Complex sentence: Proxmire introduced an amendment into the 1982 NASA budget that effectively terminated NASA's nascent SETI efforts before a similar amendment to the 1994 budget, by Senator Richard Bryan, terminated NASA's SETI efforts for good.
Split into simpler sentences: Proxmire introduced an amendment into the 1982 NASA budget that effectively terminated NASA's nascent SETI efforts. A similar amendment to the 1994 budget by Senator Richard Bryan terminated NASA's SETI efforts for good.