Emily Lakdawalla • Mar 17, 2011
How to follow MESSENGER's orbit insertion today
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 |
00:45 | 17:54 | Engine ignition |
01:00 | 18:09 | Engine shutdown |
01:12 | 18:12 | Turn to Earth and acquire post-maneuver data |
01:23 | 18:32 | Reconfigure spacecraft systems for normal post-maneuver operations |