[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: starship-design: HOTOL SeaDragon idea.
In a message dated 12/3/02 1:36:38 PM, bfranchuk@jetnet.ab.ca writes:
>KellySt@aol.com wrote:
>
>>
>> Subj: Re:SSTO + Tug launcher?
>> By: ==
>>
>> On your SSTsub-O w/Tug idea, I ran some numbers:
>> At lift-off, 90K of fuel, 9K of structure, and 10K of payload. With
>LOX/LH2,
>> that ought to leave you just 6,000 fps shy of LEO. A tug with 5.5K of
>fuel
>> and 0.55K of structure could boost your 10K payload up to LEO. For
>> simplicity, let's say that the previous payload supplies the fuel. 10K
>
>> payload minus 5.5K for fuel minus 0.3K of fuel to take the Tug from LEO
>to a
>> rendezvous trajectory minus 0.2K for a fuel container, leaving 4K of
>usable
>> payload. That's a four-fold increase, IT WORKS!
>>
>I like the idea of useing methane or propane as the main fuel because
>fossil fuel will run out in the near future, and synthetic fuels will
>hve to be used. Could somebody check the numbers on this.
Sorry thats a myth. We have a estimated 4 centuries of oil if consumption
grows at current rates.
>Note the space tug could also supply some re-entry thrust so I expect
>you would only get a 3x increase but a bit of a safety margin in your
>design.
But that would require the tug to then reboost itself even more, before
rentering. It might be dangerous, or completly cancel out the advantage of
using the tug.
Kelly