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 to launch three Stacksat spacecraft on 11 April 1990. The rocket was capable of placing of payload into low Earth orbit. A Burner-2 upper stage was used on an Atlas E/F to launch the Radsat and Radcat satellites on 2 October 1972. The rocket had a payload capacity of to low Earth orbit. Atlas E/F rockets with MSD upper stages were used for four launches, with NOSS naval reconnaissance satellites between 1976 and 1980. The fourth of these launches failed when one of the booster unit engines shut down early. This configuration had a maximum payload capacity of to LEO.