STS-63 Hitchhiker Program/Payload Overview The Hitchhiker (HH) Program, managed by the Shuttle Small Payloads Project (SSPP) at Goddard Space Flight Center in Greenbelt, Maryland, is designed for customers who wish to fly quick-reaction and low-cost experiments on the Shuttle. The HH system is designed to be modular and expandable in accordance with customer requirements. HH provides power, data or command services to operate these experiments. Typically, payloads receive their power and data handling through the HH Avionics which provides standardized electrical, telemetry, and command interfaces between the orbiter and the experiments. During the mission operations, experimenters will receive real-time communications between themselves and their payloads at the Payload Operations Control Center (POCC) located at Goddard. The first of four HH missions manifested for 1995 is CGP/ODERACS-II. It is manifested to fly aboard STS-63, scheduled to launch on February 2nd and will remain in orbit for 8-days. The payload’s acronym stems from the following experiments: Cryo System Experiment (CSE), Shuttle Glow (GLO-2) experiment and the Orbital Debris Radar Calibration System-II (ODERACS-II) experiment. An IMAX Camera is also flying in this configuration. The HH carrier used to support the CGP/ODERACS-II experiments is a crossbay carrier referred to as a Mission Peculiar Equipment Support Structure (MPESS). Displays of orbit position, attitude, ancillary data, and any downlink data will allow the experimenters to monitor the status of their payloads during the mission. Experiment: Cryo System Experiment (CSE) Customer: Jet Propulsion Laboratory (JPL) and Hughes Aircraft Corporation Principal Investigator: Russell Sugimura (JPL), Sam Russo (Hughes) Mission Manager: Susan Olden, Hitchhiker Program, Goddard Space Flight Center (GSFC) The Cryo System Experiment (CSE) is a space-flight experiment conducted by the Hughes Aircraft Company in a cooperative program with NASA. The overall goal of the CSE is to validate and characterize the on-orbit performance of two thermal management technologies that comprise a hybrid cryogenic system. These thermal management technologies consist of: 1) a new generation, long life, low vibration, 65 K Stirling-cycle cryocooler, and 2) an oxygen diode heat pipe that thermally couples the cryocooler and a cryogenic thermal energy storage device. The experiment is necessary to provide a high confidence zero-gravity database for the design of future cryogenic systems for NASA and military space flight applications. These technologies promise to satisfy many of the currently defined system performance goals for planned NASA and military space programs. Feasibility of each technology has already been demonstrated in independent R&D ground based laboratory tests. However, questions raised by the scientific community relative to the performance of these components in a zero- gravity environment must be answered before these technologies can be optimized for application to flight systems. The CSE flight experiment is configured to: 1) provide data necessary to resolve performance and design issues, 2) validate capability of the hybrid cooling system to meet future mission requirements, and 3) provide for high confidence design optimization of flight system concepts currently being considered. During on-orbit operation, test data will be recorded to characterize performance of the technology including 1) oxygen diode heat pipe temperature gradient and transport capacity in steady-state and transient conditions, 2) system vibration levels attributed to the active cryocooler, and 3) integrated, extended operations of the cooling system. An understanding of the performance of these components in flight is required to develop accurate performance models for designing flight hardware. Key issues to be addressed include: 1) heat pipe transfer capacity and start up behavior, 2) cryocooler mechanical disturbance and cryocooler dynamic balance. Ground-based life testing of the cryocooler has been initiated at Hughes in support of the experiment, and will continue into next year for comparison with flight data. The flight experiment results will be significant to a number of satellites scheduled for deployment in the late 1990s, for which cryocooler technologies are contemplated, including those in support of NASA’s Mission to Planet Earth and Astrophysics Programs. The Cryo System Experiment illustrates an important type of NASA in-space flight experiment in which a relatively mature system technology is validated to provide the option for subsequent application in a near-future space system development. A successful experiment could be followed by the use of the technology in an operational system. Experiment: Shuttle Glow Experiment (GLO-2) Customer: University of Arizona and USAF/Phillips Laboratory Principal Investigator: Dr. Lyle Broadfoot (Univ. of AZ), Dr. Edmond Murad (Phillips Lab) Mission Manager: Susan Olden, Hitchhiker Program, GSFC This experiment originated as the Shuttle Glow experiment sponsored by the USAF/Phillips Laboratory. The nature of the instrument makes it ideal for studies of Earth’s thermosphere. Consequently, it has become a joint program with NASA/Space Physics Division of the Office of Space Science. The February Space Shuttle mission will carry this Hitchhiker payload to investigate the mysterious shroud of Iuminosity, called the glow phenomenon, observed by the astronauts on past Shuttle missions. Theory suggests that the glow may be due to atmospheric gasses collisionally interacting on the windward or ram side surface of the Space Shuttle with gaseous engine effluents and contaminant outgassing molecules. To understand why spacecraft glow and the potential effects of glow on space based sensors, USAF Phillips Laboratory is sponsoring the GLO experiment to collect spectral and imaging data to characterize the optical emissions. The co-principal investigators, Dr. Edmond Murad from the Phillips Laboratory and Dr. Lyle Broadfoot from the University of Arizona, plan to collect high resolution (0.5 nanometer) spectra over a wide spectral range including the ultraviolet and visible portions of the spectrum. The spatial extent of the glow will be mapped precisely (0.1 degrees), and the effects of ambient magnetic field, orbit altitude, mission elapsed time, shuttle thruster firings, and surface composition on the intensity and spectrum of the glow will be measured. An optical emission model will then be developed from the data. According to Dr. David J. Knecht, Phillips Laboratory Program Manager for GLO, the experiment consists of imagers and spectrographs, which are bore-slighted to the imagers, so that both sensors are focused onto the same area of observation, for example, the shuttle tail. The imagers serve to unambiguously identify the source region of the glow spectrum as well as to map the spatial extent of the luminosity. Unique features of the sensors are their high spectral and spatial resolution. Each spectrograph employs a concave holographic grating that focuses and disperses light within a small field of view (0.1 by 2.0 degrees) over the wavelength range 115-1100 nanometers. The sensor comprises 9 separate channels, each of which operates simultaneously and independently, to cover individual segments of the spectrum. Spectrally resolved light from the grating is amplified by image intensifiers that are optically coupled to a charge-coupled-device (CCD) detector. CCD-pixel readouts are summed in groups to achieve spatial mapping with a resolution of about 0.1 degrees. The imager comprises six separate telescopes, of which four are intensified. Images are conducted to the single CCD by fiberoptics. One image channel is wide angle, and one has high magnification. The other four channels are filtered to different wavelength bands. The spectrographs and imagers are mounted on a scan platform, which rotates about the vertical and horizontal axes, and provides sensor scanning in azimuth and elevation over glowing shuttle surfaces. Experiment hardware units include the sensor head, a scan platform, electronics, and high- and low-voltage power supplies. The shuttle glow experiments are short compared to the total flight time of the mission; therefore, the remainder of the flight is dedicated to studies of Earth’s atmosphere. The scientific objectives are related to the ionosphere, thermosphere and mesosphere (ITM) section of the NASA Space Physics Division. In this respect, we call the experiment the Arizona Airglow Experiment (GLO). A scientific team will receive the data, assist in planning the experiments, and coordinate the overflights with ground based sites or networks. The period of the flight is identified in the scientific community as a campaign. Active participants who have ground-based instrumentation try to make observations throughout the campaign. The data are correlated and deposited in a data bank at NCAR for use by the community. The coordination of this data is important to relate local observation to the global picture provided by the GLO observations from the shuttle. An accurate description of the process leading to the emissions from the sunlit thermosphere is being pursued by the GLO experiment. The two prominent ion emissions are the [OII] (7320Å) and the N2+ (1N) systems. Presently, both emissions have shortcomings as reliable signatures of the ionosphere conditions. The nature of the nitrogen ion N2+ (1N) emission in the twilight and dayglow has still not been fully explained. The intensity of the emission is greater, by about a factor of two, than models predict. The nature of the emission is further confused since neither the extended rotational nor vibrational distributions are understood. Earlier data sets have not had the quality to resolve these problems. We believe that the GLO data will provide more insight. The nature of the mesospheric reactions in the night atmosphere have eluded proper investigation. The ability of the GLO experiment to observe all of the night sky emission simultaneously has already demonstrated its usefulness. The GLO observation from a previous mission demonstrated that vertical profiles through the emitting layer are easily obtained and will add markedly to our understanding of these mesospheric processes. An important task for the GLO experiment is concerned with atmospheric model validation. Atmospheric models typically predict vertical profiles of reaction products which give rise to emissions. The models do not account for the manifold of energy distribution within systems but, rather, predict the total product in excited states. Establishing the relationship of the total production to the observation is the responsibility of the experiment and the spectral analyst. The relationship of the model to the observation is the responsibility of the theorist. Again, collaboration is the most powerful tool; each party contributes their expertise to a single problem. A graduate student program will provide the interface between the model and the experiment. The modeler will be involved in the planning to optimize his/her validation. The observation will be advocated by the graduate student and the data product will be prepared and defended by the graduate student using the spectral analysis capabilities at the GLO data center at the University of Arizona. In the next few years the GLO experimenters, USAF/Phillips Lab and the University of Arizona, will be changing research practices because the overall objective is to understand the nature of our atmosphere on a global basis. Global models are already well underway but the hope of verifying those models on a global scale is un-realistic. Our nearest approach to the global verification will come through coordinated observational opportunities. No one type of experiment, orbit or ground-based observation is a sufficient test. Our closest approach will be through coordinated studies, ground stations, rocket, and satellite coordination. Experiment: IMAX Cargo Bay Camera (ICBC) Customer: Johnson Space Center Payload Manger: Dick Walter Mission Manager: Susan Olden, Hitchhiker Program, GSFC IMAX Cargo Bay Camera (ICBC) is a space-qualified, 65 mm color motion picture camera system that consists of a camera, lens assembly, and a film supply magazine containing approximately 3500 feet of film and an empty take-up magazine. The camera is housed in an insulated, pressurized enclosure with a movable lens window cover. The optical center line of the 60 mm camera lens is fixed and points directly out of the payload bay along the Orbiter Z axis with a 15 degree rotation towards the Orbiter nose. Heaters and thermal blankets provide proper thermal conditioning for the camera electronics, camera window, and film magazines. The 65 mm photography will be transferred to 70 mm motion picture film for playing in IMAX theaters. An audio tape recorder with microphones will be used in the crew compartment to record middeck audio sounds and crew comments during camera operations. The audio sound is then transferred to audio tapes or compact discs for playing in coordination with the IMAX motion picture. The camera system is operated by the crew from the Aft Flight Deck with the enhanced Get Away Special (GAS) Autonomous Payload Controller (GAPC). Commands such as on/off, camera standby, and camera run/stop may be initiated by the crew. Additional commands for camera setups such as f/stop, focus, and frame rate status of exposed film footage are also accom-plished by the crew using the GAPC. A light level measurement unit will be used by the crew to set the lens aperture. Four focus zones and seven aperture settings are available for this flight. The normal camera speed is 24 frames per second (fps). On this flight, this can also be changed to 3 fps for photographing slower moving objects. 3500 feet of film in the ICBC will last approximately 10.5 minutes at 24 fps and much longer at 3 fps. Film cannot be changed in flight and ICBC operations are terminated when all film is exposed. ICBC is managed by Dick Walter of Johnson Space Center. Experiment: Orbital Debris Radar Calibration System-II (ODERACS-II) Customer: Johnson Space Center Principal Investigator: Gene Stansbery Mission Manager: Susan Olden, Hitchhiker Program, GSFC Man-made debris, now circulating in a multitude of orbits about the Earth as a result of the exploration and use of space, poses a growing hazard to future space operations. Since the launch of Sputnik 1, more than 3200 launches have placed about 6500 artificial orbiting objects, weighing 2 million kilograms (4.4 million pounds) in orbit around the Earth. While these objects are cataloged by the Space Surveillance Network operated by United States Command (USSPACECOM), only six percent represent functional satellites; the rest are considered debris. Additionally, USSPACECOM tracks only objects larger than 10 cm in diameter. However, history has proven that smaller objects cause considerable damage to spacecraft. Hence, orbital debris is a critical factor in the shielding design and mission planning of the International Space Station Alpha (ISSA). For the past decade, NASA Johnson Space Center has led efforts, such as using the Haystack Radar, to characterize the debris environment for sizes smaller than 10 cm. The Orbital Debris Radar Calibration System (ODERACS) provides a vehicle whereby small calibration targets are placed in Low Earth Orbit (LEO) for the purpose of calibrating ground-based radar and optical systems so that they may more accurately provide information regarding small debris in LEO. Radar facilities include: the Millstone, Haystack, and the Haystack Auxiliary Radars in Massachusetts; the Kwajalein Radars (TRADEX, ALCOR, Millimeter Wave, and ALTAIR) in the South Pacific; the Eglin Radar in Florida; the PARCS Radar in North Dakota; and the FGAN Radar in Germany. Optical facilities include: the worldwide GEODDS telescope network, the NASA/JSC telescope, and the Super-RADOT telescope facility in the South Pacific. Other USSPACECOM sensor facilities will also support the mission as necessary. This experiment enables the correlation of controlled empirical optical and radar debris signatures of targets whose physical dimensions, compositions, reflectivity, and electromagnetic scattering properties are precisely known, thereby verifying or improving the sensors’ accuracy and ultimately leading to better knowledge of the debris environment. The ODERACS-II experiment, whose Principal Investigator is Gene Stansbery of JSC, will release 6 targets, 3 spheres and 3 dipoles, of different sizes from the Space Shuttle payload bay. The targets will be observed, tracked and recorded using ground-based radar and optical sensors. The spheres are composed of polished, blackened, and whitened stainless steel and aluminum while the dipoles consist of platinum alloys chosen to maximize orbital lifetime. The sphere group consists of one 2 inch diameter stainless steel sphere, one 4 inch diameter aluminum sphere and one 6 inch diameter aluminum sphere. The dipole group consists of one 1.740 inches x .040 inch diameter wire and two 5.255 inches x .040 inch diameter wires. The targets will be ejected retrograde along the shuttle velocity vector at velocities between 1.4 and 3.4 meters per second (4.5 to 11.1 feet per second). The estimated average orbital lifetime of the targets range from about 20 to 280 days and is highly dependent on solar flux and the resultant atmospheric heating. All targets will completely burn up during reentry.