Keyhole USA 161 flaring

On the night of April 1-2, the Keyhole optical satellite USA 161 (01-044A) flared brightly to mag. -2 just after shadow exit. I shot a whole series of images (yielding 7 positions), of which this is the first (exposure starting a few seconds after flare maximum):

(click image to enlarge)

The same evening I also captured the Keyhole USA 129 (96-072A). HEO objects imaged were the SIGINT USA 200 (08-010A) and two brief glints by NOSS 2-3A (96-029A). The Russian Kosmos 2392 (02-037A) was captured as a stray on the USA 200 images.