Help with SASSI*2 Observations


#1

SASSI^2 was launched by NG-11 on 4-17-19. It’s preliminary TLE is:
1 85429U 19108.77032782 +.09622322 +11996-4 +19212-2 0 0002
2 85429 051.6030 296.1897 0013541 131.9095 230.9855 16.3035962600015

We have reason to believe we may have received a high tip-off rate and are tumbling beyond the control authority of our ACS. We use globalstar to communicate, but need to be in a stable attitude to connect. Our low perigee will result in re-entry within the next 5-7 days, but possibly may also result in aerodynamic capture resulting in enough stability to make the connection and return our payload data prior to re-entry.

Any observations of our light curve, or detection of our globalstar uplink attempts, would be very much appreciated. Thanks in advance for any help!


#2

Hello,

Please provide details about your frequencies, frequency coordination, modulation, encoding and everything else you can share so we can have a starting point.

Also: You have not had any contact with your satellite within those 3 days?


#3

SASSI transmits on Globalstar’s uplink freq at 1610 to 1625 MHz. Channel access is CDMA Code Division. SASSI would typically be transmitting for a short duration to make a connection shortly after exiting eclipse. We currently believe SASSI is tumbling and consequently unable to make that connection. We have not made a connection since launch. We have some expectation that we may aerocapture as we get lower in the atmosphere significantly improving our chances of connecting, but we also now expect to re-enter as planned around Tuesday or Wednesday.


#4

How often does it attempt an uplink to Globalstar? The only chance you’d have of some kind of confirmation of operation is someone just happening to spot an uplink packet, at the right time.
I suspect you’re going to be out of luck however.


#5

I don’t think that we have a station online which can receive within the band licensed to Globalstar.


#6

We attempt log-in just after coming out of eclipse and just before passing into eclipse. We know its a long shot, but wanted to use all resources available. Thanks.