Space access: BDBs befobeanstalks?

If carbon nanotubes were to become available in commercial quantities,
then they could be used to make better BDBs, too.

Remember Beal Aerospace? (c.f., http://www.bealaerospace.com/). Each
stage was constructed as a spun composite casing. Presumably, good
carbon nanotubes would do wonders for such casings, allowing for higher
tank pressures in such a pressure-fed system (equating to higher
performance).

There might come a time when carbon nanotube technology has progressed
greatly, but when nonetheless the bulk material properties have not
progressed far enough to enable an Earth-to-GEO space elevator. If there
were such a period of time, then that might be the sweet spot for other
less-strenuous applications of carbon nanotube technology, including
perhaps BDB propellant tanks.

Ron
*******

Lucio de Souza Coelho
04/01/02 10:48 AM
Please respond to spacesettlers

To:
cc:
Subject: Re: [spacesettlers] Space access: BDBs before beanstalks?

From: "John Frazer"
To:
Sent: Thursday, March 28, 2002 9:50 PM
Subject: [spacesettlers] Space access: BDBs before beanstalks?

...
> Fairly straightforward development of Big Dumb Boosters from presently
known
> rockets would get access to asteroids far more readily than we could get
> self-assembling planetary scale structures from materials which are
> presently only laboratory curiosities.
>

I would not say that carbon nanotubes "are presently only laboratory
curiosities", there are practical commercial applications on the way at
least when it comes to electronics. Also, I see no problem in the
"planetary
scale" of the cable by itself: linear structures thousands of kilometers
long are a common place in human civilization since the 19th Century. (Or
even earlier, if you count the Great Wall.)

Anyway, I also think that BDB's will come first than space elevators. The
most optimistic prognostics for space elevators put them 10-15 years in
the
future. BDBs, on the other hand, could conceivably be up and flying in a
few
years. I believe that development of space tourism in the next ten years
will push the development of BDBs and/or reusable launch vehicles. But I
also believe that the further step in space transportation will be the
beanstalk.

[snikt]
Lucio Coelho