Dynamics Explorer

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Dynamics Explorer 1
Mission typeMagnetospheric research
COSPAR ID1981-070A
SATCAT no.12624
Spacecraft properties
ManufacturerRCA Astro
Launch mass424 kilograms (935 lb)
Power68 W
Start of mission
Launch dateAugust 03, 1981, 09:56:00 (1981-08-03UTC09:56Z) UTC
RocketDelta 3913 642/D155
Launch siteVandenberg SLC-2W
Orbital parameters
Reference systemGeocentric
Semi-major axis18,238.0 kilometers (11,332.6 mi)
Perigee488.6 kilometers (303.6 mi)
Apogee23,246.3 kilometers (14,444.6 mi)
Period408.5 minutes
Epoch27 June 2016
Revolution no.59680
Dynamics Explorer 2
Mission typeMagnetospheric research
COSPAR ID1981-070B
SATCAT no.12625
Spacecraft properties
ManufacturerRCA Astro
Launch mass420 kilograms (926 lb)
Power115 W
Start of mission
Launch dateAugust 03, 1981, 09:56:00 (1981-08-03UTC09:56Z) UTC
RocketDelta 3913 642/D155
Launch siteVandenberg SLC-2W
End of mission
Decay dateFebruary 19, 1983
Orbital parameters
Reference systemGeocentric
Perigee309 kilometers (192 mi)
Apogee1,012 kilometers (629 mi)
Period98 minutes
Epoch03 August 1981
Revolution no.8593

Dynamics Explorer was a NASA mission, launched on August 3, 1981 and terminated on February 28, 1991.[1] 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.[2] The two satellites were launched together into polar coplanar orbits, which allowed them to simultaneously observe the upper and lower parts of the atmosphere.


Both spacecraft had a polygonal shape, and were approximately 137 cm in diameter and 115 cm high. Each also had a 200-cm radio antenna and two 6-meter booms which were needed to distance some of the equipment from the main body of the spacecraft. They were stacked on top of each other and launched aboard a Delta 3000 booster rocket. Upon reaching orbit, the two spacecraft departed from the booster and entered separate orbits. Dynamics Explorer 1 was placed into a high altitude elliptical orbit, while DE-2 was put into a lower orbit that was also more circular.

Dynamics Explorer 1 Instrumentation[edit]

Dynamics Explorer 1 carried the following instruments[3]:

  • Plasma Wave Instrument (PWI), which measured auroral kilometric radiation, auroral hiss, Z-mode radiation, and narrow band electromagnetic emissions.
  • The Spin-scan Auroral Imager (SAI)
  • The Retarding Ion Mass Spectrometer (RIMS)
  • Energetic Ion Composition Spectrometer (EICS)
  • High Altitude Plasma Instrument (HAPI)
  • Magnetic Field Observations Triaxial Fluxgate Magnetometer (MAG-A)

In addition, there were two Earth-based investigations, Auroral Physics Theory and Controlled and Naturally Occurring Wave Particle Interactions Theory. The later involved broadcasting very-low-frequency/low-frequency (0.5-200 kHz) signals from a transmitter located at Siple, Antarctica, which were received by the PWI instrument on Dynamics Explorer 1.

Dynamics Explorer 2 Instrumentation[edit]

The Dynamics Explorer 2 carried the following instruments for data collection:

Mission Results[edit]

As a result of a malfunction in the Delta 3000 booster rocket in which its main engine shut off slightly early, DE-2 was placed into a slightly lower orbit than was anticipated. This was not a serious problem, however, and the spacecraft had lasted its expected lifespan when it re-entered the Earth's atmosphere on February 19, 1983. DE-1, being in a higher orbit, continued to collect data until 1991, when the mission was officially terminated.


  1. ^ DE (Dynamics Explorer)
  2. ^ NSSDC Master Catalog
  3. ^ "National Space Science Data Center: Experiments on Dynamics Explorer 1". NASA/NSSDC.
  4. ^ Dynamics Explorer 2 Archived 2007-03-15 at the Wayback Machine
  5. ^ a b Spencer, N. W., Wharton, L. E., Carignan, G. R. and Maurer, J. C. (1982), Thermosphere zonal winds, vertical motions and temperature as measured from Dynamics Explorer. Geophys. Res. Lett., 9: 953–956. doi:10.1029/GL009i009p00953.
  6. ^ Spencer, N. W., Theis, R. F., Wharton, L. E. and Carignan, G. R. (1976), Local vertical motions and kinetic temperature from AE-C as evidence for aurora-induced gravity waves. Geophys. Res. Lett., 3: 313–316. doi:10.1029/GL003i006p00313.

External links[edit]