Re: starship-design: YES, we might do it.

[KellySt@aol.com]

In a message dated 10/8/98 8:45:51 AM, ajcrowlx2@ozemail.com.au wrote:

>Hi Group,
>
>David Levine wrote:
>
>>  So, let's say the definition is simple: a manned
>> mission that travels to the very closest star system, Proxima Centauri,
>> within the working lifetime of the crew (i.e. they are physically
>> capable crew when the mission starts and when the mission arrives).  I
>> don't even care about the return trip just yet (we can get to that
>> next).  Will it be possible or not?
>>
>> My gut instinct tells me "yes", but at a dramatic cost.  What does
>> everyone else think?
>> ------------------------------------------------------
>> David Levine                        david@playlink.com
>> Director of Development       http://www.playlink.com/
>> PlayLink                                (212) 387-8200
>> Professional Driver.  Closed Track.  Do not attempt.
>
>Possible, yes. Happening, probably not. I seriously doubt we'll be launching
>Outer Planet missions by then, let alone interstellar flights. Some Orbital
>Cities might be up and running, while Mars colonisation might be starting to
>pick up leading to terraforming tests. I'm being pessimistic, but given the
>current state of space who can blame me?

A lot depends on local space industry, tourism being the biggy.  Space is not
geting chep enough technically so serious tourist and trans atmospheric
military missions are being considered.  If that drive enough of a market to
drop costs to orbit down by a factor of few hundred (doable with current
tech), then far more expansive space ops get reasonable.

Oh, personally - I'm real dubious about Mars colonization.  A chemically toxic
planet with high rad and low G is not a great realestate value.


>I'd really like to see Stephen Baxter's Saturn mission. See his book
>"Titan". It'd be a great way to use all that 1960s and 70s tech that is rust
>arounding the US.
>
>I could be wrong, if someone develops an inertialess drive. And vacuum
>energy tapping.
>
>But since this is an engineering exercise I'm willing to go along with it.
>Just how far ahead can we imagine?
>Tech-wise I mean.
>
>Another point is how willing we are to invoke antimatter, but just how much
>energy can it realistically produce in a rocket jet? I've heard estimates of
>only 1 - 2 %. That'd be fine [better than fusion], but we'd need to make the
>stuff in massive quantities. Ultra-high energy density lasers are becoming
>possible, so some sort of direct conversion system might yet happen in the
>near term. Anti-matter would be great for Sol space travel in smallish
>quantities even. For IS flight, I'm not so sure.

Big problem is holding the stuff stables for years in major quantities.  Also
I'm not sure if we could hold enough of it in a light enough tank.  I mean it
would be silly to replace a thousand tons of fusion fuel for a quarter ton of
anti-mater in a 3000 ton containment chamber.

Also the radiatino levels are real bad.

Kelly


>
>Pardon my ignore but what's VASIMR?
>
>Adam