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Planetary News: Cosmos 1 - Solar Sail (2005)

Cosmos 1 Timeline

By Emily Lakdawalla
June 16, 2005

More On Cosmos 1 - Solar Sail


Cosmos 1, the world's first solar sail spacecraft, takes flight on June 21, 2005, and is scheduled to unfurl its shining sails on June 26. The innovative solar sail, a project of The Planetary Society and Cosmos Studios, was built in Russia and will launch atop a converted ICBM from a submerged Russian submarine in the Barents Sea. Here's a look at the progression of events that will take place on the days of launch and sail deployment.


Launch Day!

Spacecraft
time (UTC)		 Spacecraft
time (PDT)		 Time with
respect
to launch		 Event
Jun 21 19:46:09 Jun 21 12:46:09 0 s Launch!
Housed on the tip of a Volna rocket, Cosmos 1 will launch from a Russian Navy submarine, submerged beneath the Barents Sea.
19:46:26 12:46:26 17 s Spacecraft powered-on
The command to power-on the spacecraft comes from the Volna launch vehicle.
19:52:16 12:52:16 6 m 17 s Separation of Cosmos 1 from Volna Rocket
The spent rocket drops away from the spacecraft.
19:52:50 12:52:50 6 m 41 s Separation of fairing from Cosmos 1
Once Cosmos 1 has launched past the Earth’s atmosphere, the fairing (protective cover) is no longer needed. 
19:53:45 12:53:45 7 m 36 s Spacecraft spin-up
To ensure the stability of the orbit insertion rocket burn, the spacecraft will fire maneuvering thrusters to spin the spacecraft at a rate of 22.5 revolutions per minute.
19:56:56 12:56:56 10 m 47 s Cosmos 1 rises over horizon at Petropavlovsk
A portable ground station is waiting at Petropavlovsk on Russia’s Kamchatka peninsula to listen for the first signal from Cosmos 1.  The spacecraft transmits a signal for about 10 minutes after it rises over the horizon.
20:01:54 13:01:54 15 m 45 s Kick motor startup
The kick motor will fire for 231 seconds, injecting the spacecraft into Earth orbit.
20:05:45 13:05:45 19 m 36 s Kick motor shut off -- The Solar Sail is now in orbit!
The orbit is nearly polar (inclination 80 degrees) and nearly circular, with an approximate altitude of 800 kilometers (500 miles) and a period of about 101 minutes.
20:07:05 13:07:05 20 m 56 s GPS instrument activated
The Global Positioning System instrument will enable Cosmos 1 to determine its location.
20:10:19 13:10:19 24 m 09 s Cosmos 1 rises over horizon at Majuro
A temporary radio receiving station waits on the Pacific island of Majuro in order to receive radio signal from Cosmos 1 on this all-important first pass around the Earth.  The contact will last for 10 minutes.
20:23:16 13:23:16 37 m 07 s Spacecraft spin-down
With the burn over, the spacecraft can safely slow its rotation to a much more sedate 1 revolution every 3 minutes.
20:29:46 13:29:46 43 m 36 s Kick motor separation
The spent rocket will drop away from the spacecraft.
20:29:48 13:29:48 43 m 38 s Solar panels open
20:34:15 13:34:15 48 m 06 s Spacecraft orients to Sun
Cosmos 1 has a Sun sensor that will enable it to locate the Sun.  Using small thrusters, the spacecraft will rotate so that the solar panels are oriented perpendicular to the Sun.  This process may take up to 10 minutes.
20:53:51 13:53:51 1 h 8 m Spacecraft enters Earth’s shadow
The spacecraft will pass into the Earth’s shadow, hiding it from the Sun.  This will happen once every orbit early in the mission.  However, by the time the sails are deployed on June 26, the plane of the orbit will have rotated so that it never passes into the Earth’s shadow, and the Sun will shine constantly on the spacecraft.
21:11:56 14:11:56 1 h 26 m Spacecraft exits Earth’s shadow 
The spacecraft can now recharge its batteries.
21:21 14:21 1 h 35 m Ground station contact: Panska Ves
Cosmos 1’s first potential contact with a permanent ground station is with Panska Ves, in the Czech Republic.  The contact will last for 11 minutes.   Panska Ves may or may not receive data from this contact with Cosmos 1; the primary goal of this contact is to receive only a carrier signal from the spacecraft.
21:28 14:28 1 h 42 m Ground station contact: Tarusa and Bear Lakes
Cosmos 1 will pass near the two permanent Russian ground stations at Tarusa and Bear Lakes.  However, the geometry of this pass is not particularly good, as Cosmos 1 will be low in the sky for both stations.
23:39 16:39 3 h 52 m First Pancam image
The Pancam is one of two camera instruments on Cosmos 1. The spacecraft will capture one Pancam image on each orbit (that is, once every 101 minutes) for the next 59 orbits.
Jun 22 04:23 Jun 21 21:23 8 h 37 m First high-quality ground station contacts: Tarusa and Bear Lakes
On the spacecraft’s fifth orbit around the Earth, its orbital path will finally carry it high across the sky as seen from the Russian ground stations.  These contacts should provide good communication from the spacecraft.

Cosmos 1 will continue to orbit the Earth once every 101 minutes for about four more days, capturing one Pancam image on each orbit, as mission controllers check out the spacecraft’s health. Four days is estimated to be enough time for all the air that might have been trapped in the solar sails when they were packed to leak out to the vacuum of space. If all checks out, Cosmos 1 will be ready to unfurl its sails.

Sail Deployment Orbit

The following times and dates are dependent upon predictions for the spacecraft’s orbit, and will likely change after launch. Please return to planetary.org for the most up-to-date figures.

Spacecraft
time (UTC)		 Spacecraft
time (PDT)		 Time with
respect
to launch		 Event
Jun 26 04:35:17 Jun 25 21:35:17 0 s Beginning of sail deployment orbit
Jun 26 04:35:27 Jun 25 21:35:27 10 s Spacecraft spin-down
Since orbit insertion, the spacecraft has been spinning at the slow rate of 1 revolution every 3 minutes.  To ensure that the sails are deployed safely, the spacecraft’s spin will be reduced to zero.
Jun 26 04:35:37 Jun 25 21:35:37 20 s Pancam image
The panoramic camera will take a “before” picture, to compare with what happens after deployment.
Jun 26 04:41:59 Jun 25 21:41:59 6 m 42 s First tier of sails deploys
The sails are mounted on the spacecraft in two tiers of four sails each.  One tier deploys at a time.  Tubes inflate, dragging out the triangular sails.  The deployment takes only seconds. Photocam, a second camera designed to watch the motions of the sails, may be able to take a series of images showing the deployment, but this depends on exact performance of the on-board computer and spacecraft power system. 
Jun 26 04:43:37 Jun 25 21:43:37 8 m 20 s Pancam image
What does the spacecraft look like with four blades deployed?
Jun 26 04:46:58 Jun 25 21:46:58 11 m 41 s Second tier of sails deploys
Sail deployment should be complete, and Cosmos 1 is ready to sail. The deployment of the sails is planned to be done while in view of the Russian ground stations.
Jun 26 04:51:57 Jun 25 21:51:57 16 m 40 s Spacecraft spin-up
Sails deployed, the spacecraft will spin up to a slow rotation rate of 1 revolution every 12 minutes.  The slight spin will help maintain the spacecraft’s pointing to the Sun.
Jun 26 04:55:17 Jun 25 21:55:57 20 m 00 s Pancam image
The spacecraft will now get a (partial) view of the fully deployed sails.

The first images should be returned to the Earth within an hour or two after deployment. The exact schedule will not be known until after launch, when the spacecraft’s orbit is better known.

Other events to look forward to:

June 27: First attempt to rotate sail blades
June 28: First attempt to use sail blades to control orientation of spacecraft