Cosmic Ray Astronomy Satellites & Missions
A brief discussion of the Highlights of Cosmic Ray Astronomy
Satellites is available below. You can find additional information
about this topic in the
"History" section of the Cosmic and Heliospheric Learning Center.
We have tried here to focus on missions which detected non-solar cosmic rays
(intentionally or not).
1912 Cosmic ray research began in 1912 when Victor Hess, of
the Vienna University, and 2 assistants flew in a balloon to an altitude
of about 16,000 ft. They discovered evidence of a very penetrating radiation (cosmic rays) coming from outside our atmosphere. In 1936, Hess was awarded the Nobel prize for this discovery.
September 21, 1932 Dr. Robert A. Millikan of Caltech, winner
of the 1923 Nobel prize in physics, completed a series of tests on the intensity
of cosmic rays at various altitudes in a Condor bomber from March Field,
March 9, 1940 A Beechcraft AD-17 biplane was flown to an altitude
of 21,050 ft over the Antarctic to measure cosmic rays for the U.S. Antarctic
August 16, 1947 Physicist Martin Pomerantz announced at Swarthmore
College that he had sent a flight of four free balloons, carrying cosmic
ray equipment, to a record height of at least 127,000 feet over the Antarctic.
May 11, 1950 A U.S. Naval Research Lab (NRL) Viking research
rocket was fired from the U.S.S. Norton Sound near Jarvis Island in the Pacific,
at the intersection of the geographic and geomagnetic equators, to collect
cosmic ray and pressure and temperature data.
1957 The State University of Iowa completed "Rockoon" (balloon-launched
rocket) research at high latitudes which had begun in 1952. James A. Van
Allen reported that scientific measurements had included:
U.S. scientific satellite equipment, including a radio transmitter and instruments for measuring temperature, pressure, cosmic rays, and meteoric dust
encounters, was tested above Earth for the first time, as a rocket containing
this equipment was fired by the Navy to a 126-mile altitude.
- the first survey of total cosmic-ray intensity at high altitude and high latitude
- a survey of latitude variation of heavy nuclei in primary cosmic radiation
- the discovery of X-radiation associated with aurorae
- measurement of ultraviolet and soft X-radiation during solar flares
- first measurements of terrestrial magnetic fields at high altitudes in the auroral zone.
September and October 1959 Konstantin Gringauz (USSR) flew "ion
traps" on the Soviet Luna 2 and 3 missions, instruments measuring the total
electric charge of arriving ions. He found that the signal fluctuated as
the spacecraft spun around its axis, suggesting an ion flow was entering
the instrument whenever it faced the Sun.
More about Luna 2 ...Luna 3...
October 13, 1959
Explorer VII was launched into an Earth orbit.
By late December, data from the satellite indicated possible relationships
between solar events and geomagnetic storms, and revealed information about
trapped radiation and cosmic rays near the Earth.
July 31, 1961
NASA began funding of balloons, launching services, and related expenses in connection with high-altitude measurements of electron, low-energy proton, and alpha-particle spectrum of primary cosmic radiation to be conducted by the University of Chicago from Uranium City, Saskatchewan, Canada.
1961 Herbert Bridge, with Bruno Rossi and the MIT team, obtained
more detailed observations with an elaborate trap on NASA's Explorer X, a
spacecraft designed to explore the nightside tail of the magnetosphere which was often immersed in the solar wind.
August 17, 1961 NASA announced that Explorer XII had successfully
completed its first orbit, radioing data on magnetic fields and solar radiation
from an apogee of nearly 54,000 miles and perigee within 170 miles of the Earth.
November 19, 1961 The Navy Skylark balloon began a coast-to-coast
flight carrying University of Chicago cosmic ray experiment. It was launched
at Brawley, Calif., and landed near Asheville, N.C., on November 21.
October 26, 1973
IMP-8 was launched on a Delta rocket by NASA to measure magnetic fields, plasmas,
and energetic charged particles (e.g. cosmic rays) of the Earth's magnetotail
and magnetosheath and of the near-Earth solar wind. IMP-8 continues to operate
to this day in its near-circular, 12-day orbit. Its orbit is half the distance
to the moon. It continues to accumulate a long-time series database useful
in understanding long-term solar processes.
More about the IMP-8 spacecraft...
October 1975 GOES (Geostationary Orbiting Environmental Satellite)
began to monitor the Sun's surface for outbursts and therefore warn us.
This early warning can give us on Earth a few hours to prepare for potentially
More about GOES...
1977 The Voyager 1 and 2 spacecraft, both launched in 1977, embarked
on an interstellar mission, with a goal of exploring the solar wind termination
shock and the heliopause beyond. Scientists believe Voyager 1 entered the
region of the shock in early 2003.
More about the Voyager spacecraft...
July 1992 The SAMPEX (Solar Anomalous and Magnetospheric Particle
Explorer) mission was launched. It carries instruments in a polar orbit
around the Earth, sampling both interplanetary and magnetospheric particles
every orbit. These studies contribute to understanding the process of nucleosynthesis.
They allow examination of the history and evolution of the galaxy
and the solar system, as reflected in their composition, and aid in understanding
the acceleration of particles on a variety of scales.
More about SAMPEX...
The IMAX (Isotope Matter-Antimatter eXperiment) balloon-borne superconducting magnet spectrometer was launched. It measured galactic cosmic ray abundances of protons, anti-protons, hydrogen, and helium isotopes.
More about IMAX...
Additional Space History Resources