Solar Sail Launch Delayed to 2004
Written by Fraser Cain
Image credit: Planetary Society
The Planetary Society announced this week that they will be pushing back the launch of the Cosmos 1 solar sail from October to some time in 2004. This will give the mission team more time to test various aspects of the spacecraft to make that it works properly when it does launch. Their previous launch of a solar sail failed when the Volna rocket carrying it failed to deploy the spacecraft. If successful, this prototype vehicle will help demonstrate that the light from the Sun can be used for propulsion.
We have decided to delay the launch of Cosmos 1, our solar sail, from October 2003 until 2004. Despite a summer of generally good test results on hardware and software, the team is taking extra time to test as many operations as possible. The Cosmos 1 spacecraft has become much more complex than we originally planned, and the test program is proceeding slowly and methodically. We will not rush or take any risky shortcuts.
Over the summer all flight hardware was delivered to the Babakin Space Center, except for one part of the on-board radio system. A complete engineering model of the spacecraft was assembled with all elements in flight configuration. It was then tested in a thermal and vacuum environment to simulate conditions during flight.
The operations of the flight electronics were also tested. This included end-to-end system tests of data flowing from the sensors, through the computer, and to the ground station receiver hardware.
Such end-to-end testing is mandatory not only for nominal spacecraft operations — computer, sensors, the attitude control, sail deployment, and control of the sail blades — but for any unexpected situations that might occur. The spacecraft has been built with a great deal of redundancy and backup modes, both in individual components and overall operation, and thus is more complex than we first planned. This is why the team has decided to stretch out the testing program to the end of this year to run through as many operational sequences as possible.
As we reported earlier, the Volna rocket payload separation system has passed a crucial test. The engineering model of the solar sail was attached to the third stage and tested through all phases of launch. The final phase included dropping the spacecraft in a large vacuum chamber tower to simulate free-fall (zero-g) and the vacuum of space. The second and third stages separated as planned. This verified that the problems experienced on sub-orbital flights in 2001 and 2002 were now solved, and that the Volna would be approved for our launch.
The engineering model was returned from the rocket factory in Miass, Russia, to the NPO Lavochkin complex near Moscow for final tests with flight hardware. This hardware includes new solar sail blades manufactured for the flight. At the same time, the flight model was being assembled. Final assembly, however, will not occur until the electronics testing is complete.
We still have one crucial hardware problem to solve in the spacecraft radio system that will receive (telemetry) and send (commands) information. We have planned on a dual redundant system using two different frequencies — one in the UHF band, and one in the S-band. The S-band system is not yet delivered, and the UHF system has passed only half of its tests. Work is being completed on both to insure we will have a reliable system and a backup for the mission.
In addition to the great result from the Volna tests in far-away Miass (east of the Urals in Russia), the highlight of our summer was a display of a full-scale solar sail blade in the heart of New York City. Cosmos Studios and The Planetary Society were invited to include the sail as part of the Centennial of Flight exhibit in Rockefeller Center, which drew over a million people. This particular sail blade, which has now been deployed and packed several times during the test program in Russia and for our exhibit in New York, will next be exhibited in Pasadena at Planetfest 2004, where we'll be celebrating the landing of the first Mars Exploration Rover. For more information, please visit http://planetary.org/planetfest04/.
The work remaining includes completion of the software tests, additional checks of the new components on the engineering model, and the final assembly and test of the flight unit. This will take at least to the end of the year. Neither Cosmos Studios, the project sponsor, nor The Planetary Society are under any pressure — nor do we want to create any pressure — to launch before the system is ready.
Our attempt to fly the first solar sail spacecraft is risky enough without introducing additional risk due to impatience. I am grateful to both the Russian team at Babakin and IKI for taking care and attention to details and to Cosmos Studios for their patience in waiting for project results and a return on their investment.
Original Source: Planetary Society News Release
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