Headline News
Internal Communications Branch (P-2) NASA Headquarters

  Monday, May 6, 1991	Audio Service: 202 / 755-1788

This is NASA Headline News for Monday, May 6, 1991 . . .

Discovery's mission experiments were concluded successfully 
yesterday and the crew is in the process of landing preparations now.  
The deorbit maneuver to bring Discovery back from orbit is now 
scheduled for 1:49 pm EDT.  That maneuver will give Discovery a 
2:49 pm EDT landing time on Runway 22 at California's Edwards 
Air Force Base.  All orbiter systems are performing nominally and 
weather predictions for Edwards call for good landing weather.

Over the weekend, the Discovery crew was quite busy with 
several additional chemical releases; stowing and retrieving the 
Infrared Background Signature Survey package with the robot arm, 
and finally, yesterday, splicing cables to allow the three 
secondary scientific experiments to bypass their non-
functional tape recorders and send data directly to the White Sands 
tracking station.

                   * * * * * * * * * * * * * * * *

The Joust 1 launch did not occur this morning as scheduled.  
The countdown was delayed from its planned 7:00 am EDT launch due 
to a series of problems which kept cropping up.  First, a range control 
computer problem halted the count; the next halt was due to a payload 
problem; another halt was unexplained.  Joust flight management 
picked up the count with about three minutes left at 8:45 am.  At T-0, 
the Joust 1 did not ignite and the launch team declared a "hang 
fire" situation.  Flight and launch system engineers are presently in 
the process of safing the vehicle and beginning the anomaly 
investigation.  No launch decision has been made at this time.  The 
Joust is a commercial suborbital rocket carrying 10 materials and 
biotechnology experiments for the University of Alabama in Huntsville.

                   * * * * * * * * * * * * * * * *

Endeavour left Biggs Army Air Field, El Paso, this morning at 10:00 
am EDT, heading for Ellington Field, Houston.  Following the 
approximately-one-hour flight, NASA's new 747 shuttle carrier 
aircraft, with Endeavour on its back, landed at Ellington and 
will remain there for about four hours.  Endeavour will then 
depart enroute to Columbus Air Force Base, Miss.  The shuttle carrier 
aircraft crew will layover in Columbus and depart for Kennedy Space 
Center tomorrow, weather permitting.  Weather conditions 
between Mississippi and Kennedy call for thunderstorms, so 
the 747 crew will make a day-by-day assessment of flight 
weather before proceeding to Kennedy's Shuttle Landing 
Facility.

                   * * * * * * * * * * * * * * * *

The seven-member STS-40 crew arrived at Kennedy yesterday and are 
today engaged in the mission terminal countdown demonstration test.  
The test concludes tomorrow at 11:00 am.  The STS-40 mission flight 
readiness review is scheduled for next Monday and Tuesday, 
May 13 and 14, at Kennedy.

                   * * * * * * * * * * * * * * * *

Jet Propulsion Laboratory Galileo flight controllers report that 
the spacecraft entered a safe mode again on Friday.  This 
incident is reported to be similar to the previous incident which 
involved one of two control and data computers which took itself off 
line, causing the remaining one to enter the safe mode.  JPL 
management reports that this incident is not expected to have any 
impact on the mission and appears to be completely unrelated to the 
high-gain antenna partial deployment problem.  JPL expected to 
have Galileo back online and fully functional, with regard to 
the computer subsystems, by this morning.
	
Here's the broadcast schedule for Public Affairs events on NASA 
Select TV.  Note that all events and times may change without notice, 
and that all times listed are Eastern.

Monday, 5/6/91
	1:49 pm	Scheduled deorbit maneuver for Discovery (audio only).

	2:49 pm	Scheduled landing of Discovery at Edwards Air Force Base 
          Runway 22 (LIVE).

	4:30 pm	Post-landing press conference from Dryden Flight 
          Research Facility (LIVE).

	8:30 pm	STS-39 crew departure from Dryden for Houston (LIVE).
	
This report is filed daily at noon, Monday through Friday.  It is a service of 
NASA's Office of Public Affairs.  The contact is Charles Redmond, 202/453-
8425 or CREDMOND on NASAmail.  NASA Select TV is carried on GE 
Satcom F2R, transponder 13, C-Band, 72 degrees West Longitude, 
transponder frequency is 3960 megaHertz, audio is offset 6.8 MHz, 
polarization is vertical.