From: vince@offshore.ai (Vincent Cate)
Newsgroups: sci.space.tech
Subject: Re: Unguided orbital insertion (cheap upper stages)
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Message-ID: <9186edb5.0311111736.6a47d1a9@posting.google.com>

Henry Spencer:
>[...]
>Finally, most prominently, Explorer 1 was put into orbit by an 
>unguided three-stage solid cluster lobbed up to orbital altitude 
>by a stretched Redstone.  In all three cases, the launcher was 
>guided, but the guidance system stayed behind after pointing and 
>spinning up the upper stage(s). 

Nice that 3 stages of spin stabilized solid rocket were demonstrated 
45 years ago.

They were spun up to something like 750 rpm.  Also they were high
G stages, like X-prize to orbit would probably be.  Payloads for 
this type of launch would have to be a bit more rugged than normal.

Some time back I called up a company that makes solid rocket engines 
for model rockets and they were happy to make reasonably large 
engines, big enough for this, using lightweight cases (most model 
rocket engine cases are relatively heavy) for a price.  Someone who 
can make a working X-prize vehicle should be able to purchase a 
couple solids (order of 150 Kg and 30 Kg) and make a spin stabilized
2nd and 3rd stage to get a small payload with a thruster into orbit.  
Fun fun fun.

   -- Vince