86Klbs.... Sustainer thrust
needed 100 lbs at 9% duty cycle...
Or
0.01%
That's nice and low....
So for a 75lb average thrust on the tiny state one would need
0.008 lb thrust.
Given cold gas ISP of 70
That would be
0.000112 lbs of nitrogen...
Or
3.21cc more presurant tank at 200 psi
That works...
On Thu, Feb 25, 2016 at 7:48 PM, Henry Spencer <hspencer@xxxxxxxxxxxxx>
wrote:
On Thu, 25 Feb 2016, Paul Breed wrote:
With a long thin single tube rocket using 2 axis gimbals Does anyone have
any references or guidance on how much performance/delta V one should
budget for roll control in vacuum?
Much will depend on possible stray torques etc...
One data point: Atlas II (refined classical Atlas with vernier engines
deleted) used a little hydrazine thruster pack for roll control during
sustainer burn, about 120s long. The thruster pack had two 50lbf thrusters
firing in each direction (for redundancy; one would suffice), flight duty
cycle 5-9%, total fuel use 5-10lb, to limit roll angle to 3-4deg and roll
rate to 5deg/s. (Source: an old paper from GD.)
Henry