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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 271 records · Page 15
All sourcesNASA NTRSDOE OSTI
NASA NTRS1987

Aeroassisted-vehicle design studies for a manned Mars mission

An aerobrake design that has matured over several years of development accounting for all of the important flow phenomenology which are characteristic of aerobraking vehicles is proposed as the mission baseline. Flight regimes and aerothermal environments for both Mars and Earth entry are calculated using advanced methods to account for real-gas, thermochemical, relaxation effects. The results are correlated with thermal-protection and structural requirements and mission performance capability. The importance of nonequilibrium radiative heating for Earth aerocapture is demonstrated. It is suggested that two aerobrakes of different sizes will produce optimal performance for the three phases of the mission (i.e., one aerobrake for Mars aerocapture and descent of the surface lander and another for Earth return).

Menees, Gene P.↗
NASA NTRS1987

Aeroassisted-vehicle design studies for a manned Mars mission

An aerobrake design accounting for all of the important flow phenomenology which are characteristic of aerobraking vehicles is proposed as the mission baseline. Flight regimes and aerothermal environments for both Mars and earth entry are calculated using advanced methods to account for real-gas, thermochemical, relaxation effects. The results are correlated with thermal-protection and structural requirements and mission performance capability. The importance of nonequilibrium radiative heating for earth aerocapture is demonstrated. It is suggested that two aerobrakes of different sizes will produce optimal performance for the three phases of the mission (i.e., one aerobrake for Mars aerocapture and descent of the surface lander and another for earth return).

Menees, Gene P.↗
NASA NTRS1990

The effect of interplanetary trajectory options on a manned Mars aerobrake configuration

Manned Mars missions originating in low Earth orbit (LEO) in the time frame 2010 to 2025 were analyzed to identify preferred mission opportunities and their associated vehicle and trajectory characteristics. Interplanetary and Mars atmospheric trajectory options were examined under the constraints of an initial manned exploration scenario. Two chemically propelled vehicle options were considered: (1) an all propulsive configuration, and (2) a configuration which employs aerobraking at Earth and Mars with low lift/drag (L/D) shapes. Both the interplanetary trajectory options as well as the Mars atmospheric passage are addressed to provide a coupled trajectory simulation. Direct and Venus swingby interplanetary transfers with a 60 day Mars stopover are considered. The range and variation in both Earth and Mars entry velocity are also defined. Two promising mission strategies emerged from the study: (1) a 1.0 to 2.0 year Venus swingby mission, and (2) a 2.0 to 2.5 year direct mission. Through careful trajectory selection, 11 mission opportunities are identified in which the Mars entry velocity is between 6 and 10 km/sec and Earth entry velocity ranges from 11.5 to 12.5 km/sec. Simulation of the Earth return aerobraking maneuver is not performed. It is shown that a low L/D configuration is not feasible for Mars aerobraking without substantial improvements in the interplanetary navigation system. However, even with an advanced navigation system, entry corridor and aerothermal requirements restrict the number of potential mission opportunities. It is also shown that for a large blunt Mars aerobrake configuration, the effects of radiative heating can be significant at entry velocities as low as 6.2 km/sec and will grow to dominate the aerothermal environment at entry velocities above 8.5 km/sec. Despite the additional system complexity associated with an aerobraking vehicle, the use of aerobraking was shown to significantly lower the required initial LEO weight. In comparison with an all propulsive mission, savings between 19 and 59 percent were obtained depending upon launch date.

Braun, Robert D.↗
NASA NTRS1989

Trajectories for spacecraft encounters with Comet Honda-Mrkos-Pajdusakova in 1996

Early in 1996, the relatively bright short-period Comet Honda-Mrkos-Pajdusakova (HMP) will pass only 0.17 astronomical unit from the earth, providing both an unusually favorable apparition for ground-based observers and an opportunity for a spacecraft to reach Comet HMP on relatively low-energy trajectories. The Japanense Institute of Space and Astronautical Sciences Sakigake spacecraft is expected to fly by Comet HMP on February 3, 1996, after utilizing four earth swingbys to modify its orbit. If the camera on the ESA Giotto spacecraft is inoperable, Giotto may also be sent to Comet HMP. In addition, 1-year earth-return trajectories to Comet HMP are described, along with some that can be extended to encounter Comet Giacobini-Zinner in 1998.

Dunham, David W.↗
NASA NTRS1989

A get started approach for resource processing

A low-risk, high-value approach to implementing resource processing is presented. The design utilizes processing plants at Deimos and Mars, a fueling depot in a Mars parking orbit, and small shuttles transferring crew and cargo between sites. The system fuels Mars ascent and descent states and the earth-return stage. Fueling at Mars reduces launch requirements by 25 percent, or, alternatively, enables the substitution of payload for fuel on a near 1:1 basis and thereby triples the payload delivered to Mars.

Giudici, Bob↗
NASA NTRS1990

Mars parking orbit selection

For a Mars mission, the selection of a parking orbit is greatly influenced by the precession caused by the oblateness of the planet. This affects the departure condition for earth return, and therefore, the mass required in LEO for a Mars mission. In this investigation, minimum LEO mass penalties were observed for parking orbits characterized by having near-equatorial inclinations, high eccentricities, and requiring a three-dimensional departure burn. However, because near-equatorial inclination orbits have poor planetary coverage characteristics, they are not desirable from a science viewpoint. To enhance these science requirements along with landing-site accessibility, a penalty in initial LEO mass is required. This study shows that this initial LEO mass penalty is reduced for orbits characterized with low to moderate eccentricities, nonequatorial inclinations, and a tangential periapsis arrival and departure burn.

Desai, Prasun N.↗
NASA NTRS1990

Next-generation in-situ science concepts and technology

This paper discusses the concepts of a next-generation in situ science program, named Sample Acquisition, Analysis, and Preservation (SAAP), established by NASA to develop critical technologies for remote identification, acquisition, processing, analysis, and preservation of materials for the in situ science, engineering characterization, and earth return. Special attention is given to the SAAP architecture, system design, remote sensing system, sample acquisition system, and methods for sample analysis. A diagram of the SAAP preliminary system conceptual design is included.

Muirhead, Brian↗
NASA NTRS1991

Interplanetary trajectory optimization of Mars aerobraking missions with constrained atmospheric entry velocities

Many current manned Mars mission studies are using low lift-to-drag ratio (L/D) vehicles to aerobrake at both Mars and earth. The use of these low L/D vehicles imposes constraints on the allowable velocity at the atmospheric interface. This paper will demonstrate that if these entry velocity constraints are incorporated into the interplanetary analysis, more opportunities can be achieved for a small increase in initial LEO mass. These additional opportunities result from varying the initial launch date, the encounter dates, and possibly using a powered Venus swingby on either the inbound or outbound transfer. This paper presents results for three atmospheric entry velocity ranges at Mars arrival and one velocity limitation upon Earth return. The results indicate that by carefully selecting the interplanetary trajectory, an optimum initial LEO mass mission can be found for even highly restrictive entry velocity missions in practically all of the 15 years studied.

Striepe, Scott A.↗
NASA NTRS1991

Lunar mission aerobrake performance study

Nine lunar mission scenarios were developed to show the transfer vehicle performance benefits of aerobraking into low Earth orbit (LEO) upon Earth return as opposed to an all-propulsive maneuver. The initial mass in LEO (IMLEO) of the lunar transfer vehicle is considered the measure of vehicle performance. Four types of mission profiles in conjunction with two vehicle concepts were used to construct the scenarios. These nine scenarios were designed to represent a broad range of possible lunar missions so that a general knowledge base of aerobraking and lunar transfer vehicle performance levels could be obtained. Also discussed are the mass sensitivities of each transfer vehicle to changes in the selected design parameters: Isp, crew module mass, payload to surface, and aerobrake mass fraction. A parametric study was performed on two of the mission scenarios to help quantify the performance benefits by adding a set of drop tanks to the vehicle. The parametric study also provides partial derivatives which show the sensitivities of IMLEO to the four design parameters listed. A ranking is given based on vehicle performance.

Mulqueen, J.↗
NASA NTRS1992

Project Minerva: A low cost manned Mars mission based on indigenous propellant production

Project Minerva is a low-cost manned Mars mission designed to deliver a crew of four to the Martian surface using only two sets of two launches from the Kennedy Space Center. Key concepts which make this mission realizable are the use of near-term technologies and in-situ propellant production, following the scenario originally proposed by R. Zubrin. The first set of launches delivers two unmanned payloads into low Earth orbit (LEO): the first payload consists of an Earth Return Vehicle (ERV), a propellant production plant, and a set of robotic vehicles; the second payload consists of the trans-Mars injection (TMI) upper stage. In LEO, the two payloads are docked and the configuration is injected into a Mars transfer orbit. The landing on Mars is performed with the aid of multiple aerobraking maneuvers. On the Martian surface, the propellant production plant uses a Sabatier/electrolysis type process to combine nine tons of hydrogen with carbon dioxide from the Martian atmosphere to produce over a hundred tons of liquid oxygen and liquid methane, which are later used as the propellants for the rover expeditions and the manned return journey of the ERV. The systems necessary for the flights to and from Mars, as well as those needed for the stay on Mars, are discussed. These systems include the transfer vehicle design, life support, guidance and communications, rovers and telepresence, power generation, and propellant manufacturing. Also included are the orbital mechanics, the scientific goals, and the estimated mission costs.

Beder, David↗
NASA NTRS1992

Determining Mars parking orbits which ensure in-plane arrival and departure burns

A numerical method to find suitable Mars parking orbits is developed which takes into account geometries associated with the asymptotes, along with the nodal precession caused by the oblateness of Mars. A selected orbital plane which contains the arrival asymptote precesses through the stay time to the plane also containing the departure asymptote. The parking orbit is co-planar with both the arrival and departure asymptotes and only in-plane burns are required at both Mars arrival and departure. The need for a plane change at Mars departure to achieve the proper velocity vector for earth return is eliminated. The method requires very little computation time to determine a set of all possible inclinations and right ascensions of the ascending nodes.

Desai, Prasun N.↗
NASA NTRS1993

Low cost manned Mars mission based on indigenous propellant production

The paper describes a low-cost approach to the manned exploration of Mars (which involves an unmanned mission followed two years later by a manned mission) based on near-term technologies and in situ propellant production. Particular attention is given to the basic mission architecture and its major components, including the orbital analysis, the unmanned segment, the Earth Return Vehicle, the aerobrake design, life sciences, guidance, communications, power, propellant production, the surface rovers, and Mars science. Also discussed are the cost per mission over an assumed 8-yr initiative.

Bruckner, A. P.↗
NASA NTRS1993

Influence of interplanetary trajectory selection on Mars atmospheric entry velocity

Many current manned Mars mission studies are using low lift-to-drag ratio (L/D) vehicles to aerobrake at both Mars and Earth. The use of these low L/D vehicles could limit the allowable velocity at the atmospheric interface. This paper will demonstrate that if entry velocity constraints are incorporated into the interplanetary analysis of aerobraking Mars missions, many opportunities can be achieved for a small increase in initial mass in low-Earth orbit (IMLEO). These opportunities result from varying the initial launch date and the encounter dates and possibly using a powered Venus swingby on either the inbound or outbound transfer. This paper demonstrates this technique by using three atmospheric entry velocity ranges at Mars arrival (6.0-8.5, 6.4-8.1, and 7.2-7.3 km/s), unconstrained Mars entry velocities, and an Earth return entry velocity below 14 km/s. The results indicate that, by carefully selecting the interplanetary trajectory, an optimum IMLEO mission can be found for even highly restrictive entry velocity missions in practically all of the 15 yr studied.

Striepe, Scott A.↗
NASA NTRS1993

Collecting cometary soil samples? Development of the ROSETTA sample acquisition system

In the reference scenario of the ROSETTA CNRS mission, the Sample Acquisition System is mounted on the Comet Lander. Its tasks are to acquire three kinds of cometary samples and to transfer them to the Earth Return Capsule. Operations are to be performed in vacuum and microgravity, on a probably rough and dusty surface, in a largely unknown material, at temperatures in the order of 100 K. The concept and operation of the Sample Acquisition System are presented. The design of the prototype corer and surface sampling tool, and of the equipment for testing them at cryogenic temperatures in ambient conditions and in vacuum in various materials representing cometary soil, are described. Results of recent preliminary tests performed in low temperature thermal vacuum in a cometary analog ice-dust mixture are provided.

Coste, P. A.↗
NASA NTRS1994

Physics of spacecraft-based interplanetary dust collection by impact into low-density media

A spacecraft encountering an interplanetary dust particle (IDP) at a relative velocity of several kilometers per second may be used to capture that particle for in situ analysis or for analysis upon Earth return. In this paper we study the impact of a dust particle into a low-density medium (i.e., a foam) such that the foam dissipates the kinetic energy of impact over a sufficient distance to stop the particle without destroying it.

Anderson, William W.↗
NASA NTRS1998

An Overview of Mars Vicinity Transportation Concepts for a Human Mars Mission

To send a piloted mission to Mars, transportation systems must be developed for the Earth to Orbit, trans Mars injection (TMI), capture into Mars orbit, Mars descent, surface stay, Mars ascent, trans Earth injection (TEI), and Earth return phases. This paper presents a brief overview of the transportation systems for the Human Mars Mission (HMM) only in the vicinity of Mars. This includes: capture into Mars orbit, Mars descent, surface stay, and Mars ascent. Development of feasible mission scenarios now is important for identification of critical technology areas that must be developed to support future human missions. Although there is no funded human Mars mission today, architecture studies are focusing on missions traveling to Mars between 2011 and the early 2020's.

Dexter, Carol E.↗
NASA NTRS2000

Summary of JPL Activities

A viewgraph presentation outlines the Jet Propulsion Laboratory (JPL) flight programs, including past, present and future missions targeting Solar System exploration. Details, including launch dates and batteries used, are given for Deep Space 1 (Asteroid Rendezvous), Deep Space 2 (Mars Penetrator), Mars Global Surveyor, Mars Surveyor '98, Stardust, Europa Orbiter, Mars Surveyor 2001, Mars 2003 Lander and Rover, and Genesis (Solar Dust Return). Earth science projects are also outlined: Active Cavity Radiometer Irradiance Monitor (ARIMSAT), Ocean Topography Experiment (TOPEX/Poseidon), Jason-1 (TOPEX follow-on), and QuikScat/Seawinds (Ocean Winds Tracking). The status, background, and plans are given for several batteries: (1) 2.5 inch common pressure vessel (CPV), (2) 3.5 inch CPV, (3) Ni-H2, and (4) Li-Ion.

Timmerman, Paul J.↗
NASA NTRS2000

Guidance Concept for a Mars Ascent Vehicle First Stage

This paper presents a guidance concept for use on the first stage of a Mars Ascent Vehicle (MAV). The guidance is based on a calculus of variations approach similar to that used for the final phase of the Apollo Earth return guidance. A three degree-of-freedom (3DOF) Monte Carlo simulation is used to evaluate performance and robustness of the algorithm.

Queen, Eric M.↗