Conference 7.286::space

715.0. "Dynamics Explorer 1 Retired" by ADVAX::KLAES (All the Universe, or nothing!) Mon Mar 18 1991 15:49

From: [email protected] (Ron Baalke)
Newsgroups: sci.space,sci.astro
Subject: DE-1 Retired (Forwarded)
Date: 16 Mar 91 01:29:40 GMT
Sender: [email protected]
Organization: Jet Propulsion Laboratory, Pasadena, CA.
  
Michael Braukus
Headquarters, Washington, D.C.                                        
March 15, 1991 
(Phone:  202/453-1549)
 
Cheryll Madison
Goddard Space Flight Center, Greenbelt, Md.
(Phone:  301/286-8956)
  
    RELEASE:  91- 42
 
    NASA TERMINATES OPERATION OF EXPLORER SATELLITE
 
        The Dynamics Explorer (DE)-1 satellite, which acquired the
first global images of the Aurora, was officially retired by NASA on
Feb. 28, 1991, after 9 years of collecting scientific data.  Designed
to operate for 3 years, DE-1 performed for nearly a decade in space. 
 
        Fred Gordon, the spacecraft operations manager at NASA's
Goddard Space Flight Center, Greenbelt, Md., reported that the
decision to stop gathering additional data from DE-1 was based on an
evaluation of the costs for the spacecraft's operations compared to
the expected value of the science gained. Also influencing the
decision was the fact that the spacecraft has refused to accept
commands at various times since Nov. 17, 1990. 
 
        According to Dr. Robert Hoffman, NASA's Project Scientist for
the Dynamics Explorers Program, the spacecraft's cameras, in a single
view from high altitudes, could see an entire Auroral zone, a ring of
light encircling each polar region.  These images, taken 12 minutes
apart, have proven invaluable in studies of "Auroral substorms," when
the Aurora suddenly brightens and expands and when electric currents
flowing between the magnetosphere and ionosphere greatly increase in
intensity, Hoffman explained. 
 
        The Dynamics Explorers Program, which consisted of two
spacecraft, was designed to study the coupling or interchange of
energy, electric currents and mass between the upper atmosphere,
ionosphere and the magnetosphere.  Hoffman said that the quality and
quantity of data returned from the two spacecraft far exceeded the
expectations before launch.  Scientists associated with the program
will continue to analyze for many years the large volume of scientific
data accumulated by the satellites. 
 
        The DE-1 spacecraft and its companion spacecraft, DE-2, were
launched together on August 3, 1981, from Vandenberg Air Force Base,
Lompoc, Calif., on a Delta rocket and placed into polar elliptical
orbits.  DE-2 ceased operations on Feb. 19, 1983 and re-entered
Earth's atmosphere the next day. 
 
        The DE-1 satellite is among the more successful Explorers, the
oldest U.S. satellite series.  The first U.S. satellite was Explorer 1, 
launched in February 1958, which discovered the Earth's trapped
radiation, or the Van Allen belts.  Since then, 71 other Explorers
have  been launched to conduct various scientific studies.  The DE-1
spacecraft is managed and operated by the Goddard Space Flight Center
for NASA's Office of Space Science and Applications. 

      ___    _____     ___
     /_ /|  /____/ \  /_ /|      Ron Baalke         | [email protected]
     | | | |  __ \ /| | | |      Jet Propulsion Lab | 
  ___| | | | |__) |/  | | |___   M/S 301-355        | Change is constant. 
 /___| | | |  ___/    | |/__ /|  Pasadena, CA 91109 | 
 |_____|/  |_|/       |_____|/                      |