Swift Mission Director's Status Report Log - November 2004
Nov. 30, 2004
Swift continued with more progress in activating the instruments. The BAT activated the rest of the first detector block of CZT detectors (now 2048 out of 32,768 in the full array). These detectors show leakage, temperature of operation and counting rates that are similar to the first set. The XRT turned on the heaters to maintain operational thermal regulation of the XRT Tube (the 4.5 m mechanical structure linking the mirrors to the X-ray camera). UVOT continues routine monitoring and shows nominal behavior. The spacecraft continues to experiment with ACS parameters to lock on to new targets. The ACS team feels they are nearing the completion of ACS tuning and are starting to load our initial set of operational parameters. They will then collect data about the ACS performance through Friday. Tomorrow the BAT will start enabling one or two blocks (either another 2048 or 4096 detectors).
Nov. 29, 2004
Swift continued with more progress in activating the instruments. The BAT turned on high voltage for its second set of CZT detectors (now 512 out of 32,768 in the full array). These detectors show leakage, temperature of operation and counting rates that are similar to the first set. The XRT and UVOT continue routine monitoring and show nominal behavior. The spacecraft continues to experiment with ACS parameters to lock on to new targets. The ACS team feels confident of maneuvers of 50 degrees and less, and are tuning to properly handle the maximum 180 degree slews. Tomorrow the BAT will start enabling another set of 512 detectors.
Nov. 28, 2004
Swift continued with more progress in activating the instruments. The BAT turned on high voltage for its first set of CZT detectors (256 out of a total of 32,768 in the full array). These detectors show leakage, temperature of operation and counting rates that are just as expected. With a threshold setting of about 18 keV the background rates project to near or below pre-flight expectations. The XRT activated the Telescope Alignment Monitor (TAM), which shows a stable performance for the XRT optical bench. More significant measurements will occur after the XRT Tube Heaters are enabled in two days. The spacecraft continues to experiment with ACS parameters to adjust the settling speed of the ACS system in locking on to new targets. Tomorrow the BAT will start enabling the second set of 256 detectors.
Nov. 27, 2004
Swift continued with more progress in activating the instruments. The BAT turned on its first set of CZT detectors (256 out of a total of 32,768 in the full array). These detectors are checking out normally, but do not yet have the high voltage applied to detect gamma-rays. They have been able to detect charged particles, sensed during passages through the South Atlantic Anomaly. The XRT activated the Telescope Alignment Monitor (TAM), which measures the stability and relative alignment between the X-ray mirrors, X-ray detector and the star trackers. TAM data will be collected on a continuing basis to monitor the stability of XRT telescope as a function of orbital position and spacecraft orientation. The spacecraft continues to experiment with ACS parameters to support large angle slews and high speed slews used in Gamma-Ray Burst response.
Nov. 26, 2004
Swift has successfully turned on the electronics for the last instrument, the UV/Optical Telescope (UVOT). The UVOT Digital Electronics Module is now on, and operating properly. The Swift spacecraft team is continuing to refine ACS parameters. The stellar acquisitions are stable across multiple slews, and through SAA passages. Testing is now starting of slews conducted at the high slew rate used for responses to automated targets (such as new GRBs discovered by Swift). The XRT continues venting operations and collecting raw frames from the closed camera to establish baseline camera performance for Fe-55 X-ray event spectra. The BAT turned on loop heat pipes (which will carry away the heat generated when the BAT detector elements are operating). The BAT also turned on the heaters for the BAT detector blocks 0 and 1. The plan is to turn on the BAT power for blocks 0 and 1 tomorrow, but no gamma rays will be detected until the high voltage is turned on later.
Nov. 25, 2004
Swift continued with successful activation. The spacecraft continued to refine and update ACS related parameters. Testing has now gone to pseudo-normal operations with three slews per orbit from safepointing target to target. During passes the ACS team conduct systematic slew requests, including moving at the high speed slew used in normal ops (for the first time). The XRT continues venting operations and the camera pressure continues to drop. Raw frames from the closed camera show Fe-55 X-ray event spectra consistent with the current CCD temperature. The BAT electronics are turned on, and continue to function normally. Tomorrow the plan is to turn on the UVOT electronics and the BAT loop heat pipes.
Nov. 24, 2004
The BAT successfully started its activation process. The Instrument Processor (IP), which is the computer which controls the BAT and processes the gamma-ray detector events to produce a gamma-ray image of the sky, was turned on and passed its aliveness test. The BAT also activated the Power Supply (PS), which will supply power to the BAT detector elements as they are turned on over the next weeks. The XRT continues venting, and the raw door-closed image collected last night showed that the camera was cool enough (even without the Thermo-Electric Cooler turned on) to be able to detect Fe-55 X-rays generated by the radioactive sources mounted in the camera. The spacecraft ACS testing is proceeding ahead. Notable accomplishments include reducing the level of attitude drift during star tracker lock to below levels measurable by the star tracker itself (about 0.5 arc sec). Measurement of the actual ACS stability will have to wait until the UVOT and XRT doors open. We are currently operating with the full normal ACS parameters, meaning that Swift is actively slewing to observations of the 'safe points', six independent directions on the sky. We hope that UVOT electronics turn on will start on Friday.
Nov. 23, 2004
The Swift X-Ray Telescope (XRT) was powered on for the first time today. The XRT conducted an aliveness test, vented the camera, and captured a raw (door-closed) CCD frame. All tests showed nominal performance so the XRT will continue with camera venting until the ambient conditions allow main XRT door and XRT camera door openings in about three weeks. The spacecraft continued ACS testing, determining that the spacecraft moments of inertia agreed with pre-flight predictions to within 1-3%. Solar Array testing shows that the arrays have no sign of oscillation, and the attitude control is very stable. ACS stability overall is excellent, even with the current, preliminary parameters. During star tracker locks the pointing stability is within roughly one arc second.
Nov. 22, 2004
Swift spent the day largely conducting slews to test the star tracker ACS acquisition and inertial pointing mode. SpectrumAstro is working to refine the star tracker parameters to handle the effect of SAA-induced background increases in the tracker. We look forward to turning power on to the instrument electronics, starting with the XRT tomorrow.
Nov. 21, 2004
Swift continued with the initial activation of the spacecraft functions. The satellite successfully carried out its first commanded slew operation, and the star tracker successfully achieved its first attitude acquisition and attitude control. Swift is currently engaged in systematic testing of the ACS.
Nov. 20, 2004
Swift had a beautiful launch at 17:16 UT, achieving a near-perfect 586x601 km altitude by 20.6 deg inclination orbit. Mission operations at Penn State started at launch plus 80 minutes with the successful separation of the Observatory from the upper stage of the rocket. Solar panel deployment and data telemetry from all ground and space network antennae were completely nominal.