Science with the Space Interferometry Mission
The Space Interferometry Mission (SIM) will be NASA's first dedicated space-based optical interferometer.
Interferometry↗
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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Space Interferometry Mission: New System Engineering Approaches, Tools, Models and Testbeds
In 2005, NASA's Origins Program will launch the Space Interferometry Mission (SIM), a 10 meter optical interferometer instrument, into a circular 900 km earth orbit.
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Science with the Space Interferometry Mission
The Space Interferometry Mission (SIM) will be NASA's first space-based optical interferometer designed for precision astrometry.
Space↗
Space Interferometry Mission
The Space Interferometry Mission (SIM) is NASA's first space science interferometer, and will enable fundamental new discoveries in both galactic and extra-galactic astronomy, including cosmic distance scale...It demonstrates several key technologies...
interferometry↗
The dependence of the Micro-Arcsecond Metrology (MAM) testbed performance prediction on white light algorithm approach
This paper will compare the performance of various algorithms using the MAM data, and will aid in our recommendation of how the SIM flight system should process the science and guide interferometer data.
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Space interferometry mission: flight system and configuration overview
This paper addresses the issues of the System Engineering processes and validation of performance specifications. It also describes the current status of the SIM Reference System Design.
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On Multidisciplinary Modeling of the Space Interferometry Mission
This paper provides an overview of the multidisciplinary integrated modeling methodology for SIM that encompasses the optics, structures, dynamics and control disciplines within a common software environment.
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The Space Interferometry Mission
In this paper we will present selected topics from the SIM science program focusing on some specific astronomical questions to be addressed.
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Apollo 15 X-ray fluorescence experiment
The X-ray fluorescence spectrometer, carried in the SIM bay of the command service module was employed principally for compositional mapping of the lunar surface while in lunar orbit, and secondarily, for X-ray astronomical observations during the trans-earth coast. The lunar surface measurements involved observations of the intensity and characteristics energy distribution of the secondary or fluorescent X-rays produced by the interaction of solar X-rays with the lunar surface. The astronomical observations consisted of relatively long periods of measurements of X-rays from pre-selected galactic sources such as Cyg-X-1 and Sco X-1 as well as from the galactic poles.
Adler, I.↗
The design and application of an infrared simulator for thermal vacuum testing
An infrared simulator was developed and installed in SIM Chamber A in support of the Apollo lunar-exploration mission thermal vacuum testing. The simulator was designed to provide thermal simulation of the radiation emitted and reflected by the lunar surface incident on the Apollo service module in a 60-mile-altitude lunar orbit. The infrared simulator comprises 18 individually controlled zones that provide the irradiance profiles over a 180 deg arc around the spacecraft, simulating the flux levels of equatorial, polar, and 45 deg lunar orbits.
Skinner, D. J.↗
Mission description
The Apollo 15 manned lunar-landing mission is discussed. As compared with previous Apollo manned lunar-landing missions, the mission 15 is characterized by increased hardware capability, a larger scientific payload, and a battery-powered lunar roving vehicle (Rover). Benefits resulting from these additions to Apollo 15 were a mission duration of 12-1/3 days, a lunar stay time of nearly 67 hr, a lunar-surface traverse distance of 27.9 km traveled at an average speed of 9.6 km/hr, and a scientific instrument module (SIM) containing equipment for orbital experiments and photographic tasks not performed on previous missions. The primary scientific objectives of the mission were to perform selenological inspection, survey, and sampling of materials and surface features in a preselected area of the Hadley-Apennine region; to emplace and activate surface experiments; and to conduct inflight experiments and photographic tasks from lunar orbit.
Baldwin, R. R.↗
Summary of scientific results
The major scientific results of the Apollo 15 flight are summarized. The objectives of the flight are given as: (1) to carry out extensive geological exploration, comprehensive sampling, and photographic documentation of the Apennine Front at Hadley Delta, Hadley Rille, and the mare plain, (2) to emplace the ALSEP near the landing site, and (3) to perform a series of survey experiments with the scientific instrument module (SIM) equipment from lunar orbit and during transearth coast.
Allen, J. P.↗
Photographic summary
The photographic objectives of the Apollo 15 mission were designed to support a wide variety of scientific and operational experiments, to provide high-resolution panoramic photographs and precisely oriented metric photographs of the lunar surface, and to document operational tasks on the lunar surface and in flight. Detailed premission planning integrated the photographic tasks with the other mission objectives to produce a balanced mission that has returned more data than any previous space voyage. The return of photographic data was enhanced by new equipment, the high latitude of the landing site, and greater time in lunar orbit. New camera systems that were mounted in the scientific instrument module (SIM) bay of the service module provided a major photographic capability that was not available on any previous lunar mission, manned or unmanned.
Dietrich, J. W.↗
Apollo 15 mission report.
Apollo 15 was the first of the 'J' Mission Series designed to conduct an extended scientific exploration of the moon, both from lunar orbit and on the surface. The powered descent into the Hadley-Apennine site is discussed. The major hardware innovation for the lunar exploration phase on Apollo 15 was the Lunar Roving Vehicle. Lunar orbit SIM operations are considered together with transearth coast extra-vehicular activity, and entry.
Scott, D. R.↗
An adaptive replacement algorithm for paged-memory computer systems.
A general class of adaptive replacement schemes for use in paged memories is developed. One such algorithm, called SIM, is simulated using a probability model that generates memory traces, and the results of the simulation of this adaptive scheme are compared with those obtained using the best nonlookahead algorithms. A technique for implementing this type of adaptive replacement algorithm with state of the art digital hardware is also presented.
Thorington, J. M., Jr.↗
Stanford bistatic radar experiment (S-170) on Apollos 14, 15, and 16
No special equipment was placed onboard the vehicles for the bistatic radar experiments which were carried out during the lunar orbit phases of the Apollo 14, 15, and 16 flights. Radio frequency transmissions from the orbiting command service module were directed toward the moon and received on the earth after reflection from the lunar surface. Two wavelengths, 13 cm (2287.5 MHz, S-band) and 116 cm (259.7 MHz, VHF), were used. Data were obtained at the two wavelengths simultaneously during periods when the spacecraft was maneuvered to maintain a predetermined, although changing, attitude with respect to the earth and moon. Data were also obtained at the 116 cm wavelength during periods of inertial hold and SIM bay attitude maneuvers.
Howard, H. T.↗
Extravehicular mobility unit thermal simulator
The analytical methods, thermal model, and user's instructions for the SIM bay extravehicular mobility unit (EMU) routine are presented. This digital computer program was developed for detailed thermal performance predictions of the crewman performing a command module extravehicular activity during transearth coast. It accounts for conductive, convective, and radiative heat transfer as well as fluid flow and associated flow control components. The program is a derivative of the Apollo lunar surface EMU digital simulator. It has the operational flexibility to accept card or magnetic tape for both the input data and program logic. Output can be tabular and/or plotted and the mission simulation can be stopped and restarted at the discretion of the user. The program was developed for the NASA-JSC Univac 1108 computer system and several of the capabilities represent utilization of unique features of that system. Analytical methods used in the computer routine are based on finite difference approximations to differential heat and mass balance equations which account for temperature or time dependent thermo-physical properties.
Hixon, C. W.↗
Observation of lunar radon emanation with the Apollo 15 alpha particle spectrometer.
The alpha particle spectrometer, a component of the orbital Sim Bay group of 'geochemistry' experiments on Apollo 15, was designed to detect alpha particles emitted during the decay of isotopes of radon gas and her daughter products. The purpose was to measure the gross activity of radon on the lunar surface and to find possible regions of increased local activity. Results are presented from a partial analysis of Apollo 15 data. For the moon as a whole, Rn220 was not observed and the upper limit on its decay rate above the lunar surface is 0.00038 disintegrations/sq cm-sec. Rn222 was marginally observed. Possible variations of radon activity on the lunar surface are being investigated. Po210 (a daughter product of Rn222) has been detected in a broad region from west of Mare Crisium to the Van de Graaff-Orlov region. The observed count rate is (4.6 plus or minus 1.4) x 0.001 disintegrations/sq cm-sec. The observed level of Po210 activity is in excess of the amount that would be in equilibrium with Rn222 by about an order of magnitude. This implies that larger levels of radon emanation have occurred on the moon within a time scale of 10 to 100 years.
Gorenstein, P.↗