Chandra Operations CXO Status Report Friday 26 April 2002

Last week the observing schedule was halted twice due to high radiation associated with solar flare activity. The loads were halted on Apr 19 at 10:15am EDT through a ground command to execute the SI Safing SCS 107. This ensured that the accumulated radiation dose for ACIS remained below the allowed threshold. Loads were restarted at 1:43pm EDT on Apr 20.

The second interruption occurred on Apr 21 at 12:52am EDT from an autonomous trip of the radiation monitor and execution of SCS 107. In both cases, all spacecraft actions completed nominally. Observations were resumed following the second interruption at 5.30pm on Apr 23. A total of 228Ks of science was lost due to the two events, and the impacted targets will be rescheduled in a future load.

Two Chandra press releases were made on April 22 in conjunction with the combined APS and AAS HEAD meeting in Albuquerque, NM. The first describes observations of the galaxy Arp 220 that provide new insight into what happens when two galaxies the size of the Milky way collide. The second describes observations of the 30 Doradus region that provide a new and detailed view of this most active star formation region. For full details see: http://chandra.harvard.edu/photo/2002/1181/index.html
http://chandra.harvard.edu/photo/2002/0057/index.html

The observing schedule for the next week is shown below and includes a target of opportunity observation of Her X-1.

-------------------------------------------
Radiation Belts                      Apr 28
LH-NW-4                 ACIS-I
IC 342 X-1              ACIS-S       Apr 29
Capella                 ACIS-S/HETG
LH-NW-5                 ACIS-I
3C321                   ACIS-S       Apr 30
Radiation Belts                      May 1
LH-NW-7                 ACIS-I
Coma                    HRC-I        May 2
PSS1347+4956            ACIS-S
HS 1237+4756            ACIS-S
LH-NW-8                 ACIS-I
FTM1036+2828            ACIS-S
PSS 1146+3015           ACIS-S
AX J1243.8+1305         ACIS-S       May 3
LBQS 1243+0121          ACIS-S
LH-NW-6                 ACIS-I
Radiation Belts
LH-NW-9                 ACIS-I       May 4
Aql X-1                 ACIS-S
2MASSW1507-16           ACIS-S
1739-304                ACIS-S       May 5
Her X-1                 ACIS-S/HETG
-------------------------------------------