The day is finally here! In only five and a half hours, at 00:45 on March 18 (according to the spacecraft's clock), MESSENGER must ignite its main engine and run though a third of its fuel in only 15 minutes in order to enter its planned orbit around Mercury. One-way light time will be about 9 minutes, so it'll be about 00:54 (just before 6 p.m., my time) when the Deep Space Network antennas in Canberra that'll be tracking MESSENGER's signal should hopefully see the Doppler shift in MESSENGER's broadcast frequency that'll signal that the burn is happening.
I erred previously in saying that NASA TV would be covering this -- they won't. Turns out NASA TV will, in fact, be broadcasting tonight. Sigh.
So here is how I plan to follow MESSENGER's Mercury Orbit Insertion (referred to as "MOI" by acronym-happy NASA types):
- Daniel Muller's realtime countdown clock (which includes key events other than the moment of orbit insertion), running now
- Eyes on the Solar System'srealtime visual simulation complements Daniel's text-based clock nicely. You can choose whether to view it in spacecraft event time or Earth received time (Earth received time is spacecraft event time plus one-way light time).
- Twitter, following the hashtag #MOI2011; the official mission Twitter account is @MESSENGER2011
- MESSENGER's website, which will begin a live webcast at 23:55 UTC / 4:55 p.m. PDT according to the mission website, but 23:30 / 4:30 according to Twitter; I'll certainly be tuned in at the earlier time.
- I'll have NASA TV on as well.
- I'll also probably check in on the mission's Facebook page from time to time.
I linked to the official mission timeline before, but here's a short version, of the key events I'll be looking for this evening.
|Time (SCET, UTC)||Time (ERT, PDT)||Event|
|00:15||17:24||Turn spacecraft to burn attitude and configure attitude control for burn execution|
|00:25||17:34||Configure solar arrays for burn execution|
|00:40||17:49||Configure spacecraft fault protection for burn execution|
|01:12||18:12||Turn to Earth and acquire post-maneuver data|
|01:23||18:32||Reconfigure spacecraft systems for normal post-maneuver operations|