I don't know about gimballing, but I do think it makes sense to put their already-developed 4-engine system and their already-developed jet vane system together and just be done with major development work.
Cheers, Roger -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Russell McMahon Sent: Tuesday, June 08, 2004 2:02 PM To: ERPS list Cc: John Carmack Subject: Re: Multiple engines (was RE: [ERPS] Liquox) Not that I claim to know anything, but: I'm wondering if John is walking (or flying) the inevitable path to gimballing? Starting with multiple engines seemed really marvellous (and it was) but he found that jet vanes were immensely more satisfactory in practice. The first successful mass produced liquid fuelled rocket used jet vanes, but they have pretty much vanished from the medium to large sector and been replaced either by vectoring using fluid injection or by gimballing. What are the advantages of jet vanes over gimballing? Perhaps: - Less actuator force? - Quicker response? - Includes roll control? - Engine rigidly fixed to frame. - ??? Once you have gimballing implemented, the actual control aspects look like theyd be a dream compared to multiple engines or jet vanes. Longevity (measured in burn time) is preseumably less of a problem than jet vanes. Engineering deals in providing adequate force rather than thermomechanical considerations (vane ablation/survival, bearing/shaft life. ...). Reliability and safety would seem to be superuor - it does or doesn't work and as long as it can survive the (horrendous) vibration environment it keeps working. Thoughts? (may be from John?) Russell McMahon _______________________________________________ ERPS-list mailing list [EMAIL PROTECTED] http://lists.erps.org/mailman/listinfo/erps-list _______________________________________________ ERPS-list mailing list [EMAIL PROTECTED] http://lists.erps.org/mailman/listinfo/erps-list
