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The comparison of programming languages is best seen while evaluating similar systems. The strengths and weaknesses of both languages were investigated as the scheduler was being implemented. Some features used in both languages shall be object-oriented paradigms, parallel programming, search and production heuristics, and other classical artificial intelligence implementations.
The design, predicted performance, and scientific objectives of the 20-30,000-MeV gamma-ray telescope EGRET for the NASA GRO spacecraft (scheduled for Space Shuttle launch to a 450-km 28.5-deg orbit in 1990) are reviewed. The other GRO instruments are briefly characterized, including the burst and transient-source experiment, the oriented scintillation spectrometer, and the imaging Compton telescope. EGRET comprises an anticoincidence system, a spark chamber, a triggering telescope, an NaI total-absorption spectrometer, a gas supply capable of refilling the chamber four times, and support electronics. EGRET will operate with energy resolution about 15 percent, effective area about 2000 sq cm, sensitivity about 5 x 10 to the -8th/sq cm sec, angular resolution 0.1-0.4 deg, and FOV about 40 deg FWHM. Observations of Galactic point sources, Galactic and extragalactic diffuse emission, gamma-ray bursts, and solar flares are planned.
Results are presented on a calibration with X-rays of a front-illuminated virtual phase CCD with a 1024 x 1024 pixel array, performed as a part of the Solar-A preparation, which is a joint Japanese-U.S.-UK space project scheduled for a launch in August 1991. In the experiment, absolute quantum efficiency (QE) of a virtual CCD was measured at 14 wavelengths between 5.4 and 67.7 A, and its flat field responses to the illumination by C-K and Al-K X-rays were investigated together with its imaging properties in visible light. Higher than expected QE measurements were obtained at soft X-ray and EUV wavelengths; these are considered to be caused by fluorescence occurring in the absorbing layers on the CCD-entrance aperture.
The feasibility is analyzed of upgrading the Intel 386 microprocessor, which has been proposed as the baseline processor for the Space Station Freedom (SSF) Data Management System (DMS), to the more advanced i486 microprocessors. The items compared between the two processors include the instruction set architecture, power consumption, the MIL-STD-883C Class S (Space) qualification schedule, and performance. The advantages of the i486 over the 386 are (1) lower power consumption; and (2) higher floating point performance. The i486 on-chip cache does not have parity check or error detection and correction circuitry. The i486 with on-chip cache disabled, however, has lower integer performance than the 386 without cache, which is the current DMS design choice. Adding cache to the 386/386 DX memory hierachy appears to be the most beneficial change to the current DMS design at this time.
The primary objective of the proposed research is to provide additional groundbased support for the flight experiment 'Casting and Solidification Technology' (CAST). This experiment is to be performed in the International Microgravity Laboratory-1 (IML-1) scheduled to be flown on a space shuttle mission scheduled for 1992. In particular, we will provide data on the convective motion and freckle formation during directional solidification of NH4Cl from its aqueous solution at simulated parameter ranges equivalent to reducing the gravity from the sea-level value down to 0.1 g or lower. The secondary objectives of the proposed research are to examine the stability phenomena associated with the onset of freckles and the mechanisms for their subsequent growth and decline (to eventual demise of some) by state-of-the-art imaging techniques and to formulate mathematical models for the prediction of the observed phenomena.
The feasibility is analyzed of upgrading the Intel 386 microprocessor, which has been proposed as the baseline processor for the Space Station Freedom (SSF) Data Management System (DMS), to the more advanced i486 microprocessors. The items compared between the two processors include the instruction set architecture, power consumption, the MIL-STD-883C Class S (Space) qualification schedule, and performance. The advantages of the i486 over the 386 are (1) lower power consumption; and (2) higher floating point performance. The i486 on-chip cache does not have parity check or error detection and correction circuitry. The i486 with on-chip cache disabled, however, has lower integer performance than the 386 without cache, which is the current DMS design choice. Adding cache to the 386/387 DX memory hierarchy appears to be the most beneficial change to the current DMS design at this time.
An overview of the Vented Tank Resupply Experiment (VTRE) program is presented in outline and graphical form. The goal of the program is to develop, design, build and provide flight and post flight support for a Shuttle Hitchhiker Experiment to investigate and demonstrate vented tank venting in space. Program schedules and experiment subsystem schematics are presented and specific technical objectives, power requirements, payload assemblies, Hitchhiker canister integration, and orbiter mission approach are addressed.
The Automated Conflict Resolution System (ACRS) is a mission-current scheduling aid that predicts periods of mutual interference when two or more orbiting spacecraft are scheduled to communicate with the same Tracking and Data Relay Satellite (TDRS) at the same time. The mutual interference predicted has the potential to degrade or prevent communications. Thus the ACRS system is a useful tool for aiding in the scheduling of Space Network (SN) communications.
Live footage of a preflight interview with Mission Specialist Jean-Francois Clervoy is seen. The interview addresses many different questions including why Clervoy became an astronaut, what were the events that led to his interest. Other interesting information that this one-on-one interview discusses is an explanation of the why this required mission to service the Hubble Space Telescope must take place at such an early date, replacement of the gyroscopes, transistors and computers. Also discussed is an explanation of the ESA (European Space Agency) involvement in this mission, and a brief touch on Clervoy's responsibility during any of the given four space walks scheduled for this mission.
Live footage of a preflight interview with Commander Curtis L. Brown is seen. The interview addresses many different questions including why Brown became an astronaut, the events that led to his interest, any role models that he had, and his inspiration. Other interesting information that this one-on-one interview discusses is an explanation of the why this required mission to service the Hubble Space Telescope must take place at such an early date, replacement of the gyroscopes, transistors, and computers. Also discussed is Brown's responsibility during any of the planned space walks scheduled for this mission.
Live footage of a preflight interview with Pilot Scott J. Kelly is seen. The interview addresses many different questions including why Kelly became an astronaut, the events that led to his interest, any role models that he had, and his inspiration. Other interesting information that this one-on-one interview discusses is an explanation of the why this required mission to service the Hubble Space Telescope must take place at such an early date, replacement of the gyroscopes, transistors, and computers. Also discussed are the Chandra X Ray Astrophysics Facility, and a brief touch on Kelly's responsibility during any of the given four space walks scheduled for this mission.
Live footage of a preflight interview with Mission Specialist John M. Grunsfeld is seen. The interview addresses many different questions including why Grunsfeld became an astronaut, and the events that led to his interest. Other interesting information that this one-on-one interview discusses is an explanation of the why this required mission to service the Hubble Space Telescope must take place at such an early date, and a brief touch on Grunsfeld's responsibility during any of the four space walks scheduled for this mission.
Live footage of a preflight interview with Mission Specialist Claude Nicollier is seen. The interview addresses many different questions including why Nicollier became an astronaut, the events that led to his interest, any role models that he had, and his inspiration. Other interesting information that this one-on-one interview discusses is an explanation of the why this required mission to service the Hubble Space Telescope must take place at such an early date, replacement of the gyroscopes, transistors, and computers. Also discussed are the Chandra X-Ray Astrophysics Facility, and a brief touch on Nicollier's responsibility during any of the given four space walks scheduled for this mission.
Live footage of a preflight interview with Mission Specialist C. Michael Foale is seen. The interview addresses many different questions including why Foale became an astronaut, what were the events that led to his interest. Other interesting information that this one-on-one interview discusses is an explanation of the why this required mission to service the Hubble Space Telescope must take place at such an early date, and a brief touch on Foale's responsibility during any of the four space walks scheduled for this mission.
Live footage of a preflight interview with Mission Specialist Steven L. Smith is seen. The interview addresses many different questions including why Brown became an astronaut, the events that led to his interest, any role models that he had, and his inspiration. Other interesting information that this one-on-one interview discusses is an explanation of the why this required mission to service the Hubble Space Telescope must take place at such an early date, replacement of the gyroscopes, transistors, and computers. Also discussed is Smith's responsibility during any of the planned space walks scheduled for this mission.
Live footage of a preflight interview with Pilot Scott J. Horowitz is seen. The interview addresses many different questions including why Horowitz became an astronaut, the events that led to his interest, any role models that he had, and his inspiration. Other interesting information that this one-on-one interview discusses is the reaction and reasons for the splitting-up of the objectives for STS-101 with STS-106. Horowitz also mentions the scheduled space-walk, docking with the International Space Station (ISS), the new glass cockpit of Atlantis, the repairs of equipment and change of the batteries. Horowitz also discusses his responsibilities during the space-walk, and docking of the spacecraft. He stresses that he will have an added challenge during the space-walk, his inability to see where he needs to place the Extravehicular Activities (EVA) crew.
Live footage of a preflight interview with Mission Specialist Mary Ellen Weber is seen. The interview addresses many different questions including why Weber became an astronaut, the events that led to her interest in chemistry and sky diving. Other interesting information that this one-on-one interview discusses is the reaction and reasons for the change of the mission objectives. Weber also mentions the scheduled space-walk, docking with the International Space Station (ISS), the repairs of equipment and change of the batteries, and the installation of handrails. Weber also discusses her responsibilities during the space-walk, and docking of the spacecraft.
Live footage of a preflight interview with Mission Specialist Jeffrey N. Williams is seen. The interview addresses many different questions including why Williams became an astronaut, and the events that led to his interest. Other interesting information that this one-on-one interview discusses is his reaction to and the reasons for the change of the mission objectives. Williams also mentions the scheduled space-walk that he will perform, docking with the International Space Station (ISS), the repairs of equipment, and the change of the batteries.