----- Original Message -----
From: "Randall Clague" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Cc: <[EMAIL PROTECTED]>
Sent: Tuesday, June 24, 2003 1:56 AM
Subject: Re: [ERPS] What is F.A.S.T.?
> >Phase 3 - The vehicle must demonstrate the ability to travel
> >between two points at least 3,000 kilometers apart in less
> >than 20 minutes, a trip only attainable by rocket.
>
> A rocket that was designed and built for exactly this mission *might*
> make 3000 km in 20 minutes, with seconds to spare. The ballistic
> flight to go 3000 km is very close to 15 minutes, and allowing only
> five minutes for boost and reentry *combined* just doesn't give enough
> time to get out of the atmosphere and back in. We need to change this
> to 3000 km in 30 minutes.
Well, in fact, it should be possible for a pseudo-ballistic surface
transport to acheive this kind of point to point performance, but that's a
much more expensive system to create than a rocket (though it's likely
cheaper to operate once the development cost is amortized). One form of
this kind of transport would be an evacuated tube in which passenger and
cargo capsules are propelled by hydrogen/oxygen combustion in the tube;
these can significantly exceed orbital speed over continental distances
without exceeding 3G startup or braking accelerations.
No, I don't think I'll be able to buy a ticket on one in my lifetime, and
they can't take me to the Moon in any case, but "only attainable by rocket"
is a canard even for the tighter 20 minute figure over 3000 km.
--
What you own is your own kingdom, what you do is your own glory.
What you love is your own power, and what you live is your own story.
-- Neil Peart, 1976
Donald Qualls, aka The Silent Observer
Lathe Building Pages http://silent1.home.netcom.com/HomebuiltLathe.htm
Speedway 7x12 Lathe Pages http://silent1.home.netcom.com/my7x12.htm
Opinions expressed are my own -- take them for what they're worth
and don't expect them to be perfect.
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