Sunday, 25 March 2018

The atmospheric reentry of the Soyuz upper stage 2018-026B on March 25

click map to enlarge

On March 21 at 17:44 GMT,  a Soyuz rocket (Soyuz MS-08) was launched from Baikonur in Kazakhstan, bringing three new astronauts to the International Space Station.

The upper stage from this rocket (2018-026B) reentered the atmosphere last night, producing a nice spectacle in the sky. The reentry was seen from southern Europe, and filmed from Italy. The still below is from video footage that you can find here on the Italian Ondanews website.

click image to enlarge. Link to newsitem with video

The US Military tracking network JSpOC gives a final TIP bulletin placing reentry at 25 March 1:25 UT ± 1 minute near 41.9 N, 8.1 E, depicted as a star symbol in the map in top of this page. The ± 1 minute indicates that this time and position come from an Infrared observation by one of the US Early warning satellites and hence should be very accurate.

I had been issuing forecast on twitter prior to this reentry, based on modelling in SatAna/SateEvo and GMAT. In addition to the JSpOC TIP position and time, the map above also gives some of my own modelling results for this reentry. The open circles were my two last proper forecasts, made before the actual reentry happened. The red dots are two "post-casts", i.e. forecasts made after-the -fact using orbital elements that were not yet available when I made my last forecast the evening before. The nominal position of the SatAna/SatEvo post-cast is only 10 minutes from the JSpOC TIP.

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