Retired engineer Stephen R. Fleeman describes the wonder of an assignment at the KSC in the summer of 2000.
This article was contributed by Stephen R. Fleeman, a retired electrical engineer and professor.
Engineering opens your world to unimagined possibilities. When I was a young boy in Jeffersonville, Indiana, I used to lay in the grass at night and gaze up at the stars. In 1963 I was 14 years old and there was little light pollution then. The stars were bright and seemed to hang in the sky. I dreamed of travel in outer space.
I graduated from Purdue University in West Lafayette, Indiana. After graduation, I was hired to teach classes in Purdue’s Electronic Engineering Technology (often described as an “applied engineering” program). I taught as a graduate instructor while in graduate school and then later as an assistant professor. In 1977, I moved to Rockford, Illinois to work at an aerospace company called Sundstrand as an electrical engineer.
In 1978, I was a assigned my first project to support the Space Shuttle Orbiter. For several years I supported the Space Shuttle program as part of my work assignments. My specific role included the design and support of the Controller Checkout Unit (CCU). The CCU was classified as Ground Support Equipment (GSE). It was used to verify the integrity and the redundancy of the electrical system in the Orbiter Auxiliary Power Units (APUs). The APUs provide the hydraulic power required for main engine thrust vectoring during launches. During landings, the APUs provide the hydraulic power to control steering surfaces and the air speed brakes. Each orbiter has three APUs.
In 2000, I was assigned to go to Kennedy Space Center (KSC) to witness the CCU verifying the integrity and the functional redundancy of the APU 2 Controller. This was a dream assignment! Maybe I never made it to outer space, but I would be next to an Orbiter!
A colleague, Ray Weyl (also of Sundstrand in the Missiles, Space, and Undersea Systems Enterprise) and I got to inspect the APU system in the Discovery’s aft compartment. The APUs are shown in the picture below.
As an electrical engineer, I did not become involved with the mechanical intricacies of the APU. However, I appreciated the incredible amount of power they produced. Hydrazine is their fuel source, and the APU turbines reach speeds in the range of 78,000 to 90,000 rpm! My assigned interest in the APUs was with their electrical components, which included three magnetic speed pickups (MPUs), a gearbox pressure transducer, a heater thermal switch, a resistive temperature sensor, the electrically-operated fuel, water (cooling), and gearbox pressurization valves. The APUs are controlled by their respective APU Controllers. The CCU verified the proper operation and the functional redundancy of the circuitry within the APU Controllers. The CCU’s interfacial harness plugged into the ground test connector (J4).
An APU Controller is pictured below. It is the black box on the left side. The J4 connector had its protective cap in place. The aft compartment was a bit cramped, as you can see by my picture which follows. Even though I ran regularly, I found myself a little stiff the next day.
After our examination of the APUs within Discovery, we exited as shown in the picture below. To enter the orbiter, ALL pockets must be empty, and protective booties must be worn. Watches and rings that are not removed MUST be secured with tape. The obvious purpose was to prohibit the addition of extraneous payload. This prevented FOD (Foreign Object Damage).
We also observed testing of the rudder airspeed brake. My colleague, Ray captured the image below. The rudder airspeed brake is part of that Orbiter’s vertical tail. This image was taken from a downward viewpoint.
There were two operational orbiter launch pads, which were designated Launch Pad 39A and Launch Pad 39B. Mr. Ken Smith of Boeing took us the top of launch Pad 39A. (Launch Pad 39C has never been completed). By the way, the USA on our hardhats stood for United Space Alliance.
Although we could not get next to it, we also saw the Crawler. This 100-ton vehicle carried the Orbiter, and the two Solid Rocket Boosters (SRBs) to the launch pad at the rate of 1 mph.
We also were permitted to see the staging area for the International Space Station. We were shown the contributions of the United States, Italy, and Canada. In fact, we watched the Canadians work on the robotic arm to be used for the space station.
The image below contains the gyroscopes (gyros). The gyros are the large black units.
The technician was observed wrapping harness assemblies with protective tape. This unit eventually became part of the payload for a Space Shuttle mission. The astronauts were trained to place the unit into its proper position in the International Space station. Some of the astronaut training was held in the facility. Ground support equipment to handle payloads such as the one above were also designed in this area.
The picture below shows one of the displays to help the technicians, and (primarily) the perplexed visitors understand where the finished components fit into the overall Space Station design.
The next picture shows a main truss assembly. Two technicians were performing some unrelated work in the foreground. There is a second-story window that permits visitors to look down at the staging area. I could see a father holding up his young son so he could see. I thought about many years ago when I held up my own sons to that same window. Briefly, tears formed in my eyes. (It is a “dad” thing and I got past it.)
The Vehicle Assembly Building (VAB) is illustrated in the next picture. The Orbiter is attached to its two Solid Rocket Boosters (SRBs) in the VAB. Pictures were not taken inside the VAB. Flashes were not permitted. This was because they can set off alarms, which in turn resulted in a great deal of rather embarrassing paperwork. It is difficult to grasp the size of the VAB. Each star on the American Flag is about the height of a man.
Being given the opportunity to get such an up-close look at a space program, like the Space Shuttle, gives one a great sense of pride. The Space Shuttle program stands “shoulder-to-shoulder” with the other great achievements accomplished by humankind. Despite its maturity, no other nation has been able to approach the level of success enjoyed by the American Space program. The Orbiter was unsurpassed in its ability to carry huge payloads and accomplish incredible feats routinely. That is also one of the major problems.
Many Americans have lost that child-like awe of America’s Space Program. It is sad that much of the early history of the first launches have been lost. The image below is of a converted oil well that was used as the launch pad for a Redstone Rocket. That vehicle was used to carry the first manned space flights (Project Mercury) with astronauts like Gus Grissom (a Purdue graduate.) It is part of the Airforce Space Museum located at Kennedy Space Center.
Tearing ourselves away from consuming activities at KSC, Ray and I discovered other consuming activities in the form of drinking Old Thumper beer at Marlin’s on Cocoa Beach Pier.
The Space Shuttle is now retired, but that is great because I am too. There is much more ahead. A lunar base, Mars missions, and commercialized space travel are all in development, currently. These offer fantastic opportunities for young engineers and those who are perhaps just beginning to consider it.
My son, Brennan, has followed such a path. Brennan is a Part Manager for the Blackjack mission at Raytheon Space and Defense. He is also a Components Engineering Lead within the Component Engineering Department supporting a dozen classified Space Force and defense programs. He has worked at Raytheon for the past two years, and previously worked four years at their partner Collins Aerospace.
The Blackjack program is a DARPA (Defense Advanced Research Projects Agency) funded initiative to replace and/or supplement the current high-cost GEO (Geosynchronous Equatorial Orbit) satellite network with hundreds of LEO (Low-Earth Orbit) low-cost satellites with customizable electronics.
Acknowledgements: Many thanks are due to the managers, engineers, and technicians at Sundstrand. It has been a pleasure working over the years with Eugene Davis, Elaine Fosler, Mark Fransen, Karl Hamilton, Joe Jonakin, Clark Keeton, Dave Kristiansen, Bob Smith, Jittendra Solanki, Steve Tollefson, Rick Toomey, Louis Vanderwyst, Ray Weyl, Steve Williams, Jim Wilson, and many others. The Boeing APU team: Ken Smith, Tim Boltz, and John Hilde went out of their way to extend every courtesy, and patiently answered every question. Great people keep the Space Programs great.
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