NG-14/ELaNa 31 Launch and Deployment Information

Hi,

I am part of the team that built the Bobcat-1 Cubesat from Ohio University. I’m making this thread to centralize the information I have on the launch and deployment dates/info for all the satellites onboard (including ours).

Launch Date (as of 2020-08-11): 29 September, 2020
Deployment Date (as of 2020-07-30): 16 November, 2020.

Satellites:

Deployment info: Satellites will deploy in the order listed above, with 1.5 hours between each deployment.

I will continue to update this thread as I get more information from Nanoracks and elsewhere.

Best,
Kevin

[Last updated: August 9, 2020 with additional frequency information from Nanoracks]

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Hi,

Here is some information on Bobcat-1:

  • Baud rate at launch: 1200 baud

  • Baud rate during normal operation: 9600 baud

  • Baud rate during passes over OU Groundstation: 100,000 baud

  • Beacons: We have a short and long beacon, described in the Kaitai Struct below.

  • Beacon Periodicity: Configurable/variable. During LEOP, expect short beacons at least as often as every 30s.

  • Frequency: 436.600MHz

  • Modulation: GFSK at 1200/9600 baud, GMSK at 100kBd

  • Protocol: AX100 Mode 5 (ASM+Golay), CSP at data layer.

  • Callsign: W8PZS

I have uploaded a .zip here that includes several IQ recordings and a kaitai struct for decoding the beacons: https://aec.eecs.ohio.edu/sharing/6AddYQjUj

During passes over the OU Groundstation, we typically will initiate a FTP download of collected data. There is an example FTP download in the above zip, the content of the file download was the LSF Manifesto. The data we are downloading is essentially just messages from our NovAtel, and that format is described elsewhere online (see NovAtel’s website). During these high-baud-rate (100kBd) observations, the normal beacons will still be transmitted, but at the higher baud rate. There is also a mode implemented on the cubesat where we can request a burst of beacons, typically 10 beacons in a row with 400ms between bursts, but this is not always reliable and may not be used during actual operation.

Last thing, here is our mission patch:

Kevin

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@lopezai in the SatNOGS chat has provided some documents regarding NEUTRON-1’s uplinks and downlinks:

https://docs.google.com/document/d/19nDOlsQggvXoOxZUgi4Pxes6zuFuZwvkA8kq0KORjX4/edit?usp=sharing

Some have reported issues accessing these documents so I have uploaded PDF versions here:

Attachment A_ LinkBudget.xls(1).pdf (2.6 MB)
KCC GS Overview (Public).pdf (314.5 KB)

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Hello,

Here is some information about the SATLLA-1 nano-satellite. SATLLA-1 nano-satellite is the first of a trio of nano-satellites aimed at demonstrating the ability of laser-based communications from space and testing the systems that enable it, which are being built by a team of students under the guidance of Prof. Boaz Ben Moshe at Ariel University.

The communication with SATLLA-1 is done via LoRa VHF and S-BAND. There are two types of beacons, short and long. Both beacons are byte array and we will share the beacons structure soon.

For more information, feel free to contact us at: kcg (at) g.ariel.ac.il (replace at. Avoiding spammers).

Following is our patch.

Thanks,
SATLLA Team

Unfortunately there will likely never be a LoRa flow-graph in SatNOGS due to the patent-encumbered nature of the LoRa physical layer.
The gr-lora project (which seems mostly abandoned?) does exist, but is reverse engineered, doesn’t perform well, doesn’t work with all parts of the LoRa protocol, and still has the patent issues surrounding it.

This means that while SatNOGS has a huge network of receiving stations around the world, none of them will be able to automatically receive telemetry from satellites transmitting LoRa. This is what you get for using a proprietary modulation technique unfortunately.

I should also point out that LoRa’s chirp spread-spectrum modulation is designed for use on the ISM bands, where there are usually many competing stations resulting in interference, which the spread-spectrum part of the modulation helps deal with. LoRa is well suited for those bands.

However, on the amateur satellite band, with frequency coordination and much less interference issues, all that spread-spectrum modulation does is use up far more bandwidth than is necessary (250 kHz on Norbi, really?!?!), resulting in potential interference to other satellites.

At some point there needs to be a discussion with the IARU about the use of proprietary PHY on the amateur radio bands…

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We already had some discussions here: https://forum.amsat-dl.org/index.php?thread/3215-lora-via-qo-100/

On 435 MHz amateur radio band LoRA is already used for some APRS applications.
The above article mentions LoRA via VHF? The required bandwidth would not be compatible with existing IARU/ITU regulations on the 145 MHz amateur satellite band.

Not to to talk about legal issues, which may also be different in some countries and are still unclear…

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