9 Nov 2024
Hello Folks,
Your continued collection of telemetry data for MO-122/MESAT1 is always appreciated. For the next couple of days the telemetry beacon on MO-122 will remain at its lowest power level. This puts the signal down a couple of dB, and it's noticeable from the ground. The low signal is a great opportunity to work on improving the sensitivity of our receiving stations! The transponder power remains the same--it's strong, thanks to AMSAT's LTM (Linear Transponder Module)!
The satellite remains in good health. Since launch in early July, eclipse periods have increased a good deal, going from about 15 mins to nearly 29 mins. At the same time, the orbit has precessed so the bird appears over populated areas where the transponder gets more use while in eclipse. These conditions mean the battery is getting used more with less time to fully recharge.
We keep a watchful eye on the battery and its reported capacity, and when there is an apparent decline it seems prudent to turn off the transponder for a couple of days to allow recovery. The low beacon for the next couple of days will allow us to see how much "relief" that gives to the power budget; it won't be much, but we can watch and learn. Managing a satellite's power budget is a balancing act of sorts.
The good news is that by the end of February it looks like eclipse periods will drop back to around 17 mins. At the same time, the battery will be 4 months older--and have gone through a lot of orbits. Some fun math- from today until the end of February, there are 112 days. There are 1440 minutes per day, and MO-122 orbits about every 95 mins. 1440 min/day / 95 min/orbit is about 15 orbits per day. So, 15 orbits / day X 122 days means almost 1700 orbit and discharge/recharge cycles will occur before the end of February! Do that with your power drill battery pack ;)
Hopefully my update will help provide an answer to the logical question, "why is the transponder being turned off and on?" As the guest payload on UMaine's satellite, we are doing our best to be good stewards of an important resource, while also learning about LTM, lithium batteries, and powerbudgets---all of which is helpful to our engineering teams as they work on new birds like Fox-Plus and the Golf family.
Enjoy the bird!
73,
Mark L. Hammond [N8MH] AMSAT Director and Command Station