Atlas V 401 - Landsant 9 - 2021-09-27 18:12 UTC

Any feedback on how closely the CUTE observations so far have tracked with the prelim TLE posted for Object 99510?

Thanks!

-Scott, K4KDR

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Pretty well for the data we had to generate the TLE set. For example check this observation SatNOGS Network - Observation 4788289 some minutes ago.

However we still need something more accurate, especially for decoding.

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Sounds good - thanks!

East Coast U.S. pass in an hour based on the prelim TLE, but only modest elevation for me. Others will likely have a better chance, but I’ll be watching regardless!

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~0200 UTC, U.S. East Coast:

Based on report from JA0CAW, I was tracking 3 minutes earlier than prelim TLE posted above.

That was not enough - more like 6 minutes would have been closer. Between low elevation & incorrect antenna pointing, I was just barely able to make out the packets (‘if’ blips seen were from CUTE). Hope for better when the elevation is higher & TLE’s have been identified. Best of luck to everyone!

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New TLE set generated for CUTE by @EelkeVisser and some precious help of @cgbsat:

CUTE
1 99510U          21271.15496300  .00000000  00000-0  50000-4 0    07
2 99510  98.0299 338.9387 0001000   0.0000  91.1154 15.01454597    07

As this TLE set describes an object that it is far away from the previous one, I’ve removed all the future observations of CUTE and I’ve re-scheduled them.

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I posted this in the other thread as well, but here is the most recent Goddard TLE from this morning (~10 AM UTC-6:00):

1 99999U          21271.77083333  .00145021  00000-0  11565-1 0 00007
2 99999 097.6135 339.7814 0024140 250.2663 283.5278 15.00181134000153

EDIT: Also see this comment from myself from the other thread:

By the way, we just had a pass in the past ~30 minutes over Boulder, CO, and we tried using the most recent TLE that Goddard gave us, only to find that the current SatNOGS TLE outperformed it by about 5dB of extra signal :slight_smile:

In good news–we managed to get two commands in! Both were to increase the beacon rate to 4 seconds. Note that these are automatically overridden after about 5 minutes by an internal macro, so the next observations obtained by SatNOGS ground stations will see beacons at 16 second intervals again.

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Hi Nick, I am surprised that our tle works much better than the Nasa one. We based it first on a tle we believe is Landsat 9, updated that with the STRF measurements I did. This worked quite good. But @cgbsat suggested and helped to make a tle from scratch. Also @fredy was checking the intermediate tles to the observation that where already in the network. In the end we settled on our tle based on 4 passes which looked like:


Thanks for your feedback and good luck with your mission!
Best regards, Eelke.

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According to Jonathan McDowell, there where two other cube sats. Cesium Sat 1 and 2 (Cesium Space, Austin, TX).

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There are “To Be Assigned”(TBA) TLE sets from space-track.org for all the satellites from this launch:

Running ikhnos on our observations for CUTE it looks like that the best fit is OBJECT D(49263), with OBJECT E(49264) follow closely.

As the TLE are in TBA status, we should wait to identify CUTE. But for now in DB and Network CUTE will follow OBJECT D(49263).

With the assumption that CuPID was deployed at the same time with CUTE (@aregan or @nsdecicco could you confirm that?) and the the other objects are not close, I’ve changed CuPID to follow OBJECT E(49264).

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@EelkeVisser

According to Jonathan McDowell, there where two other cube sats. Cesium Sat 1 and 2 (Cesium Space, Austin, TX).

Yes, that is correct. But these are commercial missions that I don’t believe beacon on amateur bands. My understanding is that these are meant to be test bed missions for Cesium’s Nightingale 1 Ka band radio.

@fredy

With the assumption that CuPID was deployed at the same time with CUTE (@aregan or @nsdecicco could you confirm that?) and the the other objects are not close, I’ve changed CuPID to follow OBJECT E(49264).

IIRC I believe the order of deployment was:

  1. One of the Cesium sats
  2. CuPID
  3. The other Cesium sat
  4. CUTE

(But I could be mis-remembering.)

I am not sure how much time elapsed between each deployment.

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Thanks for the details… so for CuPID we will wait to receive it to be sure by scheduling observations over US.

We’re configured to track NORADID 49263 as CUTE now as well. We have a pass in about 8 hours but plan to receive only. We’ll command again at ~2021-09-29 16:38:00 UTC.

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Hi all,

Emil here from the CuPID team. We are still working on establishing first contact with our satellite. We think our current challenge is just knowing where our satellite is. We have a few TLEs but none of them successful. CuPID is set at 400.5MHz and 38.4 downlink. These settings were decided upon years ago for some reason I am not aware of. We don’t beacon because of our frequency and license.

Thank you for looking for us up there. Once we establish contact we will certainly let this awesome community know!

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Thanks for the update, Emil.

Many stations are capable of receiving 400.5 MHz & also decoding 38k4. Will CuPID only downlink immediately when receiving a command from the ground? Or, once a command is received, will there be transmissions from the satellite for some (???) period of time after?

Also, from what location(s) will ground commands be sent. It would be helpful to know when the satellite might be heard.

Thanks!

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Hi @K4KDR - Thanks for your help. CuPID is working from a ground station at Boston University.

The design of CuPIDs ground pass begins with 3 commands from the ground that tell the satellite to open some filters, and stream an EPS packet. From there we command it to stream more data packets. After looking at live data packets, we then try and downlink a file. CuPID will not downlink files unless it receives a specific command from the ground.

Cheers!

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Very good - thanks! So depending on the satellite’s transmitter effectiveness, I might have a chance to receive it here in Virginia. Ditto SatNogs stations in the region.

I’ll try to watch for it as often as possible but if you would like to post somewhere when you intend to attempt uplinks, that might increase the number of stations listening on the ground.

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Hi @ematz and welcome!

Thank you for the details about CuPID.

About the TLE sets, CuPID’s orbit is described from one of the following (source space-track.org):

0 TBA - TO BE ASSIGNED
1 49261U 21088B   21271.93862092  .00004000  00000-0  32217-3 0  9995
2 49261  97.6253 339.9480 0022102 249.0096 110.8769 15.00318609   161
0 TBA - TO BE ASSIGNED
1 49262U 21088C   21271.93862092 -.00008855  00000-0 -69621-3 0  9999
2 49262  97.6215 339.9481 0021940 248.2474 112.3009 15.00476349   161
0 TBA - TO BE ASSIGNED
1 49263U 21088D   21271.93774192 -.00005522  00000-0 -42110-3 0  9995
2 49263  97.6240 339.9472 0017328 244.9374 115.0011 15.01538841   167
0 TBA - TO BE ASSIGNED
1 49264U 21088E   21271.87104219 -.00010846  00000-0 -83052-3 0  9991
2 49264  97.6227 339.8824 0016098 252.5125 107.4340 15.01631683   152

Currently all of them are close enough, so for reception any of them should work for now. Also our findings is that 49263 is CUTE, so the other three are good candidates. Depending on the angle of your transmission beam, trying all these TLE sets interchangeably would be a good strategy.

As @K4KDR said, knowing the timestamp of your transmissions and the TLE that you follow will be very helpful for us to organize the observations of our stations and have better chance to receive it.

Tracking CUTE as 49263 last night worked extremely well; our best downlink to date. We also just completed our pass with commanding and it also worked exceptionally well. We saw beacons from 0º elevation rising to 0º elevation setting and were getting commands in at <5º elevation on both sides.

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Ditto on letting us know about uplink times, I prioritize my station #2134 time to satellites flown by educational institutions. … and I’m in western MA :slight_smile: So lots of overlap.

Cheers
,

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CUTE is now identified as OBJECT D(49263), here are the results of ikhnos on observation 4792784. NORAD ID is now changed in DB and Network, if someone uploads data on the temporary NORAD ID will be merged with the satellite in the next days.

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