MIT Reports to the President 1994-95

Center for Space Research

The Center for Space Research (CSR) conducts an active program of research in astronomy, space science, and related technology, with emphasis on experimental and theoretical investigations in support of various National Aeronautical and Space Administration (NASA) flight missions. Specific areas of research include gravity-wave, X-ray, optical, radio, and radar astronomy; theoretical and experimental space plasma physics; planetary surfaces and atmospheres; and the space life sciences. CSR is heavily involved in the following ongoing or upcoming NASA missions: Voyager, the Magellan Venus Radar Mapper mission, the Cosmic Background Explorer (COBE), the Japanese-US ASCA satellite, the Advanced X-ray Astrophysics Facility (AXAF), the X-ray Timing Explorer (XTE), the Space Transportation System (Shuttle) Spacelab series, and an investigation of Earth's plasma environment as part of the International Solar Terrestrial Physics Program (ISTP). The High-Energy-Transient Experiment (HETE), is a small, inexpensive satellite under CSR's direct control. CSR also supports investigators in the Space Engineering Research Center and administers a program of theoretical astrophysics and of optical observations carried out at the Michigan-Dartmouth-MIT (MDM) Observatory. Much of the research carried out in CSR is reported by the following departments: Physics, Earth Atmospheric & Planetary Sciences, and Aeronautics & Astronautics.

ASTRO-D (ASCA) MISSION AND ANALYSIS OF DATA FROM SATELLITE X-RAY OBSERVATORIES

CSR has been participating in the operations planning, calibration, and data analysis of ASCA, which was launched in 1993. The CSR provided CCD X-ray detectors (developed in collaboration with Lincoln Laboratory) continue to operate well and are returning spectrally resolved images of unprecedented quality. MIT personnel are participating in numerous astronomical projects, including studies of the diffuse X-ray background, supernova remnants, clusters of galaxies and distant quasars. The MIT X-ray group also continues its observational program using the German ROSAT X-ray telescope, as well as archival studies of galactic and extragalactic objects from previous US, Japanese and European X-ray missions.

DEVELOPMENT OF X-RAY ASTRONOMY EXPERIMENTS

The XTE instrumentation is being readied for launch in August 1995. XTE will study the time variability of celestial X-ray sources at time scales ranging from tens of microseconds to years over energies of 2-100 keV. HETE, which will search for bright transient emissions from astronomical objects over a very broad energy interval from the UV to gamma rays, will be launched in late 1995 or early 1996. AXAF is a major NASA mission of the "great observatory" series, scheduled for launch in 1998. Two of the four major instruments being developed at MIT, the High-Energy Transmission Grating Spectrometer and the AXAF Charge-Coupled Device (CCD) Imaging Spectrometer, have passed the major milestone of Preliminary Design Review.

MICHIGAN-DARTMOUTH-MIT OBSERVATORY

MDM is located on Kitt Peak near Tucson, Arizona, where two telescopes, 1.3 m and 2.4 m in diameter, are operated jointly by the University of Michigan, Dartmouth College and MIT. A new, very large format CCD camera was commissioned by MIT for the observatory. Active projects at MDM include studies of the cosmic distance scale, gravitational lenses, detection of galaxies at very high redshifts, mapping the structure of the Milky Way and the classification of asteroids.

INTERPLANETARY, MAGNETOSPHERIC AND IONOSPHERIC PLASMAS

Study of the properties of solar wind plasma at large distances from the Sun continues with Voyager 2, which is on its way out of the solar system. The launch of the WIND spacecraft, which will carries a plasma cup built at CSR, is part of an international program to study the solar wind and its interaction with the earth's magnetosphere. The MIT instrument is working flawlessly. The Center of Excellence in Theoretical Geo/Cosmo Plasma Physics continues to compare the apparently excellent agreement between theoretical models of ionospheric plasma phenomena and the recent data obtained from the Freja, Viking satellites, and TOPAZ rocket series.

PLANETARY MISSIONS

The Magellan mission radar experiment was turned off following its successful mapping of the entire surface of Venus at a resolution approaching 100 m. Analysis of the radiometer data continues, with special emphasis on the surprising discovery of unusually high reflectivity regions of unknown composition on the planetary surface.

GRAVITATIONAL WAVE RESEARCH & COSMOLOGY

The Laser-Interferometer Gravitational Wave Observatory (LIGO), a joint project of Caltech and MIT to develop and construct two 4km baseline gravitational wave interferometers in the continental United States to operate in concert with interferometers in Europe, continues research and development. Ground breaking at the Washington state site occurred last year and is now taking place at the Louisiana site. Current work on the MIT 5m interferometer centers on understanding and controlling the sources of phase noise and investigating active seismic isolation control systems.

AEROSPACE PHYSIOLOGY AND MAN-MACHINE SYSTEMS

Results of more than a dozen ground and flight experiments conducted on the Space Life Sciences 2 Spacelab mission were presented by the Man Vehicle Lab at scientific meetings in September and April, and have been submitted for publication. An experiment selected for the 1998 "Neurolab" mission is now entering the development phase. Ground based research on human spatial orientation in real and virtual environments, and tactile cueing systems continues. A new FAA sponsored project on cockpit displays for GPS instrument approaches is underway, in collaboration with the DOT Volpe Center in Cambridge.

THEORETICAL ASTROPHYSICS

Several faculty associated with the Center for Space Research carry out research programs in theoretical astrophysics. Topics include cosmology and the inflationary universe scenario, the large scale structure of the universe, galaxy formation, studies of solar oscillations and the structure of the solar interior, stellar accretion disks, binary star evolution, physics of active galactic nuclei, and other topics. For details see the report of the Astrophysics Division of the Physics Department.

SPACE ENGINEERING AND TECHNOLOGY

CSR supports spaceflight activities of the Space Engineering Research Center and of other faculty in Aeronautics and Astronautics. After last year's flight of the shuttle-based MODE dynamics experiment, its cousin: MACE, the actively controlled dynamics experiment, flew successfully. Planning and modifications continue in preparation of another re-flight in support of the US/FSU joint program in the Mir Space Station.

Claude R. Canizares

MIT Reports to the President 1994-95