There appears to be a problem with the TLE we have for CXRB.  In the TLE, 
field 5 of line 2, which should be the eccentricity is listed at

e=0.0001301

Based upon what Wim has calculated for our STARE CubeSats, we should 
see the following

a=700km+6378km=7078km
b=400km+6378km=6778km

From the TLE that Matt gave me for CXRB, we have

a=310km+6378km=6688km
b=290km+6378km=6678km

But I am a dumbass, and the first TLE was actually for the International 
Space Station.  The TLE for CXBN shows that e=0.28, so we have 

a=800km+6378km=7178km
b=400km+6378km=6778km
