STA-21 to program other than Nuke

[ShellSheff]

Hello!  I'm going to make this as brief as possible - Is it possible to apply for an STA-21 program other than the nuclear program, while in A School in the Nuke pipeline?  I can provide more details as to the why I'm asking, if necessary, but I'm finding conflicting information in my search, and was hoping that someone would know for fact that it is or is not possible. Thank you!