If the STS-131 mission launches as planned on Monday, 5Apr10, and if the mission is not extended, then the Shuttle will undock from the ISS at 0355 EDT on Friday, 16Apr10. The flyaround starts at 0420 EDT. There is a visible pass for the two craft beginning at 0415 EDT and ending at 0420 EDT. So the two craft will appear as distinct objects in the sky but in very close proximity and possible changing positions. The low altitude at appearance and continual low of altitude will make this a difficult event to see.
| Appears | Disappears | |
|---|---|---|
| Time | 0415:37 EDT | 0420:00 EDT |
| Alt. | 16.6° | horizon |
| Az. | 343.0° NNW | 46.2° NE |
| Mag. | -1.8 | 2.4 |
The waning gibbous Moon should be southing around that time and astronomical twilight doesn't begin until 0456 EDT.
The countdown for the launch began at 0300 EDT this morning.
