[AR] Re: SSTO
- From: Keith Henson <hkeithhenson@xxxxxxxxx>
- To: arocket@xxxxxxxxxxxxx
- Date: Wed, 14 Feb 2018 13:39:29 -0800
William Claybaugh <wclaybaugh2@xxxxxxxxx> wrote:
Is anyone aware of a careful comparison of LH2 vs. Propane fueled SSTO?
Hydrogen tanks generally weigh around 10% of the fuel mass whereas Propane
tanks are closer to 1%....
I think any hydrocarbon fuel will have about the same performance.
That means that while you can do SSTO, it will not have a payload or
be reusable (at the current state of the art). Skylon cheats by
avoiding the rocket equation till it is already up to Mach 5.5 and 26
km and even there uses wings to offset gravity drag.
I suppose REL could burn propane up to where they go pure rocket.
Given how much heavier the propane would be, I don't know if the trade
would work or not.
Norman Yarvin <yarvin@xxxxxxxxxxxx> wrote:
I don't think either of those examples fully captures the glory of an
aircraft whose essential centerpiece would be a super-high-performance,
super-delicate heat exchanger filled with hydrogen and exposed to
incoming airflow.
It's helium in the fine tubes. Otherwise, you would have hydrogen
embrittlement. But you are close to the initial reason I rejected the
concept. Thousands of brazed joints and it's not going to leak? But
they built some furnace brazed test articles and they did not leak.
That's when I started to take them seriously.
Keith
Other related posts: