May 1982:STS-1 mission report, part 1

Who can forget the thrill of the first Space Shuttle launch from Florida, or of its landing two days later in California? Until mission STS-1 took off from Pad 39A at Cape Canaveral on 12 April 1981, an American had not been into space for almost six years. The impetus we saw in the days of the Apollo Moon landings is perhaps lost forever, but who can deny that we now stand on the verge of the “real” space age? It was made possible by the flight of Young and Crippen aboard “Columbia”, a truly magnificent achievement.

Pre-Launch Activities

Shortly after 07:00 GMT (all times are in GMT unless otherwise stated) on 12 April 1981, astronauts John Young and Robert Crippen were awakened in their crew quarters in the NASA Operations and Checkout (O & C) building on Merritt Island at the Kennedy Space Center in Florida. Following a brief physical examination, which showed that both men were in excellent shape, they donned blue NASA flight suits adorned with the NASA emblem and their own STS-1 mission patch. They headed over to the breakfast area for the traditional steak and eggs pre-flight meal, and were joined by several of their colleagues, as well as former Apollo 17 astronaut Harrison H. Schmitt.

Following breakfast, Young and Crippen received a “go” from Shuttle Launch Director George Page to proceed to the Suiting Room in the O&C building, which they did at 08:20. The countdown was about mid-way through a two hour built-in hold at the T minus 2 hour 5 minute mark as they began the suiting procedure. Biomedical sensors were attached to their bodies to measure heartbeat, respiration and temperature, after which they began struggling into their rust-colored Emergency Ejection Suits (EESs).

The EES is identical to the suits used by pilots of the US Air Force’s SR-71 reconnaisance aircraft, and arc worn by Shuttle pilots during launch and reentry to provide emergency life support in the event of a malfunction serious enough to require ejection from the Orbiter. Using the suits. Young and Crippen could eject at any speed below Mach 3 and any altitude lower than 100,000 ft.

Before leaving the Suiting Room, the astronauts received a weather briefing over closed-circuit television from the Johnson Space Center in Houston. The forecast for the planned launch time of 12:00 was looking very good: temperature was 70° F, cloud cover minimal, wind speed fairly low and the relative humidity 55 per cent. The low humidity was welcomed because it meant that the launch control engineers would not have to worry about excessive ice building up on the External Tank (ET). Ice normally coats the exterior because of the supercold liquid oxygen and liquid hydrogen inside it. If the humidity is high, the ice coating becomes thicker and there were worries that falling chunks could hit and damage some of the thermal tiles on the Orbiter. But television cameras out on the pad showed that there was no need to be concerned. In fact, a planned excursion out to the pad by an ice inspection team was cancelled.

At 09:02, a cheer went up as Young and Crippen walked out of the O&C building into the glare of the television lights. Neither man was wearing his helmet, and each had an attendant walking behind to carry his portable air conditioning unit. The astronauts climbed aboard the "astronaut van” for the trip out to Pad 39A, where launch preparations for Columbia were moving along smoothly. After a short drive the van came to a stop at the base of the Fixed Service Structure (FSS) at 09:19.

The astronauts took the FSS elevator up to the White Room, donned their helmets and quickly went aboard Columbia, crawling on their hands and knees across an ingress bridge placed over the hatch rim. Both men were inside by 09:25 when the countdown was resumed at T minus 2 hours 5 minutes following the built-in hold. Once aboard, they were assisted by astronaut Loren Shriver. He connected their communication and breathing lines, as well as the wires leading from the biomedical sensors.

The first voice communication with Young and Crippen in the cockpit took place at 09:34, indicating that the communications lines were hooked up properly. Problems were encountered, however, with the breathing lines. When the men lowered and locked their faceplates, they found that they could not breathe - they threw the plates open and gasped for air. Young momentarily worried that they could have a major problem on their hands which would force a second scrub, but Shriver quickly located the problem. A connector was not properly seated. He took care of the matter, and by 10:00 Launch Control was able to report that all was well. After one last check of the cockpit, Shriver bade Young and Crippen farewell, and crawled out through the hatch at 10:18. Three minutes later, as the first indications of morning twilight began to lighten the eastern sky, the hatch was closed.

The astronauts, now alone in the cockpit, were enjoying the view from Columbia's wrap-around windows. They could see the stars overhead and as the sky began to grow lighter with the rapidly approaching Sunrise, they were able to enjoy the beautiful colours to the east. Crippen, who was on the side facing the ocean, was able to see pelicans flying about. He found the scene very peaceful and relaxing.

It was not all sightseeing, however. They had a very critical task to perform at the T minus 51 minute mark (10:40 GMT). At that point, the astronauts began the pre-flight alignment of their Inertial Measurement Units (IMU’s). The IMU’s provide a stable navigational reference to the Orbiter’s five General Purpose Computers (GPC’s), and it is extremely important that they are accurately aligned shortly before launch. The entire IMU pre-flight alignment process takes about 50 minuter, and it was due to be completed during a 20 minute built-in hold at the T minus 20 minute mark. Also during this planned hold, the two NASA Shuttle Training Aircraft (STA’s) went aloft with astronaut Joe Engle at the controls of one and NASA pilot Edward Mendenhall flying the other. Their task was to measure cloud perimeters around KSC to ensure that weather would be no problem in the event of an aborted launch.

As the countdown resumed at 11:30, the all-important check to ensure proper communications between Columbia's single backup and four primary computers was conducted. This was the area that had forced the scrub on 10 April, and when it was verified at 11:33 that all five GPC’s were in proper synchronisation, a cheer went up from launch controllers in the Firing Room.

There was yet one more built-in hold scheduled in the countdown, a 10-minute period at the T minus 9 minute point. When the count was resumed for the final time at 11:51, all of the remaining countdown events were automatically under the supervision of the Ground Launch Sequencer (GLS). So many events have to be monitored in these last few minutes that human controllers cannot cope.

There was a manual task to be performed, however, which was not entrusted to the GLS. This occurred at T minus 5 minutes when Bob Crippen activated the Auxiliary Power Units (APUs). These are turbine devices powered by hydrazine which supply hydraulic power to drive Columbia’s elevons, rudder and speed brake. In addition, they also drive the Main Propulsion System (MPS) engine gimbal mechanisms. APU startup was normal and on time. Events were happening at an extremely rapid rate by this time. At T minus 3:30, the Orbiter aerodynamic control surfaces were run through a pre-arranged manoeuvring profile to help condition the hydraulic fluid being supplied to them by the APU’s. Also at T minus 3:30, Columbia went onto internal power.

At T minus 3, the three MPS engine bells went through a gimbal profile much as the aerosurfaces had done 30 seconds earlier. At T minus 2:55, the vent valve on the LOX tank was closed to allow tank pressurisation to begin, and at T minus 1:57, the same was done on the LH 2 tank.

It was not until T minus 25 seconds, when Columbia’s computers took over supervision of the countdown from the GLS, that Crippen finally let the realisation sink in that this was it - they were really going into orbit. At that point, his heartrate shot up to a reading of 130 beats per minute, while John Young’s stayed down in the mid-eighties.

Liftoff and Ascent

At T minus 3.46 seconds, Columbia's three main engines started. Up in the cockpit. Young and Crippen heard what they later described as a “bang”. There was some vibration, but nothing serious. They expected Solid Rocket Booster (SRB) ignition to produce a much more severe jolt. Crippen thought it would be similar to being shot off an aircraft carrier by a hydraulic catapult. But ignition proved to be a pleasant surprise. As the two rockets fired up, unleashing a combined total of 5.3 million pounds of thrust, the astronauts felt only a smooth, steady push upwards - not unlike a fast elevator ride.

First motion came al exactly 12:00:03.983 GMT on 12 April 1981.

Columbia's launch was a fantastic sight for the many spectators around the Kennedy Space Center. It moved upward much more rapidly than many veteran “bird watchers” were used to for a manned launch. It trailed two huge tongues of bright orange-yellow flame from the SRB’s, and left a towering pillar of grey-white smoke in its wake which extended all the way back to the launch pad.

After clearing the FSS, Columbia began moving through a programmed roll and pitch manoeuvre to put it in the proper attitude and heading for orbit. On Pad 39A, the astronauts’ heads had been pointed almost due south but as they twisted around 120 degrees to the right they were pointing northeasterly. Columbia then began pitching over gradually onto its back, carrying the vehicle out northeasterly over the Atlantic.

In order to ease the passage through the period of maximum aerodynamic pressure (Max-Q), expected at about 50 seconds Mission Elapsed Time (MET), the GPC’s commanded the three main engines to reduce thrust. They had been burning at maximum thrust since ignition back on the pad but at 32 seconds MET, the throttle was cut to 65 per cent. After Max-Q passage, the engines came back up to full thrust.

Just prior to Max-Q, at about 40 seconds MET, the astronauts noticed material flying past their forward windshield, apparently coming from the ET. It bounced off the windshield and flew back over the top of the Orbiter, leaving streaks on the windows. Crippen said later that he believed the material was either ice or particles of the spray-on foam insulation coating the ET. In Columbia’s cockpit, Young and Crippen were having a fairly rough ride, although not nearly as rough as they had been expecting based on their experience in the Shuttle Mission Simulator.

While Columbia was flying under the power of the SRB’s, on-board and ground readings showed the vehicle to be in a 5 per cent steeper climb than programmed. Although the problem was puzzling, it was not considered to be dangerous because the guidance system could easily compensate for the “loft” after SRB separation. The problem had to be solved though because a steep climb on operational flights would have reduced the payload capability.

Shortly after 2 minutes MET, the SRB thrust began to drop off, and at 2 minutes 11 seconds the astronauts saw a breathtaking orange-yellow flash through their windows as the eight SRB separation rockets fired. Onlookers lining the Florida beaches could clearly see the two pencil-thin rockets fall away from the climbing craft. The SRB’s fell into the Atlantic about 5 minutes later, ready to be picked up and refurbished for re-use on a later Shuttle flight.

With the SRB’s gone, the extra altitude gained had to be taken out. The guidance system was performing superbly and the vehicle was back on track in a very short time. Main engine performance was also excellent, in fact, it was slightly better than expected.

During the ascent, capcom astronaut Daniel Brandenstein periodically infornped Young and Crippen that they were entering different abort mode capabilities. Up until about 4 minutes MET, any major systems failure would have dictated a Return-To-Launch Site (RTLS) abort. RTLS is an extremely complicated and time-critical manoeuvre designed to turn the Orbiter/ET stack around from its eastward course and start it heading back to the landing strip at the Kennedy Space Center. Columbia was nearing the point at which it would be too far downrange to fly an RTLS, and at 4 minutes 20 seconds MET, Brandenstein told the astronauts they were "negative return,” meaning that any abort from that time on would have to be forward, bringing them down on contingency landing strips at either Rota Naval Air Station in Spain, or Northrup Strip in New Mexico.

As part of the programmed ascent trajectory, the Orbiter/ET combination was pitched over into a shallow “dive", with the astronauts' heads pointed toward the Earth and Columbia's nose pointed 4 degrees below the horizon. As a by-product of the dive, Young and Crippen got their first breathtaking view of the Earth. Until that point, their windows had been pointed upward at the blackness of space. “What a view, what a view!,” Crippen exclaimed just after 5 minutes MET as the dive got underway. The Orbiter’s six windows afforded the astronauts a nearly 180-degree view, much better than on previous manned space flights. As Columbia continued in its shallow dive to the planned Main Engine Cut-Off (MECO) altitude of 63.9 nautical miles it was accelerating rapidly. As engine cutoff approached, the main engines were throttled back so that the loads would go no higher than 3g. The astronauts reported the throttling to be very smooth.

As the three main engines shut down at 8 minutes 34 seconds MET, the astronauts found it to be very gentle. For Young. MECO was much smoother than he had remembered from his previous Gemini and Apollo flights. The entire ascent had been perfect. Columbia was at an altitude of 63 nm,travelling at a velocity of 25,670 feet per second (fps). and climbing at a rate of 220 fps. All the figures were well within limits.

OMS Manoeuvres

At MECO. Columbia was in space, but not yet in orbit. If nothing further were done, it would follow a long, arcing ballistic path before reentering the atmosphere over the Indian Ocean. The cutoff velocity targeted for MECO had purposely been kept short of orbital speed in order to ensure that the ET would reenter and break up over the ocean away from major land masses. Most notably, NASA wanted to keep it away from Australia, which was still smarting after being hit by Skylab debris in 1979.

In order to push Columbia into orbit, there were to be two burns of its Orbital Maneuvering System (OMS). The first of these, called OMS-1, was to take place immediately after ET separation and would put the spacecraft into an orbit of 57x130 nm. The second burn, OMS-2, would take place half¬ way around the world from the first, at the 130 nm apogee point. The effect of OMS-2 would be to raise the 57 nm perigee up to 130 nm and thus make the orbit circular.

The first order of business, however, was to release the spent ET. This took place automatically about 20 seconds after MECO; the tank separated cleanly, so smoothly the astronauts could not feel it. Before OMS-1, the astronauts wanted to put some additional -distance between them and the ET, so Young took over manual control for the first time. He used the Reaction Control System (RCS) jets to move the vehicle sideways along the ground track to take it north of the ET.

Safely away from the spent tank, Young manoeuvred Columbia into the proper attitude for OMS-1. Ignition of the twin 6,000-lbf OMS engines came right on time at 10 minutes 37 seconds MET. The engines burned for 1 minute 27 seconds, increasing Columbia's velocity by 164.7 fps. This was enough to put it into a 57X132 nm orbit.

At 12:12 GMT, just as the OMS engines were shutting down, Columbia moved out of range of the Bermuda tracking station. The next station to acquire the signal would be Madrid in Spain but before then, Crippen had a couple of tasks to perform. The first of these was to shut down Columbia’s APU’s. These units have a limited supply of hydrazine which had to be preserved for reentry. The second task was to close the ET umbilical doors on the Orbiter’s belly. The door covers are layered with the black high-temperature TPS tiles and in order for the spacecraft to reenter safely the doors have to close tightly. They did.

Columbia passed into and out of contact with Madrid, and at 12:36, it was within range of the Indian Ocean Station (IOS). While over the IOS, Young and Crippen took some time out to comment on the spectacular sight: "Well, the view hasn’t changed any,” Young said, “it’s really something else!” Crippen added, “I tell you, John has been telling me about it for three years, but ain’t no way you can describe it. It’s hard to get my head in the cockpit here and do my procedures.” Crippen also mentioned that, despite all the efforts to keep the Orbiter clean, there was debris floating around the cabin. He promised to use a vacuum cleaner later to clean it up.

As Columbia moved out of contact with the IOS, the time for OMS-2 ignition was rapidly approaching. At exactly 44 minutes MET, the two OMS engines ignited for the second time. Again, the burn was perfect. The 1 minute 17 second manoeuvre added 136.5 fps and put Columbia into an orbit of 133.5X132 nm. With the successful OMS-2 burn, Columbia was at last in a good, stable orbit. The next item on the flight plan called for Crippen to re-configure the computers for the on-orbit phase of the flight.

Just before liftoff, the GPC's had been loaded with a program known as “OPS-1.” This software package controls all launch and abort functions but now that the ascent was safely over a new computer load, OPS-2, was being put into use. The OPS-2 software consists of all the basic computing and diagnostic functions that would normally be used by a Shuttle crew while in orbit. Four of the Orbiter’s five GPC’s were loaded with OPS-2, while the fifth had OPS-3, the normal reentry and landing software. OPS-3 would be kept in at least one of the computers at all times as a precautionary measure in the event of an emergency landing.-

By 13:01, as Columbia moved into acquisition range of the Orroral Valley (Australia) tracking station, Young and Crippen were busy unstrapping themselves from their ejection seats. Space rookie Crippen was careful to avoid rapid head move¬ ments in his early free-floating encounter with zero-g. He was going to be far too busy to become sick, so as an added precaution he had taken an anti-motion sickness pill before launch. Young didn’t worry quite as much about zero-g since he had had no problem with motion sickness on any of his previous flights. As it turned out, both Young and Crippen felt fine for the entire flight.

Payload Bay Door Tests

After getting out of their seats, the astronauts floated back to the aft flight deck area. There they began running through a checklist in preparation for the opening of Columbia's two huge Payload Bay Doors (PLBD’s). This was an extremely critical operation. Inside the doors are large radiators for carrying heat away from the Orbiter. If it became impossible to open the doors, Columbia would be forced to reenter and land within several hours, relying on the limited supply of secondary cooling provided by the flash evaporator system.

While engineers were primarily interested in simply opening the doors for cooling purposes, there were also a series of tests to be carried out designed to evaluate door performance under flight conditions. Crippen began the test procedure by releasing the PLBD latches. There are four latches on each bulkhead and 16 latches down the door centreline. He simply opened all of these latches, one at a time, without opening either door, and then closed them all again to make sure they were working properly. He then started releasing the latches a second time in preparation for opening the starboard door. Meanwhile, Columbia moved into contact with the Tula Peak (New Mexico) station at 13:31 to begin its first 16 minute pass over the United States. The astronauts gave an update to Mission Control on their progress. “We’re just about at the point where we’re ready to open the right door,” Crippen told capcom Brandenstein.

Moments later, Crippen opened the starboard door and the payload bay flooded with bright sunlight. Columbia was still upside down and the astronauts could see the Earth moving past 130 nm below them. "You’re missing one fantastic sight,” Crippen told Brandenstein, “here comes the right door and, boy, that is really beautiful out there.” ”We appreciate the great view updates,” lamented Brandenstein, who had nothing to look at but a blank TV screen. Mission Control was unable to receive live television until the Orbiter reached the Merritt Island (Florida) station at about 13:36. Young was recording everything on the on-board video tape recorder, however, so nothing was lost. “We can see a little trash floating out the payload bay, but nothing really all that significant,” Crippen said, “All the latches work fine and the door looks like she’s doing her thing.”

Only the starboard door was opened on this first test; the port door remained closed. By the time the live TV came up in Mission Control, the starboard door was already closed again. Young was using a theodolite to sight along the door centreline to ensure that no warpage had occurred in the starboard door during the time it had been open. There was none. ”Okay,” Crippen said, "doors all latched up beautiful. We are getting ready to open them back up again.” To do so, Crippen released the latches once more. But before either door could be opened to give television viewers on Earth a look outside, Columbia passed out of range of Merritt Island at 13:43 and the picture was lost. The crew still had voice contact through Bermuda for another four minutes, but additional television had to wait until the Madrid pass.

Missing Tiles

When Columbia came into contact with Madrid at 13:52, both doors were fully open. The down-link TV was sending live pictures to Mission Control from three remote-controlled cameras in the payload bay, showing stunning clarity. As the cameras panned around the bay, viewers on Earth were startled to see several squarish dark spots on the surface of both OMS pods. As the forward camera zoomed in on one of the pods, Crippen confirmed what many were already suspecting.

“Okay, we want to show you our OMS pods,” he said, “we do have a few tiles missing off both of them. Off the starboard pod it’s got basically what appears to be three tiles and some smaller pieces and off the port pod looks like I see one full square and looks like a few little triangular shapes that are missing and we’re trying to put that on TV right now.”

The astronauts were unable to see Columbia’s underside, so they had no idea whether tiles were missing there or not. But Young did look over as much of the spacecraft as he could from the windows. “From what we can see of both wings and leading edges,” he said, “all those are fully intact.” Young and Crippen were not worried about the underside. Crippen felt that the OMS tiles probably popped off due to pressure flexing of the pods during launch. On the underside of the vehicle, which was flatter and more uniformly shaped than the OMS pods, he believed that the tiles were probably unaffected by the flexing. Nevertheless, NASA made arrangements to photograph the underside with high-resolution US Defense Department cameras. The ground-based cameras reportedly had good enough resolution to spot a missing tile as the Orbiter flew overhead. The equipment is highly classified, so none of the pictures were released. The missing tiles easily stole the show during the television transmission through Madrid, and it was easy to lose sight of the important fact that the PLBD’s were open and the radiators successfully deployed,so there was now no need to worry about overheating.

IMU Alignment

At 13:56, Madrid lost the signal and Young and Crippen moved on to the next item on their flight plan - an in-flight alignment of the IMU’s. As mentioned earlier) the IMU’s had been aligned prior to launch, but they do tend to drift and have to be re aligned periodically so that the GPC’s always have an accurate fix on the Orbiter’s location. The plans for STS-1 called for three IMU alignments daily, and Young and Crippen were about to do the first of these. If it did not come off properly, mission rules dictated that they must return to Earth.

The alignment process made use of the Orbiter’s star trackers, but Young and Crippen were also going to evaluate the use of the Crew Optical Alignment Sight (COAS) as an alternative for obtaining star sightings. The COAS was mounted in Young’s forward cockpit window, and was considered to be strictly a backup to the star trackers. The IMU alignment was accomplished at 14:50 while the craft was flying in darkness over the Pacific Ocean. There were no problems and everything went so well that the astronauts found themselves about 10 minutes ahead of the flight plan.

Columbia came into contact with the Buckhorn (California) station at 15:02, beginning its second crossing of the United States. During this pass, there was just one more event remain¬ ing in order to allow Young and Crippen to remain in orbit longer than just a few hours. The fuel cells had to be flushed of impurities - a relatively simple operation, but a critical one. If the purge were not accomplished, the cells’ power output would be seriously impaired and an early return necessary. "Okay,” Crippen said, “I’m Go to initiate that purge whenever you guys are.”

“Roger, we’re ready to go,” Brandenstein responded. Several minutes later, the operation was finished without any problems. Everything required to set the Orbiter up for an extended stay in orbit had been accomplished - the GPC reconfigurstoon, the PLBD-opening and radiator deployment, the IMU alignment and now the fuel cell purge. According to the flight plan, Flight Director Neil Hutchinson took a poll of his “Silver” flight controllers in the Mission Control Center to decide whether or not to allow Young and Crippen to stay in space. The decision was Go.

“Columbia, Houston,” Brandenstein radioed at 15:16, “you guys did so good we’re going to let you stay up there for a couple of days. You’re GO for on-orbit.” “Let’s go for on-orbit,” Young responded enthusiastically, “this thing is performing just outstanding.” As Columbia passed out of range of the tracking stations across the United States at 15:21, Young and Crippen found themselves with a ship-shape spacecraft.