[AR] Re: Circa 1968 video about NERVA nuclear rocket program
- From: "Troy Prideaux" <troy@xxxxxxxxxxxxxxxxxxxxx>
- To: <arocket@xxxxxxxxxxxxx>
- Date: Mon, 16 Apr 2018 16:59:31 +1000
The power required to create thrust T by expelling an exhaust jet at
velocity Ve
is 0.5*Ve*T/e, where e is efficiency. In fact, conveniently, rocket
efficiency is
often somewhere in the neighborhood of 50%, so Ve*T is a plausible first
guess
Where is that 50% efficiency number coming from? A mid point between typical
sea level and vacuum ops? If you look at the SSME for example, its
efficiency would be over 70% in vacuum ops.
Troy
Other related posts: