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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

Human Flight to Lunar and Beyond - Re-Learning Operations Paradigms

For the first time since the Apollo era, NASA is planning on sending astronauts on flights beyond Low-Earth Orbit (LEO). The Human Space Flight (HSF) program started with a successful initial flight in Earth orbit, in December 2014. The program will continue with two Exploration Missions (EM) to Lunar orbit: EM-1 will be unmanned and EM-2, carrying astronauts, will follow. NASA established a multi-center team to address the communications, and related navigation, needs. This paper will focus on the lessons learned in the team, planning for the missions' parts that are beyond Earth orbit. Many of these lessons had to be re-learned, as the HSF program after operated for many years in Earth orbit. Fortunately, the experience base from tracking robotic missions in deep space by the Deep Space Network (DSN) and close interaction with the HSF community to understand the unique needs (e.g. 2-way voice) resulted in a ConOps that leverages of both the deep space robotic and the Human LEO experiences. Several examples will be used to highlight the unique operational needs for HSF missions beyond Earth Orbit, including: - Navigation. At LEO, HSF missions can rely on Global Positioning System (GPS) devices for orbit determination. For Lunar-and-beyond HSF missions, techniques such as precision 2-way and 3-way Doppler and ranging, Delta-Difference-of-range, and eventually on-board navigation will be used. - Impact of latency - the delay associated with Round-Trip-Light-Time (RTLT). Imagine trying to have a 2-way discussion (audio or video) with an astronaut, with a 2-3 sec delay inserted (for Lunar distances) or 20 minutes delay (for Mars distances). - Balanced communications link. For robotic missions, there has been a heavy emphasis on the downlink data rates, bringing back science data from the instruments on-board the spacecraft. Uplink data rates were of secondary importance, used to send commands to the spacecraft. The ratio of downlink-to-uplink data rates was often 10:1 or more. For HSF, rates for uplink and downlink, at least for high-quality video, need to be similar.

Kenny, Ted↗
NASA NTRS1973

The deep space network, volume 13

The objectives, functions, and organization of the Deep Space Network are summarized. The deep space instrumentation facility, the ground communications facility, and the network control system are described. Other areas reported include: Helios Mission support, DSN support of the Mariner Mars 1971 extended mission, Mariner Venus/Mercury 1973 mission support, Viking mission support, radio science, tracking and ground-based navigation, network control and data processing, and deep space stations.

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NASA NTRS1990

Environmental projects. Volume 12: Friable asbestos abatement, GDSCC

The Goldstone Deep Space Communications Complex (GDSCC) is part of the NASA Deep Space Network, one of the world's largest and most sensitive scientific telecommunications and radio navigation networks. Activities at the GDSCC are carried out in support of six large parabolic dish antennas. These activities may give rise to a variety of environmental hazards, particularly the danger of exposure of GDSCC personnel to asbestos fibers that have been shown to be responsible for such serious ailments as asbestosis, lung cancer, and mesothelioma. Asbestos-containing materials (ACM's) were used in the construction of many of the approximately 100 buildings and structures that were built at the GDSCC during a 30-year period from the 1950s through 1980s. The friable asbestos-abatement program at the GDSCC is presented which consists of text, illustrations, and tables that describe the friable asbestos abatement carried out at the GDSCC from December 21, 1988 through May 11, 1989.

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NASA NTRS2010

Distributed Observer Network

The Distributed Observer network (DON) is a NASA-collaborative environment that leverages game technology to bring three-dimensional simulations to conventional desktop and laptop computers in order to allow teams of engineers working on design and operations, either individually or in groups, to view and collaborate on 3D representations of data generated by authoritative tools such as Delmia Envision, Pro/Engineer, or Maya. The DON takes models and telemetry from these sources and, using commercial game engine technology, displays the simulation results in a 3D visual environment. DON has been designed to enhance accessibility and user ability to observe and analyze visual simulations in real time. A variety of NASA mission segment simulations [Synergistic Engineering Environment (SEE) data, NASA Enterprise Visualization Analysis (NEVA) ground processing simulations, the DSS simulation for lunar operations, and the Johnson Space Center (JSC) TRICK tool for guidance, navigation, and control analysis] were experimented with. Desired functionalities, [i.e. Tivo-like functions, the capability to communicate textually or via Voice-over-Internet Protocol (VoIP) among team members, and the ability to write and save notes to be accessed later] were targeted. The resulting DON application was slated for early 2008 release to support simulation use for the Constellation Program and its teams. Those using the DON connect through a client that runs on their PC or Mac. This enables them to observe and analyze the simulation data as their schedule allows, and to review it as frequently as desired. DON team members can move freely within the virtual world. Preset camera points can be established, enabling team members to jump to specific views. This improves opportunities for shared analysis of options, design reviews, tests, operations, training, and evaluations, and improves prospects for verification of requirements, issues, and approaches among dispersed teams.

Conroy, Michael↗
NASA NTRS2012

Deep Space Communication

ITU defines deep space as the volume of Space at distances from the Earth equal to, or greater than, 2 106 km. Deep Space Spacecraft have to travel tens of millions of km from Earth to reach the nearest object in deep space. Spacecraft mass and power are precious. Large ground-based antennas and very high power transmitters are needed to overcome large space loss and spacecraft's small antennas and low power transmitters. Navigation is complex and highly dependent on measurements from the Earth. Every deep space mission is unique and therefore very costly to develop.

deep space communications↗
NASA NTRS2016

Enabling Affordable Communications for the Burgeoning Deep Space Cubesat Fleet

The low costs of development and launch, coupled with new propulsive technologies, have made CubeSats increasingly popular for use in science investigations beyond geosynchronous orbit. As this deep space CubeSat fleet grows in size, the challenge of trying to provide affordable communications for it grows commensurately. The mass, power, and volume constraints inherent to CubeSats limit the antenna size and transmit power that they can use to close the deep space link. As a consequence, CubeSats need to rely more heavily on ground antennas that are characterized by large aperture, low noise temperatures, and relatively high-power transmitters. Such antennas are not in great abundance, nor are they inexpensive to build. For this reason, NASA’s Deep Space Network has been advocating a three-pronged approach to meeting anticipated CubeSat demand: development of simultaneous, shared-beam multi-spacecraft communications capabilities, development of large-antenna cross-support arrangements with other agencies and universities, and development of less uplink-intensive navigation techniques. This paper focuses on the pursuit of simultaneous, shared-beam multi-spacecraft communications capabilities. While the Multiple Spacecraft per Antenna (MSPA) technique has existed for over a decade, it has generally been limited to supporting downlink for just two in-beam spacecraft at a time. This limitation has largely been a function of the number and cost of available receivers. A relatively new technique that potentially overcomes this limitation is Opportunistic MSPA (OMSPA). Instead of relying on additional receivers, OMSPA makes use of a digital recorder at each ground station that is capable of capturing the intermediate frequency (IF) signals from every spacecraft in the antenna beam within the frequency bands of interest. When CubeSat projects see one or more opportunities for their CubeSat(s) to intercept the traditionally scheduled antenna beam of a “host” spacecraft, they can arrange for the CubeSat(s) to transmit open loop during those opportunities. Via a secure Internet site, the CubeSat mission operators can then retrieve the time- and frequency-relevant portions of the digital recording for subsequent demodulation and decoding, or subscribe to a service that does it for them. This “opportunistic” use of a host spacecraft’s ground antenna beam potentially enables CubeSat projects to make use of large ground antennas for downlink without having to compete with bigger, better-funded missions for antenna time in the formal scheduling process. In so doing, it also potentially enables CubeSat projects to avoid the aperture fees associated with formally scheduled downlink time - fees that factor into the “bottom-line” of competitively-bid NASA missions and that actually get charged to non-NASA missions. Taking advantage of these potential OMSPA benefits, however, will require CubeSat projects to pursue mission designs that ensure at least periodic in-beam operations relative to a “host” spacecraft. In the case of a constellation of CubeSats with inter-spacecraft distances that do not extend outside of the beam-width of the desired ground antenna at the given range, one CubeSat can serve as the “host” and have a formally scheduled downlink while the rest of the CubeSats can downlink essentially for “free” via OMSPA. Deep space CubeSats, of course, will need uplink in addition to downlink. Beyond commanding, this need is driven by the use of two-way ranging and Doppler for navigation. While OMSPA may not directly facilitate uplink, it does have the potential to free up antennas for those spacecraft that periodically require formally scheduled links for commanding and two-way radio metrics. NASA is also exploring the physical feasibility of an in-beam, simultaneous multi-spacecraft uplink technique. As with OMSPA, if successful, it will require little new equipment, further enabling affordable deep space CubeSat communications.

Abraham, Douglas S.↗
NASA NTRS1972

Applications Technology Satellites -F and -G.

The objectives of the Applications Technology Satellite (ATS) Program are to advance space technology in areas of importance to mankind. A brief description of the planned satellites and experiments is presented. The experiments include instructional television, communications, navigation, meteorology, spacecraft technology and science. The ATS-F and -G satellites will have 30-foot deployable antennas and will serve as three-axis stabilized platforms in geostationary orbit with 0.1 degree pointing accuracy.

Gerwin, H. L.↗
NASA NTRS1990

Environmental projects, volume 10. Environmental assessment: New 34-meter antenna at Apollo site

The Goldstone Deep Space Communications Complex (GDSCC) is part of NASA's Deep Space Network (DSN), one of the world's largest and most sensitive scientific telecommunications and radio navigation networks. A detailed description of the GDSCC is presented. At present the Venus Station has an unused 9-meter antenna and a 26-meter (85 ft) antenna known as DSS-13. Construction of a new 34-meter (111.5 ft) antenna at the Venus site is under way to replace the present DSS-13 26-meter antenna. The proposed construction at the Apollo Site of a new, high efficiency, 34-meter, multifrequency beam waveguide-type antenna to replace the aging, 20-year old, DSS-12 34-meter antenna located at the Echo Site is analyzed. This new 34-meter antenna, to be constructed at the Apollo Site and to be known as DSS-18, will be of a design similar to the new DSS-13 34-meter antenna now being constructed at the Venus Site. When the new 34-meter antenna is completed and operational at the Apollo Site (planned for 1993), the old DSS-12 34-meter antenna at the Echo Site will be decommissioned, dismantled, and removed.

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NASA NTRS2002

The Living With a Star Geospace Investigations

The Living With a Star Geospace Investigations is established to effectively address those phenomena the Geospace environment that directly affect life and society. The priority science questions focus on two broad areas: (1) ionospheric variability, especially at mid-latitudes, that affects navigation and communications and (2) the source, acceleration mechanisms, and sinks of the radiation belts that degrade satellite lifetimes, produce surface charging, and threaten manned space flight. Candidate missions to address these science foci will be presented as well as possible additional investigations and experiments that would enable an understanding of the Geospace at the system level.

Spann, Jim↗
NASA NTRS2005

Chapter 19B - Antenna Radiation Patterns

Modern civil and military aircraft are equipped with a variety of communication devices, radio navigation equipment, and air traffic control systems. For all of these devices appropriate antennas must be available to transmit and receive the signals. As a result, as many as 30 antennas, and sometimes even more, are mounted around today's aircraft. For this reason, it is necessary to know the capabilities of the receiving/transmitting equipment on board. These capabilities are driven by the antenna characteristics. Therefore, coverage, shading, and beam pointing pattern data are necessary for optimum electronic coverage. The aircraft antenna has to convert the available power density of the electromagnetic field to an electric voltage at its connector. This voltage level must be sufficiently high to operate the connected equipment. The reciprocity principle states that it makes no difference if the antenna is receiving or transmitting. For the certification of the aircraft antennas it must be proven that the antennas are at least generating the minimum receiver input voltage which is required for each radio service. The prime condition is, of course, that the specified field power densities of the different radio navigation and communication services are available. An important property of a radio frequency link is the electro-magnetic field intensity at every point in space for a given output power of the antenna. As the propagation of radio frequency waves in free space is well known, the spatial distribution of the field intensity needs only be measured at one spatial sphere around the antenna. The information is usually given as distributions along the circumference of flat sections through this sphere: each of these is called an ARP. Several ARPs are usually required to describe the complete spatial antenna pattern of an antenna. In addition to mathematical modeling, measurements on sub-scale models, and static measurements on full size models or aircraft on the ground, dynamic measurements on aircraft in flight play the most important role in the aircraft antenna testing and certification. [19B-1] The shape of an ARP, for one given frequency, is determined by the shape of the antenna and the shape and material of the surface it is mounted on. As the directly transmitted waves interfere with waves reflected by the aircraft skin with its complex geometry, and the surface material parameters are only roughly known, it is not possible to predict the ARP with the required accuracy. In ground measurements the earth's surface also acts as a reflector thereby causing the ground ARP to be different from the in-flight ARP. As the in-flight ARP is the ARP we are actually interested in it becomes clear that it is necessary to conduct in-flight ARP measurements. The Flight Test Engineer must be aware of the needs of the specialists who are establishing the test program for measuring antenna patterns and radar cross sections. These tests will require special test equipment and dedicated flights to obtain the data that they require. This Section provides an introduction to the principles of determining antenna patterns and the flight techniques for determining both antenna patterns and radar cross section. Reference 19B-1 provides detailed information.

Helmut Bothe↗
NASA NTRS2005

Human Exploration and Avionic Technology Challenges

For this workshop, I will identify critical avionic gaps, enabling technologies, high-pay off investment opportunities, promising capabilities, and space applications for human lunar and Mars exploration. Key technology disciplines encompass fault tolerance, miniaturized instrumentation sensors, MEMS-based guidance, navigation, and controls, surface communication networks, and rendezvous and docking. Furthermore, I will share bottom-up strategic planning relevant to manned mission -driven needs. Blending research expertise, facilities, and personnel with internal NASA is vital to stimulating collaborative technology solutions that achieve NASA grand vision. Retaining JSC expertise in unique and critical areas is paramount to our long-term success. Civil servants will maintain key roles in setting technology agenda, ensuring quality results, and integrating technologies into avionic systems and manned missions. Finally, I will present to NASA, academia, and the aerospace community some on -going and future advanced avionic technology programs and activities that are relevant to our mission goals and objectives.

Benjamin, Andrew L.↗
NASA NTRS2021

NASA’s Deep Space Network: Automation in the Follow-the-Sun Era

The Deep Space Network (DSN) comprises three sites, located in California, Spain, and Australia; each site operates one 70m and multiple 34m antennas that provide communications and navigation services to NASA and international partners. As part of a multiyear upgrade in automation of the network, the DSN has undertaken a series of operations efficiency improvements which has fundamentally changed the operations paradigm of the network. At the start of this effort, each site operated only their local antennas and equipment 24 hours/day, 7 days/week, and each spacecraft activity (link) had a single dedicated Link Control Operator. In its final stage, realized in 2020, each one of the three sites operates the entire network during their local day shift, handing off control to the next site as their day ends, and tracks can be run in a fully automated manner with no operator intervention. This paradigm change has realized significant operations cost savings, but has posed some major challenges along the way. This paper describes the system changes that enabled the operations efficiency improvements, some the challenges, and plans for the future.

Levesque, Michael↗
NASA NTRSDate not supplied

Plans for NASA Contributions to Position, Navigation, and Timing at the Moon

Dating back to the Apollo missions, navigation in cislunar space has traditionally been performed with radiometric tracking and orbit estimation in Earth-based systems. The selected landing zones for Apollo enabled direct to Earth line of sight. Up to the present day, lunar orbiting science missions continue to rely on Earth sensors and processing. The upcoming Artemis and science missions seek different objectives, including landing and traversing in lunar locations occulted from view by Earth. Sustaining a burgeoning and diverse lunar mission set requires in-situ navigation capabilities that do not rely exclusively on Earth-based tracking and provide accurate and timely position, navigation, and timing (PNT) knowledge defined in a lunar reference system. These missions prefer a seamless transition from Earth-centric to lunar-centric PNT systems to reduce complexity and size, weight, and power (SWaP) on their missions. NASA’s heritage in successful high-altitude Global Navigation Satellite System (GNSS) reception is informing an expanded Space Service Volume to the moon and the development of lower SWaP GNSS receivers for the lunar missions. To overcome the geometric restrictions from GNSS –from both limited Dilution of Precision at the moon and lunar occultation – NASA is pursuing PNT services from the Lunar Communications Relay and Navigation System (LCRNS) as part of the interoperable LunaNet architecture to provide lunar-centric navigation services. For situations that require additional sensors, e.g. hazard detection, NASA’s optical navigation algorithms and close-range topographic sensors combine with observables from LunaNet in autonomous navigation software that brings robustness to the PNT solution. This presentation will provide an overview of NASA’s LCRNS PNT services, high-altitude GNSS and close-range sensors, processing algorithms and performance analysis, as well as efforts underway to define the underpinning Lunar Reference System.

Cheryl J. Gramling↗
NASA NTRS2006

End-to-end information system concept for the Mars Telecommunications Orbiter

The Mars Telecommunications Orbiter (MTO) was intended to provide high-performance deep space relay links to landers, orbiters, sample-return, missions, and approaching spacecraft in the vicinity of Mars, to demonstrate interplanetary laser communications, to demonstrate autonomous navigation, and to carry out is own science investigations.

EEIS↗
NASA NTRS2006

End-to-end information system concept for the Mars Telecommunications Orbiter

The Mars Telecommunications Orbiter (MTO) was intended to provide high-performance deep space relay links to landers, orbiters, sample-return missions, and approaching spacecraft in the vicinity of Mars, to demostrate interplanetary laser communications, to demonstrate autonomous navigation, and to carry out its own science investigations.

MTO↗
NASA NTRS2016

Architecture and CONOPS of Next-Generation Ground Network for Communications and Tracking of Interplanetary SmallSats

As small spacecraft venture out of Earth orbit, they will encounter challenges not experienced or addressed by the numerous low Earth orbit (LEO) CubeSat and Smallsat missions staged to date. The LEO CubeSats typically use low-cost, proven CubeSat radios, antennas, and university ground stations with small apertures. As more ambitious yet cost-constrained space mission concepts to the Moon and beyond are being developed, CubeSats and smallsats have the potential to provide a more affordable platform for exploring deep space and performing the associated science. Some of the challenges that have, so far, slowed the proliferation of small interplanetary spacecraft are those of communications and navigation.

Cheung, Kar-ming↗
NASA NTRS2018

In-Situ Navigation and Timing Services for a Human Mars Landing Site Part 2: System Design and Simulations

In a previous paper, we described the system concept of a proposed Mars Regional Navigation Satellite System (MRNSS) that is built upon a number of notional Mars orbiting and surface missions in the human exploration era of Mars. We assume two areostationary Mars relay orbiters that have continuous line-of-sight visibility with the Mars landing site, a Deep Space Habitat (DSH) in an inclined 48-hour circular orbit, and a surface communication lander that could serve as the reference point. These orbiting and surface infrastructure elements broadcast GPS-like ranging signals and other ephemeris information to the mission users. With one or more additional orbiters in areosynchronous orbits that trace around a figure-8 path, a regional navigation satellite system can be realized that provides in-situ course absolute localization and precision relative localization and timing services to the users in the vicinity of a Mars landing site. We also introduced a new geometric trilateration method that simultaneously performs absolute positioning and relative positioning. The relative position is derived from a “differencing” function of two raw-range measurements between a known reference point and of the target from a navigation satellite, thereby eliminating most of the common errors like atmospheric delays, ephemeris errors, and instrument delays in real-time. In the Mars environment, this “error-cancellation” function greatly reduces the need to perform extensive orbit determination (OD) of the navigation satellites like the Earth’s GPS, and only requires occasional tracks from the Earth’s large-aperture deep space antennas to perform OD’s. In this paper, we provide detailed simulations on both the absolute positioning scheme and the relative positioning scheme, and show that the relative positioning scheme provides 200 – 400 times improvement in localization accuracy. On the ground side, we discuss new approaches that simultaneously perform 2-way Doppler/ranging, and re-introduce the method of Same Beam Interferometry (SBI) for the Mars navigation orbiters. This helps to further reduce the tracking burden of the ground antennas required to support the OD of the Mars orbiters, making the concept of MRNSS more realizable.

Lightsey, Glenn↗
NASA NTRSDate not supplied

NASA’s Interest in 3GPP Mobile Telecommunications Protocols for Near Earth Space and the Lunar Surface

In the next several years, NASA intends to return astronauts to the Moon through the Artemis Program. Under Artemis, NASA plans to collaborate with commercial and international partners to establish a long-term presence on the Moon. Near-term Artemis missions will be analogous but much more sophisticated versions of the last couple of Apollo missions. For example, the first area expected to be explored by an Artemis mission is near the south pole as opposed to the mid-latitudes visited by the Apollo astronauts, which makes direct communications with Earth more complicated. Lunar infrastructure will eventually be built over time by many organizations, public and private, to support sustained human exploration, science, and industrial activities on the Moon. A robust lunar communications and navigation infrastructure will be essential to realizing this long-term vision. Meanwhile, on Earth, major advances are being made as5G mobile telecommunications rollout across the globe. Furthermore, the 3rdGeneration Partnership Project (3GPP) is beginning to define future 6G capabilities. NASA envisions a lunar communications and navigation network with capabilities similar to those of communication networks we enjoy here on Earth. Building such a network will require participation by many organizations. NASA’s Tipping Point program seeks industry-developed space technologies that can both foster commercial space capabilities and benefit future NASA missions. This paper provides an overview of NASA’s interest in 3GPPanddescribescurrent work based on 3GPP standards within NASA or funded by NASA, such as Nokia’s upcoming Tipping Point demonstration of 4G/LTE on the lunar surface in early 2023.

Bernard L Edwards↗