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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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All sourcesNASA NTRSDOE OSTI
NASA NTRS2016

My Internship at NASA

My name is Isaac Lopez and I am a junior at the University of Houston majoring in Mechanical Engineering Technology. I will be completing my first tour at the NASA-Johnson Space Center ("JSC") as a Mechanical Engineer within the Human Interfaces Branch. Throughout my tour, I was given the opportunity to work on multiple projects that have expanded my knowledge and interest in acoustics and engineering design. One of the projects I worked on at JSC consisted of doing acoustic simulation of the EVA comm. cap. While working on the comm. cap headset, my main duty consisted of simulating the acoustics of the headset to find a solution to the condensing water that can accumulate and block the acoustic tube, causing attenuation or complete loss of audio in one ear for an astronaut using the EVA. For this project, I had to create a Creo model of the comm. cap so that I would be able to import it into Comsol for acoustic simulation. I also had the opportunity to design a portable and lightweight beam degrader for the EEE Parts and Radiation team. With the help of Creo, I was able to make a CAD design and put together a small working prototype for the radiation team to demonstrate the capabilities that the beam degrader had. In addition to these projects, JSC allowed me to work closely on projects with other interns. I had the opportunity to help another intern with his acoustic diverter, intended to improve the sound quality in Node 1 of the ISS. During this project, I helped with some of the acoustic testing inside the anechoic chamber as well as helping record data during testing at the ISS mock up. During the course of my first tour, I was able to learn and continually improve on my CAD drafting skills. With each project I worked on, I acquired new ways to create and improve various designs with various constraints. Furthermore, I also had the opportunity to work with electrical engineers and learn about the electronic components that would provide control of the beam degrader functions. I was able to take the knowledge, skills and designs I had acquired during my tour at JSC (such as Finite Element Analysis) and apply them to my work on the Comsol Multiphysics software for acoustics simulation. I was also able to use it to do some stress analysis on a proposed design for a proposed Habitat structure. My time at JSC has been invaluable as it helped me grow and more fully-comprehend my major as well as spark an interest in acoustics and how much it relates to mechanical engineering. This internship has taught me that engineering is much more than a profession - it is embedded in our daily lives as a puzzle that requires critical thinking as an everyday challenge that makes life more interesting.

Lopez, Isaac↗
NASA NTRS1972

Power conditioning equipment for a thermoelectric outer planet spacecraft, volume 1, book 1

Equipment was designed to receive power from a radioisotope thermoelectric generator source, condition, distribute, and control this power for the spacecraft loads. The TOPS mission, aimed at a representative tour of the outer planets, would operate for an estimated 12 year period. Unique design characteristics required for the power conditioning equipment results from the long mission time and the need for autonomous on-board operations due to large communications distances and the associated time delays of ground initiated actions. The salient features of the selected power subsystem configuration are: (1) The PCE regulates the power from the radioisotope thermoelectric generator power source at 30 vdc by means of a quad-redundant shunt regulator; (2) 30 vdc power is used by certain loads, but is more generally inverted and distributed as square-wave ac power; (3) a protected bus is used to assure that power is always available to the control computer subsystem to permit corrective action to be initiated in response to fault conditions; and (4) various levels of redundancy are employed to provide high subsystem reliability.

Andrews, R. E.↗
NASA NTRS2008

Orbit Control Operations for the Cassini-Huygens Mission

The Cassini-Huygens spacecraft was launched in 1997 as an international and collaborative mission to study Saturn and its many moons. After a seven-year cruise, Cassini began orbiting Saturn for a four- year tour. This tour consists of 157 planned maneuvers, and their back-up locations, designed to target 52 encounters, mostly of Saturn's largest moon Titan. One of the mission's first activities was to release the Huygens probe to Titan in December 2004. Currently in its last year of the prime mission, Cassini-Huygens continues to obtain valuable data on Saturn, Titan, and Saturn's other satellites. Return of this information is in large part due to a healthy spacecraft and successful navigation. A two-year extended mission, beginning July 2008, will offer the opportunity to continue science activities. With a demanding navigation schedule that compares with the prime tour, the Cassini Navigation team relies on operations procedures developed during the prime mission to carry-out the extended mission objectives. Current processes for orbit control operations evolved from the primary navigational requirement of staying close to predetermined targeting conditions according to Cassini science sequence planning. The reference trajectory is comprised of flyby conditions to be accomplished at minimal propellant cost. Control of the planned reference trajectory orbit, and any trajectory updates, is achieved with the execution of Orbit Trim Maneuvers (OTMs). The procedures for designing, processing, and analyzing OTMs during Cassini operations is presented. First, a brief overview of the Cassini-Huygens Mission is given, followed by a general description of navigation. Orbit control and maneuver execution methods are defined, along with an outline of the orbit control staffing and operations philosophy. Finally, an example schedule of orbit control operations is shown.

navigation↗
NASA NTRS2006

Cassini-Huygens maneuver automation for navigation

Many times during the Cassini-Huygens mission to Saturn, propulsive maneuvers must be spaced so closely together that there isn't enough time or workforce to execute the maneuver-related software manually, one subsystem at a time. Automation is required. Automating the maneuver design process has involved close cooperation between teams. We present the contribution from the Navigation system. In scope, this includes trajectory propagation and search, generation of ephemerides, general tasks such as email notification and file transfer, and presentation materials. The software has been used to help understand maneuver optimization results, Huygens probe delivery statistics, and Saturn ring-plane crossing geometry. The Maneuver Automation Software (MAS), developed for the Cassini-Huygens program enables frequent maneuvers by handling mundane tasks such as creation of deliverable files, file delivery, generation and transmission of email announcements, generation of presentation material and other supporting documentation. By hand, these tasks took up hours, if not days, of work for each maneuver. Automated, these tasks may be completed in under an hour. During the cruise trajectory the spacing of maneuvers was such that development of a maneuver design could span about a month, involving several other processes in addition to that described, above. Often, about the last five days of this process covered the generation of a final design using an updated orbit-determination estimate. To support the tour trajectory, the orbit determination data cut-off of five days before the maneuver needed to be reduced to approximately one day and the whole maneuver development process needed to be reduced to less than a week..

propulsion maneuvers↗
NASA NTRS1988

Materials processing in space: An introduction to the G-480 payload

The Space Research and Development Organization at San Jose State University designed and developed a small self-contained payload (designated G-480 by NASA) which will perform four materials science experiments in low Earth orbit aboard the Space Shuttle. These experiments are categorized under two areas of investigation: corrosion and electrodeposition. While none of these experiments have previously been performed in space, both government and industry have expressed great interest in these and related areas of materials processing and engineering. A brief history of the G-480 project development is given along with a description of each experiment, followed by a tour of the G-480 payload. Expected results are discussed along with the function, design and operation of the payload hardware and software.

Butow, Steven J.↗
NASA NTRS2005

Cassini orbit determination performance during the first eight orbits of the Saturn satellite tour

From June 2004 through July 2005, the Cassini/Huygens spacecraft has executed nine successful close-targeted encounters by three major satellites of the Saturnian system. Current results show that orbit determination has met design requirements for targeting encounters, Hugens descent, and predicting science instrument pointing for targetd satellite encounters. This paper compares actual target dispersion against, the predicte tour covariance analyses.

navigation↗
NASA NTRS2006

Cassini distributed instrument operations – what we’ve learned since Saturn orbit insertion

The Cassini mission to Saturn is complex with 12 science teams conducting distributed operations across the United States and Europe. Each Team includes scientists from around the world who actively participate in operations, including observation design, instrument commanding, downlink processing, and archiving. This represents a change in how JPL complex deep-space missions have been operated. Since Saturn Orbit Insertion (SOI), the Cassini Project has spent 17 months conducting science operations and has gained realworld experience that has tested the assumptions and rationale for this approach. We have learned that many of the expected benefits have been realized, but there were numerous unexpected challenges as well. This paper will discuss the lessons learned from the Cassini Tour experience to date. It will revisit the assumptions and rationale behind the distributed instrument operations design and will describe the results, good and bad, of implementing this method of operations. We will describe how Instrument Teams are structured, their roles and responsibilities, what challenges they faced going into orbital operations (the “tour”) and what creative solutions were proposed when funding limitations and schedule milestones prevented optimum solutions. We will also discuss the problems that have been encountered both on the ground and with the instruments, how these problems and anomalies were overcome, and what was learned along the way about the characteristics of distributed instrument operations.

Woncik, Pam↗
NASA NTRS2006

Cassini Distributed Instrument Operations: What We've Learned Since Saturn Orbit Insertion

The Cassini mission to Saturn is complex with 12 science teams conducting distributed operations across the United States and Europe. Each Team includes scientists from around the world who actively participate in operations, including observation design, instrument commanding, downlink processing, and archiving. This represents a change in how JPL complex deep-space missions have been operated. Since Saturn Orbit Insertion (SOI), the Cassini Project has spent 17 months conducting science operations and has gained real-world experience that has tested the assumptions and rationale for this approach. We have learned that many of the expected benefits have been realized, but there were numerous unexpected challenges as well. This paper will discuss the lessons learned from the Cassini Tour experience to date. It will revisit the assumptions and rationale behind the distributed instrument operations design and will describe the results, good and bad, of implementing this method of operations. We will describe how Instrument Teams are structured, their roles and responsibilities, what challenges they faced going into orbital operations (the 'tour') and what creative solutions were proposed when funding limitations and schedule milestones prevented optimum solutions. We will also discuss the problems that have been encountered both on the ground and with the instruments, how these problems and anomalies were overcome, and what was learned along the way about the characteristics of distributed instrument operations.

Cassini↗
NASA NTRS2004

A Summer Research Program of NASA/Faculty Fellowships at the Jet Propulsion Laboratory

The NASA Faculty Fellowship Program (NFFP) is designed to give college and university faculty members a rewarding personal as well as enriching professional experience. Fellowships are awarded to engineering and science faculty for work on collaborative research projects of mutual interest to the fellow and his or her JPL host colleague. The Jet Propulsion Laboratory (JPL) and the California Institute of Technology (Caltech) have participated in the NASA Faculty Fellowship Program for more than 25 years. Administrative offices are maintained both at the Caltech Campus and at JPL; however, most of the activity takes place at JPL. The Campus handles all fiscal matters. The duration of the program is ten continuous weeks. Fellows are required to conduct their research on-site. To be eligible to participate in the program, fellows must be a U.S. citizen and hold a teaching or research appointment at a U.S. university or college. The American Society of Engineering Education (ASEE) contracts with NASA and manages program recruitment. Over the past several years, we have made attempts to increase the diversity of the participants in the NFFP Program. A great deal of attention has been given to candidates from minority-serving institutions. There were approximately 100 applicants for the 34 positions in 2002. JPL was the first-choice location for more than half of them. Faculty from 16 minority-serving institutions participated as well as four women. The summer began with an orientation meeting that included introduction of key program personnel, and introduction of the fellows to each other. During this welcome, the fellows were briefed on their obligations to the program and to their JPL colleagues. They were also given a short historical perspective on JPL and its relationship to Caltech and NASA. All fellows received a package, which included information on administrative procedures, roster of fellows, seminar program, housing questionnaire, directions to JPL, maps of the local area, and a copy of the JPL Universe (a JPL newsletter). A calendar of events for the 2002 NFFP Program was designed to expose the fellows to the full range of JPL activities, seminars, tours, and trips to NASA Dryden, Goldstone, and Palomar Observatory. Weekly brown-bag lunches were also scheduled. The lunches provided a time for airing problems that may have arisen during the previous week, soliciting suggestions for program enhancement, announcements, and general socializing. Professor and Mrs. Albee also hosted the annual Summer Faculty Welcome Party at their home. During their ten-week tenure at JPL, the visiting faculty carried out projects in a wide variety of JPL's science, engineering, and technology disciplines, including communication, planetary science, materials research, reliability and quality assurance, astronomy, guidance and control, and micro-sensors. At the end of the NFFP Program, all fellows were required to complete a one-page summary of their summer s work. This was in addition to any documentation required by their host organization. Distribution of the final paycheck was dependent upon submission of this one-page summary and completion of NASA's NFFP evaluation in the EdCATS system. Fellows were also asked to complete a questionnaire for JPL, which enables the program administrators to make any appropriate changes to make the program more beneficial and effective for all involved. The 2002 NFFP Program at JPUCaltech was considered unanimously highly successful by both fellows and JPL colleagues. It provided a significant experience to most faculty members and fresh ideas to JPL researchers. Each year, suggestions for improvement include expansion of the program, longer terms, larger stipends, funds to support graduate students, and funds to continue collaborative research. The NASA Faculty Fellowship Program continues to occupy a significant place in JPL programs and serves to strengthen the ties between NASA, JPL, Caltech, and t academic community. This program is an important part of NASA's commitment to education. No inventions or patents were created during this program.

Albee, Arden↗
NASA NTRS2004

Cassini science planning process

The mission design for Cassini-Huygens calls for a four-year orbital survey of the Saturnian system and the descent into the Titan atmosphere and eventual soft-landing of the Huygens probe. The Cassini orbiter tour consists of 76 orbits around Saturn with 44 close Titan flybys and 8 targeted icy satellite flybys. The Cassini orbiter spacecraft carries twelve scientific instruments that will perform a wide range of observations on a multitude of designated targets. The science opportunities, frequency of encounters, the length of the Tour, and the use of distributed operations pose significant challenges for developing the science plan for the orbiter mission. The Cassini Science Planning Process is the process used to develop and integrate the science and engineering plan that incorporates an acceptable level of science required to meet the primary mission objectives far the orbiter. The bulk of the integrated science and engineering plan will be developed prior to Saturn Orbit Insertion (Sol). The Science Planning Process consists of three elements: 1) the creation of the Tour Atlas, which identifies the science opportunities in the tour, 2) the development of the Science Operations Plan (SOP), which is the conflict-free timeline of all science observations and engineering activities, a constraint-checked spacecraft pointing profile, and data volume allocations to the science instruments, and 3) an Aftermarket and SOP Update process, which is used to update the SOP while in tour with the latest information on spacecraft performance, science opportunities, and ephemerides. This paper will discuss the various elements of the Science Planning Process used on the Cassini Mission to integrate, implement, and adapt the science and engineering activity plans for Tour.

Cassini↗
NASA NTRS1970

Reliability in long-life missions

Long life spacecraft design and reliability based on marine practices and advanced system technology project, considering grand tour outer planets mission

Draper, R. F.↗
NASA NTRS1990

Automated design of multiple encounter gravity-assist trajectories

Given a range of initial launch dates and a set of target planets, a new approach to planetary mission design is developed, using an automated method for finding all conic solutions. Each point on the diagrams reproduced represents a single ballistic trajectory and is computed by modeling the trajectory as a conic section and solving the corresponding Lambert problem for each set of launch and arrival dates. An example which prescribes a launch period of 1975-2050 and target planets Uranus, Saturn, Jupiter, Neptune and Pluto is described whereby, all possible grand tour missions of this class are found, including the Voyager II trajectory. It is determined that this automated design tool may be applied to a variety of multiple encounter gravity-assist trajectories that are being considered for future missions.

Longuski, James M.↗
NASA NTRS1986

Space Station Habitability Recommendations Based on a Systematic Comparative Analysis of Analogous Conditions

Conditions analogous to the proposed NASA Space Station are systematically analyzed in order to extrapolate design guidelines and recommendations concerning habitability and crew productivity. Analogous environments studied included Skylab, Sealab, Tektite, submarines, Antarctic stations and oil drilling platforms, among others. These analogues were compared and rated for size and composition of group, social organization, preparedness for mission, duration of tour, types of tasks, physical and psychological isolation, personal motivation, perceived risk, and quality of habitat and life support conditions. One-hundred design recommendations concerning, sleep, clothing, exercise, medical support, personal hygiene, food preparation, group interaction, habitat aesthetics, outside communications, recreational opportunities, privacy and personal space, waste disposal, onboard training, simulation and task preparation, and behavioral and physiological requirements associated with a microgravity environment, are provided.

Stuster, Jack W.↗
NASA NTRS1972

Outer planet Grand Tour missions photometry/polarimetry experiment critical components study

Work performed during this effort was limited to two primary areas of technical concern: optical design optimization, and sensor selection. An optical system concept was established, and various system components were evaluated through experimental test sequences. Photodetectors were investigated for the applicability in meeting OPGT requirements as constrained by the photometry/polarimetry team directives. The most promising (gallium arsenide PMT) was further experimentally tested to ascertain its behavior with respect to anticipated environmental conditions. Results of testing and summary of the preceding tradeoff study effort are presented.

Pellicori, S. F.↗