Explorer 52
Encyclopedia
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| Organization: | NASA - Langley Research Center Langley Research Center Langley Research Center is the oldest of NASA's field centers, located in Hampton, Virginia, United States. It directly borders Poquoson, Virginia and Langley Air Force Base... |
| Major Contractor: | Department of Physics and Astronomy, University of Iowa University of Iowa The University of Iowa is a public state-supported research university located in Iowa City, Iowa, United States. It is the oldest public university in the state. The university is organized into eleven colleges granting undergraduate, graduate, and professional degrees... |
| Mission Type: | Space Physics Space physics Space physics, also known as space plasma physics, is the study of plasmas as they occur naturally in the universe. As such, it encompasses a far-ranging number of topics, including the sun, solar wind, planetary magnetospheres and ionospheres, auroras, cosmic rays, and synchrotron radiation... |
| Satellite of: | Earth Earth Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets... |
| Launch: | June 3, 1974 at 23:09:11 UTC Coordinated Universal Time Coordinated Universal Time is the primary time standard by which the world regulates clocks and time. It is one of several closely related successors to Greenwich Mean Time. Computer servers, online services and other entities that rely on having a universally accepted time use UTC for that purpose... |
| Launch Vehicle: | Scout-E1 Scout (rocket) The Scout family of rockets were launch vehicles designed to place small satellites into orbit around the Earth. The Scout multistage rocket was the first orbital launch vehicle to be entirely composed of solid fuel stages.... |
| Decay: | April 28, 1978 |
| Mission Duration: | 1,425 days |
| Mass Mass Mass can be defined as a quantitive measure of the resistance an object has to change in its velocity.In physics, mass commonly refers to any of the following three properties of matter, which have been shown experimentally to be equivalent:... : |
22.7 kg |
| NSSDC ID: | 1974-040A |
| Webpage: | NASA NSSDC Master Catalog |
| Orbital elements Orbital elements Orbital elements are the parameters required to uniquely identify a specific orbit. In celestial mechanics these elements are generally considered in classical two-body systems, where a Kepler orbit is used... |
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| Semi-major axis Semi-major axis The major axis of an ellipse is its longest diameter, a line that runs through the centre and both foci, its ends being at the widest points of the shape... : |
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| Eccentricity Orbital eccentricity The orbital eccentricity of an astronomical body is the amount by which its orbit deviates from a perfect circle, where 0 is perfectly circular, and 1.0 is a parabola, and no longer a closed orbit... : |
.901272 |
| Inclination Inclination Inclination in general is the angle between a reference plane and another plane or axis of direction.-Orbits:The inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit... : |
89.8° |
| Orbital Period: | 3032.4 min |
| Apogee: | 125570 km |
| Perigee: | 469 km |
| Orbits: | 667 |
| Instruments | |
| Plasma wave receiver: | Plasma distribution in solar wind |
| Fluxgate magnetometer: | Magnetic field in the solar wind |
| Low energy proton-electron differential energy analyzer: | Polar magnetosphere of the earth out to 21 earth radii, Type-3 radio emissions caused by solar electron streams in the interplanetary medium. |
Explorer 52 was a US
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
satellite
Satellite
In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....
launched on June 3, 1974 from Vandenberg Air Force Base
Vandenberg Air Force Base
Vandenberg Air Force Base is a United States Air Force Base, located approximately northwest of Lompoc, California. It is under the jurisdiction of the 30th Space Wing, Air Force Space Command ....
on a Scout booster.
This satellite was also known as:
- Hawkeye 1
- IE D
- Injun 6
- Injun F
- Neutral Point Explorer
- 07325
The primary mission objective of Hawkeye 1 (Explorer 52) was to conduct particles and fields investigations of the polar magnetosphere of the earth out to 21 earth radii. Secondary objectives were to make magnetic field and plasma distribution measurements in the solar wind, and to study Type-3 radio emissions caused by solar electron streams in the interplanetary medium. To accomplish these objectives, the spacecraft was instrumented with following instruments:
- a plasma wave receiver,
- a fluxgate magnetometer, and
- a low energy proton-electron differential energy analyzer.
The spacecraft was spin stabilized with a nominal rotational period of 11 s. In celestial coordinates, the positive spin axis coordinates were right ascension 299.4 deg (plus or minus 1.1 deg) and declination 8.6 deg (plus or minus 1.5 deg). There was no onboard orientation or spin rate control, but the orientation of the spin axis was stable. An optical aspect system operated from launch until September 3, 1974. After this period, aspect had to be determined from magnetometer measurements. The complete spacecraft with instruments had a mass of 22.65 kg. Power of 22 to 36 W, depending on solar aspect, was obtained from solar cells. Hawkeye 1 participated in the International Magnetospheric Study (IMS) and during the first half of 1977 data acquisition was confined to IMS special intervals. Data were obtained in real time only, at frequencies of 136 MHz and 400 MHz at 100 bit/s (or 200 bit/s with convolutional coding) plus wideband VLF data.
It was designed, built, and tracked by personnel at the Department of Physics and Astronomy, University of Iowa
University of Iowa
The University of Iowa is a public state-supported research university located in Iowa City, Iowa, United States. It is the oldest public university in the state. The university is organized into eleven colleges granting undergraduate, graduate, and professional degrees...
whose sports teams are the Hawkeyes. The spacecraft was launched on June 3, 1974 into a polar orbit with initial apogee over the North Pole and re-entered on April 28, 1978 after 667 orbits or nearly four years of continuous operation. The spacecraft apogee was between 20.28 and 20.92 Earth radii with less than a 1.7 Earth radii perigee. The orbital period was 51.3 hours. During its lifetime, the inclination of the plane of the spacecraft's orbit to the Earth's equator decreased monotonically from 89.81 to 81.85 degrees. The spacecraft's axis of rotation at launch was inertially fixed in its orbital plane, directed towards a constant right ascension and declination, and nearly parallel to the Earth's equatorial plane.