Complex sentence: The Space Age might also be considered to have begun much earlier than October 4,1957, because in June 1944, a German V-2 rocket became the first man-made object to enter space, albeit only briefly.
Split into simpler sentences: The Space Age might also be considered to have begun much earlier than October 4,1957, because in June 1944, a German V-2 rocket reached space. It thus became the first man-made object to enter space, albeit only briefly.