what’s the n number of the space shuttle carrier 747 in use?
there are two
its not
n911na or at least that one is not showing its history here on the tracker.
(on an off note - why is everything 911? weird?)
N905NA
flightaware.com/live/flight/NASA905
call sign NASA 905 heavy but no tracking available for Endeavor flights. 
Interesting to note, as I come back inside to my desk as it flew directly over my building at work in Sacramento…
In listening to the NorCal LiveATC feed, they are flying VFR, and remaining at roughly 1500ft MSL all the way down the coast. Also, by judging from the TFRs in place, you could track where it is at (at least in the vicinity) by when the TFRs go into effect. So you do have somewhat of a way to track it.
BL.
I believe the SCA callsign was NASA95 heavy today (liveatc.net/listen.php)
The SCA shot the first low app to the North Complex at about 1857Z then shot the second low app at about 1940Z w/the full stop at 1950Z or so…use the LiveATC.net archives to see if you can make out the xmsns…they are a bit garbled in the 1830Z-1900Z feed. 1930Z-2000Z is much clearer…