SAMPEX

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SAMPEX
SAMPEX
Type: Research satellite
Country: United StatesUnited States United States Germany
GermanyGermany 
Operator: National Aeronautics and Space AdministrationNASA NASA , Max Planck Institute
for Extraterrestrial Physics
COSPAR-ID : 1992-038A
Mission dates
Dimensions: 158 kg
Begin: July 3, 1992, 14:19 UTC
Starting place: Vandenberg Air Force Base
Launcher: Scout-G1
Status: Burned up on Nov. 13, 2012
Orbit data
Rotation time : 96.69 min
Orbit inclination : 81.69 °
Apogee height :  687 km
Perigee height :  512 km

SAMPEX ( Solar Anomalous and Magnetospheric Particle Explorer ), also Explorer 68 , was a small NASA research satellite used to study high-energy particles that originate from the sun , the earth's magnetosphere or from galactic radiation , whereby the anomalous component was also measured. The satellite was realized as the first mission as part of the Small Explorer Program by the Goddard Space Flight Center in cooperation with the Max Planck Institute for Extraterrestrial Physics (MPE). SAMPEX carried four complementary, high-resolution, high-sensitivity instruments used to study the high-energy particles.

SAMPEX during the start preparations

construction

The SAMPEX satellite consisted of a box-shaped satellite body, which contained the control systems and the instruments, as well as two fold-out solar cell booms with an area of 1.7 m² and 100 watts of power for the energy supply. The satellite was three -axis stabilized by three magnetic coils and a gyroscope . In orbit, SAMPEX was always oriented so that the instruments pointed towards the zenith and the solar cells towards the sun. There was no drive system. The on - board computer was very powerful for the time, and the data was stored in semiconductor memories instead of the magnetic tape data recorder that had been common up until then . The internal data transfer took place via a fiber optic network . The data was transmitted to Earth via S-band . SAMPEX was designed for a nominal life of three years, but remained active until it burned out after more than 20 years.

Structure of SAMPEX

Instruments

The SAMPEX instrumentation consisted of four instruments:

  • HILT (Heavy Ion Large Area Proportional Counter Telescope) was a detector for heavy ions ( helium to iron ) in the energy range from 8 to 220  MeV / nucleon . The detector consisted of a three element drift chamber with two multilayer inlet windows and 16 solid state detectors . The drift chamber used isobutane as the fill gas. The instrument recorded medium energy solar ions, galactic cosmic rays, and the area of ​​greatest intensity of the anomalous component of cosmic rays. HILT was the contribution of the Max Planck Institute for Extraterrestrial Physics to the SAMPEX mission.
  • LEICA or LICA (Low Energy Ion Composition Analyzer) was a time-of-flight mass spectrometer for the analysis of solar and magnetospheric ions ( helium to nickel ) in the energy range from 0.5 to 5 MeV / nucleon.
  • MAST (Mass Spectrometer Telescope) was a mass spectrometer to measure the isotope composition of cosmic rays for elements from lithium (Z = 3) to nickel (Z = 28) in an energy range from about 10 to several 100 MeV / nucleon. MAST consisted of an arrangement of eleven solid-state detectors, which also made it possible to determine the trajectory of the incident particles.
  • PET (Proton / Electron Telescope) was a spectrometer that supplemented MAST for light particles such as protons and helium nuclei in the energy range from 18 to 350 MeV / nucleon and electrons in the energy range from 0.4 to around 30 MeV. In addition, particle emissions from nuclear reactors in orbit (e.g. snapshot and the RORSAT satellites) could be recorded.

A special feature of SAMPEX was the inclusion of the earth's magnetic field as an essential component of the measurement method. The earth's magnetic field served SAMPEX as a huge magnetic spectrometer to resolve and analyze various energies and charge states of the particles.

Mission history

Scout-G1 missile with SAMPEX before the start

SAMPEX's mission began on July 3, 1992 with a successful launch of the Scout-G1 launcher from launch pad SLC-5 at Vandenberg Air Force Base . The four-stage rocket brought the satellite into an almost polar orbit with an orbit height between 512 and 687 km and an orbit inclination of 81.69 °. In this orbit, SAMPEX orbited the Earth every 96.69 minutes.

The official science mission of SAMPEX and with it the mission support by NASA ended on June 30, 2004. However, since the satellite was still in a functional condition, The Aerospace Corporation took over the costs for further operation and Bowie State University took over the control and the data downloads.

During the sunspot maximum around the year 2000 and the associated expansion of the earth's atmosphere, it was expected that SAMPEX would enter the earth's atmosphere, but the orbit remained stable beyond that and the satellite could continue to be used until the next sunspot maximum.

On November 13, 2012, the orbit of the satellite had sunk so much that SAMPEX entered the earth's atmosphere and burned up after more than 20 years.

Discoveries

Over the years, the SAMPEX data has made numerous discoveries about the composition of cosmic rays and the interaction with the earth's radiation belts . Among other things, SAMPEX discovered another radiation belt, composed of heavier elementary particles within the Van Allen belt .

The measured values ​​that SAMPEX transmitted in the last weeks of its existence could be correlated with those of the Van Allen Probes , which was restarted in August 2012 , so that the old and new data can be compared.

Web links

Commons : SAMPEX  - collection of images, videos and audio files

Individual evidence

  1. ^ LASP: SAMPEX spacecraft
  2. ↑ NASA SMEX website: SAMPEX ( Memento from July 16, 2011 in the Internet Archive )
  3. ↑ LASP: HILT: A Heavy Ion Large Area Proportional Counter Telescope for Solar and Anomalous Cosmic Rays
  4. ↑ a b Max Planck Institute for Extraterrestrial Physics: SAMPEX
  5. ^ LASP: LICA: A Low Energy Ion Composition Analyzer for the study of Solar and Magnetospheric Heavy Ions
  6. ↑ LASP: MAST: A Mass Spectrometer Telescope for Studies of the Isotopic Composition of Solar, Anomalous, and Galactic Cosmic Ray Nuclei
  7. ^ LASP: PET: A Proton / Electron Telescope for Studies of Magnetospheric, Solar, and Galactic Particles
  8. ↑ SAMPEX Data Center
  9. ↑ a b c d NASA: NASA's SAMPEX Mission: A Space Weather Warrior
  10. ↑ SAMPEX Re-Enters Earth's Atmosphere after 20 Years of Service ( Memento of the original from November 23, 2012 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  @1@ 2Template: Webachiv / IABot / www.spaceflight101.com
  11. ↑ LASP SAMPEX discoveries