American rocket designs are based on nuclear missiles, and use technology dating from the 1960s and 1970s. (newscientist.com)
They realized that incremental improvements in rocket design would not provide enough lift. (gse.harvard.edu)
A 1.2 - metre - wide rocket designed by John Carmack, creator of the hugely successful Doom video games, crashed about 20 seconds after launch in Texas on 7 August. (newscientist.com)