John Carmack, founder and lead engineer of Armadillo Aerospace 2006:
"I have been corresponding with Lutz [Kayser] for a few months now, and I have learned quite a few things. I seriously considered an OTRAG style massive-cluster-of-cheap-modules orbital design back when we had 98% peroxide (assumed to be a biprop with kerosene), and I have always considered it one of the viable routes to significant reduction in orbital launch costs. After really going over the trades and details with Lutz, I am quite convinced that this is the lowest development cost route to significant orbital capability."
https://en.wikipedia.org/wiki/OTRAG
Aber Armadillo Aerospace ist nicht mehr:
"Im August 2013 gab John Carmack bekannt, dass das Projekt (unter anderem nach dem Crash der Rakete STIG-B) vorübergehend auf Eis gelegt werde, er jedoch „aktiv nach externen Investoren suche, um die Entwicklung neuer Raketen wieder aufzunehmen."
https://de.wikipedia.org/wiki/Armadillo_Aerospace