UPDATE: 12/20/2003

A transcript of voice communication during reentry between the shuttle crew and Mission Control Huston is in the document STS-107_Reentry_Text_J.pdf.  In this transcript at 13:41:35 Commander Rick Husband states' "Two minutes to entry interface.", to the other crew members.  Then again at 13:43:42 Commander Husband says, "OK. We're just past EI.".  If an official time for entry interface is not given then we know that it occurred somewhere in the 7 seconds between 13:43:35/42, the time 13:43:37 could be picked arbitrarily and made the official time of EI for use on this site.  The problem is that an official time for EI is given and it's 13:44:09, 32 seconds after the point where Commander Husband tells his crew that they just passed EI.

It could simply be assumed that Commander Husband checked his watch for the time not realizing it was off by 32 seconds or that Commander Husband was simply in error.  However several of the astronauts, Husband, McCool and Clark who are all veterans of at least one other shuttle mission, make statements about seeing plasma out of the front and side windows after 13:43:37 and well before 13:44:09.  If the time at which Columbia reached EI was changed after the loss of the shuttle as an effort to cover up something that happened to Columbia during reentry, the reason for the change cannot be found.  Since the Columbia was traveling at Mach 25 before EI the 32 seconds translates into 217 miles of travel over open empty ocean with no discernable observations or data points which may have required the 32 seconds to prove their legitimacy.

After looking at Fig. A10 and the STS-107 Ground Track documents, it does not appear that a 32 second shift would have significantly changed any of the data that creates the chart, (any changes in velocity, altitude or angle of attack would be negligible to nonexistent).  Based on the analysis done on Chris Valentine's visual data, the shuttle was where it was supposed to be when it was supposed to be there much later in reentry showing that other location data was not affected by a 32 second time shift.  EI may have been moved to accommodate the substitution of STS-5 telemetry data for STS-107 data as an early step in a cover up process when little to nothing was know about the shuttle data.  Because many of the data analysis posted on this site were done assuming that EI occurred at 13:44:09, that value will be maintained for the time being.

Any place where a total time after EI is referred to such as EI+500, 32 seconds can be added to give the time after EI per the cockpit intercom transcript  (EI+532).

Theory Under Consideration:

If a cover up exists within the Columbia investigation, then the 32 second shift in EI time may be connected to the additional 32 seconds of data taken from the 1OEX data recorder after LOS occurred at 13:59:32.  Most likely all of the error messages and aerosurface position data were shifted 32 seconds forward along with the time of EI so that there would be 32 seconds of data available after LOS.  However, this has not been proven.

05/15/2004

Based on the only definition for Entry Interface that has been found, it has been determined that the time of EI was shifted by 32 seconds specifically to alter the reentry timeline.  Entry Interface is defined as the point when the shuttle has descended to an altitude of 400,000 Ft. per the Reentry document on the NASA Human Space Flight Website.  The official altitude at EI has consistently been given as 395,010 Ft. for STS-107, (in direct conflict with NASA's own definition).  Therefore, EI occurred at the earlier time, 13:43:37, with the 5,000 Ft. difference accounting for the 32 seconds.  Much if not all of the telemetry data that is time stamped between 13:59:32 and 14:00:00 should be moved back 30 to 32 seconds with shuttle breakup then confirmed as occurring at LOS.  The effect this time shift has on other telemetry data throughout the STS-107 Timeline and Ground Track documents is currently unknown.

There are currently no plans to change the times of any events or telemetry data contained in the various tables and sections of this site.  The 32 second shift would not seriously affect any of the key findings and it is impossible to know how much data would need to be shifted if none at all.  If the time shift does have an effect on any of the conclusions it will be noted.

  1. It has been shown that the OEX recorder was removed from Columbia before STS-107 and was then planted in the debris field after the exterior was made to appear heat damaged.