Edmund Memi, Boeing space explorations division's media relations manager compiled a series of recollections of Boeing employees who supported STS-1, the first Space Shuttle test flight on April 12, 1981. Here is an unedited version of these testimonials.

 Alvin Anderson, a Boeing Space Shuttle engineer in Element Avionics Systems Integration, but who was working at Kennedy Space Center for Rockwell on math model development for ground checkout software.  “We were developing the models that they use to verify the ground checkout software.  What they use back then had to be validated against the math models before actually being run against the hardware.  We basically wrote the software for the vehicle simulator,” said Anderson.  The software was designed to react the way the vehicle would behave so the NASA launch control center could prepare for launch. 
 “The fidelity was pretty good at that time,” he said about the software code that they wrote.  The Launch Control Center had the computers that ran the simulators and they were tied into the different firing rooms and consoles.
 Anderson join the Space Shuttle program in 1972, right after Rockwell had gotten the contract.  He fondly remembers watching the first launch at Kennedy Space Center from outside the Launch Control Center.  “It was unbelievable because of the configuration of it.  To see something that un-aerodynamic looking, it was just amazing,” he said.  “We had to be in there before 11p.m. the night before because of security so I spent the night out there sleeping in a van,” he said to watch the first launch. “Thousands of people did it.  I mean every road was crowded with cars.  It was unbelievable!”
 Anderson has never seen a shuttle landing and hopes to see one before the shuttle retires. He saw the first nine shuttle launches before he was transferred to California.  Although eligible for retirement, he says he will stick around for awhile, perhaps until the shuttle is finally retired.
 
 Bill Andrews, a Senior Thermal Analyst in Orbiter, was a thermal analyst with Rockwell in Houston back in 1981 during the first flight. “I was there to predict temperatures on the aft fuselage compartment for prelaunch and for on orbit conditions,” he said.  “We had models that approximated what the thermal environment would be.  Essentially they were uncorrelated, so it was really the best guesses we had at the time.  As soon as we flew, we found out that the temperatures were indeed off by about 20 degrees.  We needed to revisit them and adjust them according to what we’re seeing in flight data,” Andrews said.
 The Orbiter had operational instrumentation that provided temperature measurements for the first five flights.  Andrews said industry and NASA were very prepared for that first flight, but the first flight provided a lot of useful information.  “There were a lot of surprises in almost every area from the first flight.  Remember this is the one of the first times that they had  launched a manned unsymmetrical vehicle.  In this particular case, they were attaching an aircraft to the side of a rocket.  They had never done that before.  So there were a lot of surprises,” he said.
 Andrews had the job of supporting the NASA mission evaluation room during that flight in Building 45 at Johnson Space Center. “What we did is we had a facility back there in this room called the Trim Monitoring System (TMS) and we would do plots and we would scan through the plots of all the temperature measurements on the vehicle and compare them against predictions, which we were able to load.  This was a state-of-the-art facility at the time.  But we would go through and ensure that all the temperatures were within expected limits,” he explained. 
 Besides the NASA flight controllers, Andrews was there to look for anything that was unusual.  He said the first flight offered up no unusual surprises other than to having to revise their models because of the higher heating. 
 Andrews remembers the first flight as hair raising and remembers, “everybody was just  super excited at the launch. This is the first time this had happened and nobody really knew how the system was going to operate.  Everybody was grabbing the table and when they completed launch, it was quite a relief.” 
 Today, Andrews is a senior analyst and is one of three that actually worked the first flight.  “They recruited me out of the University of Texas and I started in the thermal world.  Even on station I was doing thermal and power resources, but essentially I was still attached to the thermal area,” he explained.  Andrews hopes someday before the shuttle retires, he’ll get down to Kennedy Space Center to see a launch in person.  
 
 Lance S. Borden, is the Boeing Space Shuttle NAVAIDS (Navigation Aids) Subsystem Manager, but who was a lead quality inspector for the Shuttle avionics in 1981, working at the Johnson Space Center Shuttle Avionics Integration Laboratory (SAIL) for Boeing. 
 “I monitored all of the flight software and hardware integration testing and also monitored any installations and repairs and so forth that they did to the laboratory,” he said. The Shuttle Avionics Integration Laboratory is basically a Space Shuttle in a lab and has all the electronics of the real hardware for the Space Shuttle and a cockpit and so forth.  “Any place where they can’t have actual hardware, they have it simulated like the fuel tanks and the rocket engines and so forth are simulated.  It’s still there.  They verify all the flight software before the Space Shuttle flies and the lab allows them to simulate the flight.”
 “Most of the stuff that’s been used in the Shuttles over the years has been tested in SAIL first.  That’s like the glass cockpit and the new television system, all of the payloads and satellites and many things have been tested there,” he explained.   Borden started his career in NAVAIDS in 1965 with the U.S. Air Force, served in Laos as an Air Commando before working at Ellington Field as an avionics technician for several different companies.  He also spent five years in Iran working for Bell Helicopter from 1973-1979 and eventually became an avionics engineer after returning to Houston following the Iranian revolution.  In November 1981, he went to work for Rockwell as an engineer.
 NAVAIDS (R.F. Navigation Aids) is the radio frequency instrument landing system for the Shuttle. It consists of three systems.  The Tactical Air Navigation System (TACAN) guides the Shuttle from about 400 miles out to the landing field.  The Microwave Scanning Beam Landing System (MSBLS) takes over at about 18 miles out and gives the Space Shuttle the steering information for azimuth, elevation and the distance to the runway and is considered the instrument landing system that brings it right down to the runway.  “Another system is the RADAR Altimeters which give the height above the ground information which tells the crew when to flare the Shuttle for landing so it makes a nice smooth landing,” he said.
 Borden remembers the first launch vividly and was in the SAIL control room monitoring the data for the first launch.  “All of us were just holding our breath.  My fear was what a disaster it would be if one of the Solid Rocket Boosters fired and the other one didn’t.  I think a lot of us were worried about that.  There was a lot more to worry about.  So just before lift-off, the Shuttle rocked back and then fell forward, my heart stopped for just a second because I thought it was going to fall over, but then it went.  Then we all cheered and it took off so fast it was just amazing because we were used to seeing the Apollo rockets that lifted off so slowly.” 
 “Later on, I met Bob Crippen at SAIL.  We had a SAIL celebration with a picnic, a ballgame, and so forth, and I got to talk to him for quite a while.  He was real excited about the first flight and he’s a real super nice guy and unassuming.  He signed my ball cap for me and he said that he thought the age of the everyday citizen being able to fly in space was here.  It didn’t really work out to be exactly like that, but those were very exciting times.”
 The Space Program has always attracted Borden to the field.  “I always built model airplanes and model rockets when I was a kid in the 1950’s and I watched every science fiction movie I could see.  I really knew quite a bit about rockets and propulsion, and also electronics and so forth when I was a kid.  I didn’t think that we were actually going to fly in space as soon as we did when I was a kid.  But then when it actually did start happening, I was thinking yeah, I’d really like to work in that program.”
 “I worked on Apollo XVII out of Ellington Field on the NASA airplanes.  I was there when they came back from the mission and I watched them fly the lunar landing training vehicles and so forth.  Those were exciting times too.  Of course, I knew a lot of those astronauts, the Apollo astronauts when I was working there.  Then I left that and went over to Iran with Bell Helicopter for five years.  Then when I came back, I went to work for Boeing.”

 John Erickson, Boeing space station software, was working in Buildings 5 and 35 at Johnson Space Center working on the Space Shuttle simulator in 1981. “It was after Apollo, the proposals for Shuttle came along and NASA realized that we needed trainers and we also needed procedure simulators so that people can get in there and figure out how to do a rendezvous with the Shuttle, and actually how to do a landing,” he explained.
 Erickson had studied computer programming in college, which was a rare major back then.  He started with NASA on the Apollo program in June 1967.  His job was to build the new simulators and was working on the software for the Shuttle simulator. 
 “John Stump, an electrical engineer, made a board that fit into the computer so we could update the actual position of a Shuttle so that the flight displays would work the way they were supposed to.  So I helped him check out that board, wrote some software that would send character strings and stuff and he could look at them on an oscilloscope and make sure everything was working right,” he explained.
 Erickson was a little worried for the launch and took some vacation time to drive down to see the launch at Kennedy Space Center.  “Actually because the solids had never been used and we thought, “Gosh, when they light that if the clamps don’t release right or there are lots of things that could of gone wrong. Actually anytime you have a big tank of fuel like that and you light it off, you never know what is going to happen especially on the first one,” he said.
 Erickson was impressed with the first launch and remembers the Space Shuttle accelerating a lot faster than the first and last Saturn V launches that he had seen previously.  “It was surprising how fast the Shuttle took off with those solid boosters, “ he said.  He later started working for McDonnell Douglas once the Space Shuttle started flying, but chose to stay in the technical areas.  “I learned about FORTRAN and ADA.  I really kind of wanted to learn database software and so that’s where I’m at now,” he said. 
 Erickson did have some contact with the first shuttle commander, astronaut John Young in the simulators.   He tells the story about Young’s last flight in the simulator.  “He was in the motion based simulator over in Building 5 and it was like he was coming in for his last landing and he wanted to see if the Shuttle could do a snap roll and then touch down on the runway and he did it in the simulator.  Of course, if he had done that before a flight nobody would of trusted him,” he explained. He added the wings probably would have broke off too, but it looked smooth in the simulator. 

 Diane Freeman, manager of Flight Operations under Systems Engineering and Integration for the International Space Station program, was working for McDonnell Douglas as the lead timeliner for the mission. 
 “In 1974, McDonnell Douglas had a contract with NASA, and the group that I supported was the NASA/JSC Missions Operations Directorate.  I was assigned as the lead timeliner/flight planner for STS-1 and was on console in Mission Control for that first flight,” she stated.
 A lead timeliner schedules the on-orbit crew activities for a given flight.  The lead timeliner must understand all of the tasks and requirements that need to be scheduled, and then upon preparing the Flight Plan, follows and replans, as required, the timeline while on-console during execution of the flight.  STS-1 was a three-day mission and she remembers the ‘rumor’ that the crew never really went to sleep even though sleep periods were scheduled for the two crew members.
 “Before the flight we had several thousands of hours of simulations until we finally flew.  Originally STS-1 was scheduled to fly in 1978, but because of delays, it didn’t until 1981.  I recall that we were up to about Revision P for the Flight Plan before the final was released.  When we first started preparing timelines, we would take day/night times from ephemeris data, resulting from a given launch date, mark the times on lined paper, and put down lengths of black tape to display the duration of the night cycles – most archaic indeed!” she said. 
 She remembers being very concerned about the mission.  “Well, the whole thing really, but first, of course, was launch.  We were very happy that they were allowing us to even watch the launch because originally they wanted us to concentrate on the displays and communication with the crew and flight controllers.  However, we were able to watch TV, and it was such a wonderful thing to see,” Freeman said. 
 “There was a lot of concern about whether or not the payload bay doors were going to open, and once opened, would they close before entry.  It was mandatory that once on orbit those doors opened.  There are always those uncertainties, but I had gone through similar and different experiences while on console for the earlier Skylab flights as a timeliner” she said.
 After the flight, Freeman remembers that Bob Crippen came around to all who supported him over the years and during the execution of his flight, and he thanked and gave us hugs and hand shakes for our efforts.  She said that it was a very emotional event.
  Freeman has worked on Skylab, Space Shuttle and now ISS.  “I have worked for McDonnell Douglas/Boeing for almost 32 years. Before that with Skylab, I had another five years with Martin Marietta,” she said.  She mentioned that over all of those years, a vast number of changes have certainly occurred, including an increase in the number of female engineers, and all of the dramatic technological advancements.

 Anita Gale, senior project engineer in Payload and Cargo Integration for the Space Shuttle, had just joined Rockwell in 1974, left for a couple of years, then rejoined the company in August 1980 in the Payload and Cargo Integration area at Downey, Calif..
  “Mostly what I was doing at that time was manifesting work.  So I was working the Flight Assignments Working Group (FAWG).  Payload and Cargo Integration didn’t have direct involvement with that flight as far as my job was concerned.  However, I did have direct involvement in that I was one of the Speaker’s Bureau members who was sent up to Palmdale when the landing happened, and was actually a bus captain for one of the tour buses,” she said.  She had a chance to escort Dr. Robert Forward who was a famous engineer for his work on space colonization and who wrote several science fiction novels. 
 “One of the things that was always a distinguishing characteristic of Dr. Forward is he dressed up in a nice three piece suit with an extremely colorful vest,” she remembered. 
 Rockwell had organized more than 20 buses to watch the landing of the first shuttle mission at Edwards Air Force Base.  “Landings are interesting because after it’s over, the Orbiter is still there.  With a launch, after the smoke is gone, it’s like well okay that’s cool!  You see an empty launch pad which is the same as the launch pad looked two months before launch,” she said. 
 “The noise of all the people cheering -- it’s really an amazing thing.  There were thousands of people with their cars there.  They are honking their car horns and you get this incredibly wonderful feeling,” she said about the first landing.  She also saw the approach and landing tests in 1977. 
 Her job was to make sure the Shuttle payloads were properly arranged.  “On the first flight, it was mostly instrumentation called Development Flight Instrumentation.  So mostly I was working on later flights with the FAWG committee.  I was the Rockwell representative to the FAWG…a NASA committee that basically collected requests for launch opportunities from the Air Force, the commercial guys, the science guys, and scheduled the payloads for those flights.”
 “I was helping determine where and how each payload was installed in the cargo bay. One of the very important things that we were doing as Rockwell was to try to fit as much as possible on all of those missions because there were so few of them at first.  There were so many requests to get on them, so NASA was trying to maximize and there were a lot of constraints on how you could load them and how you could unload them.  I would sit in on the meetings and if they came up with a question they weren’t able to resolve within NASA, I brought that back to Downey and gave that off to the technical guys who then came up with the design.”
 Gale remembers watching construction of portions of the orbiter in the Downey facility, which closed in 1999.  “They were manufacturing the aft thrust structure, basically the back bulkhead of the payload bay and everything aft of there not including the Orbiter Maneuvering System pod or the engines; and also the forward bulkhead and everything in front of that.  So we saw the crew compartment being built as well,” she said.
 Gale also remembers that each orbiter was expected to fly 100 flights each and they believed they could fly every two weeks. Gale hopes to work on future shuttle derived launch vehicles like the Crew Launch Vehicle and Heavy Lift Vehicle. 

 Ray Gonzales, a product project engineer in the Houston Product Support Center, was working at Downey for Rockwell in 1981 as a systems engineer for the fuel cells and power reactant and storage distribution system on the Space Shuttle. The fuel cells provide all the electrical power for the vehicle.  Fuel cell technology was adapted from the Apollo era for use on the Space Shuttle. 
 Gonzales remembers some problems with the valves that control the flow of the cryogenic fluids (oxygen and hydrogen) that supply the fuel cell during the Flight Readiness Review.  “We had some problems with our valves and the valve panels in the mid body. We had some valves that we had used for tests and it was my suggestion that we use these valve panels as a replacement because we didn’t have any more valves and we could not make new valves in time for the flight.  So we did that.  We took these valve panels and we certified them for flight and I took them to the Cape and we changed out those valve panels in time for the flight. “
 Gonzales went to KSC to have the replacement valve panels installed and ran into a unique problem gaining access to the mid-body of the Space Shuttle.  “We had problems trying to install it because the vehicle was in the vertical position.  We found the two smallest techs that they had out there.  So we were using an 18 inch GSC plank that was tied up so the two guys had to go in there and try to reach into that area.  It was very congested.”
 “But the one thing I remember about the first flight is that after we had installed them and I went back to my hotel room, they called me later on at night so I had to go back out there about midnight and everything was quiet except for the vehicle that was on the launch pad.  As you recall the external tank was all white. It was quite a sight with the floodlight shining on it as I was walking out towards the ramp.  So that was something.  I’ll never forget that.”
 Gonzales returned to Downey for the launch and provided support through the Mission Support Room, but has seen many other launches since that first flight.  “I’m speaking for myself, but I think everybody was too excited to be nervous.  After working so long on this vehicle, we were ready for it to fly. We were confident in our subsystem.” He added that there were no problems in his subsystem area during the actual first flight.
 Gonzales remembers working in a large group in Downey when he stared in 1974.  He stayed in this subsystem area until the 1990s.  He joined the Space Station program in 1998 until joining the Houston Product Support center in 2004. Gonzales plans to retire this year after working for 32 years for Boeing and Rockwell. 
 Gonzales fondly recalls the tremendous amount of leeway that engineers had during the design cycle.   “Today we have a lot more reviews and oversight than we did back then.”

 Bruce Graumann, manager for the Shuttle Active Thermal Team in Cargo Integration, was a lead engineer for the Active Thermal Analysis in 1981 working for Rockwell International in Houston.  He started with TRW in January 1974, who had the engineering support contract and moved over to Rockwell in July 1974. 
 “Up until 1980, I was responsible for thermal mass modeling of the Active Thermal Control systems doing failure analyses to define flight rules until October of 1980, when I moved over to a different group,” Graumann said. 
 Active Thermal Control is the cooling system for the Orbiter.  “All the avionics have to be cooled, the cabin and the crew need to be cooled, and the Active Thermal Control system basically takes all that heat and rejects it to space through the radiators.  If that doesn’t do the total job then, you have the Flash Evaporator System which uses water to take the heat out of the Freon loops,” Graumann explained. 
 Graumann was heavily involved in the system analysis and in the testing done on the Active Thermal Control System loop.  “We did the thermal vacuum testing over in JSC (Building 31),” he said.  He described the Active Thermal control systems as evolutionary designs from the Apollo systems, but with a lot more capacity and much bigger in scope. 
 When STS-1 launch date rolled around, he did not have any concerns.  “I was excited.  It was finally going to launch after seven years of working on it,” Graumann said.  Graumann continues to work with the Space Shuttle Active Thermal Control Systems, but in a management role instead. 
 

 Bill Higgins, a Boeing quality engineer on the Space Shuttle program in Houston, was doing the same job in 1981, but for Rockwell in Downey, Calif. 
 “In 1981, I was working in the Nondestructive Evaluation Group (NDE) and what we were doing was developing methods to test the tile.  We came up with tests such as pulse velocity testing which was directing a beam of sound waves through the tile to measure the density of the tile to see if there are any voids in the tile,” he explained. 
 Besides the sonogram method, he also tested how well the tile was bonded to the vehicle by performing a pull test.  He also examined how far apart the tiles were and the height of one tile to another.  “You want them all to be uniform and we developed various techniques to measure those.”
 Higgins joined the Space Shuttle program in 1974 and left for about five years to run his own company but rejoined the shuttle program again in 1980 and describes the working environment at Downey as great.   
 “I went out to Edwards Air Force Base to watch the landing of STS-1 and it was pretty thrilling.  I went with a whole bunch of guys that worked on it.  The tile was an unknown and it was the first time it had ever been used on a spacecraft.  Over the years, the tile has come through with shining colors and we were really surprised,” he said. 
 “I did go down to KSC before STS-1 to help out, but actually we developed the tile tests and actually other people run the tests.  We would come up with the procedures and the tools to do the testing, but we actually didn’t perform it on the production spacecraft,” he said. 
 Higgins saw the roll-out of the Space Shuttle for launch.  He still enjoys his job on the Space Shuttle program.  “In the last 26 years, I have been able to meet a lot of good people and get to go out to meet with subcontractors all over the country.  I have seen just about every state in the country and been able to travel a lot and seen a lot of good people.” 

 Robert Hill, a project engineer in Crew Systems in the Houston Product Support Center on the Space Shuttle program and who was doing the same job for the first launch.  He began with Rockwell in Houston in 1979.  Crews Systems entails the hardware that the crew uses inside the vehicle mostly. 
 “We do some work in the payload bay, but I’ve been working with the seats and the slides and the stowage lockers.  Some of the other stowage areas in the mid deck too,” Hill said. 
 For STS-1, Hill was working with the tool stowage facility in the payload bay.  “It was a stowage pallet in the payload bay where they had their emergency tools and we built some of the bags here that flew on STS-1, -2, -3, and -4.  He added many of the tools were there in case the payload doors were stuck open.  “It was an unknown.  They wanted to have some way of pulling them shut and holding them shut in case the latches did not work,” Hill said. The astronauts had centerline latch tools that they could hook to both doors and latch them together using a winch. 
 The payload doors operated normally.  “The comments we got from the training was yes, they worked, seemed like it ought to be usable if we ever had to use them in flight.  To my knowledge they’ve never had to use them on any of the flights,” Hill added.
 Hill supported the crew equipment seat over in the NASA mission evaluation room.  “We didn’t have a whole lot to do.  It was just very interesting hearing what was going on and being there in case they needed to look for things,” Hill added.
 “Back when we were first starting, anytime we came up with a new tool there was always a lot of testing.  We’d go over there and go through it with the crew and they would make their suggestions, we’d make their try to incorporate them as best we could.” 
 Hill worked on the crew sleeping bags for the later flights (STS-6 and later), since the first flight was such a short flight.  “It had to be a multi use thing that would either work when there were just seven crewmen and they did not have the sleep station installed (located on the mid-deck) or it had to work inside the sleep station too,” Hill remembers.  The sleep station was a four tier bunk stacked one on top of the other on the starboard side of the vehicle.  “When they don’t have that in there, they just kind of attach themselves to the locker face of the wall or they tie themselves into the pilot or commander seats.  Just wherever they think they can tie off and not float around and hit something.  We had to look at things to one, not make them too binding, make sure they were warm enough, make sure they fit big crewmen and little crewmen,” he said. 
 “We probably had eight or ten reviews and every time we thought we’ve got it, we’d take it back over for the crew to review and they would say no, this isn’t what we want.  Put the zipper here or put snaps there.  It was just a lot of going back and forth.  We looked back at the Skylab sleep facilities and sleep provisions and started there and worked forward,” he said. 
 Hill says the crews have crew compartment stowage lockers, called pilot preference kits,  that they can store personal items in for each flight. “Most of the time we never knew what was in those other than…but it turns out there was frequently a lot of jewelry that the crew took up.  So it would be certified as having flown in orbit.  We were always amazed at the number of flags that were flown.  They would pack up to 50-60 flags and put them in a stowage volume so they could certify that those were flown on STS whatever, and be brought back and given to certain dignitaries or whatever.  Various countries had flags,” Hill remembers. 
 “I think one of the more interesting things that happened, it wasn’t STS-1, but it was shortly thereafter the Canadians when they first put the shuttle arm in the payload bay they had a Canadian flag on the side of it which was very prominent and very readable by all the televisions, and everybody all of a sudden woke up and said, “We don’t have an American flag anywhere.”  So inside of about three days we had to come up with a design and a way of hanging an American flag on the aft bulkhead of the payload bay.” 
 Hill, before joining Rockwell, worked on the Apollo program for General Electric beginning in 1969 until 1974.  “I worked on Apollo 10-17, until I got laid off,” he said.  “The astronauts that went to the moon they too had the option of bringing things back, but because of the way the Spacecraft was, we had to know the weights of the bags so that the mass properties folks could tell us where to put them in the vehicles so the vehicle was loaded correctly, and there was always one bag that was 24.5lb miscellaneous items and they would work on the crew and say, “Well, what’s in that bag?”  “Just miscellaneous items sir.”  But tell us, “What’s in the bag?  Miscellaneous what?” and they would say, “Miscellaneous items.” And it was always their lunar boots they were bringing back, which according to NASA rules should not be brought back because of concerns about dust from the boots. 
 “Everybody knew it though as soon as they kept the weight at 24.5 pounds.  A couple of them got smarter and put a couple of other things in there and it came up to 26 pounds and they said, “Oh, what did you add besides your boots?”
 Hill says Shuttle astronauts have always had a personal locker about 2-1/2 cubic feet and limited to about 60 pounds.  But with Shuttle there is a potential of 42 lockers and a big difference in stowage volume from those early Apollo missions.  Rockwell had initial responsibility for the design and fabrication of them.  “That was done in California, but we did the maintenance on them here in Houston,” Hill said.  In 1996, the lockers were replaced with lightweight carbon fiber ones that were about half the weight of the ones on STS-1.

 Michael Hughes is currently working engineering integration on the Boeing Vehicle Integrated Performance & Resources (VIPER) team for the International Space Station. Mike began working for Hamilton Standard on sight at JSC in 1979. Hamilton Standard developed the Extravehicular Activity Mobility Unit (EMU), more commonly known as the space suit.  During the first Shuttle flight, Hughes was working in Building 7 at Johnson Space Center assembling, testing and certifying the new space suits.  The suits traveled around JSC for months undergoing environmental testing at several facilities on sight.  Three shifts ran to assure the suits would be ready for the first flight.  The same suits are used today on the Shuttle and ISS. 
 “The suits were launched on the first Shuttle and were ready to work if needed.  Hughes remembers watching the first launch in the auditorium in Building 7 at Johnson Space Center.  “The entire Crew and Thermal Systems team crowded into the conference room, I can’t remember a more exciting moment in my career.  Mike joined Lockheed in 1983 and worked on Satellite retrieval missions, and many Detailed Test Objective’s until Space Station work began.  He worked on Station development with Lockheed on the service, performance, checkout system for the Station airlock with Lockheed.  Mike joined the Boeing station program in 1998 and continued his support on the ISS.  
  “Witnessing the first launch, I felt I was involved in something that would make a difference in our lives, witnessing every launch since has given me an insight to how important this job is for each one of us on these programs. I look forward to seeing the ISS completed and as many new programs initiated as possible in my remaining years supporting NASA.

 Richard LaBrecque, currently works as the Boeing 787 Functional Integration manager, but in 1981, he was the program manager for the Spacelab and Space Shuttle simulators with a company called Singer Link.  He started on the space program in 1965 working for NASA Marshall Spaceflight Center during the Gemini missions .
 “They were building the first spacecraft about the same time that we were building the simulators, because they knew we needed to train the crew in time to fly the first mission, as they had done for Apollo,” he said.  “But they wanted a more sophisticated integrated training environment than what they had on Apollo, so Singer Link got the contract to develop those. There was also developed a detailed network simulator that would simulate the communications between the spacecraft itself and the Control Center, so that you could get loss of signal and gain of signal just like if they were actually going around the earth.”
  “We had motion and fixed based simulators that gave accurate views out the front and back of the crew cabin.  The feedback from the astronauts after that very first mission was very positive; they felt they had flown the mission many times in our simulators so accurately that nothing surprising occurred.  All they could say was how great the simulator was in preparing them to fly those missions,” he said. He worked out of Building 4 at JSC.  “We learned a lot from those first missions about sound levels, vibrations and the regimes that it was going to fly in, but there were very few updates that we had to do to our modeling,” he said.

 Wayne Musial, a senior Consolidated Labs Manager on the space station, managed a team of people who built some of the software analysis tools that basically was used for planning the Shuttle missions.  “We built some gigantic computer software systems and through the use of our computer tools, we could plan the ascent, orbital and reentry trajectories.  We were tool builders, but they were rather elaborate for their day.”
 Desktop computers hardly existed. “We used big giant central computer facilities and we had some terminals to access them, but very few people had a computer on their desk.  Mostly we had pools of computer terminals that sat in rooms and people took turns using them,” said Musial, who was working for McDonnell Douglas when he joined in 1964 on the Gemini program.
 He remembers it was difficult to meet your milestones when you didn’t really have total control of the computer facilities.  “You were sharing them with lots of other people and the reliability of those computers wasn’t what it is today, so you would always have problems with turnaround because of some unknown problem in the computer system.”
 In 1966, the Gemini Space program in St. Louis came to its logical end.  “There were a lot of engineers up there who were quite talented and NASA had all this money at that time to go to the Moon with Apollo and so they asked the management up in St. Louis if we would be interested in working on Apollo, but the deal was we had to come to Houston,” he explained. “So myself, with along maybe about 50 others from the Gemini program took the opportunity and moved to Houston in late 1966, early 1967, and we started working on the Apollo program.”
 Musial worked on Apollo, then Skylab before starting on the Space Shuttle program. “You know the hardware once it’s built, pretty much just stays the same, but the computer software goes through quite an evolution and so we were able to work and have very interesting work evolving the flight software of the Shuttle,” Musial said.
 Remembering back to that first flight, Musial remembers.   “You can design and build these equations which are then fed into the computer and you do all your work on that stuff, but the real proof of it is how will this thing really fly?  Of course, the mission was a success, but once we got some of the post flight analysis data we went into a mode of trying to compare how it really flew versus the way our computer systems had predicted it would fly, and we were elated in that 90-95 percent of our predictions of how the flight would occur were accurate.  So that was our big joy in life at that time.” 
 “We did the same thing or similar things for Apollo.  So the only difference was the computers were getting more powerful.  The equations were slightly different.  Since the Shuttle was a flying vehicle with control surfaces, as opposed to the blunt capsule type of vehicle of Apollo, we had more aerodynamics involved,” said Musial.  In 1988, Musial joined the space station program to help with the proposal and is also providing some advisory assistance on Crew Exploration Vehicle. 
 “So there were quite a few years of prep work leading up to the first flight and so it was just such a relief and such a joy to see that first mission.  It was…you know a lot of blood and sweat went into getting there,” he remembers.    “You know the launch phase scared everybody and once we got through and made it through the solid rocket booster jettison phase, we felt pretty good about that, but we were holding our breath those first two minutes,” he said.   

   Mike Rasmussen, manager for Launch Package and International Integration on the ISS, was working for McDonnell Douglas Technical Services Company as the manager for Inertial Measurement Unit Redundancy Management in 1981.  The Inertial Measurement Units were responsible for recording accelerations and flight attitudes and fed that information into the navigation system and produced position, velocity, and flight attitude for the instruments.
 “We had three inertial measurement units and we had to pick out the best one, watch out for failures of any one of the three, and we fed that information into the ascent, on orbit, and entry navigation software programs,” he explained.
 Rasmussen manned a back room console watching performance and was part of the mission planning and analysis. “We supported Guidance and Control and wrote the software requirements for the sensors console to be able to watch and compare the performance of these three inertial measurement units in a manner that was different than what the onboard system was doing so that you would have a separate method of judging whether or not you had a potential failure of a unit. I wrote the requirements for the onboard software that did the onboard computations.”
 There were no IMU failures on the first flight, but they were prepared. “You needed only one good one, but the trick of it was to figure out which one of the three was the good one,” he said.  “On the first flight, we got telemetry during ascent that was downlinked.  We did a real fast analysis of that telemetry.  Right after ascent, we went to Building 12, which was the computer center at the time. We did some post-ascent analysis of the data to make sure that the onboard system was working properly, that the IMUs were working properly, and that everything was compatible.  So the best thing about that was we were in Building 12 which was right next to 30, was we finished our analysis and ran into Gene Krantz during shift turnover and he gave a big thumbs up on what we had done.”
 “We covered all three phases of flight, ascent, on orbit and entry.  The onboard system has to keep doing the comparisons of the three IMUs and do selection filtering to make sure we picked out the right one.  During entry, we had the black out region where you didn’t get any telemetry. “
 Rasmussen started on the shuttle program in 1975 with McDonnell Douglas on the approach and landing tests with Enterprise and his last mission was STS-51L, the Challenger accident, before he switched over to the space station program.
 He had a lot of interaction with the first crew.  “We knew it was a risky business and I had quite a bit of interaction with Bob Crippen in terms of explaining navigation systems and the inertial measurement unit. I have a lot of admiration for astronauts.  It was a risky business and as we found out later, there’s risk in the system still.  I was very nervous on all of the flights.” 
 “We’re anxious to complete the rest of the Space Station assembly and continue our presence in space.  That’s still important to me personally and I look forward to finishing up the Space Station work.”

 Greg Ray, Boeing deputy director for Space Shuttle program development, has fond memories of working as an external loads engineer at Downey.  He was one of about 30 engineers looking at the mated vehicle aerodynamic, thermodynamic, vibration, lift off and acoustic loads environment.  “We were combining all those loads environments into an envelop that the designers and stress personnel could further analyze and determine if the shuttle was indeed strong enough to survive that profile,” he said.  “It was challenging work because we were trying to define an environment that nobody had measured before.”

 Anthony Sava is a systems engineer in the ISS Systems Integration Laboratory (ISIL) that is used to test flight software and its interaction with the different elements of station.  In 1981, Sava was working for IBM in the Flight Software Test and Operations group in the Shuttle Mission Simulator (crew trainer) at Johnson Space Center in Building 5.
 “We installed and maintained the flight software portion of the trainer.  In other words, they flew the same flight software that was going to fly in the Shuttle for lift-off, orbit and landing. We had to do a few timing things to it to make it work on the ground since it did not have all of the equipment a real vehicle would have.  We processed any discrepancies they might have had and we helped integrate the flight software with the personnel from Singer-Link, which was in charge of the simulator in those days,” Sava said.
 Sava remembers interacting with astronauts John Young and Bob Crippen for the first flight.  “Each Crew Trainer support group had to brief the crew on what they could expect with each change in the software, whether it was the trainer simulation software or the flight software,” he said.  “They were very sharp people,” he said.  “The commander was usually more concerned about what was going to happen, how it flew, when he moved the stick, or a switch, or whatever.  The pilot, who is the right seat guy, had the task of keeping up with vehicle systems and what the flight software was capable of doing, or would do, for the crew or vehicle.  He did most of the keyboard entries.  So they had the responsibilities parceled out before we got to work with them.  They looked at it from two different points of view.  They were certainly professionals.” 
 Sava doesn’t remember being nervous for the first flight.  “We were young, and maybe we were naïve, but we felt that the system was well-designed, that it was put together well, and, of course, we had the five free-flights—flying Enterprise off of the 747.   Enterprise wasn’t designed to go into orbit, but it would operate in the atmosphere.  We had a year of that before we ever began preparations for the first launch.”
 Sava started working for IBM in June 1966.  He worked on Apollo-Saturn out of Huntsville for the first eight years and worked with Shuttle crew trainers starting in 1974, through early 1985.  While with the Apollo program, he carried out design analysis and performance tests for the Flight Control System on the Saturn vehicle.  He also worked on the Flight Control System for the Space Shuttle Approach and Landing tests.  He joined Boeing in May 2002.
 “Following the approach and landing tests, we made some minor modifications, so that the crew was reasonably happy with the trainer by the time they flew Orbiter missions,” he said.  He added that the trainer cannot duplicate the micro–gravity of orbital flight or the G-forces of the launch, but is still an accurate training device. 
 Sava was working at Marshall Space Flight Center before he joined the Shuttle program in 1974. “The two centers do things differently and they approach things differently.  Even the company I worked for had different management approaches here than there, so they did things a little differently, but the attitude was the same: to make it right—make it safe.  We were all seriously indoctrinated for manned flight safety awareness in the Saturn program.  That carried over to Shuttle for us.”

 Hernando Serrano, who works in electrical design on the Space Shuttle payloads section in Houston, but back in the early shuttle days, his job was to support Columbia at KSC when it arrived in 1981 for launch.  On the first flight, he supported it from the launch control room and its subsequent flights.  His area was to support the data processing system console, which monitored all line replaceable units in the Space Shuttle (MDMs, MMUs, EIUs, etc.) These computers (onboard computer system) supported all the phases of flight (ascent, orbit, descent).The multi-function displays created by us gave us the status of health of the system thorough all the phases of flight.  He joined the space shuttle program with Rockwell in 1976.
 “We had a pretty good display that will tell us exactly what was going on.  We had a general purpose computer failure in the first flight, which ended up delaying the launch.  We had not installed a patch, and once it was installed, the shuttle took off from KSC into space,” he said. 
 For the rest of the flight, Serrano says the GPCs worked fine and the back-up computer never had to be engaged.  Serrano manned the DPS console for the first launch at KSC.  Following launch, he remembers everybody lighting up a cigar.  He doesn’t remember being nervous for the launch because everyone was extremely focused on their respective area.  “You didn’t have time to say, “Oh my God!”  It was very professional,” he remembers. 
 “I flew from KSC to California and saw the landing.  I had seen the landing many times in the approach and landing tests.  So this was going to be like a repetition of one of those, but this was the “real McCoy” coming from space,” he said. 
 “When I was working for Rockwell at the beginning of the Space Shuttle program, I worked on the testing unit for the vehicle. I was the System Engineer for the Space Shuttle main engines test station. We developed all the displays.  We made the first payload testing laboratory there in Downey too,” he said.  It was a beautiful experience working in the Shuttle in those early days.

 Ruben Smith, Boeing Separation and Crew Escape System Subsystem Manager (SSM) on the Space Shuttle program, was a brand new engineer fresh out of college working for Rockwell International in Downey, Calif. in 1980 on the Separation/Pyrotechnic systems group.  His group was responsible for the design of the Orbiter/ET separation and the Crew Escape systems. 
 “It was a challenging work and after twenty-five years, I’m still in the pyrotechnic/separation systems group, but only now as the SSM,” he said.  The Crew Escape System consists of the overhead crew escape window in the event of a ground emergency and a crew escape side hatch that is to be used in event of a controlled gliding flight requiring crew emergency escape.  The crew escape side hatch was added following the Challenger accident. 
 “There were thousands of people working at Rockwell at the time in Downey and there was a lot of money available to do testing for the first flight,” Smith remembers. His Separation/Pyrotechnic systems group had some 30 engineers and he is the only engineer remaining from the group.  “The separation of the tank from the Orbiter was brand new technology at the time,” he added.  He added they did some testing during the shuttle approach and landing tests when the Orbiter separated from the Boeing 747 aircraft.
 “Those early tests gave us confidence.  What we did first was to certify the pyros for the separation then we did a qualification test for the three Orbiter/ET structural attachments (forward, aft and umbilical).  The pyros are unique and they go through a lot of technical reviews before we certify a pyro device.”
 Smith hopes to work on the Crew Exploration Vehicle (CEV) someday and is one of the remaining Space Shuttle engineers who has extensive experience with development and test of the pyrotechnics.

 Jeff Sugano, who works in Space Shuttle flight software and supports glass cockpit testing and upgrades, was working in the Aircraft Operations group at NASA Ellington Field in Houston in 1981 at the time of STS-1. His job back then was as a flight simulation software engineer whose job was upgrading and maintaining the Shuttle Training Aircraft (STA) flight software.  The STA was a highly modified corporate Gulfstream 2 jet that flew like the Shuttle Orbiter in the landing phase of the entry trajectory.  Sugano was responsible for the aerodynamics, flight controls, navigation, and guidance systems software in the STA.  He began working for NASA in 1976.
 “When you sit in the Space Shuttle, you are about 35 feet off the ground at main gear touchdown so when pilots practiced landing in the smaller Gulfstream, they would fly just above the runway to mimic the way it would fly if it were the actual space shuttle,” he explained. 
 Sugano started working for NASA at Ellington in 1978 and said the Gulfstream flight computer was modified to run an emulated Shuttle flight software along with a model of the Orbiter vehicle. “So in other words, the STA could fly like the Shuttle flying at a 19 degree glideslope that a normal Gulfstream would not fly because of a very steep dive angle.  To simulate a steep dive angle, we had to make the thrust reversers of the engine fire during descent, to slow down the STA in order to dive very steeply,” he explained.
 Sugano said there were about four people working on the flight software during that time as well as many of the astronauts.  Sugano remembers having interaction with that first shuttle crew before launch.  “Whenever we made a change to the software, we had to fly to make sure it flew okay.  We were sort of guinea pigs, and we also went along on some of the training missions as well.  We would fly out to White Sands Missile Range near El Paso.  We would fly out of El Paso and flew over the White Sands area to simulate the Shuttle landing.” 
 Sugano vividly remembers that first shuttle flight.  “It was one of those experiences that you won’t forget.  I was actually over on-site in Building 2 watching the launch in the Teague Auditorium. We were afraid that some of the tiles might have come off.  I think there were some reports of high powered telescope from Hawaii looking at the bottom side of the Shuttle. During the re-entry when the blackout occurs, I held my breath and hoped for the best.  I was listening to all the media reports at that time.”
 The landing was the moment of truth for Sugano and it proved that the shuttle training aircraft had done its job in preparing the crew.  “What I was doing working on the shuttle training aircraft was one of the most fruitful experiences I’ve had learning about the Shuttle itself.  Prior to that, I was working through the approach and land tests which occurred back in 1977 at Edwards AFB as a part of the Mission Control Team.  I was one of the flight guidance officers and so I was able to experience the actual shuttle landing at Edwards from the Mission Control Center in Houston.” 
 Following the flight, we made a few adjustments to the Shuttle Training Aircraft based on the feedback from the crew. “The Shuttle training aircraft was never meant to fly exactly like the Shuttle.  So there were some discrepancies as expected.  So we did some tweaking afterwards.” 
 The Shuttle Training Aircraft flies differently from the Orbiter because it is much smaller than the Orbiter.  “You are more susceptible to winds and it’s generally exhibits a more rapid response when you command an input.  The Shuttle orbiter is a much more docile, heavier aircraft. It’s just like comparing a big boat in water versus a smaller one.  So that’s why they say the Shuttle flies better than STA because it is much more rock solid.” 
 Today, Sugano is working on the Orbiter glass cockpit and the flight software for the Shuttle.  “The glass cockpit is a lot of fun because you actually get to see some of the changes you make on the new software,” he added.  Sugano hopes to stay on the Space Shuttle program for another five years, which is around the same time that it is expected to be retired. 
 “Space exploration has always been my dream, and when I was a little kid, I remember Sputnik launch back in 1957 as I was just totally and actively interested in space.  So coming from that kind of background it was just an amazing path for myself to be able to get to where I wanted to be and stay as long as I have.  It was literally a dream come true career for me.  I am very fortunate that actually get to use what I learned at school and it’s been a lot of fun.”

 Roy Tharpe, who is Chief of Staff, Boeing Florida Operations, was NASA's Support Test Manager (STM) in the prime Firing Room for STS-1 and provided my test team "Go for Launch."
 “I was the Team Leader on STS-1 for our government and contractor team that was responsible for the Launch Processing  System, major support structures, facilities and equipment, propellants and gases for the Space Shuttle's ET and orbiter, Fire Rescue of the crew and Conus Operations Support at Edwards and White Sands,” he said.  
 Following the successful launch of STS-1, Thorpe was amazed.  “Since I was a veteran of all the Apollo/Saturn launches of the IB and V, this new reuseable Space Vehicle configuration shocked me as how big it was plus how fast it left the launch pad,” he said.  Tharpe had worked at Edwards Air Force Base on the Orbiter/Shuttle Carrier Aircraft Approach and Landing Test, the Mated Ground Vibration Test activities at Marshall Spaceflight Center  and at the Facility Verification Vehicle flow at Kennedy Space Center. 
 “I was very anxious awaiting the successful launch and return of Columbia at the landing site at Edwards. John Young and Bob Crippen thanked us all for our efforts both at KSC and Edwards Air Force Base. Those were special times but Exploration is the future and we need to get excited about our future since time is our ally or the enemy and we aren't getting any younger.”

 Hoa Vu, Space Station Mission Evaluation Room Structures and Mechanisms flight lead, was a part of the stress and analysis group supporting the NASA Structure Team with McDonnell Douglas.  “I was a part of the tiger team that was troubleshooting the TPS system problems when they were designing it before the first launch,” Vu said.   He started on the Space Shuttle program in 1979. 
 “Back then they had not settled on the TPS systems that you have right now, because they were still trying to find an optimum TPS design. We (the structure team) were investigating whether the shuttle structure can support different types of TPS design.” he said. 
 Hoa remembers watching the first flight, but still had a lot of apprehension.  “We were just anxious to see it work because we went through a lot of analysis and testing, but as engineers, we felt we had not done enough testing to be completely sure,” he said.
 Hoa remembers running much of their analysis on large IBM mainframes that took up two rooms of hardware.  After the first three launches, Hoa went to work on commercial airplane designs before rejoining the station program, then called Freedom, in 1991.  Hoa is pleasantly surprised that the shuttle is still flying after 25 years.  “I think we were designing it for only 15 years, but it turned out to be a much better design than we thought.” 
 “After more than 100 launches, I still get goose bumps watching it on TV.  I think pretty much every flight is a test flight and you learn something new everyday.” 

 Brad Wissinger, a senior manager for Boeing Service Company Satellite Operations, was working for McDonnell Douglas on the Shuttle program beginning in 1975.  In 1981, Wissinger was a Ground Navigation Flight Controller for the STS-1 mission. He worked in a back room with a navigation console and reported to the Flight Dynamics Officer.
 “Before the Tracking and Data Relay Satellite, the only way you could get a good navigation vector on the Orbiter was to do ground tracking; we used a combination of S-band and C-band tracking sites.  C band is the skin track.  We got those from the Air Force and the S bands were a combination of DoD and NASA.  We would have to collect the tracking data, edit it, filter it, and try to fit a solution to the data and get a good state vector.  When we got a good vector, we would send it to the Flight Dynamics Officer, and the Flight Dynamics Officer would look it over and if he was happy with it, he would have it uplinked to the Orbiter,” he explained. 
 “They would replace the state vector in the Orbiter with the one that we developed; ours was more accurate because they were just propagating a state vector rather than using any tracking data,” he said so that the Orbiter was where they thought it was and flying the right trajectory. 
 He added this data had a big impact whenever the shuttle was ready to perform a maneuver such as when they reenter the Earth’s atmosphere.  “It was very important to have a good state vector then because otherwise you won’t hit the runway,” he said.
 He remembers that many were concerned about the shuttle launch during the first eight minutes.  “Everybody was really worried about the Return to Launch Site in case something went wrong with one of the engines, they would have to do a pretty dangerous turnaround maneuver and get back to Kennedy and land,” he said. “But from our standpoint we had rehearsed things so long, that we were pretty confident that we were going to be able to do it, if we had to.” 
 “I had been working about a year and a half on navigation before we did the mission.  But we had been doing lots of long simulations and lots of training, it was pretty intense,” he said.  He remained on the shuttle program for the first 12 missions.  “Our first FDO was Jay Greene and he was a tough customer,” he said.
 During the mission some of the tiles on the Orbiter Maneuvering System (OMS) pod had come off, but DoD had some cameras taking shots at the underside so they knew it was okay.  “I think of course the biggest part was that before you have the days of TDRS, there’s a fairly long blackout period when it comes back into the atmosphere and it ionizes the air around it so you can’t get a radio signal in or out.  So this is the first time that you had to try and control such a large Spacecraft through that pretty dynamic region where its heating up, the air is getting thicker, you’re starting to get all kinds of aerodynamic moments on the vehicle and the control system absolutely has to work to keep the Orbiter pointed in the right direction or else that thing will burn up.  So when it came out of blackout and we picked it up we were pretty happy.”

 Tom Zakrzewski, a Boeing manifest lead for hardware being sent up to the International Space Station, was responsible for analyzing the solid rocket booster (SRB) separation from the rest of the Space Shuttle “stack” in 1981. 
 “I was with a group that was doing Shuttle Separation analysis and I worked on the SRB separation event. We developed hundreds and hundreds of simulations,” he said. “Although I worked with Rockwell engineers who were also doing the same thing I was doing.  We had three separate teams doing this task to make sure that we would not have any kind of common code problems in between our simulations that would give us an error.  We were all matching up our predictions,” he said about the efforts of engineers from Marshall Space Flight Center, McDonnell Douglas and Rockwell.
 Zakrzewski joined the Space shuttle program in 1974 with McDonnell Douglas in Houston.  McDonnell Douglas role was to support the Johnson Space Center engineering department.  “The person that I interfaced with on the SRB separation task (during the launch) were in the Control Center and he would take down the state vectors for the altitude, velocity, rolls rates, and the accelerations for the vehicle that they could determine at the time.  Then I would walk over to Building 12 where we had all of our computer facilities at the time and would run one of our simulations to try to predict how the actual separation sequence worked during that flight.”
 Zakrzewski describes the engineering work pretty complex for its time.  “It was a very dynamic environment with the aerodynamics.  When the forward booster separation motors would fire, the entire airflow around the Shuttle was disturbed considerably.  The shock waves would come over the front nose of the Orbiter.  It’s a very unpredictable environment.  I don’t even think current Computational Fluid Dynamics programs could predict that environment adequately.  So we had to do a lot of wind tunnel testing,” he explained.
 “We were doing three body simulations.  It’s like an 18 degree-of-freedom simulation.  Three separate bodies all tracking the individual elements on it to determine how close they come.  It was pretty sophisticated for that time,” he said.
 “Our predictions were very close to what the actual vehicle showed,” he added.  “It’s interesting since that was probably one of the riskier things people were worried about (separation of the solid rockets), but we had multiple redundancies for firing all the initiators and explosive bolts.” But even then, Zakrzewski remembers being worried for the whole flight.

 Craig Zook, currently the Lead Network Design for Boeing at its Houston site, but worked for McDonnell Douglas doing computer math modeling for the Shuttle Auxiliary Power Unit (APU) and hydraulics system.  He was primarily modeling the consumables requirements for those two systems.  The APU provides power to run the hydraulic systems which are used to move aero surfaces, gimbal and throttle the Space Shuttle Main Engines (SSME), and run the brakes and nose wheel steering.  These systems are used during ascent and reentry.  Zook started on the Space Shuttle in 1978 straight out of college and supported the JSC Mission Evaluation Room (MER) in building 45 from STS-1 through STS-25.
 “The MER held about 75 people and each major Shuttle system had a console or would share a console and we would look at data from prelaunch, during the flight and through post landing shutdown. The systems I monitored were the APU and the hydraulic systems.  Some of the parameters were temperature, hydraulic pressure, fuel and cooling water quantities.” Zook remembers. 
 He does remember working one issue with a clogged oil filter on the APU for the first flight.  “Some hydrazine fuel had leaked past a seal into the fuel pump gear box and formed a wax, which had clogged the oil filter.  The system was designed with a filter bypass, so the APU operation was not impacted.  The blocked oil filter made the news, but turned out to not be a very serious problem.  This problem occurred during other flights.  It was something we looked at and analyzed each time.  The system was designed to run with a blocked oil filter, but we did look at it each time it occurred,” Zook said.
 “The Shuttle APU is similar to the F-16 emergency APU.  Both are single disk turbines that are powered by decomposing hydrazine.  The Shuttle APU pulses fuel to control the power output and the F-16 runs the fuel through it at a constant rate and the excess gas is vented out of a bypass port.  The technology has been around quite a while -- very reliable.  The only novel feature of it was the way you fed fuel into it,” he said.
 Zook remembers being very nervous for the first flight and was worried whether their math models were correct.  “It was nice to see things worked the way that we expected them to work,’ he said. 
 Today, Zook enjoys his job of designing the computer data network and keeping these systems working.  Back then, he remembers working on STS-1 mission and remembers a lot of cheering when the shuttle landed.  “My job actually ran for about 10 minutes after they landed, but there was lots of cheering when the Shuttle landed, but I still had the job to watch the numbers and make sure the shutdown of the APU occurred properly.”

Source: Flight International