The Mexican commercial communications satellite Solidaridad-1 has been declared a total loss after its primary control system failed in April 99 and the backup system failed on 27 Aug. The systems keep the solar power panels aligned with the sun; without the system, the satellite simply lost power and went inert. The satellite was a Hughes 601, one of 20 satellites of that type which had relays made out of tin. Four have failed previously due to little understood phenomenon in which a crystal lattice grows on the tin, shorting out the system, and this is thought to be the fifth such failure. Hughes switched to using nickel in its relays in 1997.--Stephen V Cole