RE: starship-design: Deceleration scheme

["L. Parker" <lparker@cacaphony.net>]

Jim,

>Sigh, I'm beginning not to like the sail concept as much.  It is simple
>and elegant, but between the deceleration problems, plus the difficulties
>of such mega-structure operation, and the power beam generation problems,
>I think the use of matter-antimatter and/or fusion ideas may be the
>ultimate best way to go.

The sail concept never has been a GREAT way to get there. It just offers 
the advantages of simplicity and efficiency. It is however, SLOW. At 
least it is if we are talking about relatively large manned missons. As 
a method for propelling light Starwisp type probes, it can get them up 
to relativistic velocities using only a few weeks worth of time from an 
orbital power array.

For manned missions we will need something that can provide much higher 
thrust over longer periods of time. Since you just recently joined the 
group you may have gotten the impression that one or more of us are proponents of sails. Actually, I don't think any of us expect them to be used for manned missions although we do continue to explore the possibilities.

There are too many things that can go wrong to depend upon a beam or fuel canisters from Earth for manned missions. The only thing left that we KNOW has sufficient thrust is antimatter, which we are far from sure we can generate and store in sufficient quantities.


Lee Parker

                                                          (o o)
------------------------------------------------------oOO--(_)--OOo---------
"This double nature of radiation (and of material corpuscles) is a major 
property of reality, which has been interpreted by quantum-mechanics in 
an ingenious and amazingly successful fashion. This interpretation, which 
is looked upon as essentially final by almost all contemporary physicists, 
appears to me as only a temporary way out."

Albert Einstein