Race Against Time

''Okay, the arm is out and it works beautifully,'' STS-2 Pilot Dick Truly told Mission Control excitedly on the afternoon of 13 November 1981. On only his first flight into space, the 44-year-old US Navy Captain had been given the enviable task of putting the Shuttle's Canadian-built robot arm - called the Remote Manipulator System (RMS) - through its paces. His enthusiasm, however, was tempered with disappointment, for yesterday evening, only hours after reaching orbit, Truly and Commander Joe Engle had lost more than half of their mission.

Their task now was now to cram five days' worth of scientific research and complex engineering tests into just over 54 hours. It had all seemed so much brighter yesterday and a perfect birthday present for Truly when he and Engle roared into orbit from Pad 39A, becoming the first team of astronauts to fly a 'second-hand' spacecraft. Despite the fantastic achievement of sending Columbia into space the previous April, bringing her home like an airliner and turning her around to fly again, NASA's promise of a Shuttle launch every two weeks was still a long way off.

Although, admittedly, the first four missions were considered to be test flights and not under tremendous schedule pressure, the space agency had hoped to have Columbia ready for STS-2 in considerably less than seven months. The delays had come partly from problems experienced during her first flight and partly from the fact that NASA had underestimated the sheer amount of attention that the Shuttle would require between missions. It was not an airliner and it was doubtful that it could ever be operated like one.

Still, the preparation time for STS-2 was much lower than for STS-1. When Columbia arrived in Florida in March 1979, she spent almost two years undergoing flight preparations; the work to ready her for her second mission, on the other hand, took a quarter of that time. She returned to KSC by 747 on 29 April 1981, two weeks after landing at Edwards Air Force Base, in need of a great deal of attention. The most pressing issue was repairing the damaged tiles: 350 were replaced, 818 removed and repaired and a further 2,000 serviced while still attached to Columbia.

Launch was originally targeted for 9 October 1981. A six-month turnaround was less than ideal, even at this early stage, but a significant amount of work was needed to prepare Columbia for her second flight. STS-2 would be the first Shuttle mission to carry a fully fledged scientific research payload - developed by NASA's Office of Space and Terrestrial Applications (OSTA) - and to make room for it in the payload bay, technicians needed to move the DFI pallet further aft. OSTA-1, as it was called, housed seven 'pathfinding' scientific instruments.

The history of OSTA-1 can be traced back to 1976 - the same year the author of this book was born - when a five-day Earth-observation mission was first sketched out. Shortly afterwards, NASA selected six experiments from a total of 32 proposals to fly on the Shuttle's second orbital mission; the seventh, a test of an investigation slated for the Spacelab-1 mission, was added later. Initial analyses showed that Columbia's payload bay could be pointed Earthward for up to 88 hours of the five-day mission, which would demonstrate its ability to hold major scientific instruments steady and acquire data.

OSTA-1 is installed into Columbia's payload bay.

The OSTA-1 experiments were mounted on an engineering version of the U-shaped Spacelab pallet, located at the midpoint of the payload bay. The DFI sat further back, near the aft bulkhead. The Spacelab pallet measured 3 m long by 3.9 m wide and was physically identical to those scheduled to be used on later Spacelab missions, but for STS-2 it was not fully equipped. Operational missions would also feature a cylindrical, temperature-controlled 'igloo' to provide cooling, power and data-management facilities. Pallets, it was intended, would be used to carry instruments requiring large, unobstructed fields-of-view, such as telescopes or radars.

Five of the OSTA-1 experiments were attached to the pallet, of which the largest and most visible was the Shuttle Imaging Radar (SIR), designed to assess the Shuttle's performance as a scientific research platform and further geologists' understanding of the radar signatures of various terrestrial features for mineral and

Was this article helpful?

0 0

Post a comment