Still sailing on

Plans to launch the first solar-sail satellite on a converted Russian
ballistic missile will go ahead despite the failure of a sub-orbital test in
July. Solar sails propel a spacecraft using the pressure of sunlight alone. The
Planetary Society now blames the recent failure on abnormally low thrust from
the final stage of the Russian rocket. This prevented separation of the payload
that was to test deployment of two blades of the solar sail. Planners say they
learned enough to proceed this year with launching the Cosmos 1 satellite, which
will deploy a 30-metre-wide solar sail.