Estes Rockets (estesrockets.com) makes a C5-3 engine that provides "a 50% increase in maximum thrust over a standard C engine and the punch you need to propel those heavier rockets off the pad" (their own words).

Sign this petition to show them that there is enough of a demand for a booster (C5-0) version of the engine. 

A booster C5 would be the perfect engine to get a Booster Bertha off the pad, as well as any number of other, heavier two stage rockets.  Even certain oddrocs would benefit from the extra boost.

A C5 would provide more initial thrust than a C6, at the expense of a lower average thrust and a slightly shorter burn time. This chart from Thrustcurve.org shows a comparison with the C6.

Please sign this petition so that Estes knows that there is enough of a market to make this engine worthwhile!

Thank you!

Ken Berkun

About me: Just an old model rocket fan.