Hotol 2 - Hotol 2 is launched from the back of an Antonov 225 Credit: British Aerospace. 25,186 bytes. 408 x 257 pixels.

Initiated by a British Aerospace team led by Dr Bob Parkinson in 1991, this was a less ambitious, scaled-back version of the original HOTOL. The single-stage to orbit winged launch vehicle using four Russian rocket engines. It was to have been air-launched from a Ukrainian An-225 Mriya (Dream) aircraft. Interim HOTOL would separate from the carrier aircraft at subsonic speeds, and would then pull up for the ascent to orbit. It would return via a gliding re-entry and landing on gear on a conventional runway. Interim HOTOL suffered from the same aerodynamic design challenges as HOTOL and went through many, many design iterations in the quest for a practical design.

Liftoff Thrust: 800,000 kgf. Total Mass: 250,000 kg. Core Diameter: 10.0 m. Total Length: 44.0 m. Launch Price $: 110.00 million. in 1985 price dollars.

• Stage Number: 0. 1 x An-225 Gross Mass: 600,000 kg. Empty Mass: 216,000 kg. Thrust (vac): 141,442 kgf. Isp: 9,000 sec. Burn time: 3,375 sec. Isp(sl): 8,000 sec. Diameter: 18.1 m. Span: 88.4 m. Length: 84.0 m. Propellants: Air/Kerosene No Engines: 6. D-18T

• Stage Number: 1. 1 x Interim HOTOL Gross Mass: 250,000 kg. Empty Mass: 33,100 kg. Thrust (vac): 800,000 kgf. Isp: 455 sec. Burn time: 122 sec. Isp(sl): 352 sec. Diameter: 10.0 m. Span: 21.6 m. Length: 36.5 m. Propellants: Lox/LH2 No Engines: 4. RD-0120

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  Buran Atop Mriya - Buran atop its An-225 Mriya carrier, as displayed at the Paria Air show shortly after its spaceflight. Credit: © Mark Wade. 22,168 bytes. 538 x 262 pixels.

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• Interim HOTOL designed by British Aerospace

  This was a less ambitious, scaled-back version of the original HOTOL. The single-stage to orbit winged launch vehicle using four Russian rocket engines. It was to have been air-launched from a Ukrainian An-225 aircraft.

• 236 - Aviation Week and Space Technology, "HOTOL-2", 1991-09-09, page 68.

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Interim HOTOL - 68-H version of Interim HOTOL atop the An-225 launching aircraft. Diagram produced by Fastlight. Used with permission. 48,507 bytes. 750 x 1220 pixels.

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