2007 / Dec 2007
Rocket Lab / captured 23 July 2011 from http://www.rocketlab.co.nz/rocket-lab-news.html
December 16th 2007 – Rocket Lab's 2nd stage rocket engine will be hybrid. December 7th 2007 – Rocket Lab has developed and patented a new fuel for hybrid rocket engines that provides high regression rates and excellent mechanical properties.
The quote is the release as captured. Not a rklb.report rewrite. Not affiliated with Rocket Lab.