Shuttle Technology's Progress a Function of Necessity

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

Forexample, the space shuttle External Tank (ET) Vent Hood Alignment Tool is usedto align the vent positioned on the ET tip. This “Beanie Cap,” prevents icefrom forming on the vent, avoiding harm during launch. The tool came aboutbecause of the enthusiasm of end user engineer Jorge Rivera, who accepted itfor use. He recognized that it would align the vent safer and faster thanbefore. Despite management’s concern that it needed additional capabilities,Jorge recognized that it would perform the job.

With thetool, alignment can be quickly and safely performed, not only before anyExternal Tank propellant load occurs, but also after a scrubbed launch.

A tool thataids in the task of providing leveling to an orbiter in the Orbiter ProcessingFacilities after missions was also in demand because excessive access to theplatform system could damage the vehicle. The end user, NASA contractor ofUnited Space Alliance (USA), Mike McClure, recognized the need for an improvedleveling tool.

ThisImproved Orbiter Jack and Leveling System using laser rangefinders wasmemorable; when funding was tight, the users and APL took it to the KSC ShuttleProcessing Chief, Michael Wetmore, and fought for upgrades together. “Developmentof the Improved Orbiter Jack and Leveling System is an outstanding example ofhow groups from different organizations with different responsibilities canwork together to achieve a goal even in times of tight funding,” remembersCharles Stevenson of the Shuttle Chief Engineers Office.

End userMike McClure, worked “hand in hand” with the lab to develop it, remembersYoungquist. “Without Mike’s support, technically and politically, the systemwould 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 systemuses Leica laser rangefinders under the jacks that transmit readings to acomputer. It is literally a vital tool for the orbiter’s safety that would nothave come about without the push from Mr. McClure’s group.

Sometimesthe lab assists the users in improving the equipment they already use. DuringNASA's return to flight, the Discoveryshuttle's STS-114 mission in 2005, problems with the External Tank liquidhydrogen pressurization system occurred.A Tanking Test indicated excessivehelium pressurizing gas usage and the launch was nearly scrubbed.

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

Replacingthe existing orifice with one that controls the helium quantity would solve themeasurement problem. “We talked to the top people in the field and they saidthe existing orifices couldn’t be calibrated, and even the best lab in thecountry initially refused to test them,” said Starr. In the end, testing wassuccessful; 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. Thetool was designed to remove water from Orbiter tiles after the March 2001Atlantis mission, which was rained on after landing in California.The WET wasdeveloped as a five times faster method than that for drying Atlantis, heatingwith infrared lamps.

The toolnow dries 150 tiles in two hours, not days as before. It vacuums water outthrough waterproofing compound injection holes in each tile after the compoundis burned away on reentry.

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

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

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

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

The SurfaceLight Optimizing Tool (SLOT) highlights defects on orbiter windows. The plastictool suctions to the window and uses internal light reflection with a prism totrap light in the glass. Thus small micro-meteor defects on the windows show upas bright points.

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

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

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

“Technologyis a function of how ardent the customer is on getting the product; it is needand personality driven,” asserted Youngquist. This may just be the secret tohow innovation impacts the Shuttle Program at KSC and how KSC keeps the shuttleflying.

Parts ofthis content were originally published in NASA Kennedy Space Center’spublications, “Spaceport News”, Space Times Magazine, and also in the Instituteof Engineering & Technology’s magazine.

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

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