![]() Explorer 10 satellite | |
Names | P-14 Explorer X |
---|---|
Mission type | Space plasma physics |
Operator | NASA |
Harvard designation | 1961 Kappa 1 |
COSPAR ID | 1961-010A |
SATCAT no. | 00098 |
Mission duration | 52 hours (achieved) |
Spacecraft properties | |
Spacecraft | Explorer X |
Bus | P-14 |
Manufacturer | Goddard Space Flight Center Massachusetts Institute of Technology |
Launch mass | 35 kg (77 lb) |
Start of mission | |
Launch date | 25 March 1961, 15:17:04 GMT [1] |
Rocket | Thor DM-19 Delta (Thor 295) |
Launch site | Cape Canaveral, LC-17A |
Contractor | Douglas Aircraft Company |
Entered service | 25 March 1961 |
End of mission | |
Last contact | 27 March 1961 |
Decay date | 30 June 1968 |
Orbital parameters | |
Reference system | Geocentric orbit [2] |
Regime | Highly elliptical orbit |
Perigee altitude | 221 km (137 mi) |
Apogee altitude | 180,100 km (111,900 mi) |
Inclination | 33.0° |
Period | 83.50 hours |
Instruments | |
Faraday Cup Plasma Probe Rb-Vapor and Fluxgate Magnetometers Sun-Moon-Earth Aspect Sensor (Spacecraft) | |
Explorer program |
Explorer 10 (also known as Explorer X or P14) was a NASA satellite that investigated Earth's magnetic field and nearby plasma. Launched on 25 March 1961, it was an early mission in the Explorer program and was the first satellite to measure the "shock wave" generated by a solar flare. [3]
The objective was to investigate the magnetic field and plasma as the spacecraft passed through Earth's magnetosphere and into cislunar space. The satellite was launched into a highly-elliptical orbit and was spin-stabilized with a spin period of 0.548 seconds. The direction of its spin vector was 71° right ascension and −15° declination. [3]
Explorer 10 was a cylindrical, battery-powered spacecraft instrumented with two fluxgate magnetometers and one rubidium vapor magnetometer extending from the main spacecraft body, and a Faraday cup plasma probe. The magnetometers were produced by Goddard Space Flight Center, and the Massachusetts Institute of Technology (MIT) provided the plasma probe. [3]
This experiment consisted of a Faraday cup with four grids and a collector designed to provide data on the density of the solar plasma and the magnitude and direction of its bulk motion. Protons were measured in the following energy ranges: 0 to 5, 0 to 20, 0 to 80, 0 to 250, 0 to 800, and 0 to 2300 eV. The experiment was mounted on the spacecraft so that the symmetry axis of the plasma probe was perpendicular to the spacecraft spin axis. The Faraday cup had its maximum response to particles incident at 0° to its symmeter axis. The response fell off rapidly until the instrument had a zero response to particles coming in at 63° and greater to its normal. The effective area of collection for normal incidence was 28-cm2. The instrument had two outputs: a DC component related to photoelectric effects and the plasma flux, and an AC component related only to the plasma flux. The shift in the frequency of the AC output component was encoded to be proportional to the plasma flux. The upper energy limit of the plasma particles generating the AC component was determined by the value of a positive retarding voltage applied to one of the grids. This "modulating voltage" had six possible values, from 5 to 2300 eV, and it could also be set to 0. During each 148-second telemetry sequence, 5 seconds were used by the plasma probe. These 5-second intervals, subcommutated by an interval program, were used to transmit sequentially a marker signal, the DC output of the instrument, and the AC output of the experiment at one of the six modulating voltages. Thus, a complete plasma probe sequence, consisting of eight telemetering cycles, lasted 19 minutes and 44 seconds. No inflight calibration was provided, and no onboard processing was done. Because of the limited lifetime of the spacecraft battery, only 52 hours of data were acquired. [4]
A dual gas rubidium alkali vapor instrument and two monaxial fluxgate magnetometers were designed to obtain vector magnetic field measurements of all three field components along a 1.8- to 42.6-Earth radii trajectory traversing the geomagnetic field and extending into the interplanetary medium. The fluxgate magnetometers were oriented at an angle of 57° 45' to the satellite spin axis and were placed on the ends of 79 cm (31 in) booms to reduce to less than 1 nT the possibility of spacecraft magnetic field contamination. Data were transmitted to ground stations in periods of 126 seconds from the rubidium magnetometer and 3 seconds for each of the fluxgate magnetometers, in sequence with the other experiment transmissions. Performance was excellent, and data were obtained for 52 hours. During launch, however, outgassing caused deposition of a film on the sphere containing the rubidium-vapor magnetometer. This increased the absorbency of the surface and raised the rubidium vapor magnetometer's temperature to 60°C after 2 hours in sunlight, which interrupted the continuous operation of the magnetometer at 18 Earth radii. Intermittent operation occurred for the next 6 hours and this permitted inflight vector calibration of the fluxgate magnetometers in weak fields. [5]
The optical aspect sensor consisted of a Sun-Moon-Earth sensor and associated electronics. The Earth-Moon part of the sensor consisted of a fan field of vision, 3° wide and 120° long, which swept through the sky as the probe rotated in space. The appearance of the Moon or Earth in the sensor's field of view caused a step change in subcarrier frequency. The Sun part of the sensor consisted of a digital coded slit 2° wide and 100° long. The appearance of the Sun in the field of view of the slit caused a discrete frequency on the subcarrier which corresponded to the position of the Sun in the field of view. [6]
Because of the limited life of the spacecraft batteries, the only useful data were transmitted in real-time for 52 hours on the ascending portion of the first orbit. The distance from the Earth when the last bit of useful information was transmitted was 42.3 Earth radii, and the local time at this point was 22:00 hours. All transmission ceased several hours later. [3]
Explorer 35,, was a spin-stabilized spacecraft built by NASA as part of the Explorer program. It was designed for the study of the interplanetary plasma, magnetic field, energetic particles, and solar X-rays, from lunar orbit.
Explorer 6, or S-2, was a NASA satellite, launched on 7 August 1959, at 14:24:20 GMT. It was a small, spherical satellite designed to study trapped radiation of various energies, galactic cosmic rays, geomagnetism, radio propagation in the upper atmosphere, and the flux of micrometeorites. It also tested a scanning device designed for photographing the Earth's cloud cover. On 14 August 1959, Explorer 6 took the first photos of Earth from a satellite.
Explorer 52, also known as Hawkeye-1, Injun-F, Neutral Point Explorer, IE-D, Ionospheric Explorer-D, was a NASA satellite launched on 3 June 1974, from Vandenberg Air Force Base on a Scout E-1 launch vehicle.
The Fast Auroral SnapshoT Explorer was a NASA plasma physics satellite, and was the second spacecraft in the Small Explorer program (SMEX). It was launched on 21 August 1996, from Vandenberg Air Force Base aboard a Pegasus XL launch vehicle. The spacecraft was designed and built by NASA's Goddard Space Flight Center (GSFC). Flight operations were handled by GSFC for the first three years, and thereafter were transferred to the University of California, Berkeley's Space Sciences Laboratory.
Explorer 33, also known as IMP-D and AIMP-1, is a spacecraft in the Explorer program launched by NASA on 1 July 1966 on a mission of scientific exploration. It was the fourth satellite launched as part of the Interplanetary Monitoring Platform series, and the first of two "Anchored IMP" spacecraft to study the environment around Earth at lunar distances, aiding the Apollo program. It marked a departure in design from its predecessors, IMP-A through IMP-C. Explorer 35 was the companion spacecraft to Explorer 33 in the Anchored IMP program, but Explorer 34 (IMP-F) was the next spacecraft to fly, launching about two months before AIMP-E, both in 1967.
Dynamics Explorer was a NASA mission, launched on 3 August 1981, and terminated on 28 February 1991. It consisted of two unmanned satellites, DE-1 and DE-2, whose purpose was to investigate the interactions between plasmas in the magnetosphere and those in the ionosphere. The two satellites were launched together into polar coplanar orbits, which allowed them to simultaneously observe the upper and lower parts of the atmosphere.
Magsat was a NASA / USGS spacecraft, launched on 30 October 1979. The mission was to map the Earth's magnetic field, the satellite had two magnetometers. The scalar and vector magnetometers gave Magsat a capability beyond that of any previous spacecraft. Extended by a telescoping boom, the magnetometers were distanced from the magnetic field created by the satellite and its electronics. The satellite carried two magnetometers, a three-axis fluxgate magnetometer for determining the strength and direction of magnetic fields, and an ion-vapor/vector magnetometer for determining the magnetic field caused by the vector magnetometer itself. Magsat is considered to be one of the more important Science/Earth-orbiting satellites launched; the data it accumulated is still being used, particularly in linking new satellite data to past observations.
Spacecraft magnetometers are magnetometers used aboard spacecraft and satellites, mostly for scientific investigations, plus attitude sensing. Magnetometers are among the most widely used scientific instruments in exploratory and observation satellites. These instruments were instrumental in mapping the Van Allen radiation belts around Earth after its discovery by Explorer 1, and have detailed the magnetic fields of the Earth, Moon, Sun, Mars, Venus and other planets and moons. There are ongoing missions using magnetometers, including attempts to define the shape and activity of Saturn's core.
Explorer 18, also called IMP-A, IMP-1, Interplanetary Monitoring Platform-1 and S-74, was a NASA satellite launched as part of the Explorer program. Explorer 18 was launched on 27 November 1963 from Cape Canaveral Air Force Station (CCAFS), Florida, with a Thor-Delta C launch vehicle. Explorer 18 was the first satellite of the Interplanetary Monitoring Platform (IMP). Explorer 21 (IMP-B) launched in October 1964 and Explorer 28 (IMP-C) launched in May 1965 also used the same general spacecraft design.
Explorer 14, also called EPE-B or Energetic Particles Explorer-B, was a NASA spacecraft instrumented to measure cosmic-ray particles, trapped particles, solar wind protons, and magnetospheric and interplanetary magnetic fields. It was the second of the S-3 series of spacecraft, which also included Explorer 12, 14, 15, and 26. It was launched on 2 October 1962, aboard a Thor-Delta launch vehicle.
The ISEE-1 was an Explorer-class mother spacecraft, International Sun-Earth Explorer-1, was part of the mother/daughter/heliocentric mission. ISEE-1 was a 340.2 kg (750 lb) space probe used to study magnetic fields near the Earth. ISEE-1 was a spin-stabilized spacecraft and based on the design of the prior IMP series of spacecraft. ISEE-1 and ISEE-2 were launched on 22 October 1977, and they re-entered on 26 September 1987.
The ISEE-2 was an Explorer-class daughter spacecraft, International Sun-Earth Explorer-2, was part of the mother/daughter/heliocentric mission. ISEE-2 was a 165.78 kg (365.5 lb) space probe used to study magnetic fields near the Earth. ISEE-2 was a spin-stabilized spacecraft and based on the design of the prior IMP series of spacecraft. ISEE-1 and ISEE-2 were launched on 22 October 1977, and they re-entered on 26 September 1987.
Explorer 12, also called EPE-A or Energetic Particles Explorer-A and as S3), was a NASA satellite built to measure the solar wind, cosmic rays, and the Earth's magnetic field. It was the first of the S-3 series of spacecraft, which also included Explorer 12, 14, 15, and 26. It was launched on 16 August 1961, aboard a Thor-Delta launch vehicle. It ceased transmitting on 6 December 1961 due to power failure.
Explorer 28, also called IMP-C, IMP-3 and Interplanetary Monitoring Platform-3, was a NASA satellite launched on 29 May 1965 to study space physics, and was the third spacecraft launched in the Interplanetary Monitoring Platform program. It was powered by chemical batteries and solar panels. There were 7 experiments on board, all devoted to particle studies. Performance was normal until late April 1967, when intermittent problems began. It stayed in contact until 12 May 1967, when contact was lost. The orbit decayed until it re-entered the atmosphere on 4 July 1968. The spacecraft design was similar to its predecessors Explorer 18 (IMP-A), launched in November 1963, and Explorer 21 (IMP-B), launched in October 1964, though this satellite was a few kilograms lighter. The successor Explorer 33 (IMP-D) began the use of a new design.
Explorer 15, also called EPE-C or Energetic Particles Explorer-C, was a NASA satellite launched as part of the Explorer program. Explorer 15 was launched on 27 October 1962, at Cape Canaveral Air Force Station, Florida, United States, with a Thor-Delta A.
Explorer 21, also called IMP-B, IMP-2 and Interplanetary Monitoring Platform-2, was a NASA satellite launched as part of Explorer program. Explorer 21 was launched on 4 October 1964, at 03:45:00 GMT from Cape Canaveral (CCAFS), Florida, with a Thor-Delta C launch vehicle. Explorer 21 was the second satellite of the Interplanetary Monitoring Platform, and used the same general design as its predecessor, Explorer 18 (IMP-A), launched the previous year, in November 1963. The following Explorer 28 (IMP-C), launched in May 1965, also used a similar design.
Explorer 47, was a NASA satellite launched as part of Explorer program. Explorer 47 was launched on 23 September 1972 from Cape Canaveral, Florida, with a Thor-Delta 1604. Explorer 47 was the ninth overall launch of the Interplanetary Monitoring Platform series, but received the launch designation "IMP-7" because two previous "Anchored IMP" flights had used "AIMP" instead.
Explorer 50, also known as IMP-J or IMP-8, was a NASA satellite launched to study the magnetosphere. It was the eighth and last in a series of the Interplanetary Monitoring Platform.
FIELDS is a science instrument on the Parker Solar Probe (PSP), designed to measure magnetic fields in the solar corona during its mission to study the Sun. It is one of four major investigations on board PSP, along with WISPR, ISOIS, and SWEAP. It features three magnetometers. FIELDS is planned to help answer an enduring questions about the Sun, such as why the solar corona is so hot compared to the surface of the Sun and why the solar wind is so fast.
Dynamics Explorer 1 was a NASA high-altitude mission, launched on 3 August 1981, and terminated on 28 February 1991. It consisted of two satellites, DE-1 and DE-2, whose purpose was to investigate the interactions between plasmas in the magnetosphere and those in the ionosphere. The two satellites were launched together into polar coplanar orbits, which allowed them to simultaneously observe the upper and lower parts of the atmosphere.