pogbackg.htm JELAC/Pogo - Background


POGO - BACKGROUND


BACKGROUND

Advanced Concepts Working Group

During a period of cataloging old and new concepts for the ACWG it was noted that, since the 1950s when DoD was looking at vertical take-off and landing (VTOL) aircraft, the technology for jet engines had improved dramatically. As the study progressed, additional information was obtained that the Pogo, as a launch-assist concept, had the potential for significantly reducing the cost of spacelift and adding benefit to other technology areas, some of which are described in Appendix A. This preliminary concept study was concluded when it appeared that little more was to be gained in comparative analysis or by gathering professional opinions from engineers and scientists.

Historical Pogos Identified

The name Pogo was selected based on this author's vague memory of a similar spacelift concept dating back at least 30 years. Research was unable to find a reference to such a vehicle. One document[1] did reference the possibility of using air-breathing engines for vertical boost assist. Numerous references to aerospace planes using jet propulsion were found[2-4].

The research also turned up three U.S. VTOL aircraft built and flown in the 1950s and 1960s which were nicknamed "Pogos."[5] These were the Ryan Model 69 turbojet, Lockheed XFV-1, and the Convair XFY-1.

There have also been many other VTOL vehicles built and tested including the West German Mach 2 VJ-101 tested in the early 1960s[6-7]. Other than helicopters, the most successful VTOL aircraft appears to be the British Harrier (U.S. designation AV-8), which is still in use today. Research revealed several reasons for the U.S. not pursuing its own VTOL fighters. These included competition for money with more desirable fighters, vehicle controllability, and the thrust/weight (T/W) of the engines. According to the reports read, some controllability problems were found during hover and transition to normal flight, but none that were considered critical to operations.

Related Concepts Identified

At the time of this writing, a scaled prototype of the Kistler Launch Platform was under construction at Scaled Composites[a] in Mojave, CA. This platform, powered by several hydrogen/peroxide monopropellant motors, was to lift an upper stage, similar in shape to the DC-X, to some predetermined height before upper-stage engine ignition. The platform was to return to the launch pad for a soft landing and reuse. While the details of the concept were not known, the fabrication of the two major components were nearing completion.
[a] Tour of Scaled Composites, Mojave, CA, 15 Aug 95, conducted by Bob Williams
...(Editor's note: Since the original writing Kistler had abandoned the concept described above. As of May 97 Kistler was building a much improved vehicle. This new one used Russian NK-33 LOx/Kerosene engines. Information on this vehicle can be easily found on the web.)

The Boeing Corporation had performed an internal engineering study [b] in 1993-1994 on a vertical take-off launch vehicle using 10 F-100-PW-229 jet engines as strap-on boosters. These engines would have carried the vehicle to 50,000 ft and Mach 1.7 before being staged and individually returned to Earth via parachutes for recovery and reuse. The three-part (in parallel) upper stage used six RL-10A-3 liquid oxygen/liquid hydrogen (LOX/LH2) engines and weighed 85,000 lb. The launch system was to deliver 6,700 lb. to low Earth orbit (LEO).
[b] Personal communiques with Dani Eder, Boeing Corp., Huntsville, AL




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This Page Last Updated 29 May 97