 In the HBO miniseries "From the Earth to the Moon", Houbolt was played by Reed Birney.Although the basics of the lunar orbit rendezvous (LOR) concept had been expressed as early as 1916 by Yuri Kondratyuk and 1923 by German rocket pioneer Hermann Oberth, NASA would provide the first practical application of the concept.Some engineers were concerned about the risks of space rendezvous, especially in lunar orbit, where there would be no fallback options in case of a major mishap.