PARIS acquires visual tracking capability

Long focal length telescope + piggyback camera

You can piggyback a camera onto the top of the telescope. This is pretty common, you use a big telescope for astrophotography and a second smaller scope strapped to the top with a webcam attached - if you're taking a 30 minute exposure, even an expensive motorised scope will drift slightly off target, you can correct it using the webcam view.

Note that you might need a bigger mount mind. And a second scope, one for visual tracking and one for the camera.

Am I missing something?

"capturing an A4 sheet of cardboard from 23,000 metres was a big ask, but it's hats off to Alejandro for this view."

If you were looking for an A4 sized target against wall to wall blue sky it would surely be harder than finding a big pile of pipes first and then locating the target against them.

I'm not worried about Google surveillance anymore...

...but I'm now seriously concerned that Lester has access to a telescope.

[drawing the curtains]

Simple Baloon Release Mechanism

This is probably in the wrong area, but the proper one was closed.. An idea for a more simple, less mechanical, possibly more reliable release mechanism. A baloon in a clear glass or plastic tube, open to the atmosphere, a valve in the inflating end to pressurize, the baloon painted black at the other end to block light from an LED to a light sensor. When the baloon expands linearly along the tube to block the light path through or just outside the tube, it would cause an electro-magnetic latch to release the package. It would take some experimenting and calibration to find the proper size tube and baloon, and amount of pressure to make it work reliably... but, certainly more simple and less mechanical, possibly smaller and lighter, too.

Need lasers

This is just not going to work. A better way might be to attach a "corner cube" reflector and track it by aiming a wide beam laser at it. The corner cube will always return a signal in the exact opposite of the direction it receives it, so you can "ping" it with a broad beam and it will always ping back with a tightly focused beam. This method is is used on scientific experiments like the Lunar Laser Ranging Reflector from the Apollo missions, you can put corner cubes on the moon, ping it from earth, and get a signal return from 240k miles.

See, I can have good ideas sometimes.

From the last installment:

"Last but not least, I hope you can get a couple of nice telescopes to film this thing through. That or let any commentards know where and when with enough notice that they can bring theirs. This is daftness on a scale of painting a Robin Reliant up as a radio-controlled space shuttle and sending it heavenward on the most powerful non-commercial rocket built in Europe. It'd be a shame to not have a video of the fun."

Thanks for listening. ;)

I'm impressed he found the target...

...although that big red arrow must have made it easier.

Altitude release

A GPS indicates altitude, could you not use this signal for the release?

To those suggesting alternate release mechanisms

One of the stated objectives was that the release mechanism be as purely mechanical as possible.