Shuttle Mission 8, now set for launching at 2:15 a.m. next Tuesday, will be another precedent-setting spaceflight.
* The Aug. 30 liftoff will be the first night launch for the shuttle, to be followed by a night landing early Sept. 5. The aim: to demostrate the shuttle's around-the-clock capability. (The only other manned spaceflight to take off at night was the Apollo 17 moon mission launched some 11 years ago.)
* The five-man shuttle crew includes Air Force Lt. Col. Guion S. Bluford, who will become the first United States black astronaut to go into space.
* For the first time, the McDonnell Douglas/Johnson & Johnson electrophoresis experiment will begin processing living cells. Electrophoresis is a process for separating biological materials using electrical forces. Up to now, only proteins have been processed in this experiment, which is the precursor of a pharmaceutical factory in space.
* And, like an athlete preparing for competition, the shuttle's manipulator arm will be working out with a massive dumbbell. This barbell-shaped simulated payload, some 19.75 feet long by 15.5 feet wide, will allow the astronauts to practice the launch, retrieval, and manipulation of massive payloads that take up most of the payload space in the orbiter's cargo bay.
* Finally, for stamp collectors, Challenger will be carrying 250,000 US Postal Service covers commemorating the National Aeronautics and Space Administration's (NASA) 25th anniversary. The Postal Service and NASA expect to share nearly $4 million by selling the covers at $15.35 apiece.
Shuttle flights now are said to be operational and quite routine. But their missions still involve much pioneering.
The main commercial objective of Mission 8 is to launch the Insat IB communications and weather satellite for India. This is to be done on Aug. 31, the second day in orbit. The bulk of the seven-day (145 hr., 10 min.) mission, however, involves testing and practice crucial to making the Space Shuttle System (STS) a truly operational facility.
Besides Astronaut Bluford, the STS-8 crew includes Capt. Richard H. Truly, Comdr. Daniel C. Brandenstein, and Lt. Comdr. Dale A. Gardner - all of the US Navy - plus Dr. William E. Thornton, a civilian. Dr. Thornton will continue the in-orbit studies of astronaut adaptation to weightlessness begun with the previous shuttle flight.
One of the most important of the tests these astronauts are to perform is communication through the Tracking and Data Relay Satellite (TDRS). This satellite was almost lost after deployment from the shuttle April 4. Malfunction of an Air Force booster rocket - the so-called Inertial Upper Stage (IUS) - placed TDRS in a wrong orbit. It finally was maneuvered into its proper orbit using its station-keeping and attitude-control thrusters.
When operational, TDRS can provide longer periods of communication with the shuttle than now is possible using ground stations only. This capability will be critical for scentists on board the Spacelab orbiting laboratory, to be carried in late October by STS-9.
Preliminary tests have shown that TDRS seems to be functioning. But NASA engineers have had trouble in tests of the total communications system using the satellite. Data transmissions have been spotty. The astronauts will try to test the system - TDRS plus its ground links - thoroughly. The shuttle will be maneuvered to extreme orientations and its orbital height will be changed to see how well TDRS can track the spacecraft.
Exercising the manipulator arm also is important. Although the arm has worked well in the past, it has not yet maneuvered massive objects that occupy most of the shuttle bay. This is the kind of service it has to perform when astronauts rescue and repair the Solarmax sun-observing satellite next year.
Because no one knows how well these maneuvers can be performed, the time scheduled for this test is a generous 15 hours.