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Imaging the new Iranian satellite NOUR 1
On
22 April 2020 around 4:00 UT, Iran's Islamic Revolutionary Guard surprised the world by
launching a military satellite. The satellite is named
NOOR 1. The name 'NOOR' means 'Light' in Pharsi.
The object is designated
NOUR 01 by CSpOC, with catalogue number
45529 and Cospar designation 2020-024A.
NOUR 1 was launched using a new 3-stage
Qased rocket from
Shahroud (36.200 N, 55.334 E), the first Space Launch from this facility.
Little is known about NOUR 1, but the fairing of the Qased rocket depicted
what looks like a 6U cubesat, i.e. a small satellite with a bus of roughly 10 x 20 x 30 cm in dimension (not counting any deployed solar panels):
The satellite deployed in a
427 x 435 km, 59.8 degree inclined orbit. The orbit is
not sun-synchronous, but does have
a repeating ground-track about every 4 days.
Three days after the launch, on
25 April, I managed to image the
Upper Stage of the Qased rocket that launched the satellite, with a WATEC 902H camera and Samyang 1.4/85 mm lens:
Attempts to image the payload itself (NOOR 1) initially failed, because the late April/early May passes for my location were not the most favourable concerning illumination angles and sky elevation (these passes were low north for me).
But last night,
May 6 around 1:52:11 UT, I had a more favourable pass and clear skies, and
successfully managed to image the payload NOOR 1 with the WATEC 902H camera and a SamYang 2.0/135 mm lens. As this camera/lens combo has a small field of view (FOV), the observed arc is short: about 4 seconds. Here is the video:
The satellite was at a range of 595 km and a sky elevation of 46 degrees in the south-southwest at the time of the observation. I estimate it to be around magnitude +7.5 in the imagery.
The satellite shows no clear brightness variation during the captured 4 seconds, as is also visible from this 100-frame stack of the video frames:
It should be noted that there is footage from May 3rd obtained by Paul Maley in the US which does seem to show some variability. But Paul's footage is very noisy, making interpretation difficult:
At any rate, my own observation from last night does not show clear signs of tumbling, but I'll be monitioring the payload further the coming nights to look for any variability.
Why this interest in potential tumbling behaviour? There has been speculation about the state of the satellite, following derogatory remarks shortly after the launch by the US Chief of Space Operations, General Jay Raymond, who called it
"a tumbling webcam in space" (and says its a 3U cubesat):
US military sources are clearly trying to imply that the satellite is a failure, but that seems a politically inspired stance. My own optical imagery from last night, as presented here, has no indication for tumbling: if it tumbles at all, then it is at a very slow rate.
Moreover, during the three weeks after the launch, several amateurs including myself have received
strong telemetry signals from the satellite at 401.5 MHz, consisting of regularly spaced data packets with one data packet sent each 10 seconds.
The signals were first detected and identified as coming from NOUR 1 by Scott Chapman, and the story of this identification can be read in
this highly informative blogpost by Scott Tilley which also points to some interesting aspects of the signal, which can be partly decoded (!).
Below is a spectrogram of the telemetry signals as received by me from Leiden, the Netherlands, during a pass in the evening of 30 April 2020: note how strong and regular the signal is:
The Doppler curve of the signal matches that for NOUR 1 well, so there is little doubt this signal comes from the Iranian satellite.
(
note: the spectrogram also shows the signal of a second satellite at 401.5475 MHz, 'Object F', which is an unidentified cubesat from a Chinese launch in December 2019)
Radio amateurs closer to Iran have
reported data dumps when the satellite is in reach of Iranian ground stations. So clearly,
the satellite is alive and relaying data of an unspecified nature.
At the end of the first week of May, reports have been coming in that detected signals were weakening or absent. This could indicate that after 3 weeks of functioning, the satellite has developed battery problems. On the other hand it could also mean that after a check-out phase the satellite has been shifted to operational mode, and might only be sending while over Iranian groundstations. Further monitoring should shed light on this.
UPDATE 6 May 2020, 18:50 UT:
I monitored the NOUR 1 pass of 18:42 UT (May 6) and can confirm that the telemetry signal at 401.5 MHz is no longer present.
Perhaps the satellite has completed checkout and is now in operational phase, which could mean it only sends when in range of Iranian groundstations.