Robert Warden (original author of the paper "Cryogenic nano-actuator" (2006)[0]) did the first prototyping with Lego Technic [1]. From Lego to the JWST, I mean damn, like childhood dreams come true (:
I'm having a hard time understanding the axial motion from the coarse adjustment. From [0]: The Ball Screw in Figure 9 has a 21 mm range. As the ball screw nut moves up, the housing moves up too -- but then the two halves of the tumbler coupling get displaced in such a way that doesn't seem to support a 21mm displacement. How does the tumbler coupling stay mated? (I feel like I'm missing something obvious?)
I believe that everything in figure nine moves together vertically except the yellow/orange ball screw nut and pink horizontal thingie, these are fixed to the satellite.
The sensor and stabilizer on the right side are flexible.
Ball Aerospace, the manufacturer of the actual JWST actuators, traces its history to the Ball Corporation, of Ball Jar fame, which had relocated its manufacturing operations from Buffalo, NY, to Muncie, IN, following cheap fuel.
That move was made on account of the Indian Gas Boom, which ran from the 1880s through the early 20th century, when it was discovered that there were large reserves of readily-accessible natural gas to be found in Indiana in field generally centered around Muncie.
As with other natural resource extraction booms before and since, proponents argued that the resources were inexhaustible, that prospectors had freedom to use or waste the resource in any way they saw fit --- large natural torches called flambeaux were a frequent sight. Over 90% of the gas was ultimately wasted, vented to the atmosphere.
The boom died out in the first decade of the 20th century.
It appears that a star is used, while in space, with the laser being used as an artificial star. I only see this directly mentioned in the video (1:24), and indirectly in the text, "thus acting like a source of artificial starlight". I guess this makes sense, as it's the only way to do it "end-to-end" while in space.
There are actually two stages of calibration in space. The first stage is aligning the mirrors, using direct measurement of the mirror alignment with the interferometer, after they are unfolded from their unaligned stowed positions.
> To measure the shape of the Webb telescope’s primary mirror, engineers use a test device called an interferometer, which shines a laser down onto the mirror.
The next phase you’re referring to also uses a laser, but this time it’s shone off the mirrors into the actual scientific observation sensors, hence they describe it as being used as a source of artificial starlight.
On the ground, you can easily place a laser in an optically identical position as a star (near infinity). In space, I don't think this would be possible, since it would require that the laser, and the optics that would be required, would all be within a fraction of a wavelength of the true optical path. In the end, you would still need to align to a star anyways.
[0]https://www.esmats.eu/amspapers/pastpapers/pdfs/2006/warden....
[1]https://m.youtube.com/watch?v=3WBrqUa_1yk