New Satellite Suggestion: ACRUX-1 - launch on 29th June at 4:30UTC


On the next RocketLab Electron launch, Melbourne Space Program’s ACRUX-1 will be launched. It is a 1U CubeSat built by students at the University of Melbourne, Australia, where I got my undergraduate electrical engineering degree :smile:

It is the second satellite built by Melbourne Uni students. You may have heard of the first: Australis OSCAR 5 (AO-5) which was also the first satellite launched by the newly formed AMSAT! :slight_smile:

It has been coordinated with the IARU at 437.200 MHz 9k6 GMSK

According to Gunter’s Space page, other satellites include BlackSky Global, Prometheus-2 5?, Prometheus-2 6?, SpaceBEE 8, 9, ?

According to Twitter, the next launch window opens at 2019-06-27T06:30:00



@KU2Y Thanks for the info!

ACRUX-1 Entry in SatNOGS DB

I have used temporary NORAD ID 99964.

Now we need TLE for scheduling observations in Network.


I generated a pre-launch TLE based on the published target orbit (450 km x 450 km from the PressKit) with the inclination of BlackSky Global-1 (97.48°, source: - BlackSky Global) for a launch :rocket: at the beginning of the window (2019-06-27T04:30:00Z) using sattools by @cgbsat.

1 84003U          19178.18750000  .00000000  00000-0  50000-4 0    04
2 84003  97.4800 346.5340 0000001   0.0000 219.5621 15.38685052    00

Launch site including marine safety area (source: Public-viewing-restrictions-Make-It-Rain2.pdf):

Take it as a first guess (this is only the second time I’ve done this). :slight_smile: :computer:

kerel / Fabian P. Schmidt

update: The launch will likely be at 2019-06-27T04:40:00 (source: RocketLab tweet), updated TLE (using launchtle from sattools (explanation post):

1 84003U          19178.19444444  .00000000  00000-0  50000-4 0    07
2 84003  97.4800 349.0408 0000001   0.0000 219.5621 15.38685052    03


Thanks @kerel for the TLE. I’ve just scheduled some observation for the first ~12 hours.


Problem the laucnh is at 2019-06-28T4:40:0 according to the rocket lab site.

Targeting no earlier than 28 June UTC.

Target lift-off no earlier than 04:30 UTC


There are now some TLE (for 27th June) in ACRUX-1 site:

1 99999U 18001A   19179.22247685  .00000000  00000-0  40148-2 0    55
2 99999  45.0237 288.3238 0014041 260.8755 155.5228 15.39805332    02

Probably they will be updated for tomorrow’s (28th June) launch.


The epoch of the ACRUX-1-preliminary TLE you posted is 2019-06-28T05:20:22Z, so this is probably for the (28th June) launch already.

Due to the 45° inclination of this TLE the launch azimuth matches with the marine safety area now (the small green polygon):


Launch is postpoponed for the next window starting at 2019-06-29 4:30 UTC


Latest TLE from

1 99999U 18001A   19180.22247685  .00000000  00000-0  40148-2 0    68
2 99999  45.0237 289.3095 0014040 260.8773 155.5210 15.39805221    01

Observations for the first 5h are scheduled, if the launch doesn’t get postponed again more observations will be scheduled.


The launch was on time, more observations of ACRUX-1 for the next 24h have been scheduled.


Acrux-1 was received, however not consistently, we’ll keep watching.

The are post-launch TLE:

1 99998U 18001A   19180.22396991  .00000000  00000-0  38994-2 0    13
2 99998  45.0092 289.1016 0011360 272.6068 154.6569 15.37628226    03


Decodes and some data plots can be found here:

Data is decoded from a nice observation from @vk5qi!

I have just added a decoder for ACRUX-1 to satnogs-decoders - a dashboard will follow as soon as there is a fixed NORAD ID available and people start transmitting data (either via SiDS or via SatNOGS network) for it!


From latest good observations ACRUX-1 is one of 44369-44371, changed to follow 44370 in network


I’ve processed a IQ file for with direwolf.

The packets can be found here :

IQ file (complex, 48k) is here


There was a request on IRC #cubesat channel for trying to receive the satellite PAINANI-1. The person that requested that said that this satellite was in this launch.

It’s not coordinated by IARU but it has a request for coordination. I’ve added it into the DB and I’m going to schedule a couple of observations to test if it is a valid case, as there isn’t any other reference on this satellite or that it was in this rocket.


I can confirm that the packets received in observation #783079 ( were decoded using the FSK flowgraph, not the MSK one. I had intentionally changed my file to force the use of the FSK flowgraph to see if it would work - and it does.

So it might be worth changing the modulation type to FSK9k6.


Also, I’m pretty sure object 44369 fits best to ACRUX-1 at the moment:

Nothing sighted on 437.475 MHz from PAINANI-1 on any of my STRF observations.


ACRUX-1 changed to follow 44369 in network, also we have changed temporarily the decoder to GFSK, in order to be able to decode, as GMSK decoder doesn’t work very well.

@DL4PD has set up dashboard for ACRUX-1.



There is a small chance we have a beacon of ACRUX-1 in this observation:

However two other stations at the same period didn’t get anything. The difference between station #232 and the other two is that #232 has directional yagi antenna instead of omni ones on the other two.


I did notice that, and wasn’t sure if it was ACRUX or not… hard to tell without a valid decode.