Just before the astronauts re-enter the earth's atmosphere, you see Aquarius (which has just been separated) tumbling toward Earth. In the background, you can see there's a hurricane on Earth. Since its bands are going counter-clockwise, it must be in the Northern Hemisphere. But the movie takes place in April 1970, and hurricane season in the Northern Hemisphere lasts from June 1 to November 30. The odds of a hurricane ocurring in April (or even June) are pretty low, considering that the peak of activity is around August and September.