Bruce Watson (wats@scicom) Tumbra, Zorkovick; Sparkula zoom krackadomando.
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Date: 23 Aug 92 23:00:32 GMT
From: Henry Spencer <henry@zoo.toronto.edu>
Subject: Saturn class (Was: SPS feasibility and other space
Newsgroups: sci.space
In article <19AUG199220200286@judy.uh.edu> wingo%cspara.decnet@Fedex.Msfc.Nasa.Gov writes:
>>> There
>>> is a demonstrated need for larger lift capability.
>>
>>Sure, I believe you. I'm curious to know: what is the demonstrated
>>need? How is it demonstrated?
>
>... Look at the growth in size of geosync communications satellites.
>Ariannispace has and that is the basline for the growth into the Arianne 5...
Ariane's numbers on the subject are somewhat controversial, since some of
the organizations involved might be considered to have ulterior motives
(making A5 big enough for Hermes). Even setting that aside, though, we're
talking about slow incremental growth of existing boosters, the sort of
thing that is accomplished most cost-effectively by tank stretches and
more/bigger strap-ons. This is especially so when you bear in mind that the
comsat suppliers and customers are far more concerned about reliability
than cost -- as well they should be when the birds cost much more than the
launches -- and they see upgrades to an existing system as less risky.
At the moment, there is *one* firm customer that appears to really need
larger lift capability than is now available: NASA's space-station office.
Possibly I exaggerate when I call them a "firm" customer, mind you, although
their political backing appears more solid now than it used to be. In any
case, they are very heavily hemmed in by politics, and also don't want very
many launches. They aren't a very promising "launch customer" for a new
vehicle.
Apart from them, there is *no* actually-rolling project, anywhere, that
has a firm need for more than incremental improvements to existing boosters.
If there were, there would be commercial interest. There have been several
commercial heavylift projects that needed only some committed customers to
justify proceeding with privately-funded development. None have appeared.
--
There is nothing wrong with making | Henry Spencer @ U of Toronto Zoology
mistakes, but... make *new* ones. -D.Sim| henry@zoo.toronto.edu utzoo!henry
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Date: Sat, 22 Aug 1992 16:00:52 GMT
From: Livy <jhsegal@wiscon.weizmann.ac.il>
Subject: Size,Mass,and velocity....
Newsgroups: sci.space
Hi.
Can anybody please email me the Mass(in kg),the Size (r in meters),and
the x and y velocity (m/s) of all the planets in the Solar System?
Thank you very much,
Livy
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Date: 22 Aug 92 19:02 PDT
From: Mark Goodman <mwgoodman@igc.apc.org>
Subject: Space Economics
Newsgroups: sci.space
To: sci.space
From: Mark Goodman (mwgoodman@igc.org)
Re: space economics
Date: 21 aug 1992
I want to raise a subject that I have not yet seen in sci.space.
It has to do with the economic value of space activities. I use commercial viability as the sign of economic value, though I recognize that this fails to account for "public goods" values like weather forecasting or the long-term (and unpredictable) value of R&D.
Much of the discussion here has dealt with human spaceflight and
solar power satellites, neither of which is close to to being