Which passage from “President Kennedy’s Special Message to the Congress on Urgent National Needs” provides the text with an urgent tone?

Question

all of you have lived through the last four years and have seen the significance of space and the adventures in space
a new course of action, a course which will last for many years and carry very heavy costs: 531 million dollars in fiscal ’62
unless every scientist, every engineer, every serviceman, every technician
providing a means for even more exciting and ambitious exploration of space, perhaps beyond the moon, perhaps to the very end of the solar system itself

Answer 1

unless every scientist, every engineer, every serviceman, every technician