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Times of Orbital Events for Dec. 31, 2011 to Jan. 1, 2013

Created 08 March 2011

Radiation zone passages occur between the end of one orbit and the beginning of the next. During radiation zone passages, no Chandra observations are possible due to the high particle background and the need to protect ACIS. For observations which must be tightly constrained, observers may wish to check projected estimates of usable orbit intervals (and their unusable complement during the radiation zone).

The begin and end orbit times listed below are approximate but conservative projected estimates for the actual radiation zone exit and entry times, calculated as perigee times ± 10 hours. Actual segments of orbits useful for observations are likely to be somewhat longer, but should not be shorter than the times listed here. Perigee times become less accurate as time increases from the creation date. At one year after the creation date, the perigee times are expected to be about 10 minutes off from the actual perigee time.

The date/times are provided here in Calendar (UTC) format. To convert to other date formats, please see the Date Conversion Tool page.

Earlier orbital event times can be accessed on our archived orbits pages.

Last modified: 12/14/16

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