Soon followed rye and cotton. These early suborbital biological experiments were handled by Harvard University and the Naval Research Laboratory and were concerned with radiation exposure on living tissue.[19] In 1971, 500 tree seeds (Loblolly pine, Sycamore, Sweetgum, Redwood, and Douglas fir) were flown around the Moon on Apollo 14. These Moon trees were planted and grown with controls back on Earth where no changes were detected.