gsh7w@astsun.astro.Virginia.EDU (Greg Hennessy) (12/05/90)
From gull@stars.dnet.nasa.gov Tue Dec 4 19:51:09 1990
Received: from virginia.acc.Virginia.EDU by astsun.astro.Virginia.EDU (5.61/1.34)
id AA27893; Tue, 4 Dec 90 19:51:06 -0500
Received: from uvaarpa.Virginia.EDU by virginia.edu id aa28202;
4 Dec 90 19:49 EST
Received: from east.gsfc.nasa.gov by uvaarpa.virginia.edu id aa19932;
4 Dec 90 19:49 EST
Received: from STARS.DECnet MAIL11D_V3 by east.gsfc.nasa.gov (5.57/Ultrix3.0-C)
id AA29049; Tue, 4 Dec 90 19:48:57 -0500
Date: Tue, 4 Dec 90 19:48:56 -0500
Message-Id: <9012050048.AA29049@east.gsfc.nasa.gov>
From: gull@stars.dnet.nasa.gov
To: "SENT TO @MPLAN" <hennessy@uit.dnet.nasa.gov>
Subject: PRESS RELEASES
Status: R
GALILEO MISSION STATUS
December 4, 1990
The Galileo spacecraft is just over 2 million miles and 4
days from its Earth gravity assist. It is approaching Earth from
outside Earth's orbit, and will cross behind our planet and fly
over its sunward side in order to gain energy from the Earth.
This energy is needed to raise Galileo's orbit, first to the
Asteroid Belt and, in a second gravity assist, finally to meet
Jupiter in 1995.
Spacecraft speed in its orbit around the Sun is 65,800 mph,
still increasing gradually as Galileo comes closer to Earth's
orbit and to the Sun. On December 8, the Earth gravity assist
will occur during the half-hour surrounding 12:35 p.m. PST, the
time of closest approach. This boosts Galileo's orbital speed by
about 11,500 mph.
Spacecraft health and mission performance continue to be
excellent. Over the last two weeks Galileo played back the Venus
science data, stored on tape since last February, carried out a
variety of science instrument calibrations and engineering
operations, and successfully completed the last and smallest of
the trim maneuvers scheduled before the Earth gravity assist.
The spacecraft is now well within the trajectory
window for the required gravity assist. It will attain a
closest-approach altitude of about 590 miles at 12:35 p.m.
PST on Saturday, December 8. A press conference to discuss
the gravity assist and other Galileo activities near Earth
is scheduled for December 8 at 1:30 p.m. PST at JPL (and via
the NASA SELECT satellite link).
Posted: Tue, Dec 4, 1990 5:20 PM EST Msg: GJJA-1657-4946
From: PAO.POST
To: PAO
Subj: Change of Shift Summary 8
Posted: Tue, Dec 4, 1990 5:11 PM EST Msg: CJJA-1524-2738/20
From: (C:USA,PUB:TELEMAIL,PVT:NASAMAIL,O:NASA,SN:MSFC,FN:PUBINFO)
To: (C:USA,PUB:TELEMAIL,PVT:NASAMAIL,O:NASA,UN:P),
(C:USA,PUB:TELEMAIL,PVT:NASAMAIL,O:NASA,UN:PAO.LOOP),
JRUFF/GSFCMAIL
Subj: CHANGE OF SHIFT SUMMARY 08
Astro-1 Shift Summary Report #08
12:00 noon CST, Dec. 4, 1990
2/11:10 MET
Spacelab Mission Operations Control
Marshall Space Flight Center,
Huntsville, AL
During this period (4 a.m. to 12 noon CST), the Astro-1 crew
and the science investigation teams within the Spacelab
Mission Operations Control Center had the most successful
time yet during this mission. The three star trackers of the
Instrument Pointing System (IPS) for the first time were up
and running together, and except for some "fine tuning" the
IPS as ready and able to perform its functions as planned.
The closeness with which the IPS came in acquiring a stellar
object was noted when, at approximately 4:40 a.m., the crew
announced that the Hopkins Ultraviolet Telescope (HUT) had
nearly acquired the scheduled target but that the image --
while sharp -- was wandering. The "fine tuning" would
eventually eliminate problems like this, according to Mission
Scientist Dr. Ted Gull of NASA's Goddard Space Flight Center.
After that occurrence, mission and science management made a
decision for the crew to temporarily pass on several
scheduled targets in an attempt to acquire an unscheduled
one: Capella, a star which -- by virtue of its rich, bright
ultraviolet spectrum -- made it an excellent star to focus
and co-align the HUT and Wisconsin Ultraviolet
Photo-Polarimeter Experiment (WUPPE). The HUT performed a
successful acquisition in the initial stages of the
procedure, and the news was greeted with cheers and applause
in the Payload Operations Control Room.
Meanwhile, the Broad Band X-Ray Telescope (BBXRT) team had
welcome news in besting the good news from yesterday. Prior
to this time period, the BBXRT had briefly detected X-rays,
called "first light" by the science team, from the Crab
Nebula during alignment of its star tracker; today the team
witnessed "first light" by a known source -- Capella -- for a
long observation.
Ultimately, however, the focus and alignment was not
completed with Capella, and the crew moved on to attempt
acquisition of the SS Cygna, a double star. And although the
HUT did not acquire the binary, the procedure produced
nonetheless some low-level useful data. The IPS performance
was described by a crew member as "steady as a rock." Except
for minor adjustments, the IPS appeared ready to perform as
needed.
Toward the end of this time period, the crew was able to
acquire and obtain good data from a supernova remnant located
in the Large Magellanic Cloud, our nearest neighboring
galaxy. A source of high ultraviolet radiation, it was
keenly observed by the HUT and Ultraviolet Imaging Telescope
(UIT) science teams. Both teams expressed satisfaction with
the information received, although they wished they had had a
bit more time than the short observation period of four
minutes which resulted from a lengthier than expected
start-up of the procedure.
Posted: Tue, Dec 4, 1990 5:21 PM EST Msg: HJJA-1657-4947
From: PAO.POST
To: PAO
Subj: BBXRT Report 3
BBXRT Status Report #03
2:30 p.m. CST Dec. 4, 1990
Spacelab Mission Operations Control
Marshall Space Flight Center,
Huntsville, AL
The BBXRT and its Two-Axis Pointing System (TAPS) were
co-aligned at 5:30 a.m. CST today and shortly after BBXRT
locked on its first x-ray target, the bright star Capella.
"With the kind of observations we have planned we should do
tremendous science," reported Goddard's Dr. Peter
Serlemitsos, principal investigator.
This morning's observation gives scientists the temperature
and the element abundances of Capella.
Serlemitsos described the BBXRT's resolution as excellent and
added that the 300 seconds of data collected so far has
revealed information not seen in previous observations.
BBXRT team members are currently working to fine tune the
TAPS and expect to be pointing routinely to their sources by
this evening.
BBXRT and TAPS were developed and are operated from Goddard
Space Flight Center in Greenbelt, MD.
###
Command?
--
-Greg Hennessy, University of Virginia
USPS Mail: Astronomy Department, Charlottesville, VA 22903-2475 USA
Internet: gsh7w@virginia.edu
UUCP: ...!uunet!virginia!gsh7w