They are not spies. Conventionally.
However, they have indirect links. From the very beginning.
The American Spy and Intelligence agencies CIA and NRO have recently published tons of declassified documents that support that notion.
Tehelka has published a cover story. Spies in the Skies.
I am giving the link below.
Declassified documents released by US government agencies like CIA, NRO are saying so. The truth has an official seal. NASA had designed shuttles that carried US spy satellites to orbit. Declassified documents depict a disgraceful relationship between NASA and CIA, the US Department of Defense (DoD), and National Reconnaissance Office (NRO). These agencies took part in designing NASA’s Shuttles throughout the 1970s.