Jim,

 On reflection and discussion with my political advisors I've decided
that going to Congress with the save-GRO thing is unlikely to work and
will just piss NASA off (although a direct approach to Mikulski might
help). So I want to just raise the heat by naming names in my newsletter
and putting the arguments out for as many people as possible to see.
Here's what I plan to put out, let me know if you have a problem with 
any of it.

   - Jonathan



 Compton Observatory
-------------------

The Compton Gamma Ray Observatory is to be deorbited on June 3. NASA
decided to end the mission because they were worried that if another
gyroscope is lost, the heavy 14 tonne spacecraft might eventually
reenter out of control. Although engineers came up with a way to control
the descent without gyroscopes, NASA felt the risk was still too large.
However, a number of scientists find the decision perverse and are
urging NASA to keep the vehicle operating for now in view of the loss to
science if one of the Great Observatories is abandoned. In my opinion,
the decision to deorbit Compton is wrong (or at the very least, NASA has
not presented Compton's users with a convincingly argued rationale), and
the risks of keeping it in orbit are small, but it is unlikely that the
NASA administrator will override Goddard Space Flight Center's director
Al Diaz and Office of Space Science chief Ed Weiler,  who made the
decision. 

The following is extracted from a letter passed on to me by a gamma-ray
astronomer - I agree with most of the points it makes, so I quote it here.

"Safety is clearly and correctly a very high priority in everything that
 NASA does.  However, it is important to have a realistic safety policy
 that is applied uniformly to all missions.  The question is: Does
 continuing operation of CGRO present unacceptable risk?  The risk of
 continuing to fly CGRO was inconsistently described at the press
 conference on March 24, 2000.   According to the NASA officials at the
 press conference the decision was based upon a casualty risk of 1/1000
 if another gyroscope failed, yet in response to a reporter's question
 those same officials confirmed a risk estimate of 1 in 4 million for a
 controlled reentry using zero gyroscopes."

 "The scientific case for continuation of the mission is beyond question.
 The NASA Senior Review made a strong case for continuing the CGRO
 Mission.  The end of CGRO operations would affect virtually every
 sub-discipline of astrophysics. The study of gamma-ray bursts and
 high-energy emission from solar flares during the solar maximum period
 will be particularly hard-hit.  With the damage suffered by the HESSI
 satellite during tests, loss of CGRO leaves the US with no capability
 for observing high-energy radiation from solar flares during the maximum
 of solar activity.   The loss of CGRO will also be detrimental for many
 of the scientific objectives of presently operating and upcoming
 high-energy astrophysics missions, because it provides
 targets-of-opportunity, all-sky monitoring and coordinated observations
 over a very broad high-energy range.  These missions include: ASCA,
 BeppoSAX, Chandra, INTEGRAL, HETE-2, Rossi XTE, SWIFT, and XMM-Newton. There is no
 spacecraft planned for the next several years that can accomplish these
 objectives. "

On May 14, Compton was in a 482 x 487 km x 28.5 deg orbit. The
observatory was launched in April 1991 on mission STS-37. Launch mass
was 15622 kg (Shuttle Operational Data Book; the press kit gives 15713
kg); different sources give the hydrazine load as 1822 kg or 1920 kg, so
the dry mass is at most 13800 kg.