Chapter 4 The Space Shuttle Era Begins (1981 – 1987)
4.4.1 KSC Rocket Triggered Lightning Program (RTLP)
This program was organized and operated by the KSC Engineering Directorate (DE) rather than by
the KSC Weather Office. The NASA/DE RTLP lead engineer was William Jafferis, who was
extremely enthusiastic about the project. Mr. Jafferis was convinced, even before the AC 67 disaster
in 1987 (see above and Section 5.0), that not enough was known about lightning in general and
triggered lightning in particular to safely conduct space launches in the Cape Canaveral area.
Throughout its nine-year history (1983 through 1991) he managed and directed the program with
funding from the Shuttle Program at KSC, supplemented by private sources such as the Electric
Power Research Institute, Florida Power and Light, and others. By its conclusion, he had built KSC
into the world's leading center for rocket-triggering research. Three LAP members (Krider, Willett,
and Rust) participated in the RTLP at various times during its life. In addition to numerous scientific
papers and technical reports, an article about the program was
published in the New York Times in the aftermath of the AC 67 accident (Wilford, 1987).Summertime rocket-triggering experiments by the RTLP were begun in 1983 south of Melbourne, FL (Richmond, 1984). They were moved some 50 km north in 1984 to a site just east of the Vertical Assembly Building (VAB) at the NASA Kennedy Space Center (KSC). In 1985 triggering operations were moved again, about 15 km further north to the west bank of the Mosquito Lagoon, where they continued through 1991. The Mosquito Lagoon facility eventually comprised two instrumented triggering locations (the original "land pad," and a newer "water pad," described below), two control and instrumentation trailers (one a discarded
Chesapeake & Ohio railroad caboose), a "headquarters" building dubbed the Atmospheric Sciences Field Laboratory (ASFL), and an un-energized, 448 m long, electric-power distribution line running approximately between the land pad and the ASFL. Diesel generators were provided for operations during storms, when commercial power in the area was unreliable. A tethered balloon (aerostat) was even operated during 1989 and 1990 to support instruments aloft and to trigger lightning from an elevated and ground-isolated platform. In August of 1991, however, an accident with injury involving the unintended launch of a 2.75" Folding-Fin Aircraft Rocket by French investigators brought the program to an end [Mishap Investigation Team Report,
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1991]. Earlier that same season, the aerostat had blown away and been lost at sea, which did not help the program's standing with KSC management.
Thereafter, triggering activities by some of the participants and funding sources moved to Camp Blanding in Starke, FL, under the management of the University of Florida, where they continue and flourish to this day. Unfortunately, this move, coupled with the loss of Shuttle Program funding, eliminated any motivation to address the operational needs of the space program. The research at Camp Blanding became even more focused on the concerns of the electric power industry (although this focus has broadened recently because of significant long-term funding from the National Science Foundation).
Fundamentally, the demise of the KSC RTLP resulted from the contemporary reorganization of weather infrastructure throughout NASA that had been recommended by the Theon and NRC panels. The new NASA Weather Support Office (see Section 5.2.0) led by Jack Ernst at NASA Headquarters and its counterpart at KSC (see Section 5.2.2) led by Jan Zysko, assumed control of the Shuttle weather-related "research" funding to ensure that it was directed towards narrowly defined, operational needs. In February, 1989, Jim Nicholson (NASA/KSC/PT, the conduit for this funding) conducted a blue-ribbon panel review of the RTLP to get recommendations on how it could be restructured to support Shuttle operations more directly. This panel consisted of the following experts on lightning and atmospheric electricity: E. Philip Krider (University of Arizona, Chair), Jean-Louis Boulay (ONERA, France), Charles B. Moore (NMIMT), Richard E. Orville (State University of New York at Albany), Martin A. Uman (University of Florida, Gainesville), and John C. Willett (AFGL). Its report [Review of and Recommendations for the Rocket Triggered Lightning Program (RTLP) at the NASA Kennedy Space Center, revised August 1, 1989] identified several experimental efforts that would be of great value to the operational community and that could be carried out by the RTLP. It also
recommended some changes in the organization of the RTLP, its funding, and the objectives to achieve these ends. Unfortunately, the recommended changes never came to pass, and this more or less guaranteed the termination of the RTLP when the above-mentioned accidents occurred.
French technicians from the Centre Etudes Nucleaires de Grenoble (CENG), who described the campaigns in a series of technical reports (e.g., Eybert-Berard et al., 1986; Barret, 1986; Eybert-Berard et al., 1988, 1989; Barret et al., 1990; Barret et al., 1991), provided some of the infrastructure, although KSC also developed its own operational capability. Two different triggering platforms were used at the Mosquito-Lagoon site. A "land pad" was constructed near the shore of the lagoon in 1985 to facilitate engineering tests on isolated conducting bodies and other hardware, and its configuration is quite complicated (see Leteinturier et al., 1990). A simpler "water pad" was constructed about 30 m offshore in 1987 to enable more precise electromagnetic
measurements (Leteinturier et al., 1991).
The triggering techniques used in the RTLP have been described in detail by Laroche et al. (1985, 1989a, and 1991). Two basic rocket-and-wire methods were used at KSC; in both, a spool of fine Kevlar (TM)-wrapped copper wire was raised by a meter-long, plastic-bodied, black-power-fueled rocket. (This approach of raising the spool was pioneered at the RTLP in 1983. Previously a spool of cotton-wrapped steel wire had been mounted on the ground, and the rocket lifted only the free end of the wire.) The rockets could reach altitudes of about one kilometer in a several seconds. The "classical" technique (sometimes called LRSG) involved unspooling a continuous, grounded wire as the rocket ascended. This method has the advantage of allowing a direct measurement of the lightning current at the base of the wire (lightning channel). The "altitude"
technique (LRSA -- also pioneered at KSC in 1987) is similar, except that the rocket unspools a few hundred meters of non-conducting line before the conducting (un-grounded) wire was paid out. Altitude triggering was developed to simulate better how lightning strikes airborne vehicles and to study the leaders that develop early in the discharge between the lower end of the triggering wire and ground. A later innovation in the altitude technique was the addition of a short length of grounded wire below the non-conducting segment (LRSAG), to facilitate studying the ground-striking process and allow direct measurement of currents in this "lightning rod." The key scientific results from these experiments are given in Section 5.4.3.
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