[NRV Rocketry] LADEE Question (for VT Aerospace guys?)

[Thomas Weeks]

If this is the same technology, then it seems they did indeed use a thrust 
vectoring control system:
	http://brahmand.com/news/ATK-debuts-new-Thrust-Vector-Electronic-
Control-System/8545/1/14.html

"ATK's STAR 48BV incorporates a flexseal nozzle and innovative thrust vector 
electronic control system (TVECS) that provides added maneuverability and 
mission flexibility to the payload. It is designed for use where precise 
flight profiles are required, such as during satellite orbit insertion. 
...
The next flight of ATK's STAR 48BV motor will be on the NASA Lunar Atmosphere 
and Dust Environment Explorer (LADEE) mission, as the fourth stage for 
Orbital's Minotaur V launch vehicle."

Ahhh.. this info:
	https://en.wikipedia.org/wiki/Minotaur_V#Design

seems to indicate that they have two Minotaur V stabilizing systems. One has a 
spin stabilized version and the other a vectored thrust version. :) 

Watching this Antares launch from earlier this year is pretty interesting:
http://www.youtubeskip.com/watch?v=HSnOTaCeSuk

though they don't show the nozzle section during the initial stage of the 
flight.

Tweeks

> Definitely not an expert, but here's my attempt since you included VT
> Aerospace guys in general. :-)
> 
> I can't speak for solid boosters, but on the liquids I've interacted with
> there are hydraulic struts (controlled with some of either the LOx or the
> RP-1 fuel in that case, can't remember which one) to gimbal the engine;
> I'd imagine something vaguely similar with a solid nozzle, just shoving it
> around here and there. Although obviously they wouldn't be able to rely on
> fuel to operate it...
> 
> As for varying thrust, you're right that solids are either "on or off," but
> from what I understand the internal "shape" of the solid fuel can be
> varied to alter burn rates--sounds like they did this in the Space Shuttle
> SRBs to account for different loading cases along the flight profile.
> Something about 11-point stars and truncated cones... See here:
> http://en.wikipedia.org/wiki/Space_Shuttle_Solid_Rocket_Booster#Propellant
> 
> Anyway, just my 2 cents... Anyone else feel free to chime in with more
> accurate/correct details.
> 
> Brandon Smith
> 
> Sent from my mobile. Please forgive any typos.
> 
> On Sep 8, 2013, at 12:32 AM, Thomas Weeks <tweeksjunk2 at theweeks.org> wrote:
> > BTW...
> > 
> > > Hey Dr. S, or other VT Aerospace Guys..
> > > 
> > > So I've been watching LADEE footage from the launch last night and was
> > > just wondering.. how do they stabilize large rockets like LADEE that
> > > obviously have zero visible fins? Ballistically (if it flew passively)
> > > it should go end over end.. no?
> > 
> > Here's the photo I was staring at when I posed these questions:
> > http://www.nasa.gov/content/ladee-launches-from-nasa-wallops/
> > The boosters sections look as smooth as a Sono-Tube(tm).
> > Just made me start wondering...
> > Tweeks
> > 
> > > Are there ANY control surfaces on the LADEE boosters? I imagine they
> > > would have to either use some sort of active vectored thrust, control
> > > surfaces, or spin stabilization to keep it pointed up... no?
> > > 
> > > And what about controlling the % thrust? They're using solid propulsion
> > > motors (sort of like our HP ACP motors)... which are usually either
> > > 100% on or burned out/off right? Do they have some sort of burn-rate
> > > or oxidizer flow rate controls in their motors too?
> > > 
> > > Hmm..
> > > 
> > > Tweeks
> > 
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