[net.space] space plane

jrv@MITRE-BEDFORD.ARPA (James R. Van Zandt) (02/23/86)

I've heard that the new "space plane" is supposed to get things into
low earth orbit at 1% of the cost of the shuttle.  Are there good reasons
for that, or is it just hype from aerospace marketing types?
                                - Jim Van Zandt

al@vger.UUCP ( Informatix) (02/25/86)

In article <8602231253.AA23756@mitre-bedford.ARPA>, jrv@MITRE-BEDFORD.ARPA (James R. Van Zandt) writes:
> I've heard that the new "space plane" is supposed to get things into
> low earth orbit at 1% of the cost of the shuttle.  Are there good reasons
> for that, or is it just hype from aerospace marketing types?

The fundamental reason is that the proposed engines (scramjets) use the
atmosphere for oxygen.  Since oxygen accounts for 8/9ths of the weight of
hydrogen/oxygen fuel, there is a dramtic weight savings (I think the
shuttle tank holds 600 TONS of oxygen - the orbiter weighs about 200 tons).
I don't know the details
of the cost estimation, but if scramjets can be made into practical
devices we should see a large decrease in cost to orbit.

henry@utzoo.UUCP (Henry Spencer) (02/26/86)

> I've heard that the new "space plane" is supposed to get things into
> low earth orbit at 1% of the cost of the shuttle.  Are there good reasons
> for that, or is it just hype from aerospace marketing types?

It is a reasonable claim, although it would be comforting to see a prototype
flying to confirm it.  Full reusability plus less-strained engines would go
a long way toward lowering costs.  Even the present Shuttle would look a lot
better if it had fully-reusable liquid-fuel boosters and carried the external
tank into orbit for some sort of productive use there.  (If you count the
tank as payload, the Shuttle is suddenly carrying a lot more payload into
orbit.)
-- 
				Henry Spencer @ U of Toronto Zoology
				{allegra,ihnp4,linus,decvax}!utzoo!henry

mcgeer%ji@UCBVAX.BERKELEY.EDU (Rick McGeer) (03/04/86)

>> I've heard that the new "space plane" is supposed to get things into
>> low earth orbit at 1% of the cost of the shuttle.  Are there good reasons
>> for that, or is it just hype from aerospace marketing types?
>It is a reasonable claim, although it would be comforting to see a prototype
>flying to confirm it.  Full reusability plus less-strained engines would go
>a long way toward lowering costs.  Even the present Shuttle would look a lot
>better if it had fully-reusable liquid-fuel boosters and carried the external
>tank into orbit for some sort of productive use there.  (If you count the
>tank as payload, the Shuttle is suddenly carrying a lot more payload into
>orbit.)
>-- 
>				Henry Spencer @ U of Toronto Zoology
>				{allegra,ihnp4,linus,decvax}!utzoo!henry
>

I hope so, too, Henry, but as Robert Truax points out: "the TAV is going to be
a combination of the Space Shuttle and the Concorde, and there's no way
that *that's* going to be cheap".

Well, Truax has an axe to grind,  Let's hope he's wrong.

					-- Rick.

henry@UTZOO.UUCP (03/07/86)

> ...as Robert Truax points out: "the TAV is going to be a combination of the
> Space Shuttle and the Concorde, and there's no way that *that's* going to
> be cheap". ... Well, Truax has an axe to grind,  Let's hope he's wrong.

Alas, he may well be right.  I would be a lot happier about the TAV if it
was being done by private industry.  My money right now is on Gary Hudson.

Concorde, by the way, would probably have been a financial success (or at
least only mildly unsuccessful) if all those options had turned into orders.
The current transatlantic services generally make a (small) profit, if you
discount the high costs of maintaining such a small fleet.

				Henry Spencer @ U of Toronto Zoology
				{allegra,ihnp4,linus,decvax}!utzoo!henry