Well yes, I have tried it! lol The sensors were back in the fuselage
about 5mm and that must have blocked the exhaust plume (so I don't
actually know if it would have seen it or not. I have the data though
and it could be extrapolated from it). They are also well below the
nosecone. It flew on a Q impulse to 65kft and yes it survived the
transonic and supersonic flight. I'll dig up some info and photos. I
have the launch video I know. I broke out of the 60kft target because of
a slight miscalculation on the recovery system timing. You could say I
missed it by nearly a mile. lol
Funny how when I did the launch nobody cared to hear about it.
I have not finished the code that would have allowed me to use the
Ardupilot I wanted to use the Pixhawk but the software was never
finished.
I'm hoping someday to pick that ball back up.
Right now though I had to take on a 5-Axis machine project to get
funding to continue making progress. I designed the 5-Axis machine
specifically to make turbopump impellers. But the funding came from a
guy interested in selling the machine.
We have a great little machine shop now and I'm looking forward to
presenting the machine and some impeller prototypes at Space Access
2019.
After we get back from Space Access I hope to start testing pumps.
I've been completely serious the entire time you guys have known me.
The really cool thing about Ardupilot is it allows for a robust ground
station and simulation in X-Plane of the entire flight. Tracking and
telemetry.
I need to get back with Satnogs and help those guys distribute their
network.
And there is just tons of other crap to do.
I'm still doing most of this alone because I can't afford to hire anyone
and of course guys that don't get paid come and go.
But Team Prometheus is still going at it.
So yeah I'll get you what I've got on the little guidance thingy. I have
to go dig that stuff out because it's been years now since then. But
I've got stuff on it. I'm not going to stop everything I'm doing just to
prove this point. But I'll get it out there soon enough for you.
I don't really remember how I did that exactly (if not exactly as I sad
it's very close to it) but it's still here and it still works so I'll
just show it to you. Maybe I'll bring all that stuff to Space Access
anyways. Maybe now someone might want to see it.
That Ir guidance thing is simple as it gets though and it works great!
It's so cheap and easy I think everyone that wants to go straight up
should use it.
So now you want to hear about it? lol
Monroe
-------- Original Message --------
Subject: [AR] Re: Spin stabilized rocket
From: Henry Spencer <hspencer@xxxxxxxxxxxxx>
Date: Mon, December 24, 2018 6:58 pm
To: Arocket List <arocket@xxxxxxxxxxxxx>
On Mon, 24 Dec 2018, Monroe L. King Jr. wrote:
I'll add one more thing active guidance is very easy with infrared
detection. This stupid simple device is all you really need if straight
up is what you want. http://www.revolectrix.com/cpd4_description_tab.htm
Have you actually tried it? How high and how fast?
The description of how it tells the difference between ground and air is a
little vague, and I wonder how well it will work when the air gets really
thin. (The Earth fills *nearly* a full hemisphere even in LEO, so that's
not likely to be an issue with the relatively wide beams described, but if
they're relying on the atmosphere's CO2 as they imply, what happens when
there's not much CO2 to be seen?) Of course, if you're done accelerating
by that time, it may be a lesser issue.
As for "how fast", apart from the issue Derek mentioned -- aerodynamic
heating on the sensor and the problems of having it looking through
ports/windows -- I suspect that its thermal-based sensing could run into
problems when velocity gets high enough that the boundary layer right in
front of the sensors gets hot.
(Also, if you're still thrusting at high altitude, wide-beam sensors
looking sideways may start seeing your own exhaust plume. Or even having
their windows crudded up by your exhaust plume -- a problem seen on
spacecraft windows on both Mercury and Gemini.)
Definitely very promising for low and slow; for high and fast, I'd want to
see flight-test data before putting full trust in it.
No gyros no accelerometers no gps no nothing.
In practice, I think you'd want a rate sensor to limit roll rate -- any
attempt at pitch/yaw steering is going to have a maximum roll rate that it
can cope with, after which it will go bananas. (Although if hardware
details permit and control operation isn't required at high altitude,
Sidewinder-style rollerons might suffice; that's exactly what they were
for, limiting roll rate to keep pitch/yaw control stable.) Intuitively
speaking, the change in roll angle during the delay between pitch/yaw
sensor input and actuator output needs to be small, so that the axis
around which the actuator is inducing torque is still nearly the same as
the axis around which the sensor measured attitude error.
Henry