Now You See It: 25 Years Since the Mysterious Mission of STS-36 (Part 1)

The official crew patch for shuttle mission STS-36, which launched 25 years ago today, on 28 February 1990. Image Credit: NASA

The official crew patch for shuttle mission STS-36, which launched 25 years ago today, on 28 February 1990. Image Credit: NASA

Something strange happened in March 1990. Ground-based observers were busy tracking the orbital progress of a classified Department of Defense payload, recently deployed by the crew of Shuttle Atlantis on STS-36—Commander John “J.O.” Creighton, Pilot John Casper, and Mission Specialists Mike Mullane, Dave Hilmers, and Pierre Thuot—when they spotted something they did not expect. The massive satellite had proven an extremely bright object to follow in the night sky, but on 16 March the Soviet Union’s Novosti news agency reported that it appeared to have broken up into several large fragments. Thus began the strange and enigmatic story of Air Force Program (AFP)-731, the first satellite of the “Misty” series, and as with so much in the “deep black” world of Department of Defense space operations, all was not what it seemed.

Initially, the reaction of the Soviet Union—which was then a little over a year away from dissolution and already on the brink of ceding control over many of its satellite republics—was one of scorn, proclaiming that the United States’ latest national security satellite had malfunctioned and disintegrated in orbit. The Pentagon quickly rebutted such claims, insisting that “hardware elements … would decay over the next six weeks.” In total, five pieces of debris (designated “1990-019 C-G”) were monitored and speculation was rife over whether they represented a catastrophic loss of the satellite or were little more than jettisoned payload shrouds or instrument covers. One magazine published images of the STS-36 crew and cynically asked if they would have done better to stay at the breakfast table.

The visual brightness of AFP-731 reached a magnitude of -1 under favorable conditions, similar to the very large KH-9 Hexagon and KH-11 Kennan imaging satellites, and it is thought today that the STS-36 payload was probably around the same size, shape, and weight as the Hubble Space Telescope (HST). Indeed, the website www.globalsecurity.org noted that Misty weighed in the region of 36,680 pounds (16,640 kg) at launch, equipped with a half-dozen propellant tanks and a short, offset telescope with a large, black-colored photo-shutter window to permit wider fields of view. Electrical power came from a set of “curved, body-hugging solar arrays,” the website explained, consisting of “three segments … attached to a deploying boom mechanism that allows the panels to be rotated in one plane to track the Sun.” These arrays were composed of “battle-hardened” gallium arsenide.

The STS-36 stack rolls out of the Vehicle Assembly Building (VAB), bound for the pad. Photo Credit: NASA, via Joachim Becker/SpaceFacts.de

The STS-36 stack rolls out of the Vehicle Assembly Building (VAB), bound for the pad. Photo Credit: NASA, via Joachim Becker/SpaceFacts.de

Misty had been deployed into space on 1 March 1990, a day after Atlantis roared into the highest-inclination orbit ever achieved by the shuttle. Astronaut Mike Mullane described this inclination—which was tilted 62 degrees to the equator, thereby offering the STS-36 crew a broader view of Earth than any other crew in history and reached the Arctic and Antarctic Circles—as the only declassified element of their flight. Launching into this orbit had been a long time coming. When the crew was assigned in February 1989, they expected to fly in February of the following year. That much, at least, came true, but what the astronauts could not have anticipated was that they would endure no fewer than five postponements, before finally blasting off on their sixth attempt.

Originally scheduled for 22 February 1990, their launch was to occur in the early hours of the morning, which obliged them to adjust their sleep cycles accordingly in the Kennedy Space Center (KSC) crew quarters. “We were going to bed at 11:00 a.m. and waking at 7:00 p.m.,” Mullane wrote in his memoir, Riding Rockets. “Breakfast was at 8:00 p.m., lunch at midnight and supper at 6:00 a.m. A vampire kept better hours!” The reason for the first 24-hour delay was Creighton himself. For several days, he had been bothered by a steadily worsening cough and, although he tried to avoid the attention of the flight surgeon, he could not conceal it for very long and was diagnosed with an upper respiratory infection. His condition had not improved by the 23rd or the 24th, and the weather also took a turn for the worse, resulting in two more postponements.

Creighton was moved out of the crew quarters, to avoid infecting the others, and placed in an old space suit room, painted brilliant white and illuminated by a full ceiling of fluorescent lights. His crewmates wished him a speedy recovery, but the opportunity for humor was not far away. “We placed his food tray on the floor,” wrote Mullane, “and used a long-handled push broom to shove it close to his table and then immediately retreated from the room.” Creighton croaked a laugh as they greeted him with plastic bags over their heads. Years later, he remembered that a combination of the awful sleep-shifting, sheer exhaustion and possibly catching a bug had most likely conspired against him. Despite the precautions, the others began to show the signs of sickness, too. First among them was John Casper, who received medication. So too did Dave Hilmers. The only STS-36 crew members left “healthy” were Mullane and Pierre Thuot.

Commander John "J.O." Creighton leads Pilot John Casper and Mission Specialists Mike Mullane, Dave Hilmers and Pierre Thuot out of the Operations & Checkout (O&C) Building on launch day. Photo Credit: NASA, via Joachim Becker/SpaceFacts.de

Commander John “J.O.” Creighton leads Pilot John Casper and Mission Specialists Mike Mullane, Dave Hilmers, and Pierre Thuot out of the Operations & Checkout (O&C) Building on launch day. Photo Credit: NASA, via Joachim Becker/SpaceFacts.de

With the launch rescheduled for 25 February, it seemed highly unlikely, considering Creighton’s illness, that Atlantis would be able to go. As circumstances transpired, a malfunction was detected in a range safety backup computer at T-1 minute and 55 seconds. The clock continued counting down to 31 seconds and was held whilst engineers tackled the issue. During the hold, the prolonged liquid oxygen drainback resulted in the lower inlet temperature limits on Atlantis’ three main engines being exceeded, violating Launch Commit Criteria (LCC). Unacceptable weather for a Return to Launch Site (RTLS) abort caused a fifth attempt on the 26th to be scrubbed, and a 48-hour delay was enforced to give the ground crews some rest.

Finally, on 28 February—25 years ago, today—the astronauts lay uncomfortably on their backs for several hours, waiting for a break in the weather. Rain showers lashed the Cape, whilst the Transoceanic Abort Landing (TAL) sites in Spain were also coded as “No Go.” At length, fellow astronaut Mike Coats, flying the Shuttle Training Aircraft (STA) on weather reconnaissance, gave them the all-clear and confirmed with the pilots in Spain that the launch could go ahead. At 2:41 a.m. EST, the countdown came out of an extended hold at T-9 minutes. John Casper brought up the Auxiliary Power Units (APUs) shortly thereafter, and at 2:48 a.m. the crew were instructed to close their visors. For Mullane, seated downstairs on the middeck for launch, the next few minutes were a blur. Ascent was unusual, since the normal maximum inclination was around 57 degrees. To achieve a 62-degree orbital tilt, Atlantis performed a “dog-leg” exercise—flying downrange on a normal flight azimuth, then maneuvering to a higher azimuth whilst above the Atlantic—and, although this created a performance penalty, it was the only means of reaching the high-inclination orbit.

“Normally, the highest inclination you’ll ever get is 57 degrees,” said Creighton in his NASA oral history, “which keeps you just off the East Coast, so in case anything bad happened, where you blew up, you’re not going to rain debris down on a major city in the United States. This particular flight was the one exception—the only time in U.S. manned spaceflight—where we’ve ever gone beyond 57 degrees. It’s kind of hard to hide that fact after you launch, when you’re up there and the Russians are tracking you, so that was declassified after we launched.” (Prior to the loss of Challenger, the plan was for a mission requiring such a high inclination for its payload to launch from Vandenberg Air Force Base, Calif., on a north-south trajectory.) For STS-36, that payload was deemed of such importance to the national security that “normal” flight rules, which prohibited overflights of land, were suspended and Atlantis passed near Cape Hatteras, Cape Cod, and parts of Canada during her violent climb to orbit.

 

The second part of this article will appear tomorrow.

 

 

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