[amsat-bb] Re: some exceedingly clever technology
Hi Phil, KA9Q What you describes using both magnetorquers ,momentum wheels and CCD video cameras for the attitude control system is what was made on AO40 but it was a big satellite and not a microsatellite. 73 de i8CVS Domenico - Original Message - From: Phil Karn k...@philkarn.net To: R Oler orbit...@hotmail.com Cc: Amsat BB amsat-bb@amsat.org Sent: Friday, August 26, 2011 6:54 PM Subject: [amsat-bb] Re: some exceedingly clever technology On 8/24/11 8:11 PM, R Oler wrote: http://onorbit.com/node/3709 Thrusters are necessary for orbit control, but for attitude control (which I think we really need) you'd *really* prefer something that doesn't consume a fuel. These attitude control systems come in basically two types: magnetorquers and reaction wheels. Magnetorquers exchange angular momentum with the earth by acting on its magnetic field, but they tend to be slow, imprecise and require complex control and sensing systems including a magnetometer far enough from the spacecraft to get away from its own magnetic fields. Reaction wheels come in two kinds: momentum wheels and control moment gyros. Momentum wheels change speed while control moment gyros don't. The latter seem much more common in spacecraft but I'd investigate both. They're good for quick, accurate pointing like you'd need to keep an antenna pointed down or a solar panel pointed at the sun. Having both a magnetorquer and a set of wheels can be advantageous as the magnetorquer can be used occasionally to dump accumulated angular momentum from the wheels should it build up from small external torques. Controlling attitude also means measuring it, and for this I keep thinking about small, cheap CCD video cameras. If we could build good enough sunshades we could snap pictures of star fields and look them up in a database. If you can match multiple stars in an image, then a single image could fix the attitude of the spacecraft. But I'd want to put a camera on each surface if possible. They could also sense the sun and the earth, though that's not as simple as it might seem. The sun usually overloads a CCD and produces streaks while the earth is very large in LEO. It might be possible to recognize the limb of the earth and get better precision that way. A lot would depend on the software processing these images, and it would be a challenge to write. -Phil, KA9Q ___ 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 ___ 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] Re: ARISSat-1
Hi Carl, I've seen this recently myself too.. On the occasions when it happened here over the UK, the bird should have been in high power mode, but after looking at telemetry it appears that it had switched into low power mode much earlier that than usual, from memory the footprint was only half in eclipse. Also noticed that before it cuts off that there is usually 10-15 or so seconds of a silent carrier. On another occasion it cut out halfway through a SSTV transmission - this I'm almost certain shouldn't have happened due to the way the firmware was written. Perhaps a bad solar panel contributing to low voltage when approaching eclipse? I had noticed one of the panel temps was over 75c on several passes. It certainly looks like there is some intermittent problems beginning to raise their head, lets hope it's not a steady decline in the bird's performance as gathering the SSTV pics, telemetry etc has been a very enjoyable change to the usual FM/SSB activity. 73 de Pete Mi0VAX On Sat, Aug 27, 2011 at 3:59 AM, Carl Rimmer cfrim...@gmail.com wrote: I was having a really good pass gpong from my NW-SE and I had copied 6 frames of Telemetry and 5 frames of KURSK data when the bird just went silent. It never came back during this pass. It was the 08-27-2011 0241 UTC pass over Lake Erie. I am curious if anyone has heard it since than. That is probably the best I have copied it since day one. The frames where forwarded. The MET was 55' 33. Bat Voltage = 35.668; Bat Current = -16 ma. I've never heard it just go silent like that and not come back up. Carl W8KRF ___ 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 ___ 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] Southwest Texas Grids - August 22/23 SUCCESS!
I want to thank all who supported my efforts to activate DL98/DL99 on the Texas/Mexico border. I also made quite a few contacts from EL07 in Laredo, Texas. Despite two border patrol inspection stations and three border patrol drive-by's while I was operating, the boundary operation went smoothly. APRS coverage was fairly poor for most of the trip unless I was in between major metropolitan areas in the Interstate 35 corridor. My SO-50 operations weren't as smooth as on AO-27 and AO-51 because they were unplanned and I was working them from whatever place I was on the road at AOS. Sometimes it was *not* a great location. Overall I ended up making 102 contacts from grids EM00, EM01, EM02, EL07, EL08, EL09, DL98, and DL99. I've already uploaded these contacts to Logbook of the World. If you would like a paper card, please email me the QSO details or go the usual direct/SASE route. 73, Clayton W5PFG EM21 ___ 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 transponder LAST NIGHT OVER UK
rpt 5/7 sig last night via the transponder called cq a few times heard a EA station that was weak but didnt manage to work him.Its not easy to work but possable. 2E1EUB ___ 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] Re: ARISSat-1
Looks like the satellite entered eclipse about that time. The solar panels are all that is powering the satellite now. Kenneth - N5VHO From: amsat-bb-boun...@amsat.org [amsat-bb-boun...@amsat.org] On Behalf Of Carl Rimmer [cfrim...@gmail.com] Sent: Friday, August 26, 2011 9:59 PM To: amsat-bb@amsat.org Subject: [amsat-bb] ARISSat-1 I was having a really good pass gpong from my NW-SE and I had copied 6 frames of Telemetry and 5 frames of KURSK data when the bird just went silent. It never came back during this pass. It was the 08-27-2011 0241 UTC pass over Lake Erie. I am curious if anyone has heard it since than. That is probably the best I have copied it since day one. The frames where forwarded. The MET was 55' 33. Bat Voltage = 35.668; Bat Current = -16 ma. I've never heard it just go silent like that and not come back up. Carl W8KRF ___ 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 ___ 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] Re: ARISSat-1
Hi all, I found this morning in VK6 (approx. 03:45 UTC) the MET counter said 21min 45 sec, which is approx. the time ARISSat-1 would have come back into Sunlight. Strange thing is it was on High Power - got plenty of telemetry frames but was discharging at a great rate of knots.. Looking at the data it would seem there was more discharging than charging going on over it's first 21 minutes. 1 panel said 45v, the others were around 15v so the part that was facing direct sunlight was good. I will get another chance perhaps in a few hours to see if it's still alive when not in sunlight and will try to grab some more telemetry. I have a jpg screenshot of telemetry with the position info from earlier if anyone would like it. 73 James VK6FJA On 27/08/2011 7:33 PM, Pete MI0VAX wrote: Hi Carl, I've seen this recently myself too.. On the occasions when it happened here over the UK, the bird should have been in high power mode, but after looking at telemetry it appears that it had switched into low power mode much earlier that than usual, from memory the footprint was only half in eclipse. Also noticed that before it cuts off that there is usually 10-15 or so seconds of a silent carrier. On another occasion it cut out halfway through a SSTV transmission - this I'm almost certain shouldn't have happened due to the way the firmware was written. Perhaps a bad solar panel contributing to low voltage when approaching eclipse? I had noticed one of the panel temps was over 75c on several passes. It certainly looks like there is some intermittent problems beginning to raise their head, lets hope it's not a steady decline in the bird's performance as gathering the SSTV pics, telemetry etc has been a very enjoyable change to the usual FM/SSB activity. 73 de Pete Mi0VAX On Sat, Aug 27, 2011 at 3:59 AM, Carl Rimmercfrim...@gmail.com wrote: I was having a really good pass gpong from my NW-SE and I had copied 6 frames of Telemetry and 5 frames of KURSK data when the bird just went silent. It never came back during this pass. It was the 08-27-2011 0241 UTC pass over Lake Erie. I am curious if anyone has heard it since than. That is probably the best I have copied it since day one. The frames where forwarded. The MET was 55' 33. Bat Voltage = 35.668; Bat Current = -16 ma. I've never heard it just go silent like that and not come back up. Carl W8KRF ___ 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 ___ 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 ___ 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] Re: ARISSat-1
Telemetry came into the Internet telemetry server up until 02:43:37 UTC Aug 27. Then there's no further telemetry until 3:35:46 UTC. If you are receiving telemetry, please turn on the forwarding to the Internet telemetry server, and also please email in your .CSV files to telemetry at arissattlm dot org. Douglas KA2UPW/5 -Original Message- From: Carl Rimmer cfrim...@gmail.com To: amsat-bb amsat-bb@amsat.org Sent: Fri, Aug 26, 2011 10:09 pm Subject: [amsat-bb] ARISSat-1 I was having a really good pass gpong from my NW-SE and I had copied 6 frames of Telemetry and 5 frames of KURSK data when the bird just went silent. It never came back during this pass. It was the 08-27-2011 0241 UTC pass over Lake Erie. I am curious if anyone has heard it since than. That is probably the best I have copied it since day one. The frames where forwarded. The MET was 55' 33. Bat Voltage = 35.668; Bat Current = -16 ma. I've never heard it just go silent like that and not come back up. Carl W8KRF ___ 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] SO67 - HO68 Status
The SA AMSAT site states: SO67 suffered another anomaly which means that all amateur activity has been suspended. I think the translation is RIP SO67 As for HO68, the CAMSAT web page is no longer there I take that as RIP HO68 TK K7TRK ___ 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] Re: SO67 - HO68 Status
On Sat, Aug 27, 2011 at 6:54 PM, Ted k7trkra...@charter.net wrote: The SA AMSAT site states: SO67 suffered another anomaly which means that all amateur activity has been suspended. I think the translation is RIP SO67 Maybe not. Isn't the amateur side a secondary payload? As for HO68, the CAMSAT web page is no longer there I take that as RIP HO68 HO-68 was a good satellite. I worked lots of new stations and grid squares, including my first contacts in Hawaii and Europe, all in FM. I hoped to get onto the linear transponder now that I have a rig for it but it doesn't look likely. 73s Bernhard VA6BMj @ DO33FL ___ 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] Re: SO67 - HO68 Status
Ted Your translation is wrong! The ground station engineers believe that they will recover the system required to schedule amateur radio activity. 73 Hans -Original Message- From: amsat-bb-boun...@amsat.org [mailto:amsat-bb-boun...@amsat.org] On Behalf Of B J Sent: 27 August 2011 09:39 PM To: AMSAT-BB@amsat.org Subject: [amsat-bb] Re: SO67 - HO68 Status On Sat, Aug 27, 2011 at 6:54 PM, Ted k7trkra...@charter.net wrote: The SA AMSAT site states: SO67 suffered another anomaly which means that all amateur activity has been suspended. I think the translation is RIP SO67 Maybe not. Isn't the amateur side a secondary payload? As for HO68, the CAMSAT web page is no longer there I take that as RIP HO68 HO-68 was a good satellite. I worked lots of new stations and grid squares, including my first contacts in Hawaii and Europe, all in FM. I hoped to get onto the linear transponder now that I have a rig for it but it doesn't look likely. 73s Bernhard VA6BMj @ DO33FL ___ 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 ___ 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] Re: SarPC32 and local repeater
One thought would be to copy and use the keps from any geostationary satellite visible from your location. At least the Doppler would not be shifting. John WA4WDL -- From: Ronald G. Parsons w5...@w5rkn.com Sent: Saturday, August 27, 2011 4:21 PM To: AMSAT-BB AMSAT-BB@amsat.org Subject: [amsat-bb] SarPC32 and local repeater Since I use the same radio (Icom IC-910H) for both satellite and local UHF/VHF repeaters, I’d like to be able to have SatPC32 automatically switch over the radio to satellite mode when a satellite is in view, and switch back to the repeater after LOS. I seems it should be possible to use “Automatic sat change ON” and have a dummy satellite in the satellite list configured to a local repeater. When a real satellite comes into view, SatPC32 would switch to that and when no real satellites are in view, the dummy satellite (repeater) would become active. My first idea would be to have the dummy satellite in the lowest satellite priority, and a dummy keps entry which would have the dummy satellite always in view. However, I don’t know how to construct such a keps element. Perhaps there is a more elegant way. Suggestions? Ron W5RKN ___ 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 ___ 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] Re: AMSAT-BB Digest, Vol 6, Issue 492
If the ARISSat-1 satellite goes into eclipse, and the battery has failed, the software doesn't get to decide when to shut down. The lights are out with no power. On Aug 27, 2011, at 3:00 PM, amsat-bb-requ...@amsat.org wrote: Send AMSAT-BB mailing list submissions to amsat-bb@amsat.org To subscribe or unsubscribe via the World Wide Web, visit http://amsat.org/mailman/listinfo/amsat-bb or, via email, send a message with subject or body 'help' to amsat-bb-requ...@amsat.org You can reach the person managing the list at amsat-bb-ow...@amsat.org When replying, please edit your Subject line so it is more specific than Re: Contents of AMSAT-BB digest... Today's Topics: 1. CM86/CM96 rare grid activation this Saturday August 27. (John Papay) 2. ARISSat-1 (Carl Rimmer) 3. Re: ARISSAT-1 (Clint Bradford) 4. Re: some exceedingly clever technology (i8cvs) 5. Re: ARISSat-1 (Pete MI0VAX) 6. Southwest Texas Grids - August 22/23 SUCCESS! (Clayton Coleman W5PFG) 7. Arissat-1 transponder LAST NIGHT OVER UK (paul robinson) 8. Re: ARISSat-1 (Ransom, Kenneth G. (JSC-OC)[BARRIOS TECHNOLOGY]) 9. Re: ARISSat-1 (James McBride) 10. Re: ARISSat-1 (Douglas Quagliana) 11. SO67 - HO68 Status (Ted) -- Message: 1 Date: Fri, 26 Aug 2011 15:45:22 -0400 From: John Papay j...@papays.com To: amsat-bb@amsat.org Subject: [amsat-bb] CM86/CM96 rare grid activation this Saturday August 27. Message-ID: 630032.57810...@smtp104.sbc.mail.bf1.yahoo.com Content-Type: text/plain; charset=us-ascii; format=flowed Hello. K G 6 N U B/p received a positive response from his CM86 / CM96 grid activations last week from Santa Cruz California. To fill unmet demands for these grids, especially CM86, he will be traveling to the CM86/CM96 grid boundary this Saturday August 27th.For those needing cards, a SASE sent the FCC ULS listed address is appreciated, but not required. Expect a 3-12 month turnaround. He always operates with 5W or less into a hand held yagi connected to a full duplex radio.The operation plan is as follows: QTH: -122.0/37.0 -- Object AOS (utc)LOS grid(s) -- SO-5019:4719:59 CM86/CM96 AO-2720:0420:15 CM86/CM96 AO-2721:4121:56 CM86 AO-5122:1022:22 CM86/CM96 AO-2723:2623:33 CM86 AO-5123:4700:02 CM86 AO-5101:3001:39 CM86(maybe) 73, John K8YSE -- Message: 2 Date: Fri, 26 Aug 2011 22:59:54 -0400 From: Carl Rimmer cfrim...@gmail.com To: amsat-bb@amsat.org Subject: [amsat-bb] ARISSat-1 Message-ID: 4e585daa.2020...@gmail.com Content-Type: text/plain; charset=ISO-8859-1; format=flowed I was having a really good pass gpong from my NW-SE and I had copied 6 frames of Telemetry and 5 frames of KURSK data when the bird just went silent. It never came back during this pass. It was the 08-27-2011 0241 UTC pass over Lake Erie. I am curious if anyone has heard it since than. That is probably the best I have copied it since day one. The frames where forwarded. The MET was 55' 33. Bat Voltage = 35.668; Bat Current = -16 ma. I've never heard it just go silent like that and not come back up. Carl W8KRF -- Message: 3 Date: Fri, 26 Aug 2011 20:38:56 -0700 From: Clint Bradford clintbradf...@mac.com To: AMSAT BB amsat-bb@amsat.org Subject: [amsat-bb] Re: ARISSAT-1 Message-ID: 7cefeb35-e86a-4cfc-953d-6a9087035...@mac.com Content-Type: text/plain; CHARSET=US-ASCII ... I was having a really good pass ... went silent ... 08-27-2011 0241 UTC pass over Lake Erie ... All the more reason for EVERYONE to report their work on the OSCAR Status site at ... http://oscar.dcarr.org/ Our reports help not only meager fellow hams, but also the control operators of the various satellites up there! Clint, K6LCS http://tinyurl.com/ARISSAT1-STATUS -- Message: 4 Date: Sat, 27 Aug 2011 09:13:29 +0200 From: i8cvs domenico.i8...@tin.it To: k...@ka9q.net, R Oler orbit...@hotmail.com Cc: Amsat BB amsat-bb@amsat.org Subject: [amsat-bb] Re: some exceedingly clever technology Message-ID: 01cc6489$5f28ac60$0401a8c0@b3o7f1 Content-Type: text/plain; charset=iso-8859-1 Hi Phil, KA9Q What you describes using both magnetorquers ,momentum wheels and CCD video cameras for the attitude control system is what was made on AO40 but it was a big satellite and not a microsatellite. 73 de i8CVS Domenico - Original Message - From: Phil Karn k...@philkarn.net To: R Oler orbit...@hotmail.com Cc: Amsat BB amsat-bb@amsat.org Sent: Friday,
[amsat-bb] Apology
Joe (K3SZH), I'm sorry. Will you forgive me? Life is short, and this hobby should be enjoyed to its fullest. 73, Mike (K9QHO) ___ 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] Re: AMSAT-BB Digest, Vol 6, Issue 492
Hi Lou, When you're going into eclipse without a battery, what difference would it make if you could? :-) But, this post is about a different question... As the spacecraft tumbles in direct sunlight, I understand that there are some orientations it might tumble through that result in not quite enough power to run everything. First, is that correct? And, if so, what choices can the IHU make in terms of lightening the load on the solar panels? I presume the tumble would be slow enough that you could see the power dip coming... Can the various downlink components, the university experiment, etc. be independently shut down? Greg KO6TH From: w5...@mac.com Date: Sat, 27 Aug 2011 17:14:37 -0400 To: amsat-bb@amsat.org Subject: [amsat-bb] Re: AMSAT-BB Digest, Vol 6, Issue 492 If the ARISSat-1 satellite goes into eclipse, and the battery has failed, the software doesn't get to decide when to shut down. The lights are out with no power. ___ 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] XE1AO IN DK88
Thank you for all the QSO in AO-27 at 20:03 UTC 2011-08-27. The QSO will be upload to LotW as XE1AO next monday afternoon after work. If someone need the print QSL please email me; not SASE or green stamp is required. Mi log with the arrow antenna anf FT-60R: CO6CBF 20:03 UTC KD8KSN 20:03 K4FEG 20:04 WC7V 20:04 AA5PK 20:04 N9IP 20:05 KG7EZ 20:05 AJ5C 20:07 KI6YAA 20:08 Regards Omar XE1AO DK89df M.C. Omar Alvarez Cárdenas Facultad de Telematica, U de C 316 1075 xe1...@ucol.mx omar...@hotmail.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 Pass Over DO33 2011-08-28
No CW beacon was heard. FM downlink was acquired at 0312 UTC with at least S7 and no fading but some noise. MET = 49 minutes IHU temp = +39 degrees C (not sure about final integer due to noise) Control panel temp = +28 degrees C Battery voltage = 35.70 Volts Battery current = -12 mA Transmission stopped at 0313 and resumed at 0315 with ID and greeting. 73s Bernhard VA6BMJ @ DO33FL ___ 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
