CREATE TABLE table_24791 ("Pilot" TEXT, "Organization" TEXT, "Total Flights" FLOAT, "USAF space flights" FLOAT, "FAI space flights" FLOAT, "Max Mach" TEXT, "Max speed  ( mph ) " FLOAT, "Max altitude  ( miles ) " TEXT)

Who was the pilot of max altitude of 55.9 miles?
SELECT "Pilot" FROM table_24791 WHERE "Max altitude (miles)" = '55.9'
SELECT "Pilot" FROM "table_24791" WHERE "Max altitude (miles)" = '55.9'