[amsat-bb] ARISSat-1 battery
Hi all. The ARISSat team seem to have reached the conclusion that the Silver Zinc battery technology is not really suited for an orbiting satellite with a 55 / 35 minute charge and discharge cycle. I wonder if a couple of small Lithium polymer battery packs would be a suitable replacement for ARISSat-2 ? I note that there are safety issues with Li-ion technology, but there are some small battery packs of 10Whr / 20Whr 30Whr modules which have NASA approval for manned space flight. From the odd snippet of information on the power required during eclipse (is it 7 Watts for 35 minutes) it looks like 20-25% depth of discharge for the 20Whr battery pack. That's probably OK for a 9 month mission ?? Thanks David G0MRF http://www.clyde-space.com/documents/1902 ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] ARISSat-1 Battery
Dear Friends, This is speculation but it looks to me like we have had a bit of good luck regarding the battery. Looking at the battery voltage from deployment on... Up until Aug 11, the battery seems to be deteriorating normally with a slight downtrend in the max voltage as expected. But on Aug 11, the battery voltage suddenly rises up to 36 V max and the satellite has started resetting in eclipse. I think the explanation is that the battery experienced a significant event on Aug 11 where it lost the electrolyte in one or more cells. If this is true, the bad news is that it will no longer hold a charge and will not operate in eclipse any more. But the good news is that without electrolyte, it would also stop dendrite growth that causes the eventual battery short circuit. In our ground testing, our test battery failed in the usual way with the battery load increasing until the solar panels could not drive the power bus high enough to run the satellite. But interestingly, several cells also cracked and dumped their electrolyte during this testing. If a cell on the flight battery cracked and dumped its electrolyte BEFORE the shorts were formed, it should stay that way and the satellite may very well continue to operate in the sun until it starts to re-enter. We just need some luck to avoid a bad solar angle that would cause a reset in sunlight. Keep your fingers crossed! :) 73, Tony AA2TX ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] ARISSat-1 battery situation
Hi to everybody, I've a question about the ARISSat-1 battery situation : If the battery goes dead (case 1: open circuit, case 2: short circuit, case 3: current is absorbed from panels but not hold from battery) which will be the behavior of the satellite? Thanks and 73 Giulio AB2VY Sent from my BlackBerry® wireless device ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] ARISSat-1 battery eclipse voltage decreasing
The ARISSat-1 Battery voltage is decreasing each eclipse period. It therefore is taking longer for the Battery to charge up to 32.5V to allow the switch from Low Power to High Power when the satellite enters an illumination period. Kenneth Ransom, N5VHO has plotted the battery min/max for the last 8 days. We see that the battery voltage is decreasing at a faster rate than expected. Kenneth's graph can be found on the arissat1.org site under FAQ http://www.arissat1.org/v3/index.php?option=com_contentview=sectionlayout=blogid=13Itemid=134 Take advantage of the High Power mode as much as possible over the next few days. 73, Gould, WA4SXM for the ARISSat-1/RadioSkaf-b team ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] ARISSat-1 Battery Condition
... Battery voltage around 33V status - charging. -David G0MRF Wow - I showed the battery at 28.891 during a pass last weekend. Solar panels are going their jobs! Sorry ... too old for this much excitement in one day ... Clint Bradford http://web.me.com/clintbradford/k6lcs/EVA29-1.html ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] ARISSat-1 Battery Charging
At the top of today's schedule for the Russians aboard the ISS ... Operations and experiments on the International Space Station July 27, 2011 - On July 27 the Russian segment of International Space Station, astronauts plan to continue their work to prepare for spacewalk (leak check suits, ping, and medical settings via spacesuits and equipment in the docking compartment, Pierce and the transitional compartment service module Zvezda, charging unit supply for micro Cedar), control mikroekosfery habitat connectivity DPO ship Progress M-11M to the management and maintenance of the ISS coolant ... Clint Bradford, K6LCS http://www.work-sat.com ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] ARISSat-1 Battery
OK - Charging of the ARISSat-1's battery is scheduled for July 27. And a test this weekend. Will the battery be charged a second time - before EVA-29 on August 3? What is the expected/anticipated battery charge state to be after the July 30 test? Good enough for deployment without another charge? Clint Bradford, K6LCS ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] ARISSat-1 - Battery Failure
RadioSkaf's Alexander, RA3WOK, just wrote me that they do, indeed, suspect battery failure of the ARISSat-1. Investigation and plans for deployment continue. According to preliminary information the problem is a failure of the battery ... In the near future, batteries will be on Earth. It cannot be kept on the ISS. The situation will improve in June and July, when scheduled launching of ARISSat-1. Clint, K6LCS http://www.work-sat.com ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] ARISSat-1 battery.
Hi Nitin / Vince. Although the non appearance of ARISSat-1 has been a little disappointing, in the overall scheme of things we are still looking at a major AMSAT achievement here. There is after all a satellite awaiting 'launch' on the ISS. We know it's a success because so many people have named it and want it to be identified as belonging to them. We even have some working telemetry decoding software 3 months ahead of launch. - Yipee. I'm really not sure what all the confusion over the last few days tells us. Prepared press releases full of mistakes, a complete lack of preperation following the long period of testing which left the battery delpleted. No plan B to charge it during the sleep period - One wonders if the switches were even returned to the correct positions when it was last turned off. Despite a turbulent last few days, the main event is yet to come and as long as the designers have anticipated it being deployed with a completely flat battery, then we can all sit back and wait for July more prepared from this rehearsal than we would have been. Regards David G0MRF In a message dated 12/04/2011 21:13:19 GMT Standard Time, vlfis...@mcn.net writes: At 10:49 PM 4/11/2011 +0530, vu3...@amsatindia.org wrote: Nothing heard on the 16.20 UTC pass, watch the live feed from ISS from http://spaceflight.nasa.gov looks like the crew is working on addressing the issue, the last comment I heard is recharging the batteries ( Please excuse if I am wrong J ). 73's Nitin [VU3TYG] That's what I was thinking because someone should have heard it by now. Maybe in two months pass the time since it should launched, even though it was off there might have been a small drain on the batteries and now they're in a discharge state. KB7ADL ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
