From: NASA Blogs
Posted: Monday, June 22, 2009
19 June 2009 - Paul D. Tompkins
I just got off my first shift of the flight about 25 minutes ago...this is a day I will never forget. I was very confident we'd launch today, but then storm clouds advanced from the North, anticipated for arrival over Cape Canaveral at the time of our scheduled first launch opportunity. My confidence dropped a notch or two. Sure enough, with time to spare, the launch team opted to push to our third and final instantaneous opportunity to avoid the weather with greatest certainty. Our launch hung in the balance, with weather on one side, and a the launch countdown progressing methodically on the other. Magically, with about 13 minutes until the T-Zero time, the launch site weather classification changed from Red to Green, and the countdown marched without further hesitation. We realized it was almost inevitable at that point. Then...Liftoff!
The Flight Team watched the feed from NASA TV from the Mission Operations Control Room (MOCR) at NASA Ames as we at once cheered this early success, and grew accustomed to the gravity of this new and suddenly very real responsibility - the success of LCROSS was certainly ours to keep, or to lose. The cameras mounted on the Centaur provided excellent views of the receding Earth, our burst from the low-lying cloud cover into sunshine, our booster separation, and payload fairing jettison. The forward-looking camera captured LCROSS and its prominent Star Tracker as the fairing opened and exposed it directly to space for the first time.
At this point, time seemed to slow for a while as our primary focus became setting up our ground antennas for acquisition. As we approached our expected power-up time, the DSN began tracking the Centaur carrier signal and we knew they'd be on target to find LCROSS, as long as it could begin transmitting. Then the Centaur sent its commands and time accelerated. Right on time, the DSN at Canberra found our carrier and locked on to our telemetry signal. Data, and initial signs of life. Everything indicated a healthy spacecraft. Our training kicked in, and we were operating just as we had in all of our rehearsals of Activation & Checkout.
The spacecraft has been a joy so far. No major issues to report (if there were, I honestly wouldn't be able to report them like this anyhow, but you'll have to take my word for it). We're learning LCROSS ideosyncracies now - the realities that differ from the ideal behaviors models predict. So, cautious optimism so far. Our timeline this evening progressed a little more slowly than expected, though our final attitude control handover from the Centaur to LCROSS, triggered by Centaur hydrazine depletion, was a lot earlier than expected. We rolled with the change, and kept on pushing. Incidentally, preliminary indications are that our Atlas and Centaur placed LCROSS into a very nice orbit. Our Nav team will refine those initial estimates tonight.
Just an hour ago, Shift A left Shift B with a healthy spacecraft. Shift B will perform a full shakedown of our attitude control system, and run through our available downlink communications rates. Then they'll oversee planning for our first Trajectory Correction Maneuver, TCM 1, and our first powerup and checkout of the LCROSS science payload. And Shift A comes back in tomorrow to execute them both. TCM 1: burn start at 4:15 PM Pacific. Quicklook later the same day.
I will not likely be able to write like this every day, but I could not resist telling you all how this day went. Thank you everyone for your pre-launch good wishes. We got more than we bargained for today! GO LCROSS!
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