C. Gray, S. Dwyer, K. Kawabe, J. Kissel, P. Thomas, B. Weaver

After a hefty, special thursday maintenance day induced by the need to replace EX's HEPI pump station, recovery went rather smoothly. 
The major time sucks after the HEPI Pump Station was replaced and ETMX SEI system was completely restored (by 21:51 UTC, i.e. ~03:00 pm PDT, see LHO aLOG 51617):
    (1) the troubles the vacuum crew had in chasing down a sneaky leak, LHO aLOG 51624 [unavoidable commissioning of a new vacuum system component; extra 2.5 hrs]
    (2) the recovery of the COMM beatnote (LHO aLOG 51626) as a result of the change to PSL ALS path (LHO aLOG 51610) [0.5 hrs]
    (3) Initial alignment troubles with PRC and MICH (see LHO aLOG 51625), saturating suspensions. Both were fixed by just trying a 6th time. Probably should implement the suggested further changes in the last line of LHO aLOG 51409 [0.5 hrs]
    (4) Confusion about what to do in the CHECK_MICH_FRINGES state after recent commissioning work by Jenne, since MICH loop is on but not triggered. Banter about "just make flashes symmetric" or (the way it used to be when that state locked on a dark fringe) "minimize light as AS port, and make dark pattern symmetric. We didn't need to go through this state anyways, just wanted to check load on guardian computer during this state. [0.17 hrs]

I want to call out the brief outage of the LSC computer's model crash (LHO aLOG 51616) miraculously gave us no delay -- we were waiting for (2) anyway, and we now know that all settings apparently came back excellent (and our were under control by the ISC_LOCK guardian and its subordinates).

So -- even after 
     - the GIANT local earthquake this morning (LHO aLOG 51601) 
     - the sputtery start to initial alignment (EX recovery was a breeze, just a couple of small, normal-sized tweaks to ETMX and TMSX, and ALS XARM locked up beautifully), 
     - with the recovered COMM beatnote we sailed through LOCKING_ALS, 
     - PRMI acquisition, its ASC, the transition to DRMI, and its ASC all working perfectly, 
     - no lock loss at CARM_ON_TR b/c of the recent force of all subordinate IFO nodes to go *through* their down state (LHO aLOG 51465), 
     - a slow but sure trek through ENGAGE_SOFT_LOOPS, 
     - *zero* problems with violin modes before engaging DC readout, 
     - a smooth increase in power and all subsequent noise tunings, and 
We're at NOMINAL_LOW_NOISE with no striking setting differences.

Excellent work All (both today, and leading up to today)!

I would say interferometric recovery began at 00:30 UTC (17:30 PDT), and we hit NOMINAL_LOW_NOISE at 02:52 UTC (19:52 PDT), so recovery time is 2.3 hours, not so very much different than a "standard" run through an initial alignment + lock acquisition sequence these days as we wait for ASC loops to converge. But as highlighted above -- it makes for a *very* robust acquisition sequence, so it might be worth the wait.

Attached is a more detailed blow-by-blow, in case needed for future reference.