Doug:
Tom Mueller once built an about 5-6” diameter liquid using equal volume
(and dimension) tanks that relied on cooling the Propane to the Lox boiling
point.
It worked fine, of course. Making two identical tanks does reduce cost
some....
Bill
On Tue, Feb 13, 2018 at 5:34 PM Doug Jones <dmarc-noreply@xxxxxxxxxxxxx>
wrote:
Isothermal LOX and propane tanks allow the propane density to rise to
728 kg/m3, approaching the density of kerosene with nearly the Isp of
methane. No fuel vapor boiloff makes for reduced fire hazards, too.
On 2018-02-13 11:08 AM, William Claybaugh wrote:
Is anyone aware of a careful comparison of LH2 vs. Propane fueled SSTO?cost
Hydrogen tanks generally weigh around 10% of the fuel mass whereas
Propane tanks are closer to 1%....
Bill
On Tue, Feb 13, 2018 at 11:56 AM Rand Simberg <simberg@xxxxxxxxxxxxxxx
<mailto:simberg@xxxxxxxxxxxxxxx>> wrote:
I'd hope that we learned from Shuttle that the key to reducing the
of access to space is not a massive government program.to
On 2018-02-13 10:53, Keith Henson wrote:
> Henry Spencer wrote
>
> On Sat, 10 Feb 2018, John Dom wrote:
>>> ... Who knows where the Skylons would be by now if they got the
same
>>> help SpaceX got..
>
>> Probably not much farther than they are now, given that the help
>> SpaceXopinion,
>> was hundreds of millions to produce flying rockets with flying
>> capsules on
>> top, while Skylon development is still forecast to cost tens of
>> billions and
>> there is no plan for a less-expensive demonstrator first.
(Which puts
>> Skylon in the "need not be taken seriously" category, in my
>> sinceconcept.)
>> nobody is going to spend that kind of money on an unproven
>(governments
> Let's turn this around. What would it take for someone
> most likely) to fully develop Skylon?it
>
> The last time this happened was nuclear weapons during WW II. So
> would take the moral equal of a war of survival. Is the threat tobut
> climate due to CO2 high enough for that to happen? I don't know,
> there are not a lot of other carbon-free energy sources on tap.think
>
> I am agnostic about how we transport parts into space for power
> satellites. Skylon, BFR, witches brooms, all the same to me. The
> critical thing is cost. If you can't get the cost per kW of
installed
> power to $2400 or less, then power satellites are a hard sell.
At the
> current design point, that needs about $100/kg to LEO. I don't
> rockets can reach that number, but if they can, we have the toolsto
> solve the carbon and energy problems.
>
> Keith
>
> PS. The other option is to go to the moon or asteroids for
materials.