Author: SM0TGU

Re-post from ANS-315

On November 4, 2024 at 23:18 UTC, a Soyuz rocket launched from Vostochny with at least 17 satellites using amateur satellite service frequencies. Among those launched was ASRTU-1, a 12U CubeSat designed by Russian and Chinese students and developed by the Harbin Institute of Technology in Harbin, China, for education and amateur radio.

The satellite contains an FM transponder, which is currently operational, with an uplink of 145.850 MHz (67 Hz CTCSS tone required) and a downlink of 435.400 MHz. After the repeater detects the end of uplink, it will wait for 0.5s. If no new uplink in 0.5s, telemetry will be sent. So make fast QSOs so the telemetry is less like to interrupt you.

The satellite also contains two cameras with an SSDV downlink for low resolution images on 436.210 MHz, and a high speed downlink on 10460.00 MHz for high resolution images.

On November 7, 2024, the camera system was tested for the first time. N6RFM uplinked the command and the image was downloaded by Chinese stations using the UHF SSDV downlink.

Windows software for decoding telemetry is available at https://drive.google.com/file/d/1W8nm-P0_h0J1Bd1eif74mLo-EuRdWcjH

A Live ISO Linux image is also available for telemetry at https://drive.google.com/drive/folders/1T6GMNnDNEEavckoe4oPXPIU_SPFXLDd4

A Telegram group has been created for discussing the satellite: https://t.me/+I5NTtX7eAJA4ZDVl

Latest TLEs:

ASRTU-1_20241108D
1 99130U 24313.98869213 .00036395 00000-0 15511-2 0 00005
2 99130 097.3830 178.7387 0016365 224.8894 196.6964 15.22873038000014

ASRTU-1
	Uplink FM (67 Hz CTCSS)	Downlink FM	Comments
ASRTU-1	145.850 MHz	435.400 MHz	In orbit, commissioning
Also downlinks on 436.210 MHz, 10460.00 MHz. Download Live CD for telemetry decoding.

[ANS thanks BG2BHC, the IARU, and AMSAT-F for the above information]

Re-post from ANS-315

As AO-7, launched on November 15, 1974, approaches is 50th Anniversary and setting a record as the longest operating satellite, we look back at a few of its noteworthy accomplishments.

The downlink spectrum of AO-7’s UHF/VHF transponder overlapped with AO-6’s VHF-to-HF transponder. The overlap of the two was approximately 50 kHz wide. The two orbits were the same – almost. AO-7’s mean motion was slightly higher than that of AO-6, which means, once every year of so, AO-6 will “lap” its younger sibling in space. During the time when the two spacecraft are in closer proximity, it was already known to be theoretically possible (if AO-7 has its UHF/VHF transponder on) for one user to communicate through two spacecraft in succession, with the downlink of AO-7’s transponder being relayed through AO-6’s VHF/HF transponder uplink, and then, with the doubly relayed signal arriving on 29.5 MHz to another user on the ground. This could be done, in certain geometries, in both directions, making a two-way double-hop communications possible.

The first successful Earth-Space-Space-Earth relay of this type took place on January 6, 1975. This happened early in AO-7’s  “first” lifetime and during the first occasion when AO-6 approached AO-7, in their very similar orbits. The two stations were both located in the state of Texas – one in Dallas and one in Richardson. This method of communications was also conducted and reported by 55 other user stations from 12 countries during 1975. These events were documented in the IEEE Proceedings in October of 1975.

See another AO-7 50 Year Anniversary highlight in next week’s ANS Weekly Bulletin.

SONATE-2 from Space Technology Uni Würzburg is now operating as an AX.25 simplex Digipeater on 145.825 MHz.

To work this satellite you can use Greencube Terminal from OZ9AAR and the normal Soundmodem for AX.25 1200 bd.

I find it hard to get in to the satellite but as you see in the featured image in this post it is possible.

Anyway – nice to have one more amateur radio satellite.
More info at:
https://www.informatik.uni-wuerzburg.de/en/space-technology/projects/active/sonate-2/information-for-radio-amateurs/#c1137755