using a microsat as a potential high altitude VHF reflector
Hi all,
I read with interest an article on the web "ECHO - America's First Communications Satellite" By John R. Pierce which is available here: http://www.smecc.org/john_pierce___echoredo.htm
I know ham radio operators love using their hand helds to communicate using active transponders or active repeaters in space... no issue with that.
were there any ham radio projects (either through amsat-na or abroad) that implemented a passive reflector on an orbital vehicle like Project Echo
I quote from http://www.satmagazine.com/cgi-bin/display_article.cgi?number=490218137
The Echo-1 Balloon Satellite as it sits, fully inflated, at a Navy hangar in Weeksville, North Carolina. The spacecraft measured 100 feet across when deployed, and was nicknamed a ‘satelloon’ by those involved in the project. The mylar film balloon acted as a passive communications reflector for transcontinental and intercontinental telephone (voice), radio and television signals. Echo 1 re-entered the atmosphere May 24, 1968.
What strikes me is the implications of a large large very large antenna (reflector), if only it could be reflective on one side of the sphere only .... (any ideas?)
The Echo 2 was a 135-foot rigidized inflatable balloon satellite. The satellite is shown undergoing tensile stress test in a dirigible hanger at Weekesville. The satellite, 50 times more rigidized than Echo I. When folded, the satellite is packed into the 41-inch diameter canister shown in the foreground.
Did early amsat folks consider duplicating / adding to any of these projects or launch their own 'satelloon' that did not carry an active RF payload ? Could we outfit one of our future microsats to provide a reflector to aid in Earth-LEO DXing like meteor-scatter ?
73 de Samudra, N3RDX
There are two neat concepts from the early days of communications experiments using satellites and Echo is one of them (the other is SCORE).
There were a lot of "ideas" for follow on echos...one used a gravity gradient "pole" to stop the balloon from spinning and keeping it pointed to the earth, allowing a directional reflector to be installed in the balloon...another used a radar reflector like concept inside the balloon to increase the amount of DB that returned...
The problems were "large" however. Doppler shift and tracking were issues at the time (and probably still are)..the antennas were going to have to be large (really large).
My elmer in Dallas when he was in the USAF did some radar experiments with echo...I got to see it a few times.
SCORE probably has more relevance to todays possibilities.
Robert WB5MZO _________________________________________________________________ New Windows 7: Find the right PC for you. Learn more. http://www.microsoft.com/windows/pc-scout/default.aspx?CBID=wl&ocid=PID2...
were there any ham radio projects (either through amsat-na or abroad) that implemented a passive reflector on an orbital vehicle like Project Echo
Not long ago I saw some webpages and emails about some hams using ISS (or was it Mir?) as a passive reflector.
Coincidently, I was reading about the West Ford project, which was launches of millions of small wire dipoles to be used as reflectors. Some of those clusters are still in orbit. I wonder if they are still in a dense enough field to reflect the 8 Ghz? signal they were designed for.
73, Drew KO4MA
One drawback of the design was the high drag from such a large structure, coupled with the low mass. The end result was a satellite with a low ballistic coefficient and hence a short lifetime.
John WA4WDL
-------------------------------------------------- From: "Samudra Haque" [email protected] Sent: Wednesday, October 28, 2009 3:46 PM To: "Amsat-bb" [email protected] Subject: [amsat-bb] using a microsat as a potential high altitude VHFreflector
Hi all,
I read with interest an article on the web "ECHO - America's First Communications Satellite" By John R. Pierce which is available here: http://www.smecc.org/john_pierce___echoredo.htm
I know ham radio operators love using their hand helds to communicate using active transponders or active repeaters in space... no issue with that.
were there any ham radio projects (either through amsat-na or abroad) that implemented a passive reflector on an orbital vehicle like Project Echo
I quote from http://www.satmagazine.com/cgi-bin/display_article.cgi?number=490218137
The Echo-1 Balloon Satellite as it sits, fully inflated, at a Navy hangar in Weeksville, North Carolina. The spacecraft measured 100 feet across when deployed, and was nicknamed a ‘satelloon’ by those involved in the project. The mylar film balloon acted as a passive communications reflector for transcontinental and intercontinental telephone (voice), radio and television signals. Echo 1 re-entered the atmosphere May 24, 1968.
What strikes me is the implications of a large large very large antenna (reflector), if only it could be reflective on one side of the sphere only .... (any ideas?)
The Echo 2 was a 135-foot rigidized inflatable balloon satellite. The satellite is shown undergoing tensile stress test in a dirigible hanger at Weekesville. The satellite, 50 times more rigidized than Echo I. When folded, the satellite is packed into the 41-inch diameter canister shown in the foreground.
Did early amsat folks consider duplicating / adding to any of these projects or launch their own 'satelloon' that did not carry an active RF payload ? Could we outfit one of our future microsats to provide a reflector to aid in Earth-LEO DXing like meteor-scatter ?
73 de Samudra, N3RDX
Sent via [email protected]. 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
Drew. I had forgotten about West Ford...but they are all gone. While in grad school we tried some reflection test using the then prototype of the SPS 48E and there was nothing...
Robert WB5MZO
Date: Wed, 28 Oct 2009 16:12:54 -0400 From: [email protected] To: [email protected] CC: [email protected] Subject: [amsat-bb] Re: using a microsat as a potential high altitude VHF reflector
were there any ham radio projects (either through amsat-na or abroad) that implemented a passive reflector on an orbital vehicle like Project Echo
Not long ago I saw some webpages and emails about some hams using ISS (or was it Mir?) as a passive reflector.
Coincidently, I was reading about the West Ford project, which was launches of millions of small wire dipoles to be used as reflectors. Some of those clusters are still in orbit. I wonder if they are still in a dense enough field to reflect the 8 Ghz? signal they were designed for.
73, Drew KO4MA
Sent via [email protected]. 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
_________________________________________________________________ Windows 7: Simplify your PC. Learn more. http://www.microsoft.com/Windows/windows-7/default.aspx?ocid=PID24727::T:WLM...
Space-Track is still tracking several clusters of Westford needles, although they are certainly spread out and thinning fast. Some are still nearly in their original orbits. As evidence:
WESTFORD NEEDLES 1 00602U 63014E 09300.68434638 +.00000003 +00000-0 +10000-3 0 07665 2 00602 087.3316 050.1496 0032690 004.4295 355.6847 08.67203352471339
73, Drew KO4MA
----- Original Message ----- From: "Samudra Haque" [email protected] To: "Amsat-bb" [email protected] Sent: Wednesday, October 28, 2009 8:46 PM Subject: [amsat-bb] using a microsat as a potential high altitude VHFreflector
Hi all,
I read with interest an article on the web "ECHO - America's First Communications Satellite" By John R. Pierce which is available here: http://www.smecc.org/john_pierce___echoredo.htm
I know ham radio operators love using their hand helds to communicate using active transponders or active repeaters in space... no issue with that.
were there any ham radio projects (either through amsat-na or abroad) that implemented a passive reflector on an orbital vehicle like Project Echo
I quote from http://www.satmagazine.com/cgi-bin/display_article.cgi?number=490218137
The Echo-1 Balloon Satellite as it sits, fully inflated, at a Navy hangar in Weeksville, North Carolina. The spacecraft measured 100 feet across when deployed, and was nicknamed a ‘satelloon’ by those involved in the project. The mylar film balloon acted as a passive communications reflector for transcontinental and intercontinental telephone (voice), radio and television signals. Echo 1 re-entered the atmosphere May 24, 1968.
What strikes me is the implications of a large large very large antenna (reflector), if only it could be reflective on one side of the sphere only .... (any ideas?)
The Echo 2 was a 135-foot rigidized inflatable balloon satellite. The satellite is shown undergoing tensile stress test in a dirigible hanger at Weekesville. The satellite, 50 times more rigidized than Echo I. When folded, the satellite is packed into the 41-inch diameter canister shown in the foreground.
Did early amsat folks consider duplicating / adding to any of these projects or launch their own 'satelloon' that did not carry an active RF payload ? Could we outfit one of our future microsats to provide a reflector to aid in Earth-LEO DXing like meteor-scatter ?
73 de Samudra, N3RDX
Hi Samudra, N3RDX
Early 13 august 1960 about 50 years ago I have received the ECHO 1A 45 mW beacons transmitting at 108.00 and 108.03 MHz and also I got an excellent visual of the big satellite balloon only looking at it in the sky with naked eye
Receiving radio signals and looking at the orbiting satellite at the same time it was a very exciting experience and I newer forget !
I was using a home brewed downconverter for 108 MHz with two low noise triodes 6AN4 in a front end grounded grid circuit.
The second IF receiver tuned at 27.963 MHz was an Hallicrafters SX-28 and the antenna was a qubical quad.
By the way the NASA and GSFC ground stations where transmitting to the reflecting surface of the above passive satellite a very very high EIRP at 960 MHz and 2390 MHz using big dishes.
The experience gained with the passive ECHO satellites demonstrates that they are not convenient at all so that the project was soon abandoned.
73" de
i8CVS Domenico
Domenico, I had no idea absolutely that you would have responded with such relevant experience !!! It is an amazing story to hear. The recent interest and work on "inflatable" antennas may be the most interesting chapter yet (ref: JPL DESCANSO publications) in antenna theory.
Thanks
-samudra
Hi Samudra, N3RDX
Early 13 august 1960 about 50 years ago I have received the ECHO 1A 45 mW beacons transmitting at 108.00 and 108.03 MHz and also I got an excellent visual of the big satellite balloon only looking at it in the sky with naked eye
Receiving radio signals and looking at the orbiting satellite at the same time it was a very exciting experience and I newer forget !
I was using a home brewed downconverter for 108 MHz with two low noise triodes 6AN4 in a front end grounded grid circuit.
The second IF receiver tuned at 27.963 MHz was an Hallicrafters SX-28 and the antenna was a qubical quad.
By the way the NASA and GSFC ground stations where transmitting to the reflecting surface of the above passive satellite a very very high EIRP at 960 MHz and 2390 MHz using big dishes.
The experience gained with the passive ECHO satellites demonstrates that they are not convenient at all so that the project was soon abandoned.
73" de
i8CVS Domenico
participants (5)
-
Andrew Glasbrenner -
i8cvs -
jmfranke -
Rocky Jones -
Samudra Haque