Complex sentence: The British Rail flying saucer, officially known simply as space vehicle, was a proposed spacecraft, designed by Charles Osmond Frederick and a patent application was filed by Jensen and Son on behalf of British Rail on 11 December 1970 and granted on 21 March 1973.
Split into simpler sentences: The British Rail flying saucer, officially known simply as space vehicle, was a proposed spacecraft designed by Charles Osmond Frederick. A patent application was filed by Jensen and Son on behalf of British Rail on 11 December 1970 and granted on 21 March 1973.