Robot satellites relay important communications and identify weather patterns. Because the satellites can be repaired only in orbit, astronauts are needed to repair them. Without repairs, the satellites would eventually malfunction. Ttherefore, space flights carrying astronauts must continue. Which of the following, if true, would most seriously weaken the argument above? ['Although satellites are indispensable in the identification of weather patterns, weather forecasters also make some use of computer projections to identify weather patterns.', 'The government, responding to public pressure, has decided to cut the budget for space flights and put more money into social welfare programs.', 'Satellites falling from orbit because of malfunctions burn up in the atmosphere.', 'Technical obsolescence of robot satellites makes repairing them more costly and less practical than sending new, improved satellites into orbit.']