AKA: 75-1-1. First Launch: 1958-12-16. Last Launch: 1972-03-12. Number: 52 . Longitude: -120.62 deg. Latitude: 34.75 deg.
The first Agena D (#1151) upper stage vehicle was successfully flown on a Thor booster (#340) launched from Vandenberg AFB. The Lockheed Agena D was a redesign of the basic Agena B and was intended to be the standard stage vehicle for most Defense Department and NASA programs. The program was begun in August 1961, revised and accelerated in November, and had its first flight in June 1962. KH-4; film capsule recovered 4.1 days later. Severe corona static.
First launch of a triplet of Poppy naval signals intelligence satellites, which would lead to the NOSS production series. Official and secondary mission: Solar radiation data. Space craft engaged in investigation of spaceflight techniques and technology (US Cat A).
The first Thor/Ablestar launch from Vandenberg carried a Navy payload that became the first satellite to be operated completely with nuclear power. A SNAP-9A satellite nuclear power supply, built by the Martin Company and the Atomic Energy Commission, was used to power the satellite. First test of nuclear-powered Transit operational prototype. Carried SNAP-9A nuclear power source. The satellite achieved gravity-gradient stabilization, but upside down, making the signal level too low for operational users with low-gain antennas. However, geodetic and navigational evaluation data were obtained.
The first Thor/Ablestar launch from Vandenberg carried a Navy payload that became the first satellite to be operated completely with nuclear power. A SNAP-9A satellite nuclear power supply, built by the Martin Company and the Atomic Energy Commission, was used to power the satellite. The missions of Satellite 1963-038C were to measure omnidirectional flux of protons and electrons at various energy levels, radiation effects on transistors, and the effectiveness of thermal coatings. The satellite was launched together with a classified Department of Defense spacecraft on September 28, 1963. Its planned orbit was apogee 1120 kilometres, perigee 1070 kilometres, inclination 88.9 degrees. The satellite weighed 62 kg; its body was in the shape of an 0.46 m x 0.25 m octagonal prism. It was powered by four solar blades and transmited on 136, 162, and 324 mcs. The spacecraft was built for the Bureau of Naval Weapons. In 1967 it was still sending usable data from all systems.
Transit operational prototype powered by a SNAP-9A nuclear power source. First operational navigation satellite. It was used regularly by both surface and submarine units of the Navy until November 1964. From this point in time the US Navy had continuous use of satellite navigation.
An Air Force Thor/Agena B was launched from Vandenberg and placed NASA's first Nimbus meteorological satellite into orbit. Returned 27,000 cloud cover images. The spacecraft carried an advanced vidicon camera system for recording and storing remote cloudcover pictures, an automatic picture transmission camera for providing real-time cloud cover pictures, and a high-resolution infrared radiometer to complement the daytime TV coverage and to measure nighttime radiative temperatures of cloud tops and surface terrain. A short second-stage burn resulted in an unplanned eccentric orbit. Otherwise, the spacecraft and its experiments operated successfully until September 22, 1964. The solar paddles became locked in position, resulting in inadequate electrical power to continue operations.
First test of a side-looking radar from outer space. The mission lasted only four days, as planned, before the batteries ran out of power during orbits 72-73. The radar operated 14 times in orbit, between 22 and 26 December, imaging swaths of the northeastern and western United States. Data collected from the 14 radar passes were transmitted over a wideband (UHF) data link as they were obtained ("real time") to the Vandenberg or New Boston ground station in view. In addition, during the first seven radar passes data were recorded on film on board the satellite, and on 23 December, during the 33rd orbit, the reentry capsule was jettisoned and recovered. The vehicle and payload performance were within acceptable limits on all parameters. The radar maps covered about 80,000 square miles and the resolution was better than 15 feet in azimuth and 80 feet in ground range. The mission, not declassified until 2012, proved the feasibility of space-based surveillance, leading to the operational Lacrosse satellites of the 1980's.
OGO 2 was a large observatory instrumented with 20 experiments designed to make simultaneous, correlative observations of aurora and airglow emissions, energetic particles, magnetic field variations, ionospheric properties, etc., especially over the polar areas. Soon after achieving orbit, difficulties in maintaining earth lock with horizon scanners caused exhaustion of attitude control gas by October 23, 1965, 10 days after launch. At this time, the spacecraft entered a spin mode (about 0.11 rpm) with a large coning angle about the previously vertical axis. Five experiments became useless when the satellite went into this spin mode. Six additional experiments were degraded by this loss of attitude control. By April 1966, both batteries had failed, so subsequent observations were limited to sunlit portions of the orbit. By December 1966, only eight experiments were operational, five of which were not degraded by the spin mode operation. By April 1967, the tape recorders had malfunctioned and only one third of the recorded data could be processed. Spacecraft power and periods of operational scheduling conflicts created six large data gaps so that data were observed on a total of about 306 days of the 2-yr, 18-day total span of observed satellite data to November 1, 1967. The spacecraft was shut down on November 1, 1967, with eight experiments still operational. It was reactivated for 2 weeks in February 1968 to operate the rubidium vapor magnetometer experiment.
Ionospheric research; data correlated with Explorer 31. The double-launch project, known as ISIS-X was the first in a new co-operative NASA-Canadian Defense Research Board program for International Satellites for Ionospheric Studies. Alouette was in orbit with an apogee just over a kilometre lower than Explorer 31's and with a perigee of just more than a kilometre higher. The orbits were some 3000 km at apogee and 500 km at perigee.
Ionospheric research; data correlated with Alouette 2. The Explorer 31, Direct Measurement Explorer, was launched with a Canadian Alouette II on November 28, 1965, on a Thor-Agena rocket from Vandenberg Air Force Base, California. The double-launch project, known as ISIS-X was the first in a new co-operative NASA-Canadian Defense Research Board program for International Satellites for Ionospheric Studies. Explorer 31 was in orbit with an apogee just over a kilometre more than Alouette's and with a perigee of just more than a kilometre lower. The orbits were some 3000 km at apogee and 500 km at perigee. Eight ionospheric measurement experiments sampled the environment both forward and after the satellite's path.
The last Thrust Augmented Thor/Agena B was used to place NASA's NIMBUS II meteorological satellite into orbit. TV, IR cloud cover photos. The spacecraft carried an advanced vidicon camera system for recording and storing remote cloud cover pictures, an automatic picture transmission camera for providing real-time cloudcover pictures, and both high- and medium-resolution infrared radiometers (HRIR and MRIR) for measuring the intensity and distribution of electromagnetic radiation emitted by and reflected from the earth and its atmosphere. The spacecraft and experiments performed normally after launch until July 26, 1966, when the spacecraft tape recorder failed. Its function was taken over by the HRIR tape recorder until November 15, 1966, when it also failed. Some real-time data were collected until January 17, 1969, when the spacecraft mission was terminated owing to deterioration of the horizon scanner used for earth reference.
The PAGEOS (Passive Geodetic Earth Orbiting Satellite) spacecraft was a 30.48-m inflatable sphere, and had no instrumentation on board. It was the second (following GEOS 1) NASA satellite in the National Geodetic Satellites Program. The launch, orbit, separation, inflation and initial operation were nominal, with more than 40 ground stations participating in the observation program. The orbit was generally considered too high for drag-density study, although some work was done in this area by the Smithsonian Astrophysical Observatory. Additional Details: here....
OGO 4 was a large observatory instrumented with experiments designed to study the interrelationships between the aurora and airglow emissions, energetic particle activity, geomagnetic field variation, ionospheric ionization and recombination, and atmospheric heating which take place during a period of increased solar activity. After the spacecraft achieved orbit and the experiments were deployed into an operating mode, an attitude control problem occurred. This condition was corrected by ground control procedures until complete failure of the tape recording systems in mid-January 1969. At that time, due to the difficulty of maintaining attitude control without the tape recorders, the attitude control system was commanded off, and the spacecraft was placed into a spin-stabilized mode about the axis which was previously maintained vertically. In this mode, seven of the remaining experiments were turned off since no meaningful data could be observed by them. On October 23, 1969, the satellite was turned off. It was reactivated again in January 1970 for 2 months to obtain VLF observations.
The geodetic instrumentation systems included (1) four optical beacons, (2) two C-band radar transponders, (3) a passive radar reflector, (4) a sequential collation of range radio range transponder, (5) a Goddard range and range rate transponder, (6) laser reflectors, and (7) Doppler beacons. Non-geodetic systems included a laser detector and a Minitrack interferometer beacon. The objectives of the spacecraft were to optimise optical station visibility periods and to provide complementary data for inclination-dependent terms established by the Explorer 29 (GEOS 1) gravimetric studies. The spacecraft was placed into a retrograde orbit to accomplish these objectives. Operational problems occurred in the main power system, optical beacon flash system, and the spacecraft clock, and adjustments in scheduling resulted in nominal operations.
Primary experiments consisted of a satellite infrared spectrometer (SIRS) for determining the vertical temperature profiles of the atmosphere, an infrared interferometer spectrometer (IRIS) for measuring the emission spectra of the earth-atmosphere system, both high- and medium-resolution infrared radiometers (HRIR and MRIR) for yielding information on the distribution and intensity of infrared radiation emitted and reflected by the earth and its atmosphere, monitor of ultraviolet solar energy (MUSE) for detecting solar UV radiation, image dissector camera system for providing daytime cloudcover pictures in both real-time mode using the real time transmission system and tape recorder mode using the high data rate storage system, radioisotope thermoelectric generator (RTG) SNAP-19 to assess the operational capability of radioisotope power for space applications, and an interrogation, recording and location system (IRLS) experiment designed to locate, interrogate, record, and retransmit meteorological and geophysical data from remote collection stations. Nimbus-3 was successful and performed normally until July 22, 1969, when the IRIS experiment failed. The HRIR and the SIRS experiments were terminated on January 25, 1970, and June 21, 1970, respectively. The remaining experiments continued operation until September 25, 1970, when the rear horizon scanner failed. Without this horizon scanner, it was impossible to maintain proper spacecraft attitude, thus making most experimental observations useless. All spacecraft operations were terminated on January 22, 1972.
OGO 6 was a large observatory instrumented with 26 experiments designed to study the various interrelationships between, and latitudinal distributions of, high-altitude atmospheric parameters during a period of increased solar activity. On June 22, 1969, the spacecraft potential dropped significantly during sunlight operation and remained so during subsequent sunlight operation. This unexplained shift affected seven experiments which made measurements dependent upon knowledge of the spacecraft plasma sheath. During October 1969, a string of solar cells failed, but the only effect of the decreased power was to cause two experiments to change their mode of operation. Also during October 1969, a combination of manual and automatic attitude control was initiated, which extended the control gas lifetime of the attitude control system. In August 1970, tape recorder (TR) no. 1 operation degraded, so all recorded data were subsequently taken with TR no. 2. By September 1970, power and equipment degradation left 14 experiments operating normally, 3 partially, and 9 off. From October 14, 1970, TR no. 2 was used only on Wednesdays (world days) to conserve power and extend TR operation. In June 1971, the number of 'on' experiments decreased from 13 to 7, and on June 28, 1971, the spacecraft was placed in a spin-stabilized mode about the yaw (Z) axis and turned off due to difficulties with spacecraft power. OGO 6 was turned on again from October 10, 1971, through March 1972, for operation of experiment 25 by The Radio Research Laboratory, Japan.
Space Electric Rocket Test; the ion engines aboard were operated until 1981. The SERT 2 development program started in 1966 and included thruster ground tests of 6742 hours and 5169 hours duration. A prototype version of the SERT 2 spacecraft was ground-tested for a period of 2400 hours with an operating ion engine. In addition to diagnostic equipment and related ion engine hardware, the spacecraft had two identical 15 cm diameter, mercury ion engines. Flight objectives included in-space operation for a period of 6 months, measurement of thrust, and demonstration of electromagnetic compatibility. The thruster maximum power level was 0.85 kW, and this provided operation at a 28 mN thrust level at 4200 s specific impulse. Flight data were obtained from 1970 to 1981 with an ion engine operating intermittently in one of three different modes, namely, HV ion extraction, discharge chamber operation only, or just neutralizer operation. Major results were that two mercury engines thrusted for periods of 3781 hours and 2011 hours. Test duration was limited due to shorts in the ion optical system. Thrust measured in space and on the ground agreed within the measurement uncertainties. Up to 300 thruster restarts were demonstrated. One power-processing unit accumulated nearly 17,900 hours during the course of the mission. Additionally, the ion propulsion system was electromagnetically compatible with all other spacecraft systems.
A Long Tank Thrust Augmented Thor/Agena D space booster lifted NASA's Nimbus 4 meteorological satellite into orbit from Vandenberg. This was the 400th launch.. of the Thor booster that was originally developed by the Air Force as an intermediate range ballistic missile (IRBM) in the 1950s. Environmental research. Primary experiments consisted of an image dissector camera system for providing daytime cloudcover pictures both in real-time and recorded modes, temperature-humidity infrared radiometer (THIR) for measuring daytime and nighttime surface and cloudtop temperatures as well as the water vapor content of the upper atmosphere, infrared interferometer spectrometer (IRIS) for measuring the emission spectra of the earth/atmosphere system, satellite infrared spectrometer (SIRS) for determining the vertical profiles of temperature and water vapor in the atmosphere, a monitor of ultraviolet solar energy (MUSE) for detecting solar UV radiation, a backscatter ultraviolet (BUV) detector for monitoring the vertical distribution and total amount of atmospheric ozone on a global scale, a filter wedge spectrometer (FWS) for accurate measurement of IR radiance as a function of wavelength from the earth/atmosphere system, a selective chopper radiometer (SCR) for determining the temperatures of six successive 10-km layers in the atmosphere from absorption measurements in the 15-micrometer CO2 band, and an interrogation, recording, and location system (IRLS) for locating, interrogating, recording, and retransmitting meteorological and geophysical data from remote collection stations. The spacecraft performed well until April 14, 1971, when attitude problems started. The experiments then operated on a limited time basis until September 30, 1980.