OVERVIEW STATEMENT ON DATA PRODUCTS AND PRODUCT QUALITY -------------------------------------------------------------------------------- MISSION TIMELINE - DATATAKE EVENTS Data take information for the timeline was compiled from the events files used in flight to generate the actual orbiter commands. MPS is very confident that the data takes and BITE events are shown as executed. We have tried to illustrate special cases of various types in the data take or BITE comments field. This information was gleaned from our own logs as well as the logs for Librarian and C-Data, and the C-Performance and C-Data data take success files posted to the DMS during the flight. Also included in this file are the trim maneuver windows. The opening of each window should correspond very closely to the time the orbiter left mapping attitude; the closing should correspond very closely to the time the crew hit DAP A11 for stable mapping attitude. Delta-vee and Time of Ignition (TIG) are also shown from the reconstructed chart from the JSC lead Flight Dynamics Office (C. Edelen). All times should be good to 1 minute or better. MISSION TIMELINE - PLAYBACKS Like the data takes, the playbacks were reconstructed from the events files used in flight to generate the playback commands. There were a number of cases in flight where playbacks were skipped or deleted shortly before execution. Most of these were removed from the events files in flight, and we believe the remainder have been removed upon inspection of the C-Data log, and to a lesser extent, the GDPS logs. It is possible there may be one or two extraneous playbacks. TSIDs for these playbacks were derived from the C-Data log. MISSION TIMELINE - TAPE CHANGES Tape changes were reconstructed from the C-Data log as voiced down by the crew (and/or seen in telemetry by C-Data). In contrast to the spec'd events file format, the PHRR columns show the physical PHRR (1/2/3/4) that was changed, not the logical mapping (CA/CB/X). The name of the event corresponds to the tape number exiting the recorder, and the comment field shows the tape entering the recorder. MISSION TIMELINE - TAPE EVENTS In addition to tape changes, we have constructed tape events to correspond to the block of time where the PHRR was the active recorder. For C, this is not merely the block of time between tape changes (which would show significant overlap of the two C recorders due to the crew's promptness in changing tapes) but the time from handover to that recorder until end of tape. Some overlap betweeen C tape events can be seen due to the PHRR handover period. This has been reconstructed from the C-Data log and all times are believed to be good within 1-2 minutes. MISSION TIMELINE - PAO EVENTS The PAO events cover interviews and crew choice downlinks. They have been reconstructed from the delivered execute packages. It is probable that a handful of crew choice downlinks did not execute, or were shorter or longer than shown as there are no resources to provide as-executed info on PAO and crew choice events. MISSION TIMELINE - NOTES We have tried to place notes to illustrate special events that are not associated with a particular data take. The major events during OOCO and deactivation, cold gas cycling during the flight, deliveries of radar configuration files, water dumps, trim replans and other items are noted. Most of these events are reconstructed from the Librarian log. AMS was not able to confirm the major mast events and cold gas cycling in time for this release. MISSION TIMELINE - AODA OUTAGES Like the C-Performance and C-Data data take success data, which is associated with specific events, AODA published a list of times when they observed dual receiver outages (less than 4 satellites tracked). For the final version, these were reconstructed from post-flight logs provided by AODA. MISSION TIMELINE - SITES The sites list is merely a list of overflight times of interesting sites including NTV sites used by the situational awareness tool during the flight, as well as some major cities and SRL sites added later. The times should be good to within a few seconds. AS-FLOWN TDRS FILE This file was compiled in flight from delivered TDRS files from the JSC Pointing position every 12 hours. Each file was patched into the premission communications file. The "TDRE" and "TDRW" lines indicate S-band communication, whereas the "UNBLOCKED" times illustrate when the Ku antenna is geometrically visible and is not blocked by the orbiter. Handover times from TDRE to TDRW and TDRZ opportunities are not shown. Actual TDRS coverage followed this file in flight very well; nevertheless, it is probable that there are a handful of coverage opportunities that were changed or unavailable. Also, crew choice downlink and other conflicts have not been removed from this file; this just represents customer-independent geometric information. AS-FLOWN EPHEMERIS FILE The as-flown ephemeris file is a text dump of the final binary ephemeris used by MPS during the flight. It is constructed by patching together the delivered state vectors (approx. one every 3 hours) and propagating between them as well as after the last one (calculated at MET epoch 09/17:24:39). Unfortunately, the propagator can only use one set of assumptions for orbiter weight, drag scale factor, etc. Several of these changed during the flight - most notably the "vent force" caused by vernier thruster firings, which changed by 25% during the flight due to cold gas and deadband variation. This combined with the slight mismatch between the JPL and JSC propagators causes discontinuities in the ephemeris at each state vector, where the orbit is "reset" by the vector. We expect these discontinuities to be no larger than a second in downtrack since the state vectors were delivered so often. The accuracy of the state vectors themselves should be on the order of 80 feet of semimajor axis, 1 sigma. A JSC-reconstructed PATH ephemeris has been received at JPL as of 14 May. It may be processed eventually to provide a more accurate ephemeris. ----- For information of the images on this page, refer to the description links provided by each product.