Re: Why would the NSA own that satellite?
That satellite would be maintained and operated by the DSWA (Defense Special Weapons Agency) who are our nuclear arsenal stewards and whose job it is to locate treaty violations.
The DSWA is continually contracting new technologies to detect nuclear testing and launches, etc.
They used to have a website I could link everybody to (DSWA.mil) but this is defunct now since shortly after 9-11-2001... since this agency is a bit too important to air its research, activities etc. on the WWW, so I am glad it is gone.
Best wishes,
SDAI-Tech1