Blackwood convention Blackwood convention In the partnership card game contract bridge, the Blackwood convention is a popular bidding convention that was developed by Easley Blackwood. It is used to explore the partnership's possession of aces, kings and in some variants, the queen of trumps, to judge more precisely whether slam is likely to be a good contract. Two versions of Blackwood are common: "standard" Blackwood, developed by Easley in 1933, and "Roman Key Card" Blackwood ("RKC" or "RKCB"), named for the Italian team which invented it. Standard Blackwood enables one partner to count partnership aces and kings in general. Key card variants
Atlas E/F underperformance issue, the end result of which was the upper stage separating and igniting whilst the first stage was still firing. The Atlas E/F was used with a Trident upper stage, between 1967 and 1971, for suborbital tests of re-entry vehicles. Nineteen were launched, of which two failed. Atlas E/F The Atlas E/F, also designated SB-1A was an American expendable launch system and sounding rocket built using parts of decommissioned SM-65 Atlas missiles. It was a member of the Atlas family of rockets. The first stage was built using parts taken from decommissioned Atlas-E and Atlas-F missiles, with various solid