Mark pointed out to me a mistake in my narrative, namely that there are additional dips into safe mode that I had not noticed. My excuse is that it is somewhat difficult to see these in the past if you are not looking at the right place/time (you probably noticed that in the "Status" block "Safe mode" does not register correctly.)
In any case, there was a brief dip into safe mode at the time the power went up early this morning. I'm guessing it might be going into safe mode when it is in eclipse (sound familiar?) but I have not done the math. It will be good that it is going into full sun shortly (but then we have heat to contend with).
73,
Burns Fisher, WB1FJ *AMSAT(R) Flight Software*
On Thu, May 14, 2020 at 11:21 AM Burns Fisher (AMSAT) [email protected] wrote:
I have done a lot of examination of the telemetry sent today from HS-1. This is a narrative of what I believe to be the sequence of events.
As most of us are aware, HS-1 has been operating at about 17mW of power for several months without the transponder on. Turning up the digital gain by 3dB or more had only a minimal effect (maybe up to 18 or 19 mW). Turning on the transponder last weekend had little effect. It's not clear (to me at least) whether the transponder downlink power maxed out at 20mW or so, but at the very least, we know that a strong uplink signal appeared to modulate and/or take power away from the beacon.
At approximately 0456z today the power (as read by the telemetry) jumped to over 300mW. This does not appear to be related to temperature, although it should be no surprise that the RxTx temperature showed a rise shortly afterwards. In addition, there was no obvious change in bus voltage preceding the occurrence.
At approximately 0720z today, 14May, HS-1 went into safe mode. This is likely because the bus voltage went below the auto-safe threshold (there is no other reason that this will happen autonomously--I don't believe that the UW components can command it), although looking at the bus voltage graph, it is not especially low at that time. It could just have been a pulse that happened at a different time from the telemetry being read. In the meantime when the beacon was on, the radio power was still high (although varying--this could easily be telemetry data collection issues)
HS1 came OUT of safe mode back to health mode at about 0854z. Again, this is probably related to the bus voltage, but I just can't see it on the graph. This made little difference in the output power.
At about 1120 there was a brief bus voltage drop from about 6.2 to about 5.8V. which sent it into safe mode again. In the middle of this safe mode, the RF power dropped back to 20-ish mW. Health mode was restored around 1250, and the RF power remained at 20-ish mW.
Between 1252 and 1255, 10 commands were received. All the commands visible in the telemetry were CAN commands, which I assume were to turn on the EPS. We did not have enough telemetry to see all 10 commands, but Drew states that he sent telemetry power commands, so those were doubtless the ones that did not show. Indeed the telemetry power appears to have dropped a bit, consistent with reducing digital gain.
rc_eps_batt_5 and batt_2 are now sending telemetry, indicating that the restart of the EPS was successful.
73,
Burns Fisher, WB1FJ *AMSAT(R) Flight Software*