Friday, September 11, 2015

Observing the Fregat upper stage with Galileo 9 and 10 manoeuvering into transfer orbit, just 22 minutes after launch

Fregat upper stage with Galileo 9 and 10 after shadow exit, 11 Sep 2015, 2:30:12 UTC
click image to enlarge

Last night (11 Sep 2015) at 2:08:10 UT, ESA and Roskosmos launched a Soyuz from Kourou, French Guyana, with the new navigation satellites Galileo 9 and 10. The payloads are intended for a circular MEO orbit at an altitude of about 23 522 km

Cees Bassa alerted observers in Europe to the fact that the Fregat upper stage (with payloads still attached) would be visible over Europe during it's initial orbit insertion burn, exiting Earth shadow near 02:30 UT at an altitude of about 400 km altitude while cruising over Germany/Denmark. Engine cut-off for this stage of the launch would be 2 minutes later near 02:31:40 UT

This burn brought the Fregat stage and payloads in a ballistic transfer trajectory. A second burn about 3.5 hours after launch then inserted the stage and payloads in a circular orbit, upon which the payloads separated and the upper stage was de-orbitted.

Both Cees and I managed to observe the Fregat near 02:30 UT. This was about 22 minutes after the launch. Cees observed from Drente in the Northeast of the Netherlands(closer to the trajectory and with better observing conditions), while I observed from Cronesteyn Polder at the edge of Leiden in the West of the Netherlands.

Observing conditions were mediocre at my location: the sky was hazy, and light pollution a problem at lower elevations (it can be seen as an orange glow in the image above).

After exiting Earth shadow near 02:30:00 UT at about 45 degrees elevation in Ursa major, the Fregat stage was easily seen by the naked eye as an object of magnitude +2.

Above is one of my images, a 4-second exposure (Canon EOS 60D, EF 2.5/50mm lens, 800 ISO) starting at 02:30:12 UT.

Descending towards the Northeastern horizon the object became fainter, until I lost it in the light pollution and haze about a minute later.

Cees managed to image a developing hazy envelope around the trail low above the horizon (when it was already invisible to me), which is related to engine shut-down near 02:31:40 UT.

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