The end of the Cold War gave rise to an unprecedented opportunity for the United States and Russia to collaborate in a joint aeronautical flight research program. In 1993 a United States-Russian Joint Commission on Economic and Technological Cooperation chaired by then U.S. Vice President Gore and Russian Prime Minister Chernomyrdin, aggressively pursued areas of beneficial technical interchange between the two countries.
At the time, NASA and U.S. commercial aviation industries were heavily engaged in a High Speed Research (HSR) program to further develop Supersonic Transport (SST) aircraft technologies.
The goal of the HSR program was to posture the U.S. in a lead position toward the development of a second-generation SST aircraft. Russia's Tupolev Aircraft Design Bureau had proposed as early as 1990 that a Tu-144 SST could be utilized as a flying test-bed in support of the HSR program. Given encouragement from the Joint Commission, a team of senior NASA and U.S. industry aviation specialists developed a prioritized group of flight experiments and worked with a corresponding senior team from the Tupolev Design Bureau to understand modifications that would have to be made to the Tu-144 to conduct those experiments. These activities were the genesis of the Tu-144LL Supersonic Flying Laboratory used in the joint research program.
Twenty-seven research flights of the Tu-144LL were conducted over a two-year time period with apparent ease. The grace and beauty of the airplane masked the very extensive amount of effort that was required by Tupolev to re-engine it for the research flights. Further, the development, implementation, and operation of an instrumentation system that could measure nearly 800 parameters required by the experiments was another task of significant difficulty. The six thousand-mile distance between the U.S. experimenters and the airplane contributed to the difficulties of the instrumentation task. Three evaluation flights accomplished by U.S. pilots in September 1998 highlighted U.S. participation in the flight program. These flights allowed two NASA pilots to gain hands-on experience with the operation of a truly historical airplane operating as an updated test-bed for advanced technologies.TU-144LL SST Flying Laboratory in flight
The Tu-144LL program was a resounding success for both the U.S. HSR program and the Joint Commission. Seven flight and two ground-based experiments yielded flight data that greatly enhanced the supersonic flight databases available to U.S. and Russian aeronautical engineers. Propulsion, aerodynamic, structural heating, structural acoustics, ground effects, and handling qualities data from the experiments were eagerly assimilated into the program's information database. In March 1998 the Joint Commission recognized the program as "A model for U.S. and Russian government-business partnerships in the development of advanced technologies."
Upon completion of all of the programmed objectives, the TU-144LL aircraft was again relegated to a state of inactivity. Cancellation of the U.S. HSR program in 1999 resulted from the fact that an economically viable SST could not be envisioned near enough to further justify U.S. industry commitment. Russian economics were still severely depressed at that time from political change in Russia following the collapse of communism.