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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 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Generative deep-learning reveals collective variables of Fermionic systems

Complex processes of fermionic systems ranging from protein folding to nuclear fission often follow a low-dimensional reaction path parametrized in terms of a few collective variables. In nuclear theory, variables related to the shape of the nuclear density in a mean-field picture are key to describing the large amplitude collective motion of the neutrons and protons. Exploring the adiabatic energy landscape spanned by these degrees of freedom reveals the possible reaction channels while simulating the dynamics in this reduced space yields their respective probabilities. Unfortunately, this theoretical framework breaks down whenever the systems encounters a quantum phase transition with respect to the collective variables. Here, in this study, we introduce a novel generative deep-learning algorithm designed to build reaction paths that ensure that the many-fermion wave function stays differentiable with respect to the collective variables. This approach is applicable to any fermionic system described by a coherent state. We use the case of potential energy curves in the 16 O nucleus within the Hartree-Fock theory to illustrate its main features.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
NASA NTRS2008

James Webb Space Telescope - L2 Communications for Science Data Processing

JWST is the first NASA mission at the second Lagrange point (L2) to identify the need for data rates higher than 10 megabits per second (Mbps). JWST will produce approximately 235 Gigabits of science data every day that will be downlinked to the Deep Space Network (DSN). To get the data rates desired required moving away from X-band frequencies to Ka-band frequencies. To accomplish this transition, the DSN is upgrading its infrastructure. This new range of frequencies are becoming the new standard for high data rate science missions at L2. With the new frequency range, the issues of alternatives antenna deployment, off nominal scenarios, NASA implementation of the Ka-band 26 GHz, and navigation requirements will be discussed in this paper. JWST is also using Consultative Committee for Space Data Systems (CCSDS) standard process for reliable file transfer using CCSDS File Delivery Protocol (CFDP). For JWST the use of the CFDP protocol provides level zero processing at the DSN site. This paper will address NASA implementations of Ground Stations in support of Ka-band 26 GHz and lesson learned from implementing a file base (CFDP) protocol operational system.

Johns, Alan↗
NASA NTRS2017

Environmental Control System Development

With the ever-growing desire for mankind to reach destinations whose distances had been deemed impossible to transit, the largest rocket known to man was designed and is being developed. The Space Launch System (SLS), National Aeronautics and Space Administration’s (NASA) solution for deep space travel, will begin its missions with the launch of Exploration Mission 1 (EM-1) and Exploration Mission 2 (EM-2). In order to accommodate the larger rocket, Kennedy Space Center made crucial upgrades to its existing facilities. At Launch Complex 39B, an entirely new Environmental Control System (ECS) was developed to supply the vehicle with the appropriate air or nitrogen gas mixture for launch. The new ECS displays must undergo Validation and Verification (V&V) using testing procedures developed to meet this requirement.

Stewart, Raymond↗
NASA NTRSDate not supplied

Monitoring Human Performance on Future Deep Space Missions Abstract

NASA and the commercial spacecraft community are working diligently to put the first woman on the moon in the 2024 timeframe. At the same time, NASA researchers are thinking about how to solve the even larger challenges that future deep space missions will bring. Space travel itself is difficult, but astronauts on deep space missions will face obstacles and unknowns never before experienced. In addition to the altered gravity and hostile/closed environment of a spacecraft, deep space crews will face increased radiation, isolation, and distance from Earth. During Extravehicular Activity (EVA, or “spacewalk”) operations, crew will experience increased physical and cognitive workload due to extended types, frequencies and durations of tasks performed on exploration missions in partial gravity environments. All of these stressors will impact crew physical and mental health and performance in difficult-to-anticipate ways. Crew autonomy may be one of the biggest challenges faced. Communication delays and blackouts will occur, and in those situations, the crew may not have access to the Mission Control Center (MCC). They may be forced to be solely dependent on each other and the available information onboard to stay alive, healthy, and achieve the mission. The only conceivable way to meet the challenges of Earth independence is to enable the crew to monitor their own health and performance -- preferably unobtrusively as they perform their duties. Technologies and techniques must be developed to aid the crew in these assessments. A deep space mission is expected to have relatively short periods of high cognitive demand, stress, and fatigue, alongside potentially long periods of cognitive underload during the transit, where boredom, loneliness, and depression can set in. Both ends of this spectrum are dangerous. Crew must be made aware when their task performance drops significantly, when their cognitive workload is too high, when they have lost situation awareness, or when they are too stressed or too fatigued to perform well. They must be able to identify these risks, and then mitigate them with countermeasures available onboard. A number of self-monitoring technologies are presently being explored by NASA to advance crew state determination capabilities. These range from real-time, physiological workload and situation awareness assessments, to crew health measurements determining physical and mental fitness for duty, to task performance metrics such as suit resource expenditures. For EVA tasks during surface exploration missions, biomedical information such as metabolic rate may be provided to crewmembers for situational awareness related to task performance efficiency. In addition, translation distances, hydration, nutrition, inspired CO2 exposure and other consumables usage rates may be useful input metrics for modeling individualized performance during tasks to inform crew or provide estimates of work efficiency. Oculomotor metrics such as gaze dwell time, pupilometry, and eye tracking collected in advanced helmet mounted displays could potentially be used to characterize crew situation awareness. This paper highlights some of these projects, and provides broader discussion about the need for advanced monitoring and smart technologies, as NASA takes the leap into the next generation of space exploration.

Kritina Holden↗
NASA NTRS2020

Capabilities Development: From International Space Station and the Moon to Mars

The President of the United States, in signing Space Policy Directive-1, directed the NASA Administrator “to lead an innovative and sustainable program of exploration with commercial and international partners to enable human expansion across the solar system and to bring back to Earth new knowledge and opportunities. Beginning with missions beyond low-Earth orbit (LEO), the United States will lead the return of humans to the Moon for long-term exploration and utilization, followed by human missions to Mars and other destinations.” NASA is charged to land American astronauts on the lunar South Pole in 2024 and to continue a campaign of sustainable lunar surface exploration in order to develop necessary technologies and capabilities to enable initial human missions to Mars. NASA’s lunar surface exploration plans are part of a continuum of activities utilizing platforms in low Earth orbit (LEO), cislunar space, and the lunar surface to demonstrate advanced technologies, advance operations concepts, and develop countermeasures to lessen the impacts of the space environment and long duration exposure on the crew working in space. NASA is using a capability-driven approach to identify critical gaps to be addressed as part of a focused program to reduce risk for future deep space exploration missions building to eventual human missions to the surface of Mars. Teams of discipline experts from across NASA identify capability gaps between the current state of the art and the needs of proposed exploration missions and develop integrated strategies and roadmaps for filling those gaps. These inputs include assessment of platform needs for demonstration and testing of new capabilities. Generally, the International Space Station (ISS) and Gateway are needed for demonstration of capabilities for Mars transit, while Lunar surface activities focus on development of capabilities and operational protocols for Mars surface. This paper discusses the activities required to advance critical exploration capabilities, focusing on selection of demonstration and test location based upon the unique environments and characteristics of the ISS, Gateway, and potential lunar surface assets. The optimal strategy will be a combination of ISS/LEO, Gateway, and lunar surface testing; however, not all capabilities require a deep space exploration missions.

Boggs, Kathleen Gallagher↗
NASA NTRS1997

First astronomical detection of the cumulene carbon chain molecule H2C6 in TMC-1

The cumulene carbenes are important components of hydrocarbon chemistry in low-mass star-forming cores. Here we report the first astronomical detection of the long-chain cumulene carbene H2C6 in the interstellar cloud TMC-1, from observations of two of its rotational transitions: J(K,K') = 7(1,7) --> 6(1,6) at 18.8 GHz and 8(1,8) --> 7(1,7) at 21.5 GHz, using NASA's Deep Space Network 70 m antenna at Goldstone, California. In addition we also observed the shorter cumulene carbene H2C4 at the same position. The fractional abundance of H2C6 relative to H2 is about 4.7 x 10(-11) and that of H2C4 is about 4.1 x 10(-9). The abundance of H2C6 is in fairly good agreement with gas-phase chemical models for young molecular cloud cores, but the abundance of H2C4 is significantly larger than predicted.

NASA Discipline Exobiology↗
NASA NTRS2018

NASA's Space Launch System: Unprecedented Payload Capabilities

As NASA turns 60 and plans to transition the International Space Station (ISS) and other low-Earth orbit (LEO) activities to commercial enterprises, the Agency's human exploration program turns its focus to deep space. With missions planned to send astronauts back to the Moon and to construct a lunar orbiting Gateway for surface access as well as science experiments and technology demonstrations, NASA requires a vehicle with capabilities for launching more mass and volume than is currently commercially available. To that end, NASA and its private sector partners are building the Space Launch System (SLS) super heavy-lift launch vehicle, which will send the new Orion crew capsule, eventually with a complement of four astronauts, to cislunar space for the first time since the Apollo Program in the 1960s and 1970s. NASA Kennedy Space Center's (KSC's) Exploration Ground Systems (EGS) Program has upgraded and refurbished ground and launch facilities to process, assemble and launch NASA's new deep space exploration system, which is managed by the Exploration Systems Development (ESD) organization in the Human Exploration and Operations Mission Directorate (HEOMD). Offering an unmatched combination of power, payload capacity and departure energy, the evolvable SLS features the world's most proven propulsion system: solid rocket boosters and RS-25 main engines with a modified Delta Cryogenic Second Stage (DCSS) cryogenic upper stage. The initial SLS configuration, Block 1, will deliver at least 26 metric tons (t) to trans-lunar injection (TLI). The second variant, Block 1B, will deliver at least 34 t to TLI in its crew configuration and at least 40 t to TLI in its cargo configuration. The Block 1 cargo vehicle will fly with an industry-standard 5 m fairing while the Block 1B cargo configuration will accommodate 8 m-diameter fairings in varying lengths. The Block 2 vehicle will incorporate upgraded boosters and possibly larger fairings for launching Mars-class payloads to deep space. Although designed to enable human exploration of deep space, the vehicle also provides game-changing benefits for large science payloads and even harnesses excess capacity to provide small satellites with access to deep space. Three flights of the Block 1 vehicle are now planned; the first vehicle, being built for a test flight known as Exploration Mission-1 (EM-1), is nearing completion at NASA and contractor sites across the United States. In fact, hardware for the second mission has also been built. This paper will provide an overview of the SLS vehicle, with a focus on its payload accommodations and the missions enabled by the unprecedented payload volume and departure energy of SLS. This paper also describes the status of the manufacturing and integration for first flight and beyond.

Exploration Mission-1↗
NASA NTRSDate not supplied

Promoting Crew Autonomy in a Human Spaceflight Earth Analog Mission through Self-Scheduling

Deep space exploration missions face the challenge of communication transmission latencies between ground stations and astronaut crews due to increasing distance between the Earth and spacecraft in transit. To address this, research at NASA has aimed toward supporting crew autonomy by enabling astronauts to schedule their own timelines with minimal oversight from Mission Control. While self-scheduling has been shown to be feasible, it is yet to be studied as an integral part of autonomous crew operations. The current paper reviews the operationalization of self-scheduling and a number of related objectives during Campaign 6 of HERA, a Human Exploration Research Analog. Research objectives include studying the effects of phasic autonomy over the course of a 45-day mission, evaluating differences in scheduling performance produced by software interface aids, and deploying a novel measure of crew attitudes toward self-scheduling and plan execution.

crew autonomy↗
NASA NTRSDate not supplied

Promoting Crew Autonomy in a Human Spaceflight Earth Analog Mission through Self-Scheduling

Deep space exploration missions face the challenge of communication transmission latencies between ground stations and astronaut crews due to increasing distance between the Earth and spacecraft in transit. To address this, research at NASA has aimed toward supporting crew autonomy by enabling astronauts to schedule their own timelines with minimal oversight from Mission Control. While self-scheduling has been shown to be feasible, it is yet to be studied as an integral part of autonomous crew operations. The current paper reviews the operationalization of self-scheduling and a number of related objectives during Campaign 6 of HERA, a Human Exploration Research Analog. Research objectives include studying the effects of phasic autonomy over the course of a 45-day mission, evaluating differences in scheduling performance produced by software interface aids, and deploying a novel measure of crew attitudes toward self-scheduling and plan execution.

crew autonomy↗
NASA NTRS2019

Enhanced Feasibility Assessment of Payload Adapters for NASA’s Space Launch System

The first flight of NASA’s new exploration-classlaunch vehicle, the Space Launch System (SLS), will test amyriad of systems designed to enable the next generation of deepspace human spaceflight, and launch from Kennedy SpaceCenter no earlier than December 2019. The initial Block 1configuration for EM-1 will be capable of lofting at least 70metric tons (t) of payload and send the Orion crew vehicle intoa distant retrograde lunar orbit, paving the way for future crewmissions to cislunar space and eventually Mars. A Block 1Bversion of SLS will lift at least 34 t to trans-lunar injection (TLI)in its crew configuration and at least 37 t to TLI in its cargoconfiguration no earlier than 2024. For Mars-class payloads,larger fairings and payload adapters for the Block 2 cargovehicle are under consideration. For missions beyond the Earth-Moon system, SLS offers greater characteristic energy (C3)than any other launch vehicle, enabling shorter transit times orheavier payloads with more robust science packages formissions to the outer solar system. Indeed, the unmatchedcombination of thrust, payload volume and departure energythat SLS provides opens new opportunities for human androbotic exploration of deep space.

Holladay, Jon B.↗
NASA NTRS2018

Payload Utilization in NASA's Space Launch System

With Space Policy Directive 1, the United States administration has directed the National Aeronautics and Space Administration’s (NASA’s) Human Exploration & Operations Mission Directorate (HEOMD) to return to the Moon with missions and infrastructure designed to support a sustained presence in cislunar space, with robotic and human lunar surface operations. NASA’s new deep space exploration system — the super heavy-lift Space Launch System (SLS), the Orion crew spacecraft and revamped launch facilities at Kennedy Space Center (KSC) — will enable NASA and its commercial and international partners to meet this goal for human exploration of deep space. SLS is the most capable launch vehicle for these efforts, as well as for sending robotic missions deep into the solar system, or even to interstellar space. The vehicle will be available in crew and cargo configurations in progressively more powerful block variants. The initial Block 1 lift capability of at least 26 metric tons (t) to trans-lunar injection (TLI) will be followed by a more powerful Block 1B with the power to loft more than 37 t to TLI. The ultimate Block 2 variant will lift more than 45 t to TLI. For payload accommodation, the Block 1 vehicle can utilize a 5 meter (m) fairing in its cargo configuration with the crew version also able to provide berths for 6U and 12U CubeSats as secondary payloads. The Block 1B crew vehicle will provide as much volume as the space shuttle payload bay in a Universal Stage Adapter (USA) for co-manifested payloads (CPLs). Block 1B cargo vehicles will offer 8.4 m-diameter fairings in 19.1 m and possibly longer lengths, with enough volume to accommodate lunar-orbiting habitat modules and other elements of NASA’s Gateway science outpost. For Mars-class payloads, larger fairings for the Block 2 cargo launcher are under consideration. For missions beyond the Earth-Moon system, SLS offers greater characteristic energy (C3) than any other launch vehicle, enabling shorter transit times or heavier payloads with more robust science packages for missions to the outer solar system. Indeed, the unmatched combination of thrust, payload volume and departure energy that SLS provides opens new opportunities for human and robotic exploration of deep space. This paper will provide an overview of the various vehicle block configurations, their capabilities and payload accommodations for sending primary, co-manifested and secondary payloads to deep space

Creech, Stephen D.↗
NASA NTRSDate not supplied

Lunar Node – 1: Initial Flight Results and the Role of Surface Psuedolites in Lunar Navigation

On February 22, 2024, the Intuitive Machines IM-1 NOVA-C lander, nick-named Odysseus, landed on the lunar surface, carrying with it a cadre of NASA scientific and technology demonstration payloads. These payloads and missions marked the first delivery of NASA instruments to operate from the lunar surface since the Apollo landings. One of these payloads is Lunar Node -1 (LN-1), a navigation beacon demonstration mission. The payload was designed and built by NASA’s Marshall Space Flight Center. The payload’s main goal was to demonstrate and provide insight into the use of lunar surface-based radio navigation aids. As part of the mission, LN-1 successfully conducted multiple one-way transmissions from the NOVA-C vehicle to Deep Space Network ground receivers using its onboard S-band transmitter, while being disciplined by an onboard Space Chip Scale Atomic Clock. LN-1 transmitted to DSN on an almost daily basis during transit to the moon, including two surface passes. The payload was originally plan to conduct 7-10 days of surface operation as an always-on beacon. These passes focused on evaluating two main navigation approaches: performance and stability of ranging using time-based transfer techniques on a cubesat size and grade platform, as well as one-way psuedonoise ranging approaches. To assess performance, the measurements were compared to independent navigation solutions using multiple approaches including: one-way Doppler tracking, two-way Doppler Tracking, and visual verification of the landing location provided by visual observations from orbital platforms. While the mission only conducted limited surface operations, the data provides some initial insight to performance form the lunar surface. These results are compared with initial ground-based testing as well as continued evaluation of the flight-space platform using multiple grades of oscillators for maintaining clock and frequency stability. These focus on the timing stability of platform in a deep-space environment as well variations in state determination. Given these insights, this paper provides additional description and evaluation of how this approach can be utilized as part of a broader lunar navigation architecture, such as being developed and deployed across multiple international space agencies. Analysis is provided to develop overall timing requirements and assessment of operational scenarios, such as orbit and surface location determination. In addition, the results support discussion as to how surface pseudolites could best be used within existing standard signal definitions, such as defined in the LunaNet Interoperability Specifications. This will consider concerns such as the near-/far- problem as well as operational considerations, including whether a beacon is better suited as two- or one-way ranging platform. The use cases are focused on how these psuedolites can provide additional coverage to augment and support planned operational coverage. For example, this analysis provides analysis of mid-latitude surface missions, where there may be limited geometry and availability of orbital relays. The results will show how these navigation psuedolites can fit within the developing architecture to provide additional robustness, capability, and support multiple use cases. Lastly, the paper will discuss challenges and next steps to be addressed in the implementation and testing of a follow-on payload and a continued path towards demonstration and integration of this capability into Lunar PNT architectures.

Evan Anzalone↗
NASA NTRSDate not supplied

Lunar Node – 1: Initial Flight Results and the Role of Surface Psuedolites in Lunar Navigation

On February 22, 2024, Intuitive Machines NOVA-C lander, nick-named Odysseus, landed on the lunar surface, carrying with it a cadre of NASA scientific and technology demonstration payloads. These payloads and missions marked the first delivery of NASA instruments to operate from the lunar surface since the Apollo landings. One of these payloads is Lunar Node -1 (LN-1), a navigation beacon demonstration mission. The payload was designed and built by NASA’s Marshall Space Flight Center. The payload’s main goal was to demonstrate and provide insight into the use of lunar surface-based radio navigation aids. As part of the mission, LN-1 successfully conducted multiple one-way transmissions from the NOVA-C vehicle to Deep Space Network ground receivers using its onboard S-band transmitter, while being disciplined by an onboard Space Chip Scale Atomic Clock. LN-1 transmitted to DSN on an almost daily basis during transit to the moon, including two surface passes. The payload was originally plan to conduct 7-10 days of surface operation as an always-on beacon. These passes focused on evaluating two main navigation approaches: performance and stability of ranging using time-based transfer techniques on a cubesat size and grade platform, as well as one-way psuedonoise ranging approaches. To assess performance, the measurements were compared to independent navigation solutions using multiple approaches including: one-way Doppler tracking, two-way Doppler Tracking, and visual verification of the landing location provided by visual observations from orbital platforms. While the mission only conducted limited surface operations, the data provides some initial insight to performance form the lunar surface. These results are compared with initial ground-based testing as well as continued evaluation of the flight-space platform using multiple grades of oscillators for maintaining clock and frequency stability. These focus on the timing stability of platform in a deep-space environment as well variations in state determination. Given these insights, this paper provides additional description and evaluation of how this approach can be utilized as part of a broader lunar navigation architecture, such as being developed and deployed across multiple international space agencies. Analysis is provided to develop overall timing requirements and assessment of operational scenarios, such as orbit and surface location determination. In addition, the results support discussion as to how surface pseudolites could best be used within existing standard signal definitions, such as defined in the LunaNet Interoperability Specifications. This will consider concerns such as the near-/far- problem as well as operational considerations, including whether a beacon is better suited as two- or one-way ranging platform. The use cases are focused on how these psuedolites can provide additional coverage to augment and support planned operational coverage. For example, this analysis provides analysis of mid-latitude surface missions, where there may be limited geometry and availability of orbital relays. The results will show how these navigation psuedolites can fit within the developing architecture to provide additional robustness, capability, and support multiple use cases. Lastly, the paper will discuss challenges and next steps to be addressed in the implementation and testing of a follow-on payload and a continued path towards demonstration and integration of this capability into Lunar PNT architectures.

Evan J Anzalone↗
NASA NTRS1981

Cryogenic filters for RFI protection

The increased bandwidth and sensitivity of the DSN maser-based receiver systems along with the increase in worldwide microwave spectrum usage dictated the need for employing additional measures to protect these systems from RFI (radio frequency inerference). Both in-band and out-of-band microwave signals at the input of the Deep Space Network (DSN) traveling wave masers (TWM) can adversely affect the maser performance in a variety of ways. Filters fabricated from superconducting materials operating below their superconducting transition temperature (Tc) possess the most potential for providing the necessary RFI protection without degrading the system performance.

Bautista, J. J.↗
NASA NTRS2004

Standard Observing Bands: Is Now the Time to Replace S/X with X/Ka?

In this paper we will argue that the VLBI community should be developing a road map to transition from S/X to simultaneous X and Ka-band (32 GHz) observations. There are both negative and positive reasons for planning such a transition. On the negative side, we will outline concerns that S-band observations may be headed toward obsolescence. On the positive side, we will refer to evidence that X/Ka has potential for providing a more stable reference frame than S/X. We will propose timetables for a transition to X/Ka observing starting from the current status of X/Ka and plans that are now taking shape. First X/Ka fringes were obtained in 2001 with the Deep Space Network. Future plans will be discussed including a proposed X/Ka-band upgrade to the VLBA. Lastly, we will consider the need for a period of overlap between S/X and X/Ka so that the long and rich history of astrometric and geodetic VLBI is not compromised.

Jacobs, C. S.↗
NASA NTRSDate not supplied

American Society of Plant Biologists Plenary Symposium Overview Presentation

NASA’s Artemis program in collaboration with international space agencies, and various commercial partners, marks the return of humankind to the Moon. Unlike the Apollo lunar missions from fifty years ago, Artemis will set the stage for the continuous presence of humans on the Moon and pave a path for the journey to Mars and beyond. Plants will be an essential component of habitation systems that will enable humans to thrive on both the lunar and Mars surface, as well as space transit vehicles because of their nutritional and psychological benefits. Furthermore, plants will be valued in environmental control and life support systems because they generate oxygen, remove carbon dioxide, and recycle water and waste. However, an in-depth understanding of how plants and their associated microbial communities adapt to the harsh and confined environment of deep space is essential before they can be effectively used for long-duration space missions. This plenary symposium will address challenges and present potential solutions to growing plants in space. The four speakers will cover a broad range of topics, including mechanistic studies on fern resurgence after asteroid-triggered mass extinction events, artificial photosynthesis for space agriculture, and how the plant microbiome and an understanding of plant-pathogen dynamics in microgravity can guide crop production strategies in space.

Plant Space Biology↗
DOE OSTI2024

Neural network representations of multiphase Equations of State

Abstract Equations of State model relations between thermodynamic variables and are ubiquitous in scientific modelling, appearing in modern day applications ranging from Astrophysics to Climate Science. The three desired properties of a general Equation of State model are adherence to the Laws of Thermodynamics, incorporation of phase transitions, and multiscale accuracy. Analytic models that adhere to all three are hard to develop and cumbersome to work with, often resulting in sacrificing one of these elements for the sake of efficiency. In this work, two deep-learning methods are proposed that provably satisfy the first and second conditions on a large-enough region of thermodynamic variable space. The first is based on learning the generating function (thermodynamic potential) while the second is based on structure-preserving, symplectic neural networks, respectively allowing modifications near or on phase transition regions. They can be used either “from scratch” to learn a full Equation of State, or in conjunction with a pre-existing consistent model, functioning as a modification that better adheres to experimental data. We formulate the theory and provide several computational examples to justify both approaches, highlighting their advantages and shortcomings.

Science & Technology - Other Topics↗
NASA NTRS1982

Sensitive ammonia observations in the southern hemisphere

The 64-m spacecraft communication antenna of the NASA-JPL Deep Space Network has been equipped for spectral line observations at K band (18-25 GHz). To demonstrate the potential of this system, preliminary observations of the (1, 1) transition of ammonia are reported for a selection of eight southern molecular clouds. Estimates of gas density and ammonia column density are reported for six sources.

Dickinson, D. F.↗