Re: More Space Elevator news

From: Pete Lynn (pete_at_peterlynnkites.com)
Date: 07/08/04 

Date: Thu, 8 Jul 2004 12:10:13 +1200

"John Schilling" <schillin@spock.usc.edu> wrote in message
news:cchjvi$mte$1@spock.usc.edu...
>
> Are you seriously claiming that transportation to LEO by rocket is
> likely to be *an order of magnitude cheaper* than transportation to
> GEO by beanstalk, presuming the existence of a practical
> beanstalk?

Yes. If you do not believe me, just work out the comparative energy
costs and drymass fractions, with the emphasis on the latter. A mature
rocket launch industry will quickly approach around $20/kg to LEO,
(based on fuel cost and aircraft type operation). With rotating tethers
of the same performance yet around a hundredth the weight, cost and
difficulty of your beanstalk, perhaps only a few dollars.

> Because that is the core assumption of the discussion, that a space
> elevator does exist and does provide low-cost transportation
> service to GEO and only to GEO. It's not an assumption I would
> bet on in the near term, for several reasons, but if it does come to
> pass it is likely to be the biggest, cheapest game in town and to
> displace most of the alternatives.

That sounds very much like what the shuttle was going to be. Biggest
yes, but cheapest? Do you think Beanstalk CNT will be orders of
magnitude cheaper than rocket drymass?

> The assumption that a space elevator will exist, and provide
> commercial transportation services to GEO, but that rockets will be
> providing *cheaper* transportation to LEO, that I'd bet seriously
> against, ever.

Work the numbers.

> Given a beanstalk, GEO is the cheapest and most accessible
> offworld destination, even if someone else is still running a rocket
> service for what niche applications actually call for it.

Given the shuttle...

This sounds somewhat like the public verse private transport debate.
Somehow I expect rockets will be niche applications in the same way cars
are.

Pete.

Relevant Pages

  • Re: More Space Elevator news
    ... >> GEO by beanstalk, presuming the existence of a practical ... >rocket launch industry will quickly approach around $20/kg to LEO, ... >(based on fuel cost and aircraft type operation). ... >> service to GEO and only to GEO. ...
    (sci.space.policy)
  • Re: More Space Elevator news
    ... A space elevator human cargo pod will I expect have ... climber wheels going much faster than this in the short term. ... > time you have passenger-carrying intercontinental rocket planes, ... > $100K rocketplane seat to save them a week on the beanstalk. ...
    (sci.space.policy)
  • Re: Cool beanstalk side benefit
    ... > radiactive waste by shooting into the sun via a rocket. ... But aha, with a beanstalk, we winch it up past the center ... If we don't find a use then you threw away useful ballast mass. ...
    (sci.space.policy)
  • Re: More Space Elevator news
    ... >> people have to get to GEO by another route. ... To hop off at LEO, ... Space elevator to GEO: you ascend to GEO, and step outside, ... large rocket and lots of fuel, rocket off around the moon to ...
    (sci.space.policy)
  • Re: the drive to explore
    ... >>>Transportation is transportation, but there is transportation and then ... That is the distance of about 5 orbits. ... Throwing a rocket away after ... >one use isn't like throwing a car away after going to the store. ...
    (sci.space.policy)