[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

MAROC-TUBSAT....The Probable Story

My Research to those interested:

I've been debating with myself whether to write this piece and decided to 
make the effort...

MAROC-TUBSAT is the latest in a series of TUBSAT satellites developed by 
Vectronic-Aerospace GmbH of Berlin Germany.  It is an effort to provide for 
paying customers an inexpensive satellite platform ($100,000 US) for polar 
orbiting birds.

Well described on Vectronic's website (see Google.com), the typical TUBSAT 
has one or two VHF transceivers, one or two UHF transceivers and a S-Band 
(Probably just above 2.2 GHz --see Dr. Dish (Google again)).

The VHF and UHF transceivers operate FFSK and GMSK (definitions: see Google), 
and are capable of store and forward and probably real time operation. The 
VHF and UHF units are designed for Command and Control and on the past 
launched platforms have proved somewhat unsatisfactory for this use. No 
mention is made of voice capabilities.  Future platforms are scheduled to be 
controlled on S-Band.

The S-Band transmitter to this point has been designed for downlink of analog 
video signals in PAL format (Dr. Dish) received from an onboard camera with 
two set focus settings (see CRTS website). S-Band video should be able to be 
received by most AO-40 setups with a wideband analog receiver.  The  S-Band 
frequency of the last TUBSAT (TUBSAT-N) was about to be given out to the 
interested, however the satellite reentered the atmosphere and disintegrated. 
(Dr. Dish)

Scheduling for the S-Band camera and transmitter has used the TEPR system 
similar to AO-27.  As MAROC-TUBSAT services Morocco, Europeans would seem to 
have the most exposure. (Perhaps this is why North America is not hearing 
436.075 transmissions at this time).

OK...the bottom line, with some conjecture...Morocco is very concerned about 
the fragile environment which surrounds them on the northwest tip of Africa.  
The government has commissioned the Centre Royale de Teledetection Spatiale 
of Rabat  to monitor the Moroccan environment from space and suggest plans to 
protect it.
CRTS has in the past used all available satellite sources on a contract basis 
to meet this goal.

The Technical University of Berlin (TUB of TUBSAT) has up to this time 
provided Vectronics with the technology, command and control of the previous 
Control was definitely from Berlin (Dr Dish).

Final Step....Vectronics has sold the MAROC-TUBSAT platform to CRTS to survey 
their country's environment.  As part of the package, Technical University of 
Berlin has been contracted to provide the command and control and understands 
the use of frequencies and modes. TUB reports to CRTS and does their bidding.

Let's suppose....on January 10th a news report came out that the Moroccan 
government was awarding the CRTS Scientists for a successful satellite launch 
and deployment...someone from Morocco calls TUB and requests that the 
satellite make it's own "announcement" on a "receivable" frequency.  The 
Technicians at TUB try to figure out how to "modulate" a "common" frequency 
with either FFSK or GMSK.  The best they can do is "Thumpy" FM CW on 144.100. 
 They give it a few power consuming "laps" around the earth, and either 
because of power consumption or the "uproar" (they are in Germany and no 
doubt some are Hams). They discontinue the 2 meter beacon. The 436.075 is 
their control frequency , so they leave it on under TEPR and maintain control 
from Berlin.

Is it a "ham" satellite? I think it can be...if the modulation techniques are 
attainable (inexpensively), is CRTS responsible for the frequency choice, 
probably not.  Do hams have some influence?...Yes,, probably through AMSAT-DL 
contacting the appropriate people at Technical University of Berlin. Can we 
use it now?  Might give our S-Band setups have another use on bad AO-40 days.

Below are some links to the above info:





The "facts" used in this description were gleaned from German, French, 
English, and Technicalese....I only speak English....however I tried to use 
common sense.

I am not an expert on MAROC-TUBSAT (though I now know MAROC is Morocco in 
French), I am just trying to save any interested party about 6 hours worth of 

Best of the SATS to all!



Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org