Several configurations were possible; but, only a few were kept. The first was the DragonFly©®, and the second was the BlackGoose©®, with or without engines. The BlackGoose©® is derived from the BlackSwift SST©® by shifting all the aircraft's weight below the wings. The BlackSwift EST©®, a.k.a Kestrel EST©® is a smaller passenger only space plane. The Blackswift 1000©® is derived from the DragonFly EST©®, as an 1,000 seats airliner.
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