canopus

In the OS/2 2.x days my primary means of interacting with other OS/2 folks was the Canopus (Wil Zachman) forum on Compuserve (75060,264 checking in).

The Voyager Neptune Travel Guide mentions things like the Canopus Star Tracker and the Sun Sensor.

Jupiter, Venus, Sirius and, at the very limit, even Canopus are visible with the naked eye during the day.

The Sun is the brightest star and Canopus is the third brightest star (Sirius presumably is not in an appropriate position to be detected), so you don't really need a proper star tracker, you just need a brightness sensor.

I worked as a graphics driver programmer for Canopus in the nineties primarily customizing graphics drivers for Rendition (Verite), Nvidia (Riva128 TNT) and 3Dfx boards (Voodoo1 and Voodoo2).

There's a bunch of publicly available documentation about how the Canopus star tracker on the Voyager probes works out there, last I looked, and it's quite an interesting design by modern standards.

I was playing around with building retro game VMs with qemu and pci passthrough awhile back and dusted off my old canopus pure 3d to try out with a pci to pcie adapter board.

It was already known to scholars that the length of a (tropical) year is close to 365-and-a-quarter days since at least 238 BC (when Ptolemy III tried to fix the length of the year in the Egyptian calender to 365-and-a-quarter days in the Canopus Decree).

All in the space of a year or so, I somehow managed to convince them to buy me a Canopus Pure3D video card (3dfx Voodoo but with 4 MB texture memory), a big ergonomic keyboard, a Sidewinder joypad, and Tomb Raider.

Simplest implementation of star trackers I've seen is the Canopus sensor[1] used in old spin stabilized satellites: the "tracker" is just a light intensity sensor and a computer on a spinning spacecraft.

Even the Voyager probes had the ability to orient themselves relative to the Sun, Earth, and the star Canopus.

One calculation (75 BC) used the angle of Canopus, which was conveniently near the horizon.

Software Rendering -> 3dfx (Canopus Pure3D): Transparent water surfaces in Quake (if you re-vis'd the maps), smooth and fluid visuals, it was amazing.