CREATE TABLE table_20437 ("Engine type" TEXT, "Scenario" TEXT, "SFC in lb/ ( lbf\\u00b7h ) " TEXT, "SFC in g/ ( kN\\u00b7s ) " TEXT, "Specific impulse  ( s ) " FLOAT, "Effective exhaust velocity  ( m/s ) " FLOAT)

What engine type is used in a Space Shuttle Vacuum scenario?
SELECT "Engine type" FROM table_20437 WHERE "Scenario" = 'Space shuttle vacuum'
SELECT "Engine type" FROM "table_20437" WHERE "Scenario" = 'Space shuttle vacuum'