LASCO and EIT observed a full halo CME on 2002/05/22. The
event was first observed in C2 at 03:26 UT as a faint loop
front over the SE limb; by 04:06 UT the C2 occulting disk
was surrounded by a thick bright front in the W extending
over both poles and fainter extensions in the E. The front
first appeared in C3 at 03:42 UT with full coverage of the
C3 occultor by 04:18 UT. The plane of sky speed of the front
was measured as 1496 km/s at PA 237 (SE) with very slight
deceleration through the coronagraphs' fields of view.

The CME was most probably associated with a large, bright,
fast eruptive prominence that EIT observed between 03:00 -
04:24 UT, in the region of the disk centred on S19W56.
GOES notes a disappearing filament between 03:18 - 05:00 UT
and a C5.0 X-ray flare between 03:18 - 05:02 UT with peak
emission at 03:54 UT, from S30W34. Neither an EIT wave nor
a dimming were observed in association with this event.


May 22, 2002 shift report:
--------------------------
Radiation shutdown today:

Were running MAY2002C on the ascending leg, observing 'SAGITTARIUS A' with ACIS-I.

Radiation levels were high, with a sharp spike at about 143:0900.
GOES predictors of EPHIN rates indicated that an SCS107 trip was likely. 
At the start of the 143:1140 DSS-24 COMM pass we had to turn spacecraft telemetry on.
SCS107 had run, at approx 143:0958. SCS107 run was nominal, S/C is nominal. Attitude
is good at least thru radiation zone.

REPLAN SUMMARY: Two replans to be developed for load restart:

Plan A: Uplink tomorrow at 144:1100 pass, start load about 144:1200, 
        continue Sag A observation but with new OBSID
        Products out this AM, load review this afternoon.
        GO/NOGO telecon tomorrow (Friday, May24) at 7:00am EDT
        on 305-503-1818 pin 421

Plan B: If we decide radiation is too high to implement Plan A, then Plan B is to
        uplink loads tomorrow at 144:1835 pass and start about 144:1935,
        prior to radzone entry. Start observing after radiation zone exit at 145:1230 
        with ACIS CTI and then Sag A. 

May 23, 2002 shift report:
--------------------------
The Chandra radiation environment is high and decreasing. 
This radiation decline may be irregular, caused by three 
CME's produced by the sun on May 21 and May 22 which are 
overlapping in space. This variable environment will 
probably persist for another day or two.

In view of the uncertain conditions, two alternative 
plans for resuming Chandra's science mission are being 
prepared, to resume science either tomorrow morning or 
after perigee on May 25.

ACE 2 hr fluence is 2.6e8 vs. threshold 3.6e8. 
CRM-based orbital fluence is 1.9e8 vs. threshold 3.0e9.