ISRO PSLV-C54/EOS-06 Mission - 2022-11-26 06:26 UTC

More details about the launch at:

Launch Live Stream at:

India23x15 EOS-06
Switzerland16x16 4× Astrocast-2

India23x15 Dhruva Space’s Thybolt-1 & Thybolt-2
India23x15 Bhutan23x15 BhutanSat (aka INS-2B)

India23x15 Pixxel’s TD-1 Anand


Thanks for sharing this information.

Can you also help in finding and sharing information about orbit and frequency use.

Mission Brochure
ISRO’s PSLV-C54 is to launch EOS-06 (Earth Observation Satellite - 06) and Eight
Nano-satellites into two different SSPOs. The Primary satellite (EOS-06) will be
separated in Orbit-1. Subsequently Orbit change is planned by using two Orbit
Change Thrusters (OCTs) introduced in the Propulsion Bay Ring of the PSLV-C54 Vehicle.
The Passenger Payloads (PPLs) will be separated in Orbit-2.

INS-2B (18.3 kg): INS-2B or ‘India-Bhutan Sat’ is a jointly developed small satellite by SAC/URSC/ISRO and DITT of Bhutan. For this project, engineers from Bhutan received training from ISRO. Satellite will host two payloads NanoMx and APRS-Digipeater. NanoMx is a multispectral optical imaging payload by Space Applications Centre (SAC)and APRS-Digipeater payload is jointly developed by DITT Bhutan and URSC. The satellite bus was validated on PSLV-C52 flight as INS-2TD.

Anand (16.5 kg): A commercial hyperspactral imaging satellite by Pixxel which can image in 150 spectral bands. It was earlier manifested on PSLV-C51 but had to be pulled due to software related issue and readjusted on later flight opportunity. The supplier of imaging camera is Dragonfly Aerospace.

Thybolt-1 and 2 (1.5 kg): Two cubesats by Dhruvaspace to flight validate their 0.5U bus and they will be deployed by their DSOD 1U dispenser which was earlier tested on PSLV C53 with a dummy mass. Thybolt-1&2 will have a communication payload with store-and-forward functionality in the amateur frequency band for HAM radio operators.

Astrocast (4 Nos.) (18 kg): Four 3U cubesats by Astrocast for their constellation to provide Internet of Things (IoT) communication services. The cubesats will be deployed by a ISISpace Quadpack dispenser. Astrocast have previously launched with PSLV on C45 flight.

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link to IARU coordination for Thybolt-1 and 2 here

Satellite Telemetry and Beacon data with decoding schematic and links shall be available for all licensed amateur operators. Proposing UHF downlinks using CW and 9k6 2-FSK with CCSDS encoding. Planning to launch on PSLV mission C54 in November 2022. More info at **A beacon on 435.360 MHz and downlink for data and telemetry on 436.175 MHz have been coordinated

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This also seems to transmit on radio amateur frequencies but without iaru coordination as far as I searched.

By the way any help with suggestions in DB for these satellites and its transmitters will help to add them and schedule them.

Also we will need some preliminary TLE sets. Maybe @cgbsat could help on this.

Some orbit info from PSLV-C54/EOS-06 Mission


This may be INS-2B (IARU coordination)

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This is pretty confusing, is it possible to get some confirmation on satellite name and operations?

Thybolt-1 and 2 mission info updated on Dhruva Space web.

Good evening everyone, Thybolt mission update :

  1. All satellites integration with the rocket is complete
  2. The rocket as you can see if out of the launch assembly complex
  3. It will soon be on the launch pad.
  4. We expect that we will have the first pass over hyderabad on 26th night between 11:25 & 11:45. I will share the latest TLE update on 26th afternoon/evening to get the details of passes over hyderabad.
  5. We have a CW beacon that will transmit the health parameters of the satellites for the first few days.
  6. Since the satellite is a very tiny cubesat, we expect to start the payload operations with respect to store & forward by late next week or early December.
  7. A step by step process along with software for decoding of telemetry & beacon is being prepared. I will share this information within the next 24-48hrs.
  8. We are also planning to do an information session on the day of the launch in hyderabad. We are trying to finalise the venue. I will share the details also about the same within the next 24-48hrs.

Most of the engineering work on the satellite has been done by engineers who are also amateur radio operators. We are all very excited yet quite nervous about the outcome of the launch. This is also because about 95% of the entire mission is built by the team from scratch. There are several things that need to be extremely right for the overall success of this mission.

First few hours from launch :

  1. The launch vehicle(LV) will give signal to a box ( we call it the resistor box, RB ) that in turn is connected to the deployer ( DSOD-1U ). RB & DSOD-1U is also built by dhruva space team.
  2. Once the command from the LV is given to DSOD-1U, a hold down release mechanism on the deployer is supposed to unlatch the spring loaded door which is housing the satellites.
  3. We have used dual redundancy on the RB & the hold down release mechanism & these have been tested multiple times to ensure a reliable outcome.
  4. Once the door opens & the satellites are ejected out, both satellites also have to over a period of time distance themselves from each other.
  5. For distancing over a period of time we have include a few tiny springs that will ensure that there is some force imparted for Thybolt-1 & 2 to distance themselves from each other over a period of time.
  6. Don’t be surprised if we are hearing both satellites at the same time. There is a definite possibility. More on this later.
  7. Once the satellites are ejected out of the deployer they are also supposed to power on themselves.
  8. By default when the satellites are ejected out of the deployer they are in a spinning state. We have control the spin to ensure the antennas are pointing the ground to transmit the data, solar panels are pointing at the sun to generate power etc.
  9. Now after ~60 min of deployment the satellite will deploy its antennas. The antenna deployment mechanism is also developed by us & is also a very critical system on the satellite. Because if the mechanism fails, the mission is compromised.
  10. We hope that all these iterations will be done & we should be getting a successful reception by 11:30 pm on 26th.

I will share more details tomorrow & day after. Thank you everyone for all the support.

From Sanjay, the CEO of Dhruvaspace


I’ve reviewed the satellite suggestions for this mission. We are still missing TLE sets, so we can not schedule them in Network. Below are the entries:

I have made a preliminary TLE:

EDIT: This TLE is not good. It is north bound, should be South bound. 
1 99288U          22330.26458333  .00000000  00000-0  50000-4 0    02
2 99288 140.0000 258.0000 0001452   0.0000  22.0000 15.18227275    04


faketle -i 99288 -q 510.202 -Q 512.202 -I 140 -n 258 -m 22 -t 2022-11-26T06:16:00 -d 300 > isro.tle

Edit: Updated the TLE becaue I forgot the 5 minutes offset. Sorry.


@fredy I noticed that the frequencies and mode are different for Thybolt Mission on IARU coordination web and Dhruva Space’s web.

For the downlinks (CW and FSK) are the same but for uplink they give another frequency. We need to check if the uplink was coordinated.

@EelkeVisser I’m going to update them, just have in mind that these TLE, according to @cgbsat may are not very accurate on the inclination.

After suggestion of @cgbsat to not use the launch direction but use an inclination of 98 degrees I got TLE:

EDIT: This TLE is not good. It is north bound, should be South bound. 
1 99288U          22330.26458333  .00000000  00000-0  50000-4 0    02
2 99288  98.0000 242.5000 0001452   0.0000  14.0000 15.18227275    05

Using command:

faketle -i 99288 -q 510.202 -Q 512.202 -I 98 -n 242.5 -m 14 -t 2022-11-26T06:16:00 -d 300 > isro.tle

I have adjusted the -n and -m parameters to bring the satellite above the launch site 5 minutes after launch. The location is checked using:

satorbit -t 2022-11-26T06:21:00 -i 99288 -c isro.tle -B 13.7199 -L 80.2304 -q


I hope this will work out!

I have used this guide to produce the TLE:

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Here are the preliminary TLEs from ISRO and Dhruva Space that I just received.

1 54464U 22088C   22330.34726505 -.00000000  00000-0 -00000-0 0 01113
2 54464  97.5631  65.2609 0010969 257.1226 307.6549 15.18801812111118

1 54465U 22089C   22330.34726505 -.00000000  00000-0 -00000-0 0 01115
2 54465  97.5631  65.2609 0010919 257.3986 307.3787 15.18818263111118

Just curious are these somewhere published too?

The following TLEs uses dummy/ placeholder NORAD IDs and International Designators. These can be added to gpredict to determine passes at other ground stations wherever required.
We will soon update the correct NORAD and Satellite designator once Space track assignees.

Deepak - Dhruva Space Thybolts mission team.

1 54464U 22088C   22330.34726505 -.00000000  00000-0 -00000-0 0 01113
2 54464  97.5631  65.2609 0010969 257.1226 307.6549 15.18801812111118
1 54465U 22089C   22330.34726505 -.00000000  00000-0 -00000-0 0 01115
2 54465  97.5631  65.2609 0010919 257.3986 307.3787 15.18818263111118
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No. They are not posted anywhere. I got these from Sanjay (VU3ISS/AB3OE), the CEO of Dhruva Space and looks like @deepak26 from the Dhruva Space team also provided the same TLEs.

@fredy, can you please update the db with these TLEs? We have some upcoming passes over Europe. Would be helpful to see if any station can hear the birds.

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DB is already updated and there are a couple of observations scheduled in Network for the next couple of hours.

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