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Dr. Jason Hatton was one of the STS-107 scientists, working on the Leukin experiment. He saw Columbia's launch in person. Since he wasn't needed to work on the experiment after landing he returned to his home in the San Franisco area. He's also an experienced amateur astronomer and satellite observer and he decided to watch Columbia's reentry with his experiment onboard. When he saw pieces coming off he immediately realized that something was wrong - becoming the first person to realize that Columbia was in trouble.
Here's the report he sent to NASA after the accident -
Observing Location & Conditions:
I observed the re-entry of STS-107 from outside of my home in Mill Valley, California (CA94941-1551). The location of my observing site is approx. 37.8835N, 122.5549W, +20m. The local horizon provided me with a good view to the west, north and east from approx 10 degrees elevation & above. At the time of the observation there was partial cloud cover (3/8th), although the area of the sky which the re-entry was visible was largely clear of cloud. High altitude cloud or haze reduced the naked eye limiting magnitude (*see note 4) to approx magnitude +2.5 to +3. My observation site was in darkness at the time of observation. The re-entry was observed with the naked eye and 10x50 Binoculars, as noted below. I did not note down the exact times of the various events I observed, but I have I good idea of the azimuth / elevation (* see note 1 below) of the trajectory . The orbiter passed closed to Polaris during re-entry, providing a good reference for azimuth. Prior to observing the re-entry I had obtained a predicted time / azimuth / elevation table from the NASA Skywatch website for the Orbit 255 KSC re-entry track, as viewed from San Francisco which provided predicted times for the azimuth / elevation. I will refer to these predicted times in my description, although the actual time may be slightly different for the actual re-entry since my location is approx 10 miles N. of San Francisco.
Observation report:
I initially spotted the orbiter low down in the NW (~azimuth=300deg, elevation = approx 15 degrees, predicted time =05:53:00PST). It appeared as a bright yellow point of light (approx magnitude -2), probably my view was intially through thin cloud. Within a few seconds (~5s) it rapidly brightened (exited from behind thin cloud) and turned into bright fluorescent pink ball of light, which was at least magnitude -4. Trailing the orbiter was a green train (* see note 2) which persisted for at least three to four minutes after the passage of the spacecraft. I breifly (~5s) observed the bright pink fireball (* see note 3) through the 10x50 binoculars at approx Azi=325deg (predicted time = 05:53:15PST). At this time only the fireball & associated train was visible. No other particles were noted. I switched back to naked eye viewing, with the orbiter now appearing as a bright fluorescent pink teardrop shape as it approached maximum elevation. At this point I again viewed the fireball with the binoculars, observing it for approx 15 seconds from approx Azi=345 to Azi=030 (predicted time = ~05:53:25PST - 05:53:40PST)). At this point in the binoculars I noticed a small faint particle (perhaps magnitude +3) detach from the main fireball and slowly trail away followed perhaps 3-4s later by a second particle. These particles were visible for several seconds before fading. I do not recall if these small particles had trails. I breifly switched back the viewing with the naked eye, before returning to the binocular view at approx azimuth = 045degree (predicted time = ~05:53:45PST). In the binoculars I spotted more small particles trailing the orbiter fireball, perhaps a little brighter than those I saw intially. There seemed to be one particle released rom the main fireball every 1-2s. I followed the orbiter down to approximately 15 degree above the eastern horizon (azimuth = approx 65 degree), using the binoculars, when it passed out of view behind trees. I do not recall seeing any of the secondary particles being visible to the naked eye when I looked at the orbiter without binoculars from azimuth 030-045degrees.
After the orbiter had passed out of view, I observed the train which was slowly fading but remained readily visible to the naked eye for approximately 3 minutes after the passage of the orbiter. In binoculars I scanned the train and noted that it changed form over a period of perhaps 2-3 minutes from an essentially linear streak to a clumpy form, like a chain of cumulus clouds. This was reminiscent of the vapour trail left by a high altitude aircraft. The cloud like clumps appeared to rise above the linear streak component of the train at some points.
A single sonic boom was heard approximately 5 and half minutes after the passage of the orbiter past the pont of its highest elevation (approx due north) of its trajectory viewed from my site.
Notes:
*1. The Azimuth of various events that I observed was confirmed with a magnetic compass during daylight the following day, using local landmarks as reference. All Azimuths are relative to true north.
2. The term "train" is from meteor observation terminology& describes a trail which persists following passage of the meteor.
3. I use the term fireball to describe the bright ball of light which would have been the orbiter enshrouded in the re-entry ionization glow.
4. To denote brightness I use the astronomical magnitude scale . Venus is approx magnitude-4 and Jupiter is magnitude-2, while Polaris is magnitude +2. Venus, Jupiter and Polaris were all visible during the time of the observation providing a useful reference.
If you need further information or clarification of my observation please feel free to contact by phone or e-mail me at my address indicated below. I am deeply saddened by the loss of Columbia and her crew. Over the past several years I have been involved as a co-investigator in many cell biology experiments which flew on several Shuttle missions.On a couple of occasions I had the opportunity to see Columbia close up in the OPF at KSC, as well as watch two of her previous launches and landings. Our laboratory had an experiment onboard STS-107 & I was at the Cape for the launch. It is a great tragedy that what had beenup to this point such a successful mission ended in this way. I hope that my observation report of the re-entry is of some use to the accident investigation.
Yours Sincerely,
Dr Jason P Hatton
Mill Valley, CA