Sunday 12 January 2014

ISS and Orbital-1 Cygnus, 5 hours before docking

click image to enlarge

This morning near 6:56 local time (5:56 UT) I had a visible pass of the International Space Station ISS and the Orbital-1 Cygnus commercial cargoship bringing supplies to the ISS, five hours before the latter would dock to the first. The pass had a maximum elevation of 28 degrees, in the S-SE.

The Cygnus was faint: for most of the pass it was not visible by the naked eye (nor visible in my imagery, taken with an EF 2.0/35mm lens at F2.2 and 500 ISO).

Near 5:57:05 UT however, it briefly flared to mag. +2 and the duo ISS-Cygnus then became  well visible as a result, low in the sky at about 23 degrees elevation. They were quite close, with a pass-time difference in the order of 8 seconds. As always, seeing two spacecraft this close was an impressive (if brief) sight!

click image to enlarge

Thursday 2 January 2014

An unknown object in (near) Geostationary orbit: Express AM-5?

The evening of December 29 2013 started clear, so I did a small survey of a part of the geostationary belt. Main focus of the session was PAN, as well as Mentor 4 and 6.

Inspecting the images I found an unidentified object in near-Geostationary orbit some 4 degrees east of PAN, between Mentor 6 and NSS 5, on several images (positions here). The image below shows it near M42, the Orion nebula, near 19:17 UT:

click image to enlarge

In addition to the UNID you can also see a classified satellite at left, Mentor 6 (2012-034A), a SIGINT satellite also known under the code name Advanced Orion. At right are two commercial geostationary satellites, NSS 5 (1997-053A) and Galaxy 26 (1999-005A).

Cees Bassa in the Netherlands and Greg Roberts in South Africa also observed what is likely the same UNID object later that night. While it is not easy to fit a reliable orbit to such a relatively short span of observations, the suggestion is an object with an inclination near 0 and a Mean Motion of about 0.92 revolutions per day, i.e. an object near Geostationary altitudes.

The Mean Motion could suggest an old object being moved to a Graveyard Orbit. If this is the case, we haven't been able to identify which 'old' object it is yet.

Another option is that this is a new object. The only likely candidate in that case is the Russian satellite Express AM-5 which was launched on December 26th. This object seems to have been temporarily "lost" by JSpOC: as I write this (Jan 2),  Space-Track does not list orbital elements later than December 26th (when it was still in  a temporary transfer orbit).

For the moment, Mike McCants has given it the name UNK 131229 (with the acronym UNK meaning "Unknown").

This observing session also served to check on PAN (2009-047A). PAN is a highly mobile satellite and often moves position in May and December (I have written on the mystery of this satellite before). Not this time, it seems: it is still at the position it has been in for several months, forming a trio with the commercial satellites Yahsat 1B and Intelsat 10:

click image to enlarge

Other classified objects imaged this night were the old SIGINT Mercury 1 (USA 105, "Advanced Vortex", 1994-054A), and the SIGINT Mentor 4 (USA 202, 2009-001A). Mercury 1 was placed at 48 E and recovered by me about a year ago.

click images to enlarge

During this observing session, I captured a bright irregular orange light moving across the sky: a 'Thai Lantern' ( a miniature hot-air balloon). They are the cause of many false fireball and re-entry reports. Here it is, moving through Orion while carried by the wind:

Two days earlier, on December 27, I also did my periodic check on Prowler (90-097E), using the 61-cm Cassegrain of Sierra Stars Observatory in Markleeville, California (MPC G68).

I concluded the evening of the 29th by making some shots of M31, the Andromeda Galaxy. Unfortunately, some thin haze came in after a while. The image below is a stack of 16 haze-free images of 30 seconds exposure each, with a CLS filter (against light pollution - the images were taken from Leiden town center)) and Zeiss 2.8/180mm lens piggyback on the mount of my C6:

click image to enlarge