The Znamya project was a series of orbital mirror experiments in the 1990s that intended to beam

solar power Solar power is the conversion of energy from sunlight into electricity, either directly using photovoltaics (PV) or indirectly using concentrated solar power. Photovoltaic cells convert light into an electric current using the photovoltaic e ...

to Earth by reflecting

sunlight Sunlight is a portion of the electromagnetic radiation given off by the Sun, in particular infrared, visible, and ultraviolet light. On Earth, sunlight is scattered and filtered through Earth's atmosphere, and is obvious as daylight when t ...

. It consisted of two experiments – the Znamya 2 experiment, and the failed Znamya 2.5 – and the proposed Znamya 3. The project was abandoned by the

Russian Federal Space Agency The State Space Corporation "Roscosmos" (russian: Государственная корпорация по космической деятельности «Роскосмос»), commonly known simply as Roscosmos (russian: Роскосмос) ...

after the failed deployment of the Znamya 2.5.

Znamya 2

The Znamya 2 was a 20-metre wide space

solar mirror A solar mirror contains a substrate with a reflective layer for reflecting the solar energy, and in most cases an interference layer. This may be a planar mirror or parabolic arrays of solar mirrors used to achieve a substantially concentrate ...

. Znamya-2 was launched aboard

Progress M-15 Progress M-15 (russian: Прогресс М-15, italic=yes) was a Russian uncrewed cargo spacecraft which was launched in 1992 to resupply the Mir space station. The thirty-third of sixty-four Progress spacecraft to visit Mir, it used the Progress ...

from

Baikonur Baikonur ( kk, Байқоңыр, ; russian: Байконур, translit=Baykonur), formerly known as Leninsk, is a city of republic significance in Kazakhstan on the northern bank of the Syr Darya river. It is currently leased and administered ...

on 27 October 1992. After visiting the EO-12 crew aboard the

Mir ''Mir'' (russian: Мир, ; ) was a space station that operated in low Earth orbit from 1986 to 2001, operated by the Soviet Union and later by Russia. ''Mir'' was the first modular space station and was assembled in orbit from 1986 to&n ...

space station A space station is a spacecraft capable of supporting a human crew in orbit for an extended period of time, and is therefore a type of space habitat. It lacks major propulsion or landing systems. An orbital station or an orbital space station i ...

the Progress T-15 then undocked and deployed the reflector from the end of the Russian

Progress spacecraft The Progress (russian: Прогресс) is a Russian expendable cargo spacecraft. Its purpose is to deliver the supplies needed to sustain a human presence in orbit. While it does not carry a crew, it can be boarded by astronauts when docked t ...

on 4 February 1993, next to the Russian

space station. The mirror deployed successfully, and, when illuminated, produced a 5 km wide bright spot, which traversed Europe from southern France to western Russia at a speed of 8 km/h.Znamya Space Mirror
space-frontier.org, 5 February 1999 (archived) The bright spot had a

luminosity Luminosity is an absolute measure of radiated electromagnetic power (light), the radiant power emitted by a light-emitting object over time. In astronomy, luminosity is the total amount of electromagnetic energy emitted per unit of time by a st ...

equivalent to approximately that of a

full moon The full moon is the lunar phase when the Moon appears fully illuminated from Earth's perspective. This occurs when Earth is located between the Sun and the Moon (when the ecliptic coordinate system, ecliptic longitudes of the Sun and Moon opp ...

. Although clouds covered much of Europe that morning, a few ground observers reported seeing a flash of light as the beam swept by.Tim Folger, "New moon – Russian satellite acts as a mirror to light remote areas", ''Discover'', Jan, 1994
web version
, (Retrieved 29 August 2008)). Znamya-2

The mirror was de-orbited after several hours and burned up in

atmospheric reentry Atmospheric entry is the movement of an object from outer space into and through the gases of an atmosphere of a planet, dwarf planet, or natural satellite. There are two main types of atmospheric entry: ''uncontrolled entry'', such as the entr ...

over Canada. The Znamya mirror had originally been designed as a prototype of a

solar sail Solar sails (also known as light sails and photon sails) are a method of spacecraft propulsion using radiation pressure exerted by sunlight on large mirrors. A number of spaceflight missions to test solar propulsion and navigation have been p ...

propulsion system, but was repurposed as a space mirror for illumination when interest in solar sails flagged.

Znamya 2.5

The Znamya 2.5 was a successor to the Znamya 2, which was deployed on 5 February 1999. It had a diameter of 25 m, and was expected to produce a bright spot 7 km in diameter, with luminosity between five and ten full moons. However, soon after deployment, the mirror caught on an antenna on the Progress, and ripped. After several vain attempts by Russian mission control to free the mirror from the antenna, the Znamya 2.5 was de-orbited, and burned up upon

reentry Atmospheric entry is the movement of an object from outer space into and through the gases of an atmosphere of a planet, dwarf planet, or natural satellite. There are two main types of atmospheric entry: ''uncontrolled entry'', such as the entr ...

Znamya 3

The Znamya 3 was intended to be a scaled-up version of the previous two Znamyas, with a diameter of 60–70 metres. It was never built, as the project was abandoned after the failure of the Znamya 2.5.

References

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External links

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Space Mirror
N.Shpakovsky. Russian inventions Satellites of Russia