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Sailing with Solar Propulsion

Cosmos 1

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http://mediaplan.ovh.net/~up/ssc/ag2001/cosmos1_a.htm

After four years of planning, building and testing, Cosmos 1, the first solar sail spacecraft, is ready for Earth orbit.

Cosmos 1 has 8 triangular sails, each 15 meters (50 feet) in length, configured around the spacecraft's body at the center. The sails will be deployed by inflatable tubes once the spacecraft is in orbit.

The spacecraft will be launched from a submerged Russian submarine in the Barents Sea. It will be carried into orbit on board a Volna rocket - a converted ICBM left over from the old Soviet arsenal.

Cosmos 1 will orbit the Earth at an altitude of over 800 kilometers. It will gradually raise its orbit by solar sailing -- the pressure of light particles from the Sun upon its luminous sails.

The Spacecraft is being built in Russia by NPO Lavochkin under contract to The Planetary Society. Cosmos Studios is the project's sole sponsor.

The mission will demonstrate the feasibility of Solar Sail flight, opening the way to interplanetary travel and someday - sailing to the stars.

Cosmos 1 will be the first Space mission ever flown by a non-governmental advocacy group!

Cosmos 1 - Mission Timeline


The Launch of Cosmos 1
Painting: Michale Carroll, The Planetary Society (c)

Final Preparations
Three to four weeks before the launch date Cosmos 1 will be delivered to the naval base at Severmorsk, near the port city of Murmansk. Over the next few weeks the spacecraft will be checked out, batteries and pyrotechnic devices will be installed and charged, and the electrical units connecting the spacecraft to the rocket will be put in place. Then, the spacecraft will be placed in the payload area at the tip of the Volna rocket. About three days prior to the launch the rocket will be loaded on the Delta III submarine. The vessel will leave Severmorsk to the designated site half a day before launch time.

Launch!
At launch, the main engine of the first stage of the Volna rocket will burn before shutting down and disengaging from the main body. The second stage will then ignite, burn, and disengage from the third stage, which in turn will separate from the payload compartment after completing its burn. A little more than 6 minutes after shooting up from the submarine, the three-stage Volna rocket will have completed its role in the mission.

At this point the apogee kick motor, which is attached to the payload compartment and unofficially named the “TPS Motor,” will begin a 70 seconds orbit insertion burn. When this is completed the motor and the protective cover encasing the payload compartment will be discarded, leaving the spacecraft alone in orbit, spinning at 22 revolutions per minute. The entire process, from submarine launch to orbit insertion, will last just under 20 minutes.

Into Earth Orbit
The launch path will take the spacecraft from the Barents Sea, across northern Russia and Siberia, and past the Kamchatka peninsula. When the spacecraft passes east of Kamchatka over the Pacific Ocean it should enter a near-circular orbit 825 kilometers above the Earth and inclined about 78 degrees. But orbit insertion is a very sensitive phase of any mission, and errors can occur which would result in the spacecraft entering a different orbit. To make sure that Cosmos 1 is not lost to its mission controllers on Earth, it is critical to establish contact with the spacecraft as soon as possible after orbit insertion.

Cosmos 1 in Flight
During the first 30-40 minutes of the flight, Cosmos 1’s only source of power will be its batteries. The radio will be turned on from the orbit insertion burn through the passage over Majuro, transmitting information about the spacecraft’s location to the portable ground stations. It will then be deactivated to conserve power. The Global Positioning Device navigation system will also be operating from 15 to 22 minutes into the flight, to assist in the early tracking.

37 minutes into orbital flight the solar panels will deploy, and will orient towards the Sun within 15 minutes. The solar panels will then provide power to the spacecraft for the rest of the mission.

During these early days all the spacecraft’s systems will be tested. The two radio on board – one S-band,the other UHF –will be active, the attitude control jets will be fired to keep the spacecraft stable. In addition the imaging cameras will be tested, and a plasma ion analyzer will begin collecting data that will later be compared with measurements once the sails are deployed.

Mission control will be based primarily at NPO Lavochkin in Moscow – a center we call Mission Operations Moscow (MOM). The Planetary Society will be the site of another operations center, Project Operations Pasadena (POP), which will maintain full communications capability with MOM and coordinate data handling and the U.S. ground stations telemetry.

Setting Sail
Several days into the mission Cosmos 1 will deploy its sails. This critical operation will take place while the spacecraft is within range of the two Moscow-area tracking stations, so that data from the procedure can be received in real time. Initially a set of four triangular blades will unfurl, and if all goes smoothly they will be followed within minutes by the remaining four blades. It is also possible that mission controllers will wait for the spacecraft to pass over the region again on a later orbit to unfurl the second set of sails. From that point on Cosmos 1 will be truly a solar sail.

For a while after deployment the giant blades will be kept in a fixed position, giving mission controllers a chance to carefully observe the spacecraft’s behavior. Only after a few days will the Cosmos 1 team begin shifting the blades’ angles towards the Sun or perpendicular to it, in a controlled program to increase the orbit energy. Gradually, the continuous pressure of reflecting sunlight will raise the spacecraft into a higher orbit above the Earth.

The flight of Cosmos 1 will not last long. Within a month the mylar sails will begin to degrade in the harsh sunlight, and the tubes supporting the blades will be losing pressure. It is possible that by this time the spacecraft will have risen to a high enough orbit that it will remain there, forever orbiting the Earth. It is more likely, however, that the orbit will slowly decay, and Cosmos 1 will end its days as a fireball in the Earth’s atmosphere.

http://www.planetary.org/solarsail/timeline.html