Newsgroups: sci.space
Path: utzoo!henry
From: henry@utzoo.uucp (Henry Spencer)
Subject: Re: Not-Frequently Asked Space Questions
Message-ID: <1990Jan18.220949.26398@utzoo.uucp>
Organization: U of Toronto Zoology
References: <9001162022.AA04346@gn.ecn.purdue.edu>
Date: Thu, 18 Jan 90 22:09:49 GMT

In article <9001162022.AA04346@gn.ecn.purdue.edu> hasara@GN.ECN.PURDUE.EDU (Andrew J Hasara) writes:
>WHO is working on this SSX "thingy"?

Max Hunter and some associates of his, and now, apparently, some SDI money.
It's not exactly a group of giant corporations yet.  Nobody is giving away
glossy brochures.

>What is an "aerospike" engine?  Who works on it?  Where can I get info on it?

Conventional rocket engines have bell-shaped nozzles.  Turn one of those
inside out, so the combustion chamber is a ring around the top of a tapering
spike.  Turns out it still works:  the gases coming out expand against the
spike and give much the same effect as a nozzle.  The spike is a structural
and thermal nuisance, however.  Chop it off short and blow some low-velocity
gas (e.g. turbopump exhaust) into the center, and the effect is much as if
the spike were still there.  That's an "aerospike".  The concept has had
little bits of attention from a lot of people since the mid-60s; check the
rocket-propulsion literature under "aerospike" and "plug nozzle".  Again,
nobody is giving away glossy brochures -- you'll have to go digging in a
good library.
-- 
1972: Saturn V #15 flight-ready|     Henry Spencer at U of Toronto Zoology
1990: birds nesting in engines | uunet!attcan!utzoo!henry henry@zoo.toronto.edu