Is 137 KHz possible from space?
Our next Cubesat will have a 1100 meter long antenna (think tether satellite). It will ultimatelly be an electrodynamic tether but the first one will have NO ACTIVE ELECTRONICS connected to the tether.
So I have asked them to make it 1100m long instead of a generic 1km tether to try to make it resonant in an amateur band. THe path loss at 137 KHz is 60 dB LESS than it is at 2 meters, so it shouldn't take much to communicate with an 1100m long antenna.
I'm sorry I didnt think of this sooner, but I need a real SCIENCE justification for this. Maybe LF that low will never punch through the ionosphere, or maybe it will be completely absorbed. Can give good science on this idea?
Bob, WB4APR
Hello,
On 12/11/10, Bob Bruninga bruninga@usna.edu wrote:
Is 137 KHz possible from space?
Our next Cubesat will have a 1100 meter long antenna (think tether satellite). It will ultimatelly be an electrodynamic tether but the first one will have NO ACTIVE ELECTRONICS connected to the tether.
So I have asked them to make it 1100m long instead of a generic 1km tether to try to make it resonant in an amateur band. THe path loss at 137 KHz is 60 dB LESS than it is at 2 meters, so it shouldn't take much to communicate with an 1100m long antenna.
I'm sorry I didnt think of this sooner, but I need a real SCIENCE justification for this. Maybe LF that low will never punch through the ionosphere, or maybe it will be completely absorbed. Can give good science on this idea?
I think the general opinion is LF will never punch through the ionosphere, but this might only proved with a beacon orbiting and ground stations listening.
73 Frank IZ8DWF
--- On Sat, 12/11/10, Bob Bruninga bruninga@usna.edu wrote:
Is 137 KHz possible from space?
Bob,
My understanding is that LF and VLF emissions of terrestrial origin don't get beyond the 'D' layer, even at night. In fact, the 'D' layer acts as a reflector, rather than an attenuator at these frequencies. Cosmic background radiation maintains sufficient 'D' layer ionization at night.
However, your post reminded me of project INSPIRE, which was a plan to transmit VLF signals from the Space Shuttle back in 1992 using a pulsed electron gun in the payload bay. Details on project INSPIRE can be found here:
http://theinspireproject.org/index.php?page=faq
I'm not sure how this would penetrate the ionosphere except through brute force.
Nevertheless, compatible receivers are simple to build and readily available.
73, de John, KD2BD
-- Visit John on the Web at:
Hi Bob, If the ionosphere screens all the terrestrial signals at that height then maybe your 136kHz RX could be used to listen to radiation received from outer space at that frequency which normally we cannot listen to on earth. Sound like fundamental research to me but maybe it has already been done and redone. 73 GrahamG3VZV
--- On Sun, 12/12/10, John Magliacane kd2bd@yahoo.com wrote:
From: John Magliacane kd2bd@yahoo.com Subject: [amsat-bb] Re: LF Satellite ideas? To: amsat-bb@amsat.org Date: Sunday, 12 December, 2010, 2:13
--- On Sat, 12/11/10, Bob Bruninga bruninga@usna.edu wrote:
Is 137 KHz possible from space?
Bob,
My understanding is that LF and VLF emissions of terrestrial origin don't get beyond the 'D' layer, even at night. In fact, the 'D' layer acts as a reflector, rather than an attenuator at these frequencies. Cosmic background radiation maintains sufficient 'D' layer ionization at night.
However, your post reminded me of project INSPIRE, which was a plan to transmit VLF signals from the Space Shuttle back in 1992 using a pulsed electron gun in the payload bay. Details on project INSPIRE can be found here:
http://theinspireproject.org/index.php?page=faq
I'm not sure how this would penetrate the ionosphere except through brute force.
Nevertheless, compatible receivers are simple to build and readily available.
73, de John, KD2BD
-- Visit John on the Web at:
_______________________________________________ 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
Hi Grahma,
I like your idea ... to receive signals at VLF which cannot be heard on the ground and convert them to a frequency band which we can receive ... I guess this will allow us to receive some "sounds from space" which we are otherwise blocked from ...
Best regards
Matthias
www.dd1us.de
-----Ursprüngliche Nachricht----- Von: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] Im Auftrag von GRAHAM SHIRVILLE Gesendet: Sonntag, 12. Dezember 2010 09:52 An: amsat-bb@amsat.org; John Magliacane Betreff: [amsat-bb] Re: LF Satellite ideas?
Hi Bob, If the ionosphere screens all the terrestrial signals at that height then maybe your 136kHz RX could be used to listen to radiation received from outer space at that frequency which normally we cannot listen to on earth. Sound like fundamental research to me but maybe it has already been done and redone. 73 GrahamG3VZV
--- On Sun, 12/12/10, John Magliacane kd2bd@yahoo.com wrote:
From: John Magliacane kd2bd@yahoo.com Subject: [amsat-bb] Re: LF Satellite ideas? To: amsat-bb@amsat.org Date: Sunday, 12 December, 2010, 2:13
--- On Sat, 12/11/10, Bob Bruninga bruninga@usna.edu wrote:
Is 137 KHz possible from space?
Bob,
My understanding is that LF and VLF emissions of terrestrial origin don't get beyond the 'D' layer, even at night. In fact, the 'D' layer acts as a reflector, rather than an attenuator at these frequencies. Cosmic background radiation maintains sufficient 'D' layer ionization at night.
However, your post reminded me of project INSPIRE, which was a plan to transmit VLF signals from the Space Shuttle back in 1992 using a pulsed electron gun in the payload bay. Details on project INSPIRE can be found here:
http://theinspireproject.org/index.php?page=faq
I'm not sure how this would penetrate the ionosphere except through brute force.
Nevertheless, compatible receivers are simple to build and readily available.
73, de John, KD2BD
-- Visit John on the Web at:
_______________________________________________ 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
Sorry Graham that misspelled your name in the last mail.
Have a nice Sunday
Matthias
www.dd1us.de
-----Ursprüngliche Nachricht----- Von: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] Im Auftrag von Matthias Bopp Gesendet: Sonntag, 12. Dezember 2010 12:30 An: 'GRAHAM SHIRVILLE'; amsat-bb@amsat.org Betreff: [amsat-bb] Re: LF Satellite ideas?
Hi Grahma,
I like your idea ... to receive signals at VLF which cannot be heard on the ground and convert them to a frequency band which we can receive ... I guess this will allow us to receive some "sounds from space" which we are otherwise blocked from ...
Best regards
Matthias
www.dd1us.de
-----Ursprüngliche Nachricht----- Von: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] Im Auftrag von GRAHAM SHIRVILLE Gesendet: Sonntag, 12. Dezember 2010 09:52 An: amsat-bb@amsat.org; John Magliacane Betreff: [amsat-bb] Re: LF Satellite ideas?
Hi Bob, If the ionosphere screens all the terrestrial signals at that height then maybe your 136kHz RX could be used to listen to radiation received from outer space at that frequency which normally we cannot listen to on earth. Sound like fundamental research to me but maybe it has already been done and redone. 73 GrahamG3VZV
--- On Sun, 12/12/10, John Magliacane kd2bd@yahoo.com wrote:
From: John Magliacane kd2bd@yahoo.com Subject: [amsat-bb] Re: LF Satellite ideas? To: amsat-bb@amsat.org Date: Sunday, 12 December, 2010, 2:13
--- On Sat, 12/11/10, Bob Bruninga bruninga@usna.edu wrote:
Is 137 KHz possible from space?
Bob,
My understanding is that LF and VLF emissions of terrestrial origin don't get beyond the 'D' layer, even at night. In fact, the 'D' layer acts as a reflector, rather than an attenuator at these frequencies. Cosmic background radiation maintains sufficient 'D' layer ionization at night.
However, your post reminded me of project INSPIRE, which was a plan to transmit VLF signals from the Space Shuttle back in 1992 using a pulsed electron gun in the payload bay. Details on project INSPIRE can be found here:
http://theinspireproject.org/index.php?page=faq
I'm not sure how this would penetrate the ionosphere except through brute force.
Nevertheless, compatible receivers are simple to build and readily available.
73, de John, KD2BD
-- Visit John on the Web at:
_______________________________________________ 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
Drats. Bad news.. Good news!
Bad news: I was thinking that maybe 137KHz would leak through the ionosphere straight up, but then just realized that this is a tether satellite, so the antenna is VERTICAL! Thus, a null straight down.
So maybe the only application then is to use it as a receive antenna and LISTEN to the aliens (galactic noise on 137 Khz).
But still with a path loss that is a million times less than on 2 meters, it would seem that something terrestrial could be easily heard.
GOOD NEWS? Woaha? How about this. Use the 1.1km vertical long wire as a 10 wavelength end fed on the 160m band and the lobes point more downward!? The gain there would about 10 dB and the path loss is still 40 dB better than on 2m.
So if we can hear a 1W amsat on 2m, then we should be able to hear a 1 milliwatt transmitter on 160m with 20 dB stronger signal! (Of course noise level can easily be 20 dB stronger?)
I really don't know enough about 160m to go further. Gotta start reading...
Bob, WB4APR
---- Original message ----
Date: Sun, 12 Dec 2010 08:52:26 +0000 (GMT) From: amsat-bb-bounces@amsat.org (on behalf of GRAHAM SHIRVILLE g.shirville@btinternet.com) Subject: [amsat-bb] Re: LF Satellite ideas? To: amsat-bb@amsat.org,John Magliacane kd2bd@yahoo.com
Hi Bob, If the ionosphere screens all the terrestrial signals at that height then maybe your 136kHz RX could be used to listen to radiation received from outer space at that frequency which normally we cannot listen to on earth. Sound like fundamental research to me but maybe it has already been done and redone. 73 GrahamG3VZV
--- On Sun, 12/12/10, John Magliacane kd2bd@yahoo.com wrote:
From: John Magliacane kd2bd@yahoo.com Subject: [amsat-bb] Re: LF Satellite ideas? To: amsat-bb@amsat.org Date: Sunday, 12 December, 2010, 2:13
--- On Sat, 12/11/10, Bob Bruninga bruninga@usna.edu wrote:
Is 137 KHz possible from space?
Bob,
My understanding is that LF and VLF emissions of terrestrial origin don't get beyond the 'D' layer, even at night. In fact, the 'D' layer acts as a reflector, rather than an attenuator at these frequencies. Cosmic background radiation maintains sufficient 'D' layer ionization at night.
However, your post reminded me of project INSPIRE, which was a plan to transmit VLF signals from the Space Shuttle back in 1992 using a pulsed electron gun in the payload bay. Details on project INSPIRE can be found here:
http://theinspireproject.org/index.php?page=faq
I'm not sure how this would penetrate the ionosphere except through brute force.
Nevertheless, compatible receivers are simple to build and readily available.
73, de John, KD2BD
-- Visit John on the Web at:
_______________________________________________ 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
--- On Sun, 12/12/10, Bob Bruninga bruninga@usna.edu wrote:
So if we can hear a 1W amsat on 2m, then we should be able to hear a 1 milliwatt transmitter on 160m with 20 dB stronger signal! (Of course noise level can easily be 20 dB stronger?)
Bear in mind there are no Amateur Satellite Service allocations below 7 MHz so TX may be out of the question but a Rx experiment on 160m is a different matter.
Good Luck
Trevor M5AKA
IARU has been successfull in obtaining new global Amateur Service allocations such as 135 kHz and 7.1-7.2 kHz, however, the Amateur Satellite Service seems to have been forgotten. 7.0-7.1 is okay for sats but 7.1-7.2 isn't, Why? is the question that has to be asked.
Currently IARU is attempting to get an Amateur Service allocation at 500kHz - should they also be getting that band for the Amateur Satellite Service as well ?
Given the significant input of the ARRL into IARU perhaps amsat-bb members in NA could remind ARRL that, where possible, new Amateur allocations should be obtained for BOTH the Amateur and Amateur Satellite Services not just the Amateur Service.
73 Trevor M5AKA
Hi, Tevor!
The general principle is that the amateur-satellite service has frequency allocations in bands where the amateur service has frequency allocations in all three ITU regions. The only exceptions are in the bands 1260-1270 MHz and 5650-5670 MHz, which are limited to the Earth-to-space direction, and 3400-3410 MHz, which are available in Regions 2 and 3. See RR 5.282.
In Region 2, the band 7100-7200 kHz was reallocated effective 29 MAR 2009. See: RR 5.142.
Until 29 March 2009, the use of the band 7100-7300 kHz in Region 2 by the amateur service shall not impose constraints on the broadcasting service intended for use within Region 1 and Region 3. After 29 March 2009 the use of the band 7200-7300 kHz in Region 2 by the amateur service shall not impose constraints on the broadcasting service intended for use within Region 1 and Region 3. RR 5.142.
But, this is only in Region 2. So, until broadcasters vacate 7100-7200 in regions 1 and 3, the amateur-satellite service won't have a frequency allocation.
Make sense??
73, art..... W4ART Arlington VA
On 12-Dec-2010, at 03:37 PM, Trevor . wrote:
IARU has been successfull in obtaining new global Amateur Service allocations such as 135 kHz and 7.1-7.2 kHz, however, the Amateur Satellite Service seems to have been forgotten. 7.0-7.1 is okay for sats but 7.1-7.2 isn't, Why? is the question that has to be asked.
Currently IARU is attempting to get an Amateur Service allocation at 500kHz - should they also be getting that band for the Amateur Satellite Service as well ?
Given the significant input of the ARRL into IARU perhaps amsat-bb members in NA could remind ARRL that, where possible, new Amateur allocations should be obtained for BOTH the Amateur and Amateur Satellite Services not just the Amateur Service.
73 Trevor M5AKA
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
Nullum gratuitum prandium.
Art..one of the best explanations I have read of the allocations. FB
Robert WB5MZO Life member Amsat ARRL
From: afeller@ieee.org Date: Sun, 12 Dec 2010 16:18:31 -0500 To: m5aka@yahoo.co.uk CC: amsat-bb@amsat.org Subject: [amsat-bb] Re: Amateur Satellite Frequency Allocations (LF)
Hi, Tevor!
The general principle is that the amateur-satellite service has frequency allocations in bands where the amateur service has frequency allocations in all three ITU regions. The only exceptions are in the bands 1260-1270 MHz and 5650-5670 MHz, which are limited to the Earth-to-space direction, and 3400-3410 MHz, which are available in Regions 2 and 3. See RR 5.282.
In Region 2, the band 7100-7200 kHz was reallocated effective 29 MAR 2009. See: RR 5.142.
Until 29 March 2009, the use of the band 7100-7300 kHz in Region 2 by the amateur service shall not impose constraints on the broadcasting service intended for use within Region 1 and Region 3. After 29 March 2009 the use of the band 7200-7300 kHz in Region 2 by the amateur service shall not impose constraints on the broadcasting service intended for use within Region 1 and Region 3. RR 5.142.
But, this is only in Region 2. So, until broadcasters vacate 7100-7200 in regions 1 and 3, the amateur-satellite service won't have a frequency allocation.
Make sense??
73, art..... W4ART Arlington VA
On 12-Dec-2010, at 03:37 PM, Trevor . wrote:
IARU has been successfull in obtaining new global Amateur Service allocations such as 135 kHz and 7.1-7.2 kHz, however, the Amateur Satellite Service seems to have been forgotten. 7.0-7.1 is okay for sats but 7.1-7.2 isn't, Why? is the question that has to be asked.
Currently IARU is attempting to get an Amateur Service allocation at 500kHz - should they also be getting that band for the Amateur Satellite Service as well ?
Given the significant input of the ARRL into IARU perhaps amsat-bb members in NA could remind ARRL that, where possible, new Amateur allocations should be obtained for BOTH the Amateur and Amateur Satellite Services not just the Amateur Service.
73 Trevor M5AKA
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
Nullum gratuitum prandium.
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
Plus if it's listening to 135KHz and re transmitting what it hears on 2 or 70cm, it isn't transmitting on 135 so what part is not legal?
Joe WB9SBD
The Original Rolling Ball Clock Idle Tyme Idle-Tyme.com http://www.idle-tyme.com
On 12/12/2010 2:37 PM, Trevor . wrote:
IARU has been successfull in obtaining new global Amateur Service allocations such as 135 kHz and 7.1-7.2 kHz, however, the Amateur Satellite Service seems to have been forgotten. 7.0-7.1 is okay for sats but 7.1-7.2 isn't, Why? is the question that has to be asked.
Currently IARU is attempting to get an Amateur Service allocation at 500kHz - should they also be getting that band for the Amateur Satellite Service as well ?
Given the significant input of the ARRL into IARU perhaps amsat-bb members in NA could remind ARRL that, where possible, new Amateur allocations should be obtained for BOTH the Amateur and Amateur Satellite Services not just the Amateur Service.
73 Trevor M5AKA
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
Hi Bob.
Drats. Bad news.. Good news!
I don't think the ionosphere will allow 160 meter downlink propagation... on a regular basis, at least.
UoSAT-OSCAR-9 carried HF beacons on 7, 14, 21, and 28 MHz, and if I recall correctly, the only beacon never heard was the one on 7 MHz.
So, receiving might be more beneficial than transmitting. It might prove interesting to have the satellite generate a spectrogram of received signals in the form of a GIF image that could be downloaded from the satellite, thereby eliminating the requirement that the receiver's input be within a satellite sub-band. ;-)
A spectrogram plot covering a whole orbit might also prove to be very interesting. It might answer questions such as: Can sferics from lightning be received outside the ionosphere? What does the VLF spectrum look like over the poles vs. the rest of the globe? How does solar activity and auroras effect VLF energy above the ionosphere? Can energy from the 50/60 Hz power grid be received in space?
73, de John, KD2BD
-- Visit John on the Web at:
Has anyone considered the possibility of applying for an experimental license for such an experiment? AA1VS
On Sat, Dec 11, 2010 at 9:13 PM, John Magliacane kd2bd@yahoo.com wrote:
--- On Sat, 12/11/10, Bob Bruninga bruninga@usna.edu wrote:
Is 137 KHz possible from space?
Bob,
My understanding is that LF and VLF emissions of terrestrial origin don't get beyond the 'D' layer, even at night. In fact, the 'D' layer acts as a reflector, rather than an attenuator at these frequencies. Cosmic background radiation maintains sufficient 'D' layer ionization at night.
However, your post reminded me of project INSPIRE, which was a plan to transmit VLF signals from the Space Shuttle back in 1992 using a pulsed electron gun in the payload bay. Details on project INSPIRE can be found here:
http://theinspireproject.org/index.php?page=faq
I'm not sure how this would penetrate the ionosphere except through brute force.
Nevertheless, compatible receivers are simple to build and readily available.
73, de John, KD2BD
-- Visit John on the Web at:
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
Hi all,
A 1100 meter long antenna attached to a satellite moving through a very thin atmosphere would be interesting. My concern would be the static build up of energy on the antenna leading back to the satellite. I would think it this would fry any circuitry in the satellite. If I recall correctly didn't one of the shuttle mission have a problem of static build up on along tether and had to give up on the experiment?
73,
Jeff WB3JFS
----- Original Message ----- From: "Bob Bruninga " bruninga@usna.edu To: amsat-bb@amsat.org Sent: Saturday, December 11, 2010 11:13 AM Subject: [amsat-bb] LF Satellite ideas?
Is 137 KHz possible from space?
Our next Cubesat will have a 1100 meter long antenna (think tether satellite). It will ultimatelly be an electrodynamic tether but the first one will have NO ACTIVE ELECTRONICS connected to the tether.
So I have asked them to make it 1100m long instead of a generic 1km tether to try to make it resonant in an amateur band. THe path loss at 137 KHz is 60 dB LESS than it is at 2 meters, so it shouldn't take much to communicate with an 1100m long antenna.
I'm sorry I didnt think of this sooner, but I need a real SCIENCE justification for this. Maybe LF that low will never punch through the ionosphere, or maybe it will be completely absorbed. Can give good science on this idea?
Bob, WB4APR
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
Running a long conductor at high speeds through even a week magnetic field produces some impressive voltages. It has been proposed as a way to convert kinetic energy to electrical power, and run in reverse to provide a method to reboost spacecraft. Lots of theoretical and experimental studies on that aspect.
Alan WA4SCA
-----Original Message----- From: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Jeff Yanko Sent: Sunday, December 12, 2010 5:26 AM To: Bob Bruninga ; amsat-bb@amsat.org Subject: [amsat-bb] Re: LF Satellite ideas?
Hi all,
A 1100 meter long antenna attached to a satellite moving through a very thin
atmosphere would be interesting. My concern would be the static build up of
energy on the antenna leading back to the satellite. I would think it this would fry any circuitry in the satellite. If I recall correctly didn't one of the shuttle mission have a problem of static build up on along tether and
had to give up on the experiment?
73,
Jeff WB3JFS
----- Original Message ----- From: "Bob Bruninga " bruninga@usna.edu To: amsat-bb@amsat.org Sent: Saturday, December 11, 2010 11:13 AM Subject: [amsat-bb] LF Satellite ideas?
Is 137 KHz possible from space?
Our next Cubesat will have a 1100 meter long antenna (think tether satellite). It will ultimatelly be an electrodynamic tether but the first
one will have NO ACTIVE ELECTRONICS connected to the tether.
So I have asked them to make it 1100m long instead of a generic 1km tether
to try to make it resonant in an amateur band. THe path loss at 137 KHz is 60 dB LESS than it is at 2 meters, so it shouldn't take much to communicate with an 1100m long antenna.
I'm sorry I didnt think of this sooner, but I need a real SCIENCE justification for this. Maybe LF that low will never punch through the ionosphere, or maybe it will be completely absorbed. Can give good science on this idea?
Bob, WB4APR
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
Hi Bob,
I'm actually wondering if the 1100 meter long antenna would be visible from the ground. I suppose that depends on the height of the orbit, the width of the tether, orientation, and what color the tether will be. Have these been determined? Viewing the tether might be an interesting science experiment for students. Hey Bob-- Can you paint the tether bright white?
Can you make the tether out of something that's optically reflective? Hitting a corner reflector is difficult, but hitting a 1100 meter reflector strip should be much easier. Just make sure you fill out all the proper government paperwork and file all of the necessary "Notice to Airmen" forms before shining your lights upwards. :-)
How long is the tether expected to last? The Space Shuttle windows are only up for about a week at a time and they can get tiny mini-craters from the micrometeorite impacts.
Douglas
Bob Bruninga wrote:
Our next Cubesat will have a 1100 meter long antenna (think tether satellite).
Bob, WB4APR
participants (13)
-
Alan P. Biddle -
Bob Bruninga -
Charles Suprin -
Douglas Quagliana -
francesco messineo -
GRAHAM SHIRVILLE -
Jeff Yanko -
Joe -
John Magliacane -
Matthias Bopp -
Rocky Jones -
Trevor . -
W4ART Arthur Feller