A particle deflector operating on the principle of laser-induced ablation may eliminate collisions between spacecraft and small debris in low earth orbit. A practical system is constrained to deflecting particles up to a few grams mass with velocities up to 10 km/s. Fundamental concerns for such a system include particle detection and tracking, beam formation, beam steering, and energy coupling to the target. The limiting technology is the detection and tracking system, which must located fast moving (10 km/s) objects 1 cm or smaller in diameter at distances greater than 1 km. We show that a 2000 J laser beam can deflect at 10 mrad a 1-g particle approaching at 10 km/s--adequate to protect a modest sized (approximately 10 m) space structure if the particle is intercepted while still 1 km away. Methods for delivering large optical power densities onto a small (approximately 1 cm) target over moderate (1000 m) distances are proposed.

Shadowgraphic holography offers significant advantages when characterizing the particulates from debris-producing events. Holography can provide the spatial resolution to span the particle size range over a large depth of field. Also, particulate velocities can be determined by generating a double-pulsed hologram. A technique that provided such holograms of the debris over a 180- degree field of view at ordnance velocities is extended here to hypervelocities. The higher debris velocities necessitate a shorter duration laser pulse. An analysis has been performed to determine the laser pulse requirements versus particle size and velocity, and the optical conjugates of the holographic component layout. The approach includes a rigorous diffraction theory analysis for the recording of the hologram to prove the equivalence of the smearing of the reconstructed image from a hologram of a moving object to that from an object with a spatial transmission gradient. It is shown that the recorded interference pattern, while degraded because of particle motion, remains stationary over the exposure duration.

A computer simulation which estimates statistical orbital debris trajectory error arising from uncertainty of debris size, composition, geometry, and tumbling rate and also of atmospheric density is discussed. The ramification of the simulation results to debris accuracy requirements determined from maneuver rate constraints is examined.

Explicit formulas are given for the probability of occurrence of at least six successful r-day microgravityexperiments per year onboard the Space Station for a given annual expected number of collision avoidance maneuvers, where r is a parameter in the range 23 —30. Results indicate an 88% probability for 30-day experiments and a 99% probability for 25-day experiments for an expected annual maneuver rate of 8.

Space debris poses an ever-increasing hazard to the utilization of space, with the greatest perceived threat between 800 and 1200 km and at 1500 km altitude. The Midcourse Space Experiment will provide an opportunity to survey these and other high density regions of space in the infrared (IR), visible, and ultraviolet (UV) wavelengths. Concurrent observations in the IR, visible and UV will provide data sufficient to estimate debris object albedo, physical size, and some surfacematerial characteristics, in addition to a measure of spatial density as a function of altitude and inclination.

The Interplanetary Dust Experiment provided high time resolution detection of microparticle impacts on the Long Duration Exposure Facility satellite. Particles, in the diameter range of 0.2 microns to several hundred microns, were detected impacting on six orthogonal surfaces of the gravity-gradient stabilized LDEF spacecraft. The 11 1/2 month tape-recorded data set represents the most extensive record gathered of the number, orbital locations, and incidence direction for microparticle impacts on low Earth orbit. Among the results to be discussed is the discovery of orbital debris rings and clouds. In some cases, impacts occurred in a localized region of the orbit for dozens or even hundreds of orbits in Multiple Orbit Event Sequences (MOES). In addition, more than a dozen intense and short-lived `spikes' were seen in which impact fluxes exceeded the background by several orders of magnitude. An analysis is given of the orbital parameters and of possible progenitor events for a selection of MOES.

The Industry and University participants listed above have joined together to form the IMPA:Ct consortium, which offers a broad range of flight qualified technologies for real time monitoring of small particles, 0.1 micron to 10 cm, in the space environment. Instruments are available in 12 months or less at costs ranging from 0.5 to 1.5 million dollars (US) for the total program. Detector technologies represented by these groups are: impact-induced capacitor-discharge (MOS, metal-oxide-silicon), cratering or penetration of electroactive thin film (polyvinylidene fluoride), impact-plasma detection, acoustic detection, ccd tracking of optical scatter of sunlight, and photodiode detection of optical scatter of laser light. The operational characteristics, general spacecraft interface and resource requirements (mass/power/telemetry), cost and delivery schedules, and points of contact for 7 different instruments are presented.

Orbital debris in low-earth-orbit poses an increasing threat to the Space Station. A combined ground-based/on-orbit radar detection system can provide adequate warning to minimize the collision threat. Previous studies have shown that a debris warning system must be capable of providing accurate tracking information one to two orbits in advance of a possible conjunction (collision). An on-board sensor (radar) is the most cost effective method for getting this updated tracking information.

The threat posed by hypervelocity collisions with space debris and meteoroids remains an increasingly critical factor in predicting the safety and reliability of future space missions. Therefore, the use of analytical tools that allow detailed risk assessment is vital in assisting designers with balancing the exigencies of mission objectives, shielding, and orbit selection. Towards this end, EnviroNET is expanding and joining the Orbital Debris and Meteoroid Models (both developed at Johnson Space Center) to create a tool to assess the risk of collision.

A small, compact pulsed-laser and camera system for collecting data on small space debris can be put into orbit as a strap-on package on other research satellites. The system does not depend on sun glint for debris illumination. The laser could be diode-pumped Nd:YAG or Cr:LiSaAlF with high overall efficiency. It eventually could be e simple diode laser. It would operate in a pulse-rep mode of approximately 10 Hz, sampling truncated conical volumes out to < 1 km. With a 1 m primary optic, the system would see approximately 1 mm debris and larger out at approximately 800 m, and would see even smaller debris in the nearer field. The high gain of the ICCD camera enables use of lower laser energy (power). Filters eliminate most optical noise. Range-gating eliminates unwanted backscatter entering the camera. Data can be pre-processed on orbit, with only counts-per-bin (particle)-size data being transmitted. The initial lower-cost system would sample only in small diameter orbital `tubes.' Analysts would still make some assumptions about the homogeneity of distributions to develop a `picture' of the amount of small debris in orbit at various altitudes. Further trade-off studies are needed.

Orbital debris is a growing international issue, including rising visibility within the United Nations. In one or two decades, orbiting debris will significantly inhibit use of some of the most valuable orbits. This will have a significant economic impact on both government and commercial uses of space.

Near-simultaneous, multispectral, coregistered imagery of ground target and background signatures were collected over a full diurnal cycle in visible, infrared, and ultraviolet spectrally filtered wavebands using Battelle's portable sensor suite. The imagery data were processed using classical statistical algorithms, artificial neural networks and data clustering techniques to classify objects in the imaged scenes. Imagery collected at different times throughout the day were employed to verify algorithm robustness with respect to temporal variations of spectral signatures. In addition, several multispectral sensor fusion medical imaging applications were explored including imaging of subcutaneous vasculature, retinal angiography, and endoscopic cholecystectomy. Work is also being performed to advance the state of the art using differential absorption lidar as an active remote sensing technique for spectrally detecting, identifying, and tracking hazardous emissions. These investigations support a wide variety of multispectral signature discrimination applications including the concepts of automated target search, landing zone detection, enhanced medical imaging, and chemical/biological agent tracking.

We have designed a monolithic 8 X 8 optical crossbar switch that can provide a lossless link for a fiber optic databus or communication system. The device is based upon a semiconductor active (with gain) waveguide structure that can be used as a building block at a monolithic device or multi-device level to configure a high bandwidth space division switch matrix. We have fabricated and characterized a first generation of devices and currently are involved in characterizing the second and designing the third. We will discuss our concepts for applying our device concepts to higher levels of network integration for military and commercial applications.

The Chemical Oxygen-Iodine Laser has been developed at the Air Force's Phillips Laboratory since its invention there in 1977 and is a promising candidate for technology transfer from military laboratory development to industrial applications as the next generation high power industrial laser.

The High Power Semiconductor Laser Technology (HPSLT) program is currently developing, in-house, a belt pack medical laser. This compact semiconductor laser device provides the field paramedic or physician a unique portable laser capability. The pack consists of a completely self-contained laser system that fits inside a belt pack. Several other medical applications being investigated by the HPSLT program include urological applications, photodynamic therapy, and ophthalmic applications.

This paper will summarize our research in mid-infrared semiconductor lasers, focusing mainly on the GaInAsSb/AlGaAsSb material system. The technical problems that must be solved to achieve efficient operation of long-wavelength semiconductor lasers will then be outlined. Finally, options for using near- term lasers at lower temperatures will be considered.

The Flight System Testbed comprises a group of test sets, including a permanent Jet Propulsion Laboratory testbed to be used for technology infusion (e.g., an advanced lightweight camera at an early stage of development that can be integrated into a virtual spacecraft and tested) and a series of project-specific testbeds. Cost and risk are reduced, problems can be solved prior to costly flight qualification, and advanced technology can be built into the spacecraft design much earlier and with greater confidence. As new technology is accepted, it will be infused into project-specific testbeds, producing an evolving body of knowledge that will be accessible to flight projects.

Innovative designs of a space-based laser remote sensing `wind machine' are presented. These designs seek compatibility with the traditionally conflicting constraints of high scientific value and low total mission cost. Mission cost is reduced by moving to smaller, lighter, more off-the-shelf instrument designs which can be accommodated on smaller launch vehicles.

A telescope folded into minimum volume for launching can be a powerful technique for maximizing the aperture size that can be accommodated in a given launch vehicle shroud. As an example we show our concept for a Folded Astronomical Space Telescope where a 2.4-m Hubble Space Telescope class of telescope can be packaged in a 1.5-m diameter cylinder. The enabling rationale, general configuration, and optical system technologies for such a telescope will be presented.

The Students for the Exploration and Development of Space (SEDS) Satellite #1 (SEDSAT 1) will fly a unique multi-role imaging system. The system, known as SEDS Earth, Atmosphere, and Space Imaging System (SEASIS) will be used to determine SEDSAT attitude during the spacecraft's deployment, study the optical properties of the atmosphere in the visible spectrum, monitor earth cloud cover, and serve as an educational tool for primary and secondary schools. The system has two visible CCD cameras (one camera has a 10 degree telephoto lens and the other camera has a 45 degree panoramic annular lens), two filter wheel systems, a frame grabber/digitizer, a multichip module processor, and 1 Gigabit of static memory. SEASIS is in the final prototype stages, and is approved for launch aboard SEDSAT 1 from the shuttle sometime in FY '96 or '97.

We describe an integrated instrument that will perform the functions of three optical instruments required by a Pluto Fast Flyby mission: a near-IR spectrometer (256 spectral channels, 1300 - 2600 nm), a two-channel imaging camera (300 - 500 nm, 500 - 1000 nm), and a UV spectrometer (160 spectral channels, 70 - 150 nm). A separate port, aligned in a direction compatible with radio occultation experiments, is provided for measurement of a UV solar occultation and for spectral radiance calibration of the IR and visible subsystems. Our integrated approach minimizes mass and power use, and promotes the adoption of integrated observational sequences and power management to ensure compatible duty cycles for data acquisition, compression, and storage. From flight mission experience, we believe the integrated approach will yield substantial cost savings in design, integration, and sequence planning. The integrated payload inherently provides a cohesive mission data set, optimized for correlative analysis. A breadboard version of the instrument is currently being built and is expected to be fully functional be late summer.

A demonstration x-ray optic has been produced by diamond turning and replication techniques that could revolutionize the fabrication of advanced mirror assemblies. The prototype optic was developed as part of the Advanced X-ray Astrophysics Facility, Spectrographic project. The initial part of the project was aimed at developing and testing the replication technique so that it could potentially be used for the production of the entire mirror array comprised of up to 50 individual mirror shells.

Understanding the phenomena of protein crystal growth has become a critical factor in the advancement of fundamental life sciences. To characterize this process, sensitive non-intrusive monitoring systems must be utilized in a micro-gravity environment. We believe detailed optical monitoring to be the superior technique for use in micro-gravity. The proposed approach includes monitoring the nucleation event, rate and form of crystal growth, and protein density variations throughout the cell volume with four different optical metrology methods running concurrently. The system will incorporate photon correlation spectroscopy, interferometry, Zernike phase contrast imagery, and high-resolution polarization microscopy. These four systems have all been combined into a single optical module that provides crystal growth process data. The module utilizes the emerging technologies of binary optics and solid optics to shrink and stabilize the system (patent-pending).

NASA's Marshall Space Flight Center is designing, developing, and fabricating a Solar X-ray Imager (SXI) that will fly aboard a Geostationary Operational Environmental Satellite. The objective of the SXI is to obtain near real-time reconstruction of solar images from the sun in the spectral range of 6 to 60 angstroms. The SXI is being designed with the spatial resolution, sensitivity, and dynamic range sufficient to allow reconstruction of solar flares, loops, and coronal holes. To meet these design requirements the SXI utilizes a single Zerodur mirror element with a detector assembly that consists of a Galileo microchannel intensifier with a fiber optic coupler attached to a Charge Coupler Device. This paper summarizes the key design features of the SXI detector system and the challenges that are being faced in the development of the SXI detector assembly.

Flow cytometry is a popular biomedical tool used in both clinical medicine and research science. Current flow cytometers use laser light to illuminate particles in solution as they flow past a detector in a sheath fluid. This process requires vast amounts of fluids and technical expertise and is unacceptable for space science. Here, we present a design of a Closed Flow Cell^TM which eliminates most barriers to miniaturization and space science adaptation of flow cytometry.

The Sensor Satellite Expert System (SENSAT)^TM is an application of the concurrent engineering simulation methodology which utilizes fuzzy logic in an object-oriented programming environment. Several unique characteristics of SENSAT includes the implementation team, mission system parameters, and priority optimization with respect to mission, cost, schedule, technology, and funding levels. SENSAT operates within a WINDOWS^TM environment and a `simulation tour' is included in this paper along with a video to be shown with an actual SENSAT prototype simulation.

The absolute measurement of low-density gases of interest in space experiments recently underwent a major advanced when the National Institute of Standards and Technology developed a primary standard for low-density water vapor. This standard, which features arrays of laser-drilled holes, was used to calibrate and characterize the performance of several vacuum instruments and the MSX neutral mass spectrometer. The neutral mass spectrometer will be used to measure the absolute densities of molecules outgassing from the MSX spacecraft during orbit and, thus, to validate the MSX contamination models and the effectiveness of the contamination control plan. The residual gas analyzers and the flight mass spectrometer were tested over a large range of partial pressures of H₂O, H₂He, N₂, O₂, and Ar. In certain cases, water vapor caused significant changes in the sensitivity of vacuum instruments and generated several other gaseous species.

The Air Force Maui Optical Station (AMOS) conducted searches, measurements, and analyses of the orbital debris environment for the Air Force Space Command and the Phillips Laboratory since May 1991 in support of the Air Force Orbital Debris Measurements Program. The objective of this program was to detect orbiting low earth objects not currently in the United States Space Command Space Surveillance Center catalog. Once objects were detected, further objectives were to track, catalog, and maintain those objects locally, to determine statistics on detected objects, and perform relevant analyses. AMOS has developed a prototype surveillance system for the detection and tracking of orbital debris. In addition to this surveillance activity, AMOS has also automated the post-processing videotape streak detection process and is automating the analysis process. Both the optical tracking of orbital debris and the automatic streak detection process were thought to be virtually impossible only a few years ago. The AMOS program employed wide field of view optical telescopes using the Maui Groundbased Electro-Optical Deep Space Surveillance site and AMOS narrow field of view tracking telescopes, both located at the Maui Space Surveillance Site.

A review of the major European cooperation models in the field of research and development is presented and discussed with respect to the different technical areas and corresponding funding schemes. While the German situation is described in more detail, specific examples of technology transfer in the laser R&D are highlighted.

Numerous government and commercial applications of diode pumped solid state lasers (DPSSL) are emerging making it a true dual use technology. Military applications include countermeasures, remote sensing ,targettracking, and lidar. Civilian space applications include lidar for wind measurements and other remote sensing needs. Use of laser machine tools for manufacturing is growing rapidly for welding, cutting, drilling, and surface treatment applications. DPSSL technology has advanced rapidly due to government funded efforts and through corporate research programs. Power scaling to the 3-10 kW level is at hand. The technology has matured to the point that both military and laser manufacturing applications are becoming practical.

The following paper discusses the area of technology transfer of Dual-Use Technologies between government and university laboratories and industry. Variuos mechanisms for technological cooperation are summarized. The status of technology transfer activities at the Alliance for Photomc Technology and the USAF Phillips Laboratory, Lasers and Imaging Directorate, Cooperative Mfairs Office are presented as examples of technological cooperation. See report # 2214-47 for more information.

Traditional commercial remote sensing has focused on the geologic market, with primary focus on mineral identification and mapping in the visible through short-wave infrared spectral regions (0.4 to 2.4 microns). Commercial remote sensing users now demand airborne scanning capabilities spanning the entire wavelength range from ultraviolet through thermal infrared (0.3 to 12 microns). This spectral range enables detection, identification, and mapping of objects and liquids on the earth's surface and gases in the air. Applications requiring this range of wavelengths include detection and mapping of oil spills, soil and water contamination, stressed vegetation, and renewable and non-renewable natural resources, and also change detection, natural hazard mitigation, emergency response, agricultural management, and urban planning. GER has designed and built a configurable scanner that acquires high resolution images in 63 selected wave bands in this broad wavelength range.

The Clementine spacecraft was launched from Vandenberg Air Force Base on January 25, 1994 in the first lunar mission in over twenty years. After spending nine days in low-Earth-orbit, the Clementine spacecraft solid rocket motor was ignited to boost the spacecraft to a transfer orbit of 250 km by 125,000 km. The solid rocket motor was designed as a radiation experiment by mounting radiation electronic components in its interstage adapter. While this interstage adapter remained in this orbit after being released from the Clementine spacecraft, the orbit of the main craft was adjusted by raising the apogee to the lunar orbit of 385,000 km. After two and one-half Earth transfer orbits, the Clementine spacecraft was successfully inserted in lunar orbit on February 19. On February 21, a burn was performed to adjust the spacecraft to the final mapping orbit of 400 km X 2940 km. The spacecraft is scheduled to stay in this mapping orbit for over 70 days, transferring to the Earth about 16,000 images a day in the ultraviolet, visible and infrared parts of the spectrum.