The United States Department of State then put a hold on the deal, which was only lifted when Secretary of State James Baker intervened. One of the reactors was to be used in a flight test in 1995 to power experimental electrical thrusters, but there were objections from scientists concerned about the possible impact of radiation emitted by the reactor on instruments aboard space satellites and protests from opponents of space-based weapons and nuclear power. In addition, the Department of Energy was slow to grant the necessary approval and in 1993 budget restrictions forced the cancellation of the program.