSS dynamics were investigated under normal conditions and under various failure modes. Partial and complete failures of various components, such as the waste processors or the plants themselves, drive transient responses in the model system, allowing the examination of the effectiveness of the system reservoirs as buffers. The results from simulations help to determine control strategies and BLSS design requirements. An evolved version could be used as an interactive control aid in a future BLSS.

Rummel, John D.↗

NASA NTRS1987

Mass balances for a biological life support system simulation model

Design decisions to aid the development of future space based biological life support systems (BLSS) can be made with simulation models. The biochemistry stoichiometry was developed for: (1) protein, carbohydrate, fat, fiber, and lignin production in the edible and inedible parts of plants; (2) food consumption and production of organic solids in urine, feces, and wash water by the humans; and (3) operation of the waste processor. Flux values for all components are derived for a steady state system with wheat as the sole food source. The large scale dynamics of a materially closed (BLSS) computer model is described in a companion paper. An extension of this methodology can explore multifood systems and more complex biochemical dynamics while maintaining whole system closure as a focus.

Volk, Tyler↗