Znamya Space Mirrors

[World B4]

This deserves its own thread, the Znamya program was a Russian attempt to repurpose solar sail research into a space mirror. It consisted of:
Znamya 1, tech demonstrator, remained on Earth for its testing
Znamya 2, subscale prototype, successfully flown on a Progress mission in 1993
Znamya 2.5, subscale prototype, failed to unfurl on a Progress mission in 1999
Znamya 3, final product. A 70 meter reflector, never built or assigned to a Progress
http://www.old.space-regatta.ru/inform-e.htmA rendition of the Znamya 2 fully unfurled, the commonly circulated photos show a partially unfurled reflector
https://www.researchgate.net/figure/Configuration-of-Znamya-2-8_fig2_320023749I've never seen any pictures of the Znamya 1 in its testing program, and I don't know to what extent the hardware involved in the sail or its manufacturing equipment was created/assembled specifically after the objective's pivot from propulsion to reflection.

 

[publiusr]

The largest reflector concept
http://www.astronautix.com/e/energiapolatyilluminator.html
That’s as close as humanity ever got to the German “Sun gun” BS.

They *might* be enough to where you could read a paper on a moonless night.

 

[Adler]

A Russian Sonnengewehr, how peculiar.

Anyway, here are some photos (see bottom of post for references/article links):




Links: (Both in Russian but just put them through a translator)
https://www.drive2.ru/c/456724486868175546/https://dzen.ru/a/Y2PNElcln3XhRhV9

 

[Grey Havoc]

Well, Russia experimented with orbital mirror concept in early 90s. The "Znamya" project (rus. "Banner") was centered around collapsible metal film reflector, deployed from "Progress" cargo ship after it detach from "Mir" station:


View attachment 722346
"Znamya-1" was deployed in February 1993. The 20-meter diameter reflector created a bright spot about 8 km in diameter on Earth, with luminosity of full moon.

The follow-up "Znamya-2.5" was planned to use larger (25 m diameter) concave reflector, stabilized by centrifugal force, and precisely controlled. The goal was to demonstrate the ability to hold a spot at selected point of Earth surface for prolonged time. Unfortunately, due to computer error, the mirror was not properly deployed and experiment failed.

"Znamya-3" was planned to use much larger, 60-70 m diameter reflector. Unfortunately, financial troubles led to it cancellation before launch.

On a side note, the BBC website put up a story on it yesterday:
https://www.bbc.com/culture/article/20250130-how-russia-launched-a-giant-space-mirror-in-1993

 

[publiusr]

The Moon is 400 times smaller --but 400 times closer--than the Sun...perfect for an eclipse.

Over at the Cosmoquest Forum (Plaits old Bad Astronomy site), someone said that an object 400 times smaller and 400 times closer than the Moon would be a sizable disk in Earth orbit--but the eclipse only a second or so long.

 

[edwest4]

In 1961, a newspaper strip titled Our Space Age, presented a space mirror.

https://www.newspapers.com/article/courier-post-1961-06-12-our-space-age/132049541/