What engine type is used in a Space Shuttle Vacuum scenario?
CREATE TABLE table_20437 (
    "Engine type" text,
    "Scenario" text,
    "SFC in lb/(lbf\u00b7h)" text,
    "SFC in g/(kN\u00b7s)" text,
    "Specific impulse (s)" real,
    "Effective exhaust velocity (m/s)" real
)
SELECT "Engine type" FROM table_20437 WHERE "Scenario" = 'Space shuttle vacuum'
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: What engine type is used in a Space Shuttle Vacuum scenario? ### Input: CREATE TABLE table_20437 (
    "Engine type" text,
    "Scenario" text,
    "SFC in lb/(lbf\u00b7h)" text,
    "SFC in g/(kN\u00b7s)" text,
    "Specific impulse (s)" real,
    "Effective exhaust velocity (m/s)" real
) ### Response: SELECT "Engine type" FROM table_20437 WHERE "Scenario" = 'Space shuttle vacuum'