From chapter 19:

“Now that space research has been moved to the new NASA organization, we do have more opportunities for selecting projects,” Harper said.

ARPA and NASA were created in the same year: 1958.

The Advanced Research Projects Agency (ARPA) was created in February 1958 to develop space technology for military application.[12]
On July 29, 1958, Eisenhower signed the National Aeronautics and Space Act, establishing NASA.

—https://en.wikipedia.org/wiki/NASA

Both were created in direct response to the “Sputnik Crisis.” The US was worried because Russia had successfully launched an artificial satellite first.