New Satellites: Plan for Electron Curie launch on December 16th


#1

14 new satellites are going to be deployed tomorrow. I’m opening this thread for gathering information around this launch and on the satellites. Feel free to post here, I’m going to create the satellites in db if we have a transmitter for them later today.


#2

Here’s a rough TLE based on the information from the pre-launch presskit. This should be good enough for planning passes.

This TLE is valid for a 04:00UTC launch.

1 73001U 18347.16666667 .00000000 00000-0 50000-4 0 00
2 73001 85.0000 136.0000 0001454 0.0000 200.0000 15.21937999 07


#3

From @vk5qi in irc :

https://www.projectdavincicubesat.org/participate/
“Using specific frequencies such as 145.1 MHz (uplink) and 436.5 MHz (downlink), the team can upload information to the satellite and those with a receiver dongle can receive the information and decipher it”
"Messages received will be in Morse code requiring students to download a translating app or to translate it themselves. "


#4

The AMSAT IARU Sat Coordinator page has the following coordinated frequencies:
CHOMPTT 437.560 9k6 GMSK http://www.amsatuk.me.uk/iaru/finished_detail.php?serialnum=523
ISX/CP11 437.150 9k6 FSK/AX25 http://www.amsatuk.me.uk/iaru/finished_detail.php?serialnum=514
CubeSail 1 437.505 9k6 GMSK AX25 http://www.amsatuk.me.uk/iaru/finished_detail.php?serialnum=NTMSat

The other payloads are not on that website.


#5

Thanks for the info, I’m going to add them after the db migration.


#6

4 satellites added, unfortunately no information for the rest.

Temporary Norad ID    Satellite
99940                 Da Vinci
99941                 CHOMPTT
99942                 CP11 (ISX)
99943                 CubeSail-1

I’ll add TLE right after the launch, as the calculated TLE above are based on the launch time. After addind TLE scheduling will follow.

live stream for the launch: https://www.rocketlabusa.com/live-stream
twitter account about the launch: https://twitter.com/RocketLab


#7

NMTSat
(New Mexico Institute of Mining and Technology)
https://apps.fcc.gov/els/GetAtt.html?id=206045&x=.

Downlink 148.8 MHz
Uplink 431.8 MHz

Also on board: an ELROI optical beacon. (~2 mW EIRP of red light.)

This is my experiment. I will be attempting to receive the signal with my ground station, which is a 14 inch optical telescope. Things will be rather hit-or-miss until good orbits are derived (my field of view is half a degree). But when I do detect the signal, it will unambiguously identify that satellite.

Gunter’s Space page lists the other satellites on this launch.


#8

Interesting, what kind of detector and filter are you going to use? The corresponding paper seems to be:


#9

The filter is a 10 nanometer-wde wavelength filter at the laser diode’s 638 nm center wavelength, blocking ~95% of the background light.

The detector we are using is a single-photon imaging sensor. We can get the timing signal from each point in the field of view so we can eliminate the light from stars and isolate the light from the ELROI beacon.

If you have a well-determined orbit and a good tracking telescope mount, so you can focus on the light within an arcminute of the satellite location, then you can use a conventional single-pixel photon counting detector like a PMT (photomultiplier tube) or a SPAD (Single Photon Avalanche Diode).

All you need is the photon times (sub-microsecond relative timing) and you can pick out the periodic signal against a much larger number of background photons.


#10

Thanks for the info!

What kind of mode (like FSK, MSK etc) and baudrate are you going to use for downlink?

As we are getting closer to deploy in production dashboards to visualize telemetry and other data of the received decoded data, it would be great if you can share with us details of the encoding/decoding you are going to use for your downlink.

We have seen the other satellites in Gunter’s space page but unfortunately we weren’t able to find frequency and other details in order to add them into our db.

EDIT:
I’ve already added NMTSat into db with the temporary norad id 99944. With the information above we can suggest and add the transmitter too.


#11

Here’s a TLE estimate for the December 16 launch at window open 04:00:00UTC.

1 73001U          18350.16666667  .00000000  00000-0  50000-4 0    04
2 73001  85.0000 139.0000 0001454   0.0000 200.0000 15.21937999    00

#12

We have scheduled a couple of observations for the satellites in db.

We used these TLE (thx to @vk5qi and ve7til):

1 70000U          18350.27343750  .00000000  00000-0  50000-4 0    07
2 70000  85.0000 177.2762 0001454   0.0000 205.1488 15.21937999    01

For NMTSat as it is outside of the current network antennas frequencies, I’ve added a new antenna “VHF Cross Yagi” from 135-150MHz… in order to observe it please your station to this antenna. If you need any other antenna type please let me know.

For NMTSat as we don’t have more info I’ve added the generic FM transmitter. If anyone has more details about its transmitter let me know to change it.


#13

Until now only CHOMPTT has been received.

Now we use slightly different TLE from @vk5qi:

1 70000U          18350.27343750  .00000000  00000-0  50000-4 0    07
2 70000  85.0000 178.8496 0001454   0.0000 206.4938 15.21937999    06

#14

Still the only heard satellite in network is CHOMPTT. It’s signal follows well 43855 object as you can see in the image bellow.

We had also an update from CubeSail-1 team, they transmit at 437.305MHz instead of 437.505MHz which is falsely described in IARU page. Also they provide us with their decoder repo. I’m wondering if we can add it as it is or we need to create a kaitai structure for it. cc @Acinonyx and @DL4PD

PS There are some twitter reports for CubeSail-1 signal, maybe we will be able to catch it in the next observations with the right frequency.


#15

I took the liberty of decoding and submitting some frames
until 2018-12-17 04:05 UTC into https://pssl.mae.ufl.edu/#chomptt/main/

As name I used this string: SatNOGS - {ID_-_Name_Of_Station}
example “SatNOGS - 61 - TEONITE-001”

As email I used info@satnogs.org
This also is used to group the observed frames under the same user, so one user for the whole community.

As country I used the country of the station.

I’ll try to continue uploading but I don’t promise anything :slight_smile:

Unfortunately I didn’t locate any dashboard of the submitted frames in order to see the statistics.


#16

Hey @dmpalmer,

Can you confirm that the signal at ~150s and ~400s is NMTSat in https://network.satnogs.org/observations/367603/


#17

I’ve changed CHOMPTT temp norad id to 43855 as several sources and our observations match the satellite with this id.


#18

no transmitter available


#19

There was an issue, it should be fixed now.


#20

Sorry for the delay. I am just a payload operator. New Mexico Tech (the satellite owner) has been on break and I couldn’t get any further information on the signal until now.

The transmitter is 1 Watt, 148.8 MHz, G3RUH modulated 9k6. Until it has been commanded otherwise (which it hasn’t) its transmissions are a short text once every 10 minutes. (i.e. you would not expect signals at both 150s and 400s). If you can decode a signal, with this info, then that would be great.

The current state of the TLE lottery is (unofficially):
Unclaimed: Objects C,E,F,K,L ;
43851, Object C
43853, Object E
43854, Object F
43858, Object K
43859 Object L
NMTSat is presumably one of these.

Officially claimed on JSPOC:
40849 AeroCube-R3
43852 STF-1
43855 CHOMPTT
43856 ISX
43860 SHFT-1
43861 AeroCube-Eaglescout

Obviously either the 2nd stage rocket body or the Curie stage due to 200km perigee:
43863 Object Q

Unofficially but unambiguously claimed based on contacts (I don’t know how public this is, so I won’t give the correspondences):
43850 Object B
43857 Object J

Unofficially claimed by two different groups, with anomalies:
43862 Object P
At least one, and possibly both of the claimants is therefore wrong (unless both claimants are stuck together sharing a TLE).