Wednesday, 7 July 2021

Imaging objects from the 'Tubular Bells' launch

image: Virgin Orbit

During the first days of July, I have tried to image objects from the June 30 Virgin Orbit 'Tubular Bells' launch, that launched a number of smallsats including Brik-II, the first Dutch military satellite (see earlier posts here and here).

I so far managed to unambiguously image three objects from the launch. One of these is probably the LauncherOne upper stage, the other two must be payloads.

On July 2nd, I imaged objects A and B, A using a 2.0/135 mm and B using a 1.4/85 mm lens on the WATEC 902H2 Supreme low light level video camera. B was very faint and barely visible.

On July 4th, I unambiguously imaged objects B and H using a 2.0/135 mm lens.

Object A is relatively bright and well ahead of the other objects. It is in a somewhat lower orbit: a 418 x 504 km orbit, whereas the other objects are in a 496 x 522 km orbit. So object 2021-058A almost certainly is the LauncherOne upper stage.

Below is video of the A-object, shot on July 2nd with the 2.0/135 mm lens. The bright star top left is Polaris. I could not see the other objects (passing about 30 minutes later): for passes to the north of me, the illumination angle is less favourable than for passes to the south of me.


The B and H objects are fainter, and only visible during passes to the south of me. The video below shows them, faint but unmistakenly, during a pass in evening twilight on July 4th (sun at only 7 degrees below the horizon, so the sky background was still quite bright).


A fourth object, Object C, was possibly seen on July 2nd when I watched the pass live on screen, but I could not see it anymore when inspecting the footage afterwards. 

Objects D, E, F and G were not seen, but on all imaged passes observing conditions were not perfect (on July 2, cirrus clouds were invading the FOV around the time of the objects D, E, F and G passing; while on July 4th the sky background was still very bright).

It is not clear which object is which at the moment, although I have reasons to believe that Brik-II must be either object D, E or F. I have some suspicion that objects B and H are part of STP27-VPA. [edit: see updates below: Object H was, but B is not).


I obtained even better imagery of the two STORK objects (B and C) on July 17:


UPDATE 14 Jul 2021:

Object B actually appears to be one of the STORK satellites, based on Dopplerfitting of  radiosignals received at 401.1 MHz (and first detected by Alicja Musial in Poland). Object C also appears to be a STORK, based on Doppler fitting of the radio signal.. 

Objects D and E are now listed by CSpOC as CNCE3 and CNCE1, which are part of STP27-VPA.

Objects F, G and H then are Brik-II, Gunsmoke-J and Halo-NET (the latter two are part of STP27-VPA), with not certain which is which.

UPDATE 16 Jul 2021

Object F is now identified as Brik-II. Object H (One of the two objects I imaged on July 4) is now identified as Gunsmoke-J 2

As, from radio Doppler fitting, we know objects B and C are the STORKS (not yet identified as such by CSpOC), this means object G must be Halo-NET:

Object A    LauncherOne rb

Object B    Stork

Object C    Stork

Object D    CNCE3*

Object E    CNCE1*

Object F    Brik-II

Object G   Halo-NET*

Object H    Gunsmone-J 2*

* part of STP27-VPA

Bob Christy has pointed out that there might be a swap of the A and G designation in the future, to make the A designation a payload rather than the RB.

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