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NASA NTRS1988

Life sciences space biology project planning

The Life Sciences Space Biology (LSSB) research will explore the effect of microgravity on humans, including the physiological, clinical, and sociological implications of space flight and the readaptations upon return to earth. Physiological anomalies from past U.S. space flights will be used in planning the LSSB project.The planning effort integrates science and engineering. Other goals of the LSSB project include the provision of macroscopic view of the earth's biosphere, and the development of spinoff technology for application on earth.

Primeaux, G.↗
NASA NTRS1991

A spacefaring nation - Perspectives on American space history and policy

The present volume on perspectives on American space history and policy discusses decision-making, space science and scientific communities, postwar aeronautical research in the federal laboratory, and civilian and military remote sensing and reconnaissance. Attention is given to the interpenetration of science, technology, and politics; space 'sociology'; and space technology and planetary science from 1950 to 1985. Other topics addressed include the aeronautics infrastructure as it applies to aeronautics history, the Lewis Research Center and its transition to space, the relationship between NASA and the users of earth resources data, and methodology for researching a classified system for space reconnaissance.

Collins, Martin J.↗
NASA NTRS2005

NASA Project Constellation Systems Engineering Approach

NASA's Office of Exploration Systems (OExS) is organized to empower the Vision for Space Exploration with transportation systems that result in achievable, affordable, and sustainable human and robotic journeys to the Moon, Mars, and beyond. In the process of delivering these capabilities, the systems engineering function is key to implementing policies, managing mission requirements, and ensuring technical integration and verification of hardware and support systems in a timely, cost-effective manner. The OExS Development Programs Division includes three main areas: (1) human and robotic technology, (2) Project Prometheus for nuclear propulsion development, and (3) Constellation Systems for space transportation systems development, including a Crew Exploration Vehicle (CEV). Constellation Systems include Earth-to-orbit, in-space, and surface transportation systems; maintenance and science instrumentation; and robotic investigators and assistants. In parallel with development of the CEV, robotic explorers will serve as trailblazers to reduce the risk and costs of future human operations on the Moon, as well as missions to other destinations, including Mars. Additional information is included in the original extended abstract.

Dumbacher, Daniel L.↗
NASA NTRS2010

Interplanetary Transit Simulations Using the International Space Station

It has been suggested that the International Space Station (ISS) be utilized to simulate the transit portion of long-duration missions to Mars and near-Earth asteroids (NEA). The ISS offers a unique environment for such simulations, providing researchers with a high-fidelity platform to study, enhance, and validate technologies and countermeasures for these long-duration missions. From a space life sciences perspective, two major categories of human research activities have been identified that will harness the various capabilities of the ISS during the proposed simulations. The first category includes studies that require the use of the ISS, typically because of the need for prolonged weightlessness. The ISS is currently the only available platform capable of providing researchers with access to a weightless environment over an extended duration. In addition, the ISS offers high fidelity for other fundamental space environmental factors, such as isolation, distance, and accessibility. The second category includes studies that do not require use of the ISS in the strictest sense, but can exploit its use to maximize their scientific return more efficiently and productively than in ground-based simulations. In addition to conducting Mars and NEA simulations on the ISS, increasing the current increment duration on the ISS from 6 months to a longer duration will provide opportunities for enhanced and focused research relevant to long-duration Mars and NEA missions. Although it is currently believed that increasing the ISS crew increment duration to 9 or even 12 months will pose little additional risk to crewmembers, additional medical monitoring capabilities may be required beyond those currently used for the ISS operations. The use of the ISS to simulate aspects of Mars and NEA missions seems practical, and it is recommended that planning begin soon, in close consultation with all international partners.

Charles, J. B.↗
NASA NTRS2008

ESMD Space Grant Faculty Report

The strength of the Exploration Systems Mission Directorate ESMD Faculty Project lies in its ability to meet National Aeronautics Space Administration NASA's Strategic Educational Outcome 1 by developing a sustainable and long-term integration of student involvement at academic institutions with all NASA Centers. This outcome is achieved by a three-fold approach: 1) by collecting Senior Design projects pertaining to Constellation work performed at each of the ten NASA Centers, 2) by engaging students at Minority Serving Institutions in the art of systems engineering and systems design of technologies required for space exploration, and 3) by identifying potential internships at each Center relative to exploration that provide students who are supported by their institutional Space Grant to engage in on-going mission-level and explorative systems designs. The objectives of the ESMD Faculty Project are to: 1. Aid the Centers (both Education Offices and associated technical organizations) in providing relevant opportunities for the ESMD Space Grant Program to support student and faculty in Senior Design projects 2. Enable better matches between the ESMD work required and what the Space Grant Consortia can do to effectively contribute to NASA programs 3. Provide the Space Grant Consortia an opportunity to strengthen relations with the NASA Centers 4. Develop better collective understanding of the U.S. Space Exploration Policy by the Center, Space Grant, faculty, Education Office, and students 5. Enable Space Grant institution faculty to better prepare their students to meet current and future NASA needs 6. Enable the Center Education Offices to strengthen their ties to their technical organizations and Space Grant Consortia 7. Aid KSC in gaining a greater and more detailed understanding of each of the Center activities Senior Design projects are intended to stimulate undergraduate students on current NASA activities related to lunar, Mars, and other planetary missions and to bring out innovative and novel ideas that can be used to complement those currently under development at respective NASA Centers. Additionally, such academic involvement would better the prospects for graduating seniors to pursue graduate studies and to seek careers in the space industry with a strong sense for systems engineering and understanding of design concepts. Internships, on the other hand, are intended to provide hands-on experience to students by engaging them in diverse state-of-the-art technology development, prototype bread-boarding, computer modeling and simulations, hardware and software testing, and other activities that provide students a strong perspective of NASA's vision and mission in enhancing the knowledge of Earth and space planetary sciences. Ten faculty members, each from a Space Grant Consortium-affiliated university, worked at ten NASA Centers for five weeks between June 2 and July 3, 2008. The project objectives listed above were achieved. In addition to collecting data on Senior Design ideas and identifying possible internships that would benefit NASA/ESMD, the faculty fellows promoted and collected data when required for other ESMD-funded programs and helped the Center's Education Office, as,needed. 4

Guo, Jiang↗
NASA NTRS1995

New Technologies for Cost-Effective High-Performance Remote Sensing from Space

Scientific exploration of the Solar System, astrophysics discoveries, and earth observations for weather and environment have had a profound effect on our understanding of the Universe. Modern sensors, propulsion, materials technology, planetary and astrophysics missions are briefly discussed, tracing the history of the applications of technology to space science missions in a few areas.

Technology↗
NASA NTRSDate not supplied

Gateway Program Safety and Mission Assurance Integration - the Future of Safe Deep Space Human Exploration

As a foundational element of the National Aeronautics and Space Administration (NASA) Artemis Campaign, the Gateway is an incrementally built cislunar spacecraft that will serve as a platform for deep space human exploration, science, and technology demonstration. The Gateway will be a unifying catalyst for international partners around the world to establish sustained deep space scientific investigations, lunar surface access, and missions to Mars. As human exploration moves farther away from Earth, spacecraft designs must prioritize and optimize mass and volume allocations, while minimizing human and spacecraft risk. To accomplish this objective, the Gateway Program Safety and Mission Assurance functions develop, implement, and ensure compliance with requirements, in concert with the accurate characterization and transparent communication of residual hazard risks, for integrated safety, reliability and maintainability and quality assurance. Safety and Mission Assurance was a key contributor during Gateway program pre-formulation and formulation activities where safety and reliability analysis was embedded in the Gateway Systems Engineering and Integration team. During these early program stages, a preliminary Gateway Integrated Hazard Analysis and Preliminary Gateway Probabilistic Risk Assessment assisted in Gateway architectural and operational definition as part of a risk-informed design process. As the deep space architecture has matured, the integrated Safety and Mission Assurance analyses have matured, new safety review processes have been developed, and requirements have been refined to ensure compliance with integrated safety and mission assurance objectives. The Gateway Program is currently concluding the preliminary design review informed milestone, where the primary objectives included: - Ensured completeness and consistency of the preliminary design, including the meeting of all requirements within appropriate margins and acceptable risk posture. - Identification of any major issues moving forward to the Critical Design phase. At this milestone, Safety and Mission Assurance provided numerous products, including Gateway Top Risks and Risk Mitigation Plans, updated integrated hazard analyses, updated probabilistic risk assessment, Crew Survival Analysis Report, and updated Safety and Mission Assurance Requirements and Plans. These products provide a many-faceted perspective on the inherent risk and available mitigations involved in flying the current proposed vehicle design and anticipated stack configurations. In addition, Safety and Mission Assurance identified top technical, process and workforce concerns to be addressed as the program progresses toward the critical design phase. This paper will detail the evolution of the Gateway Program Safety and Mission Assurance integration functions, provide its current status and lessons learned for future human spaceflight programs. Throughout this paper the key tenets of the Gateway Program Safety and Mission Assurance will be discussed: - Application of a risk-informed approach to identify and mitigate areas of highest risk. - Leverage of valuable processes and lessons learned from earlier spaceflight programs. - Development of Safety and Mission Assurance products to inform design risk trades. - Utilization of common Safety and Mission Assurance practices to identify safety risks for multiple perspectives: top-down, bottom-up, and across lines of integration. - Approval of safety hazards at the appropriate level of authority, keeping most deliberation closest to design expertise and elevating risks of greatest concern for program-level consideration. - Championing of Safety and Mission Assurance processes and forums to foster a pervasive safety culture that is transparent, inclusive, and collaborative between all partners. These tenets have allowed the Gateway Safety and Mission Assurance function to play a key role in optimized vehicle design evolution, and early identification and mitigation of Gateway program and Artemis mission risk.

Helen Vaccaro↗
NASA NTRSDate not supplied

Addressing the High-Rate Deep Space Communications Shortfall in NASA’s Space Technology Mission Directorate's Envisioned Future

NASA’s Space Technology Mission Directorate (STMD) has identified key technologies needed for future crewed and robotic exploration and science missions. STMD is helping to build the civilian technology base by working with other NASA Mission Directorates, other United States government agencies, commercial industry, and academia to identify technology shortfalls and to develop plans to address them. One critical area of shortfalls lies with deep space communications and navigation. While NASA had huge success to date with the Deep Space Network (DSN), recent studies have shown that without enhancements to current systems, the DSN will be unable to support the anticipated increases in the pace of space exploration or the expected higher data rates from deep space needed soon without severely impacting other missions. High-rate communications from the Moon and beyond is needed to enable future exploration and science missions currently being developed or under consideration. For example, a robust communications infrastructure will be needed to support a sustained human presence on the Moon and its eventual industrialization. High data rate trunk lines between the Earth and the Moon are needed to reduce the number of individual links. The human exploration of Mars will also require high-rate communications between Earth and Mars. Return data rates to Earth from Mars for a single link, for example, are anticipated to be greater than 100 Mb/s; forward data rates to Mars, based on experience from the International Space Station, are anticipated to be greater than 20 Mb/s. Future deep space science missions will also require higher data rates than possible with today’s technology and the current capabilities of the DSN. To support future exploration and science needs, it will be necessary to upgrade the DSN to enhance its radio frequency (RF) capabilities. In addition, it is envisioned that NASA will gradually introduce optical communications to augment its RF systems. Optical communications will enable new science and exploration missions by providing high data rates and better navigation over long distances. This paper will briefly describe STMD’s envisioned future for deep space communications in the 2030+ timeframe and the technology roadmaps being developed for both radio frequency and optical systems.

Bernard Edwards↗
NASA NTRS2021

The Solar Cruiser Mission

Selected by NASA as an ESPA-class rideshare technology demonstration mission to launch with the Interstellar Mapping and Acceleration Probe (IMAP) mission in 2025, the NASA MSFC Solar Cruiser mission will mature solar sail technology for use in future Heliophysics missions, as well as missions of interest across a broad user community including NOAA, Earth, and Planetary Sciences. Solar sails, which use reflected sunlight to derive thrust, can be used to create artificial equilibria and near-indefinite station-keeping at locations sunward of L1 along the Sun Earth Line (SEL), or at any desired offset from the SEL leading or trailing the Earth in its orbit. They can change the heliocentric inclination of a spacecraft from the ecliptic to as high as solar polar, stopping and remaining at any intermediate inclination orbit in between or can be used around a range of solar system bodies. The Solar Cruiser mission will fly a small spacecraft (~100 kg) with a large (>1600 square meter) solar sail containing embedded reflectivity control devices (RCDs) and photovoltaic cells, attaining a characteristic acceleration of >0.12 mm/s2. The mission concept includes successful deployment of the solar sail, validation of all sail subsystems, controlled station-keeping inside of the Sun-Earth L1 point, demonstration of pointing performance for science imaging, and finally an increase in heliocentric inclination (out of the ecliptic plane). Solar Cruiser would serve as a pathfinder for missions that observe the solar environment from unique vantage points such as a high inclination solar mission, opening a fundamentally new range of observational capabilities for the Heliophysics Program and for space weather monitoring. Observations away from the Sun-Earth line (SEL) present unique opportunities for answering the outstanding science questions of Heliophysics, for improving space-weather monitoring and prediction, and for revealing new discoveries about our Sun and solar system. High solar inclinations are particularly compelling. Investment in, and demonstration of, the technology needed to enable polar missions is essential to making this unique vantage point a reality in the next decade.

Solar Sail↗
NASA NTRS2020

Integration, Test, and On-Orbit Operation of a Ka-band Parabolic Deployable Antenna (KaPDA) for CubeSats

In the past decade, CubeSats have undergone a revolution, moving from universityresearch projects to enabling industry opportunities and government missions. Six yearsago, the Jet Propulsion Laboratory, California Institute of Technology (JPL/Caltech)initiated a research and technology development effort to advance CubeSat communicationcapabilities, with one of the key thrusts being the Ka-band parabolic deployable antenna(KaPDA). This antenna started with the ambitious goal of fitting a 42 dB, 0.5 meter, 35 GHzantenna in a 1.5U canister. At that time, there had been very limited development in the areaof high gain CubeSat antennas which are critical for both high data rate communicationsand remote sensing science. A Ka-band high gain antenna would provide a 10,000 timesincrease in data communication rates over an X-band patch antenna and a 100 timesincrease over state-of-the-art S-band parabolic antennas. This paper discusses the process ofbuilding, integrating, and operating the flight antenna, its final performance and lessonslearned. KaPDA was an enabling technology for RainCube mission, the first Earth ScienceCubeSat to have an active instrument. RainCube was launched in May of 2018, makingKaPDA the second deployable parabolic antenna to fly on a CubeSat and the first of its kindto operate at Ka-band enabling a number of opportunities for high rate, deep space antennacommunications and remote sensing science.

Thomson, Mark W.↗
NASA NTRS1991

Taurus lightweight manned spacecraft Earth orbiting vehicle

The Taurus Lightweight Manned Spacecraft (LMS) was developed by students of the University of Maryland's Aerospace Engineering course in Space Vehicle Design. That course required students to design an Alternative Manned Spacecraft (AMS) to augment or replace the Space Transportation System and meet the following design requirements: (1) launch on the Taurus Booster being developed by Orbital Sciences Corporation; (2) 99.9 percent assured crew survival rate; (3) technology cutoff data of 1 Jan. 1991; (4) compatibility with current space administration infrastructure; and (5) first flight by May 1995. The Taurus LMS design meets the above requirements and represents an initial step towards larger and more complex spacecraft. The Taurus LMS has a very limited application when compared to the Space Shuttle, but it demonstrates that the U.S. can have a safe, reliable, and low cost space system. The Taurus LMS is a short mission duration spacecraft designed to place one man into low earth orbit (LEO). The driving factor for this design was the low payload carrying capabilities of the Taurus Booster--1300 kg to a 300 km orbit. The Taurus LMS design is divided into six major design sections. The human factors system deals with the problems of life support and spacecraft cooling. The propulsion section contains the abort system, the Orbital Maneuvering System (OMS), the Reaction Control System (RCS), and power generation. The thermal protection systems and spacecraft structure are contained in the structures section. The avionics section includes navigation, attitude determination, data processing, communication systems, and sensors. The mission analysis section was responsible for ground processing and spacecraft astrodynamics. The systems integration section pulled the above sections together into one spacecraft and addressed costing and reliability.

Chase, Kevin A.↗
NASA NTRS2003

Jet Propulsion Laboratory: Annual Report 2002

The year 2002 brought advances on many fronts in our space exploration ventures. A new orbiter settled in at Mars and delivered tantalizing science results suggesting a vast store of water ice under the planet's surface, a discovery that may have profound consequences for exploring Mars. A long-lived spacecraft made its final fly-bys of Jupiter's moons, while another started its final approach toward Saturn and yet another flew by an asteroid on its way to a comet. A new ocean satellite began science observations, joined in Earth orbit by a pair of spacecraft measuring our home planets gravity field, as well as JPL instruments on NASA and Japanese satellites. A major new infrared observatory and a pair of Mars rovers were readied for launch. All told, JPL is now communicating with 14 spacecraft cast like gems across the velvet expanses of the solar system. It is a far cry from the early 1960's, when JPL engineers made prodigious efforts to get the first planetary explorers off the ground and into space - an achievement of which we were especially mindful this year, as 2002 marked the 40th anniversary of the first successful planetary mission, Mariner 2, which barely reached our closest planetary neighbor, Venus. Added to this anniversary were celebrations surrounding the 25th anniversaries of the launches of Voyagers 1 and 2, two remarkable spacecraft that are still flying and are actively probing the outer realms of the solar system. These events of the past and present provide an occasion for reflection on the remarkable era of exploration that we at the Jet Propulsion Laboratory are privileged to be a part of. As 2002 neared its end, the Laboratory had yet another reason for celebration, as a new five-year management contract between NASA and the California Institute of Technology was signed that calls for a closer working relationship with NASA and other NASA centers as a member of the 'One NASA' team. There is a strong emphasis on cost control and management, areas in which we can improve, enabling us to become more competitive. This new agreement again confirms NASA's trust and faith in Caltech and JPL, in which we should all take great pride. If the history of JPL were a book, we are on the verge of turning the page to one that promises to be one of the most exciting and busiest chapters in JPL's history. In 2003 and 2004, we will launch 11 spacecraft or major payloads. We will land two rovers on Mars; put a spacecraft in orbit around Saturn, deliver a probe to the surface of its largest moon, Titan, and map Titan's surface withimaging radar; send a spacecraft past a comet collecting samples from its tail, while another one is launched toward a comet impact; bring a capsule back to Earth with the first samples ever collected beyond the orbit of the Moon; map the skies in the ultraviolet as well as the infrared spectrum to unprecedented accuracy; and continue the mapping of ocean topography and winds on our home planet, Earth.

National Aeronautics and Space Administration (NAS↗
NASA NTRS1992

Advanced optical instruments technology

The science objectives for proposed NASA missions for the next decades push the state of the art in sensitivity and spatial resolution over a wide range of wavelengths, including the x-ray to the submillimeter. While some of the proposed missions are larger and more sensitive versions of familiar concepts, such as the next generation space telescope, others use concepts, common on the Earth, but new to space, such as optical interferometry, in order to provide spatial resolutions impossible with other concepts. However, despite their architecture, the performance of all of the proposed missions depends critically on the back-end instruments that process the collected energy to produce scientifically interesting outputs. The Advanced Optical Instruments Technology panel was chartered with defining technology development plans that would best improve optical instrument performance for future astrophysics missions. At this workshop the optical instrument was defined as the set of optical components that reimage the light from the telescope onto the detectors to provide information about the spatial, spectral, and polarization properties of the light. This definition was used to distinguish the optical instrument technology issues from those associated with the telescope, which were covered by a separate panel. The panel identified several areas for optical component technology development: diffraction gratings; tunable filters; interferometric beam combiners; optical materials; and fiber optics. The panel also determined that stray light suppression instruments, such as coronagraphs and nulling interferometers, were in need of general development to support future astrophysics needs.

Shao, Mike↗
NASA NTRS2003

Demonstrating a Realistic IP Mission Prototype

Flight software and hardware and realistic space communications environments were elements of recent demonstrations of the Internet Protocol (IP) mission concept in the lab. The Operating Missions as Nodes on the Internet (OMNI) Project and the Flight Software Branch at NASA/GSFC collaborated to build the prototype of a representative space mission that employed unmodified off-the-shelf Internet protocols and technologies for end-to-end communications between the spacecraft/instruments and the ground system/users. The realistic elements used in the prototype included an RF communications link simulator and components of the TRIANA mission flight software and ground support system. A web-enabled camera connected to the spacecraft computer via an Ethernet LAN represented an on-board instrument creating image data. In addition to the protocols at the link layer (HDLC), transport layer (UDP, TCP), and network (IP) layer, a reliable file delivery protocol (MDP) at the application layer enabled reliable data delivery both to and from the spacecraft. The standard Network Time Protocol (NTP) performed on-board clock synchronization with a ground time standard. The demonstrations of the prototype mission illustrated some of the advantages of using Internet standards and technologies for space missions, but also helped identify issues that must be addressed. These issues include applicability to embedded real-time systems on flight-qualified hardware, range of applicability of TCP, and liability for and maintenance of commercial off-the-shelf (COTS) products. The NASA Earth Science Technology Office (ESTO) funded the collaboration to build and demonstrate the prototype IP mission.

Rash, James↗
NASA NTRS2001

A Second Generation Multi-Angle Imaging SpectroRadiometer (MISR-2)

The Multi-angle Imaging SpectroRadiometer (MISR) has been in Earth orbit since December 1999 on NASA's Terra spacecraft. This instrument provides new ways of looking at the Earth's atmosphere, clouds, and surface for the purpose of understanding the Earth's ecology, environment, and climate. To facilitate the potential future continuation of MISR's multi-angle observations, a study was undertaken in 1999 and 2000 under the Instrument Incubator Program (IIP) of NASA Code Y's Earth Science Technology Office (ESTO) to investigate and demonstrate the feasibility of a successor to MISR that will have greatly reduced size and mass. The kernel of the program was the design, construction, and testing of a highly miniaturized camera, one of the nine that would probably be used on a future space borne MISR-like instrument. This demonstrated that the size and mass reduction of the optical system and camera electronics are possible and that filters can be assembled to meet the miniaturized packaging requirements. An innovative, reflective optics design was used, enabling the wavelength range to be extended into the shortwave infrared. This was the smallest all-reflective camera ever produced by the contractor. A study was undertaken to determine the feasibility of implementing nine (multi-angle) cameras within a single structure. This resulted in several possible configurations. It would also be possible to incorporate one of the cameras into an airborne instrument.

spectroradiometers↗
NASA NTRS2000

Future Weather Forecasting in the Year 2020-Investing in Technology Today: Improving Weather and Environmental Predictions

Fast-forward twenty years to the nightly simultaneous TV/webcast. Accurate 8-14 day regional forecasts will be available as will be a whole host of linked products including economic impact, travel, energy usage, etc. On-demand, personalized street-level forecasts will be downloaded into your PDA. Your home system will automatically update the products of interest to you (e.g. severe storm forecasts, hurricane predictions, etc). Short and long range climate forecasts will be used by your "Quicken 2020" to make suggest changes in your "futures" investment portfolio. Through a lively and informative multi-media presentation, leading Space-Earth Science Researchers and Technologists will share their vision for the year 2020, offering a possible futuristic forecast enabled through the application of new technologies under development today. Copies of the 'broadcast' will be available on Beta Tape for your own future use. If sufficient interest exists, the program may also be made available for broadcasters wishing to do stand-ups with roll-ins from the San Francisco meeting for their viewers back home.

Anthes, Richard↗
DOE OSTI2026

Occurrence of seeding multi-layer clouds in the Arctic from ground-based observations

Studies of Arctic clouds often focus on low-level single-layer clouds (SLCs). Here, we use combined observations of soundings and cloud radar during the MOSAiC, ACSE, and AO2018 research cruises as well as from long-term observations at Ny-Ålesund, Svalbard and Utqiagvik, Alaska to investigate the occurrence of SLCs and multi-layer clouds (MLCs) in the Arctic and to assess the rate of ice-crystal seeding in cold MLCs. MOSAiC observations show cloudy conditions in between 70 % and 90 % of sounding-radar cases. SLCs show occurrence rates of 30 % to 40 % with the highest value of 45 % during October. Cold MLCs are most abundant from November to June (40 % to 55 % of cases). Seeding occurs in about half to two thirds of the identified cold MLCs during MOSAiC for which the sub-saturated layer extends between 100 and 1000 m. The seeding rate increases by as much as 20 percentage points as the assumed size of the falling ice crystals is increased from 100 to 400 µm. The observations reveal a stable rate of cloud-free conditions of around 20 % over the covered latitude range. Cloud occurrence during MOSAiC and at Ny-Ålesund in July, when the geographical distance between observations was minimal, shows reasonable agreement. Comparisons of MOSAiC and other research cruises to the central Arctic also indicate consistent occurrence rates of different cloud types despite the likely effect of year-to-year variability. The comparison of data from ship campaigns and land sites suggests that the latter are not necessarily a good indicator of cloud occurrence in the high Arctic.

Achtert, Peggy [Leipzig Univ. (Germany); Meteorolo↗
NASA NTRS1990

Sensor requirements for Earth and planetary observations

Future generations of Earth and planetary remote sensing instruments will require extensive developments of new long-wave and very long-wave infrared detectors. The upcoming NASA Earth Observing System (EOS) will carry a suite of instruments to monitor a wide range of atmospheric and surface parameters with an unprecedented degree of accuracy for a period of 10 to 15 years. These instruments will observe Earth over a wide spectral range extending from the visible to nearly 17 micrometers with a moderate to high spectral and spacial resolution. In addition to expected improvements in communication bandwidth and both ground and on-board computing power, these new sensor systems will need large two-dimensional detector arrays. Such arrays exist for visible wavelengths and, to a lesser extent, for short wavelength infrared systems. The most dramatic need is for new Long Wavelength Infrared (LWIR) and Very Long Wavelength Infrared (VLWIR) detector technologies that are compatible with area array readout devices and can operate in the temperature range supported by long life, low power refrigerators. A scientific need for radiometric and calibration accuracies approaching 1 percent translates into a requirement for detectors with excellent linearity, stability and insensitivity to operating conditions and space radiation. Current examples of the kind of scientific missions these new thermal IR detectors would enhance in the future include instruments for Earth science such as Orbital Volcanological Observations (OVO), Atmospheric Infrared Sounder (AIRS), Moderate Resolution Imaging Spectrometer (MODIS), and Spectroscopy in the Atmosphere using Far Infrared Emission (SAFIRE). Planetary exploration missions such as Cassini also provide examples of instrument concepts that could be enhanced by new IR detector technologies.

Chahine, Moustafa T.↗