a little video of an experiment I designed and developed

[Samudra Haque]

Ah. A good question W4KRL. The Cathode terminal of the thruster itself is
the consumable propellant (i.e., it eats itself during regular operation).
The Anode is fixed through a center screw in this model. But other models
have: (polarity switching terminals - Alternating Electrodes) and (multiple
cathodes - Bi-modal Electrodes). This version was called Coaxial Electrode
for obvious reason. Earlier we had a more difficult Ring Electrode
configuration.

I'm afraid, I can only describe in detail the thruster subsystem I designed
for an AMRAD presentation (or AMSAT?), but not the Phonesat. The nearest I
got to hold the puppy was to interface with its brains, the Google Nexus
Smartphone, but I have looked at the extremely precise cad model they used
to verify size/weight etc. The three phonesat systems reached orbit atop
antares1, and the next generation of phonesats will be part of EDSN
missions, I have been told.

I designed the system to be generic in interfaces, so I could fly with any
other small sat, if one were to look for propulsion capability on any
mission. These things can be massaged to produce 1-50 uNs of impulse-bit
thrust per channel, at least that is what I worked on, but I think the
upper limit is much higher as the system should get more efficient when the
cathode is heated up. The following picture may be not interesting to some
(you all have experience in this), but at least it shows the full subsystem
without connections to the thruster heads. (c) Samudra Haque, 2013.

Anyone attending IEPC 2013 (GWU) or any other space conference where we can
make contact with mission designers?

Lastly, in atmosphere, the spark is intense steely-blue, with sound. In
vacuum, obviously, no sound, and the plasma plume becomes long, deep
ultra-violet, but the duration is very brief, in this early model: 100
uS-250 uS.

//Samudra N3RDX

[image: Inline image 1]


On Thu, Sep 5, 2013 at 1:58 PM, Karl W4KRL <W4KRL at arrl.net> wrote:

> Samudra,****
>
> ** **
>
> Do the thrusters in your lab setup actually consume cathode material? How
> are they affected by atmosphere compared with vacuum?****
>
> ** **
>
> Seems like you should make a presentation to AMRAD on the PhoneSat bus!***
> *
>
> ** **
>
> 73 Karl W4KRL****
>
> ** **
>
> *From:* Samudra Haque [mailto:samudra.haque at gmail.com]
> *Sent:* Wednesday, September 04, 2013 2:02 PM
> *To:* Tacos
> *Subject:* a little video of an experiment I designed and developed****
>
> ** **
>
> Hi Amrad community. My GWU "microthruster" experiment for NASA has
> concluded recently, with good results. Here is a video that shows the first
> firing of a micro-cathode arc thruster subsystem that was eventually
> integrated with a PhoneSat smartphone bus, at Ames Research Center last
> month. ****
>
> ** **
>
> Some of you may remember I had started work on the microprocessor control
> system in 2011 and 2012, and now all of that work has been rolled into a
> complete subsystem where the triggers are generated by embedded software,
> and result in actual thrust impulse-bits.****
>
> ** **
>
>
> https://docs.google.com/file/d/0BzYYl-b0DOFWZ1U0RFBYdU93NW8/edit?usp=sharing
> ****
>
> ** **
>
> ** **
>
> I'd be happy to hear from the experienced designers out there, the next
> version of this system is going to have to be very small in form factor for
> fitting in a cubesat.****
>
> ** **
>
> //samudra****
>
> _______________________________________________
> Tacos mailing list
> Tacos at amrad.org
> https://amrad.org/mailman/listinfo/tacos
>
>
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