RV-9A platform for airbone Quantum Key Distribution experiment!

My academic background and current work is related to quantum cryptography. I've bee involved with a proposal underway with the Canadian Space Agency for a satellite-based Quantum Key Distribution (QKD) demonstration mission. The technical leads on this experiment are the folks from the academic research institute where I did my PhD, the Institute for Quantum Computing (IQC) (https://uwaterloo.ca/institute-for-quantum-computing/). One of the things they have been wanting to do is an airborne QKD experiment, between an aircraft and a ground station. I have begun discussions with them about the possibility of using my RV-9A. The weight and size requirements are certainly well within what could be installed in the baggage area. The idea is that the ground station would send weak laser pulses to the aircraft, which would be captured by an onboard telescope, and processed by some onboard optics gear (with an additional RF channel for classical parameters to be sent in the clear). The main questions at this point are whether the canopy would provide enough optical clarity, and whether the telescope can be sufficiently isolated from aircraft vibration.
I wanted to put this thread out there, because going-forward I may be looking to this group for ideas about how best to configure and install a mounting setup for the equipment in the aircraft.
I'll update this thread in the weeks/months ahead as this project gets underway - I'd appreciate any suggestions or ideas, or relevant experience that any of you may be able to offer me. I'm quite excited about this project, which brings together two of my interests (flying and quantum technologies).
I'm not certain, but I think this might be the first time QKD to an aircraft has ever been done.

Hi Phil.

KLN Klein of Langley, BC provides exactly the type of isolation mounts for aircraft that you are looking for.

Peter Klein is also an aircraft builder/designer.

See http://www.klnklein.com/proj13.html

prkaye said:

....and whether the telescope can be sufficiently isolated from aircraft vibration.....

Click to expand...

It certainly can, but I'd recommend an engineered solution that's designed for the weight and mass moment of inertia of the telescope assembly.

Dave

So I've been having discussions with the researchers about the best way to mount the telescope. The thing is huge... total about 21cm diameter and about 102cm long.

Pointing through the canopy is a non-starter... plexi messes up polarization which is relevant parameter.

Ideally they want it pointed between 20 and 45 degrees below the horizon. If I mount the telescope vertically (pointing straight down with respect to the airframe), this would point roughly 44 degrees below the horizon in a 45 degree banked turn (accounting for horizon being about 1 degree below horizontal). Extended 45-degree bank orbit during the experiment seems doable. Sustained 60 degree (2G) might be less comfortable.

So to mount the telescope, here's the best I have come up with. Remove the baggage compartment floor, and cut a 21cm access panel in the belly skin for the telescope to point through, directly down. We'll have to design and fabricate mounting rigs for everything, but they have a machine shop at the university.
Next questions we need to figure out is how precise the flight path and aircraft attitude need to be. Some slop can be compensated with motors that move the telescope, and some smaller spotter scope they have attached to the main scope. An RV is not a precision instrument, however (at least in my hands), so we'll have to figure out a way to determine if we'll be able to get thing pointed in the right direction with sufficient accuracy for this to work at all. Discussions ongoing... i'll post updates on here for anybody who is interested.
On the one hand I am loathe to cut a hole in my plane, but on the other hand it would be in the belly, so not a big deal aesthetically, and it is a pretty cool opportunity.

Telescope

The anti vibration mount would have to be altered if you point telescope out the belly. 45*constant bank might not be fun after a short period.
Here is an idea. Create (fabricate) a photo window in the rear baggage plexi that opens to point telescope thru at a 45* angle. This also allows anti vibration unit to be used. With tele at constant 45* angle, you fly level for a much nicer ride and you can close the photo window when you are done. Take a close look at a Civil Air Patrol airplane with a photo window in the back seat behind the pilot for a sample. When closed, they are airtight. Hinged with one turn knob to open.
Sounds like a fun experiment.
Pat Garboden
Katy, TX
RV9A. N942PT

Or, you could make it more complicated and use a mirror to target the ground station...fix the scope, and use the mirror for pointing.

(ETA: You could sniff the stream from the ADAHRS, if you have one, to get attitude, direction vector, position, etc., then just run the math through a control loop to adjust the mirror so that the scope "sees" the ground station at all times...not technically hard, just more stuff to design in like servos, control loops, etc.).

It sounds like you need a Breezy!

Sounds like a good excuse to get an RV10 and a belly pod!