Shuttle Technology's Progress a Function of Necessity

Although the mission of the Applied Physics Lab at NASA’s Kennedy Space Center is to deliver gadgets to support these launch missions and operations, the verdict of the end users of these technologies dictates which ones are used.

For example, the space shuttle External Tank (ET) Vent Hood Alignment Tool is used to align the vent positioned on the ET tip. This “Beanie Cap,” prevents ice from forming on the vent, avoiding harm during launch. The tool came about because of the enthusiasm of end user engineer Jorge Rivera, who accepted it for use. He recognized that it would align the vent safer and faster than before. Despite management’s concern that it needed additional capabilities, Jorge recognized that it would perform the job.

With the tool, alignment can be quickly and safely performed, not only before any External Tank propellant load occurs, but also after a scrubbed launch.

A tool that aids in the task of providing leveling to an orbiter in the Orbiter Processing Facilities after missions was also in demand because excessive access to the platform system could damage the vehicle. The end user, NASA contractor of United Space Alliance (USA), Mike McClure, recognized the need for an improved leveling tool.

This Improved Orbiter Jack and Leveling System using laser rangefinders was memorable; when funding was tight, the users and APL took it to the KSC Shuttle Processing Chief, Michael Wetmore, and fought for upgrades together. “Development of the Improved Orbiter Jack and Leveling System is an outstanding example of how groups from different organizations with different responsibilities can work together to achieve a goal even in times of tight funding,” remembers Charles Stevenson of the Shuttle Chief Engineers Office.

End user Mike McClure, worked “hand in hand” with the lab to develop it, remembers Youngquist. “Without Mike’s support, technically and politically, the system would never have been built.”

Mr. McClure said, “that is usually what makes or breaks a good project: a champion. You have to be willing to keep pushing.” It is clear why this determination was needed. The orbiter should be raised accurately to the height of the servicing platforms by jacks to a precision of 1/8 inch.Otherwise the orbiter could not get serviced. “From a time-savings standpoint, the laser systems were significant, especially when you add up the number of technicians and Quality Control inspectors involved with our operations,” recalls Mr. McClure. 

The system uses Leica laser rangefinders under the jacks that transmit readings to a computer. It is literally a vital tool for the orbiter’s safety that would not have come about without the push from Mr. McClure’s group.

Sometimes the lab assists the users in improving the equipment they already use. During NASA's return to flight, the Discovery shuttle's STS-114 mission in 2005, problems with the External Tank liquid hydrogen pressurization system occurred.A Tanking Test indicated excessive helium pressurizing gas usage and the launch was nearly scrubbed.

“The system was never designed to measure helium, only control pressure. But everyone wanted to know how much helium was actually being used,” said physicist Stan Starr of the APL. He worked with Tom Clark of USA to propose a unique calibration of the system.

Replacing the existing orifice with one that controls the helium quantity would solve the measurement problem. “We talked to the top people in the field and they said the existing orifices couldn’t be calibrated, and even the best lab in the country initially refused to test them,” said Starr. In the end, testing was successful; now the quantity of helium is known within 5%.

Similarly, the Water Extraction Tool (WET), a vacuum system for drying orbiter tiles, is “a case where hardware is needed for contingencies,” said Dr. Youngquist. The tool was designed to remove water from Orbiter tiles after the March 2001 Atlantis mission, which was rained on after landing in California.The WET was developed as a five times faster method than that for drying Atlantis, heating with infrared lamps.

The tool now dries 150 tiles in two hours, not days as before. It vacuums water out through waterproofing compound injection holes in each tile after the compound is burned away on reentry.

“The Thermal Protection System (TPS) team laughed when we first demonstrated the system, it was so much easier to use,” recalls Starr.

TPS approved of the tool but after we delivered it, they “kindly asked us to keep our hardware,” said Youngquist, because shuttles are rarely rained upon.

In August of 2005, Discovery landed at Edwards Air Force Base in California and was covered with two inches of rain.“When users want something, things can move very quickly”, said Youngquist.A request for the tool was sent to the lab; within two weeks, WET was being used in the field.

Another APL technology that would not have made it into the field without the end user’s involvement was the SLOT, initiated by window inspector, Robin Floyd.

The Surface Light Optimizing Tool (SLOT) highlights defects on orbiter windows. The plastic tool suctions to the window and uses internal light reflection with a prism to trap light in the glass. Thus small micro-meteor defects on the windows show up as bright points.

According to Youngquist, “the best case is when the end user wants to work with you and develops a vested interest.” Floyd conceived the idea for SLOT but had no means of fabricating it independently; he teamed up with the APL and jointly produced the tool when a “meeting of the minds occurred,” said Youngquist.

The result was the delivery of 14 working SLOT devices which detected hundreds of defects. The current fourth generation SLOT will soon be adapted for use on the International Space Station and the Constellation project, which is aiming to send the Ares I and V crew and cargo launch vehicles to the moon and Mars.

There have been over total 40 pieces of hardware and eight patents developed at the APL to assist shuttle program operations in the 19 years of the lab’s operation.

“Technology is a function of how ardent the customer is on getting the product; it is need and personality driven,” asserted Youngquist. This may just be the secret to how innovation impacts the Shuttle Program at KSC and how KSC keeps the shuttle flying.

Parts of this content were originally published in NASA Kennedy Space Center’s publications, “Spaceport News”, Space Times Magazine, and also in the Institute of Engineering & Technology’s magazine.

NOTE: The views of this article are the author's and do not reflect the policies of the National Space Society.

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