In the next few years the Remote Atmospheric and Ionospheric Detector System (RAIDS) package will be flown on a TIROS spacecraft. The Extreme Ultraviolet Spectrometer (EUVS) experiment contains a position-sensitive detector based on wedge and strip anode technology. A detector design has been implemented in brazed alumina and Kovar to provide a rugged bakeable housing and anode. A stack of three 80:1 microchannel plates is operated at 3500-4100 V to achieve a gain of about 10{sup 7} power. The top MCP is to be coated with MgF for increased quantum efficiency in the range of 500-1150 A. Fabrication of the wedge and strip anode on brazed alumina has presented some challenging problems. In this report, a summary of fabrication techniques and detector performance characteristics is presented.

In the next few years the Remote Atmospheric and Ionospheric Detector System (RAIDS) package will be flown on a Tiros spacecraft. The EUV spectrometer experiment contains a position-sensitive detector based on wedge and strip anode technology. A detector design has been implemented in brazed alumina and kovar to provide a rugged bakeable housing and anode. A stack of three 80:1 microchannel plates is operated at 3500-4100 V. to achieve a gain of about 10 to the 7th. The top MCP is to be coated with MgF for increased quantum efficiency in the range of 50-115 nm. A summary of fabrication techniques and detector performance characteristics is presented.

A microcomputer-controlled and piezoelectrically scanned Fabry–Perot spectrometer capable of being transported to remote field sites has been constructed. The Fabry–Perot has a 70-mm aperture and has a provision for computer control of the cavity drift. The instrument has been operated at resolutions from 0.06–1.5 Å in making high-speed observations of the aurora from 7500–8500 Å. A separate filter-wheel photometer section provides information on other auroral and airglow emissions such as N+2(4278) and OI(6300). The apparatus is portable and has been operated at Poker Flat, Alaska and Churchill, Canada.

Covers advancements in spacecraft and tactical and strategic missile systems, including subsystem design and application, mission design and analysis, materials and structures, developments in space sciences, space processing and manufacturing, space operations, and applications of space technologies to other fields.

A concave grating Wadsworth spectrometer designed to scan the UV limb of the earth was flown on a Defense Department meteorological satellite to obtain measurements of atmospheric emissions in the 85-395-nm wavelength range as a function of height above the solid earth. The instrument field of view was 0.14 x 3.8 degrees corresponding to 6 km in the vertical and 230 km in the horizontal at the limb. The scanning motion was controlled by a momentum compensated dc-torque motor mechanism that panned the line of sight across the limb corresponding to tangent altitudes of 80-480 km. A set of three photon counting detectors, each viewing a separate exit slit, provided simultaneous coverage of the wavelength bands of 85-120 nm (EUV), 110-163 nm (far UV), and 290-395 nm (UV) at a wavelength resolution of 0.4, 0.8, and 1.2 nm, respectively. A separate photometric channel isolated the atmospheric sodium doublet at 589.0-589.6 nm. The grating position and instrument view angle were controlled by digital circuitry operating on hardwired and uplinked command instructions. The operating modes included a variety of scanning and fixed wavelength and view angle operations. A description of the instrument and several examples of the data are presented. These include the dayglow emissions from thermospheric oxygen and nitrogen that form the basis of a thermospheric density determination, auroral enhancements observed in these emissions and in hydrogen Ly-alpha, and nighttime sodium emissions.

: A concave grating Wadsworth spectrometer designed to scan the ultraviolet limb of the earth was flown on a DoD satellite to obtain measurements of atmospheric emissions in the wavelength range of 85 nm to 395 nm as a function of height above the solid earth. The instrument field of view was 0.14 deg x 3.8 deg corresponding to 8 km in the vertical and 230 km in the horizontal at the limb. Scanning motion was controlled by a momentum-compensated DC-torque motor mechanism that panned the line of sight across the limb corresponding to tangent altitudes of 80 km to 480 km. A set of three photon counting detectors, each viewing a separate exit slit, provided simultaneous coverage of the wavelength bands 85-120 nm (EUV), 110-163 nm (FUV) and 290-395 nm (UV), respectively. A separate photometric channel isolated the atmospheric sodium doublet at 589.0-589.6 nm. The grating position and instrument view angle were controlled by digital circuitry operating on hardwired and uplinked command instructions. The operating modes included a variety of scanning and fixed wavelength and view angle operations. A description of the instrument and several examples of the data are presented. These include the dayglow emissions from thermospheric oxygen and nitrogen that form the basis of a thermospheric density determination; auroral enhancements observed in these emissions and in hydrogen Ly alpha; and night-time sodium emissions.

The CRLS-229 Solar X-ray Spectrometer/Spectroheliograph payload was launched in the solar pointed section of the U. S. Air Force Space Test Program P78-1 satellite on 24 February 1979. The payload consists of two instruments furnished by The Aerospace Corporation, known as SOLEX and MONEX, and two instruments furnished by the Naval Research Laboratory. Thp SOLEX instrument provides maps of the sun in individual x-ray spectral lines and also obtains spectra in the 3 to 25 Å wavelength interval while pointed at a specific solar region. The basic SOLEX hardware consists of two multigrid collimators with 20 arc sec and 60 arc sec spatial resolution, RAP and ADP scanning high resolution Bragg crystals, and a proportional counter and an array of channel electron multipliers as detectors. The MONEX experiment, consisting of two proportional counters, provides full disk solar x-ray intensity with moderate spectral resolution and excellent temporal resolution in the 1 to 140 keV energy interval. Examples of data from the Spectrometer/Spectroheliograph are presented.

Absolute pressure measurements are made by two instruments aboard Atmosphere Explorer (AE): a cold-cathode ion gauge and a capacitance manometer. The dual sensors feature coverage from 120 to 370 km with double coverage below 200 km, differing and complementary sensing techniques, usable output in the spinning and both normal and inverted despun satellite modes, simple formatting to facilitate dat...

An electrometer system is described which makes use of a conversion from input current to frequency. The data handling section employs digital circuit techniques which allow the dynamic range of the system to be adjusted to the requirement of the experiment, and which present the output in pulse form compatible with contemporary logic systems. The conversion of the input current variable to frequency is achieved by making use of an integrating preamplifier circuit having a capacitive feedback element consisting in part of a reed relay which resets the integrator voltage. Since leakage currents can be controlled in all components of the input circuit, the calibrated current range of the system can be extended down to the order of 10−14 A. Resolution of the system as defined by the inherent noise in the integrator circuit is discussed in an appendix note.

A very simple logarithmic response dc electrometer circuit is described which makes use of a novel connection for developing the log feedback signal. The resulting improvement in bandwidth over familiar circuits is discussed.