[AR] Re: Regarding Univerity solid rockets for cube-sat launch to orbit
- From: Henry Vanderbilt <hvanderbilt@xxxxxxxxxxxxxx>
- To: arocket@xxxxxxxxxxxxx
- Date: Sat, 3 Mar 2018 13:48:58 -0700
On 3/3/2018 12:54 PM, Henry Spencer wrote:
On Sat, 3 Mar 2018, Henry Vanderbilt wrote:
...and via liquid thrust vector control, where small amounts of a
liquid propellant are injected into fixed nozzles around the periphery
of the main engine exhaust to steer the overall exhaust direction.
Titan 4 used this last on its large solid strapons, for just one example.
Small correction: Titan III. One of the changes made for Titan IV, in
fact, was development of new improved SRBs, whose changes included
gimbaled nozzles instead of LITVC. (The first few Titan IVs flew with
the old SRBs because the new ones ran late, not least because the first
test ended early with a spectacular explosion.) The Titan III LITVC
system had been a constant ops headache, because its valves had a
tendency to leak, and when the fluid leaking would be N2O4, that forced
elaborate precautions for any pad operations after the N2O4 tanks were
filled.
Small correction to the small correction <grin> Indeed, the Titan IV A
had the old 7-segment SRM, with liquid injection TVC. The IV B had the
new upgraded 3-segment SRMU with gimballed nozzles. And yes, I'd
forgotten about the new SRMU etc, as I mainly paid attention to Titan IV
in the aftermath of Challenger, and the IV B didn't fly till 1997.
As, apparently, the new gimballed-nozzle SRMU took a while to come
online. The first 19 Titan IV launches, and 22 of 39 overall (at least
counting from the wikipedia list) were IV A types with the old SRM's
with the fluid-injection TVC.
So, not just the first few. The first seven years of launches, and a
modest majority of T IV launches overall, were as I recalled, the liquid
TVC variant with the big TVC fluid tank hanging off one side.
Henry
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