Created 22 October 2009
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.
| Orbit | Begin Orbit | End Orbit |
|---|---|---|
| 1575 | 2010 Dec 31 04:12:19.74 | 2011 Jan 01 23:41:11.36 |
| 1576 | 2011 Jan 02 19:41:11.36 | 2011 Jan 04 15:11:12.47 |
| 1577 | 2011 Jan 05 11:11:12.47 | 2011 Jan 07 06:41:19.27 |
| 1578 | 2011 Jan 08 02:41:19.27 | 2011 Jan 09 22:10:39.05 |
| 1579 | 2011 Jan 10 18:10:39.05 | 2011 Jan 12 13:38:54.55 |
| 1580 | 2011 Jan 13 09:38:54.55 | 2011 Jan 15 05:06:26.28 |
| 1581 | 2011 Jan 16 01:06:26.28 | 2011 Jan 17 20:34:22.91 |
| 1582 | 2011 Jan 18 16:34:22.91 | 2011 Jan 20 12:03:15.95 |
| 1583 | 2011 Jan 21 08:03:15.95 | 2011 Jan 23 03:30:50.04 |
| 1584 | 2011 Jan 23 23:30:50.04 | 2011 Jan 25 18:57:56.21 |
| 1585 | 2011 Jan 26 14:57:56.21 | 2011 Jan 28 10:26:25.08 |
| 1586 | 2011 Jan 29 06:26:25.08 | 2011 Jan 31 01:56:15.69 |
| 1587 | 2011 Jan 31 21:56:15.69 | 2011 Feb 02 17:26:25.82 |
| 1588 | 2011 Feb 03 13:26:25.82 | 2011 Feb 05 08:55:58.15 |
| 1589 | 2011 Feb 06 04:55:58.15 | 2011 Feb 08 00:24:25.04 |
| 1590 | 2011 Feb 08 20:24:25.04 | 2011 Feb 10 15:51:57.75 |
| 1591 | 2011 Feb 11 11:51:57.75 | 2011 Feb 13 07:19:21.82 |
| 1592 | 2011 Feb 14 03:19:21.82 | 2011 Feb 15 22:47:47.33 |
| 1593 | 2011 Feb 16 18:47:47.33 | 2011 Feb 18 14:15:38.54 |
| 1594 | 2011 Feb 19 10:15:38.54 | 2011 Feb 21 05:42:06.55 |
| 1595 | 2011 Feb 22 01:42:06.55 | 2011 Feb 23 21:09:40.97 |
| 1596 | 2011 Feb 24 17:09:40.97 | 2011 Feb 26 12:38:50.93 |
| 1597 | 2011 Feb 27 08:38:50.93 | 2011 Mar 01 04:08:37.90 |
| 1598 | 2011 Mar 02 00:08:37.90 | 2011 Mar 03 19:38:01.06 |
| 1599 | 2011 Mar 04 15:38:01.06 | 2011 Mar 06 11:06:24.55 |
| 1600 | 2011 Mar 07 07:06:24.55 | 2011 Mar 09 02:33:44.65 |
| 1601 | 2011 Mar 09 22:33:44.65 | 2011 Mar 11 18:00:42.71 |
| 1602 | 2011 Mar 12 14:00:42.71 | 2011 Mar 14 09:28:23.53 |
| 1603 | 2011 Mar 15 05:28:23.53 | 2011 Mar 17 00:56:23.38 |
| 1604 | 2011 Mar 17 20:56:23.38 | 2011 Mar 19 16:22:38.25 |
| 1605 | 2011 Mar 20 12:22:38.25 | 2011 Mar 22 07:49:04.69 |
| 1606 | 2011 Mar 23 03:49:04.69 | 2011 Mar 24 23:17:23.09 |
| 1607 | 2011 Mar 25 19:17:23.09 | 2011 Mar 27 14:46:41.05 |
| 1608 | 2011 Mar 28 10:46:41.05 | 2011 Mar 30 06:15:48.16 |
| 1609 | 2011 Mar 31 02:15:48.16 | 2011 Apr 01 21:44:03.71 |
| 1610 | 2011 Apr 02 17:44:03.71 | 2011 Apr 04 13:11:13.32 |
| 1611 | 2011 Apr 05 09:11:13.32 | 2011 Apr 07 04:37:46.13 |
| 1612 | 2011 Apr 08 00:37:46.13 | 2011 Apr 09 20:04:51.23 |
| 1613 | 2011 Apr 10 16:04:51.23 | 2011 Apr 12 11:32:40.75 |
| 1614 | 2011 Apr 13 07:32:40.75 | 2011 Apr 15 02:59:15.96 |
| 1615 | 2011 Apr 15 22:59:15.96 | 2011 Apr 17 18:25:01.30 |
| 1616 | 2011 Apr 18 14:25:01.30 | 2011 Apr 20 09:52:27.14 |
| 1617 | 2011 Apr 21 05:52:27.14 | 2011 Apr 23 01:21:26.05 |
| 1618 | 2011 Apr 23 21:21:26.05 | 2011 Apr 25 16:50:37.40 |
| 1619 | 2011 Apr 26 12:50:37.40 | 2011 Apr 28 08:19:07.58 |
| 1620 | 2011 Apr 29 04:19:07.58 | 2011 Apr 30 23:46:35.86 |
| 1621 | 2011 May 01 19:46:35.86 | 2011 May 03 15:13:16.36 |
| 1622 | 2011 May 04 11:13:16.36 | 2011 May 06 06:40:15.23 |
| 1623 | 2011 May 07 02:40:15.23 | 2011 May 08 22:08:15.73 |
| 1624 | 2011 May 09 18:08:15.73 | 2011 May 11 13:35:41.97 |
| 1625 | 2011 May 12 09:35:41.97 | 2011 May 14 05:01:50.22 |
| 1626 | 2011 May 15 01:01:50.22 | 2011 May 16 20:28:53.47 |
| 1627 | 2011 May 17 16:28:53.47 | 2011 May 19 11:57:50.71 |
| 1628 | 2011 May 20 07:57:50.71 | 2011 May 22 03:27:29.90 |
| 1629 | 2011 May 22 23:27:29.90 | 2011 May 24 18:56:40.51 |
| 1630 | 2011 May 25 14:56:40.51 | 2011 May 27 10:24:49.71 |
| 1631 | 2011 May 28 06:24:49.71 | 2011 May 30 01:52:02.35 |
| 1632 | 2011 May 30 21:52:02.35 | 2011 Jun 01 17:19:10.16 |
| 1633 | 2011 Jun 02 13:19:10.16 | 2011 Jun 04 08:47:21.47 |
| 1634 | 2011 Jun 05 04:47:21.47 | 2011 Jun 07 00:15:33.87 |
| 1635 | 2011 Jun 07 20:15:33.87 | 2011 Jun 09 15:42:24.02 |
| 1636 | 2011 Jun 10 11:42:24.02 | 2011 Jun 12 07:09:26.70 |
| 1637 | 2011 Jun 13 03:09:26.70 | 2011 Jun 14 22:38:13.30 |
| 1638 | 2011 Jun 15 18:38:13.30 | 2011 Jun 17 14:08:14.06 |
| 1639 | 2011 Jun 18 10:08:14.06 | 2011 Jun 20 05:38:07.57 |
| 1640 | 2011 Jun 21 01:38:07.57 | 2011 Jun 22 21:07:02.14 |
| 1641 | 2011 Jun 23 17:07:02.14 | 2011 Jun 25 12:34:54.98 |
| 1642 | 2011 Jun 26 08:34:54.98 | 2011 Jun 28 04:02:21.87 |
| 1643 | 2011 Jun 29 00:02:21.87 | 2011 Jun 30 19:30:35.03 |
| 1644 | 2011 Jul 01 15:30:35.03 | 2011 Jul 03 10:59:28.67 |
| 1645 | 2011 Jul 04 06:59:28.67 | 2011 Jul 06 02:27:02.00 |
| 1646 | 2011 Jul 06 22:27:02.00 | 2011 Jul 08 17:54:14.06 |
| 1647 | 2011 Jul 09 13:54:14.06 | 2011 Jul 11 09:22:52.03 |
| 1648 | 2011 Jul 12 05:22:52.03 | 2011 Jul 14 00:52:58.11 |
| 1649 | 2011 Jul 14 20:52:58.11 | 2011 Jul 16 16:23:22.18 |
| 1650 | 2011 Jul 17 12:23:22.18 | 2011 Jul 19 07:52:54.71 |
| 1651 | 2011 Jul 20 03:52:54.71 | 2011 Jul 21 23:21:16.93 |
| 1652 | 2011 Jul 22 19:21:16.93 | 2011 Jul 24 14:48:57.62 |
| 1653 | 2011 Jul 25 10:48:57.62 | 2011 Jul 27 06:16:54.49 |
| 1654 | 2011 Jul 28 02:16:54.49 | 2011 Jul 29 21:45:47.43 |
| 1655 | 2011 Jul 30 17:45:47.43 | 2011 Aug 01 13:13:47.46 |
| 1656 | 2011 Aug 02 09:13:47.46 | 2011 Aug 04 04:40:39.39 |
| 1657 | 2011 Aug 05 00:40:39.39 | 2011 Aug 06 20:08:37.93 |
| 1658 | 2011 Aug 07 16:08:37.93 | 2011 Aug 09 11:38:13.48 |
| 1659 | 2011 Aug 10 07:38:13.48 | 2011 Aug 12 03:08:25.25 |
| 1660 | 2011 Aug 12 23:08:25.25 | 2011 Aug 14 18:37:59.89 |
| 1661 | 2011 Aug 15 14:37:59.89 | 2011 Aug 17 10:06:24.02 |
| 1662 | 2011 Aug 18 06:06:24.02 | 2011 Aug 20 01:33:53.49 |
| 1663 | 2011 Aug 20 21:33:53.49 | 2011 Aug 22 17:01:16.91 |
| 1664 | 2011 Aug 23 13:01:16.91 | 2011 Aug 25 08:29:30.82 |
| 1665 | 2011 Aug 26 04:29:30.82 | 2011 Aug 27 23:57:42.89 |
| 1666 | 2011 Aug 28 19:57:42.89 | 2011 Aug 30 15:24:12.53 |
| 1667 | 2011 Aug 31 11:24:12.53 | 2011 Sep 02 06:51:10.92 |
| 1668 | 2011 Sep 03 02:51:10.92 | 2011 Sep 04 22:19:59.99 |
| 1669 | 2011 Sep 05 18:19:59.99 | 2011 Sep 07 13:49:45.50 |
| 1670 | 2011 Sep 08 09:49:45.50 | 2011 Sep 10 05:19:10.36 |
| 1671 | 2011 Sep 11 01:19:10.36 | 2011 Sep 12 20:47:31.56 |
| 1672 | 2011 Sep 13 16:47:31.56 | 2011 Sep 15 12:14:48.70 |
| 1673 | 2011 Sep 16 08:14:48.70 | 2011 Sep 18 03:41:44.78 |
| 1674 | 2011 Sep 18 23:41:44.78 | 2011 Sep 20 19:09:16.79 |
| 1675 | 2011 Sep 21 15:09:16.79 | 2011 Sep 23 10:37:21.80 |
| 1676 | 2011 Sep 24 06:37:21.80 | 2011 Sep 26 02:03:58.34 |
| 1677 | 2011 Sep 26 22:03:58.34 | 2011 Sep 28 17:29:55.68 |
| 1678 | 2011 Sep 29 13:29:55.68 | 2011 Oct 01 08:57:42.90 |
| 1679 | 2011 Oct 02 04:57:42.90 | 2011 Oct 04 00:26:57.05 |
| 1680 | 2011 Oct 04 20:26:57.05 | 2011 Oct 06 15:56:06.14 |
| 1681 | 2011 Oct 07 11:56:06.14 | 2011 Oct 09 07:24:20.79 |
| 1682 | 2011 Oct 10 03:24:20.79 | 2011 Oct 11 22:51:30.50 |
| 1683 | 2011 Oct 12 18:51:30.50 | 2011 Oct 14 14:18:03.49 |
| 1684 | 2011 Oct 15 10:18:03.49 | 2011 Oct 17 05:45:05.49 |
| 1685 | 2011 Oct 18 01:45:05.49 | 2011 Oct 19 21:12:57.48 |
| 1686 | 2011 Oct 20 17:12:57.48 | 2011 Oct 22 12:40:01.88 |
| 1687 | 2011 Oct 23 08:40:01.88 | 2011 Oct 25 04:05:47.93 |
| 1688 | 2011 Oct 26 00:05:47.93 | 2011 Oct 27 19:32:44.68 |
| 1689 | 2011 Oct 28 15:32:44.68 | 2011 Oct 30 11:01:41.39 |
| 1690 | 2011 Oct 31 07:01:41.39 | 2011 Nov 02 02:31:06.56 |
| 1691 | 2011 Nov 02 22:31:06.56 | 2011 Nov 04 17:59:47.70 |
| 1692 | 2011 Nov 05 13:59:47.70 | 2011 Nov 07 09:27:26.07 |
| 1693 | 2011 Nov 08 05:27:26.07 | 2011 Nov 10 00:54:18.91 |
| 1694 | 2011 Nov 10 20:54:18.91 | 2011 Nov 12 16:21:25.34 |
| 1695 | 2011 Nov 13 12:21:25.34 | 2011 Nov 15 07:49:33.14 |
| 1696 | 2011 Nov 16 03:49:33.14 | 2011 Nov 17 23:17:29.05 |
| 1697 | 2011 Nov 18 19:17:29.05 | 2011 Nov 20 14:44:01.00 |
| 1698 | 2011 Nov 21 10:44:01.00 | 2011 Nov 23 06:10:48.51 |
| 1699 | 2011 Nov 24 02:10:48.51 | 2011 Nov 25 21:39:37.21 |
| 1700 | 2011 Nov 26 17:39:37.21 | 2011 Nov 28 13:09:34.51 |
| 1701 | 2011 Nov 29 09:09:34.51 | 2011 Dec 01 04:39:04.42 |
| 1702 | 2011 Dec 02 00:39:04.42 | 2011 Dec 03 20:07:28.79 |
| 1703 | 2011 Dec 04 16:07:28.79 | 2011 Dec 06 11:34:56.02 |
| 1704 | 2011 Dec 07 07:34:56.02 | 2011 Dec 09 03:02:18.81 |
| 1705 | 2011 Dec 09 23:02:18.81 | 2011 Dec 11 18:30:39.65 |
| 1706 | 2011 Dec 12 14:30:39.65 | 2011 Dec 14 09:59:18.46 |
| 1707 | 2011 Dec 15 05:59:18.46 | 2011 Dec 17 01:26:42.81 |
| 1708 | 2011 Dec 17 21:26:42.81 | 2011 Dec 19 16:53:46.17 |
| 1709 | 2011 Dec 20 12:53:46.17 | 2011 Dec 22 08:22:21.48 |
| 1710 | 2011 Dec 23 04:22:21.48 | 2011 Dec 24 23:52:33.70 |
| 1711 | 2011 Dec 25 19:52:33.70 | 2011 Dec 27 15:22:52.37 |
| 1712 | 2011 Dec 28 11:22:52.37 | 2011 Dec 30 06:52:07.21 |
| 1713 | 2011 Dec 31 02:52:07.21 | - |
Last modified: 12/14/16
