This twitter post says that several small satellites will be hand-deployed during the Russian EVA tomorrow:
https://twitter.com/RF2Space/status/897841299377709057
Anyone know the details? I assume they would want to release them "towards earth" and not in the other direction so that they would have a lower orbit than the station and not run into them at some point. Do they just toss them out?
I jokingly describe the launch of a satellite from the ISS as the crew opening a window and tossing the satellite out. But, in fact, there is a very carefully planned direction to which the crew "toss" the satellites. I believe it's to the rear and below of the ISS, such that when the orbits cross in the future there is no danger that the two will collide.
If, for example, they were to push the satellites to the side of the ISS, then an orbit later the two would meet again as the satellite's orbit would be oscillating to one side and then the other of the ISS. Going to the rear, making the satellite's orbital velocity slightly slower than the ISS, would put the satellite in a lower orbit. But that lower orbit makes the satellite complete its trip around the Earth faster than the ISS, so should put it ahead of the ISS when they meet again. If launched behind and below, then by the time it gets around to the ISS again, it should be far enough away that there would be no possible danger of a collision.
Or, something like that. I forget the details, but it's been discussed here a while ago.
Greg KO6TH
Peter Pauly wrote:
Anyone know the details? I assume they would want to release them "towards earth" and not in the other direction so that they would have a lower orbit than the station and not run into them at some point. Do they just toss them out?
It's my belief that ISS sits in a decaying orbit on purpose so other debris is limited. They constantly have to keep pushing up their orbit to stay in space and not fall back to earth.
73 de KA9SCF
On Wed, Aug 16, 2017 at 2:12 PM, Greg D ko6th.greg@gmail.com wrote:
I jokingly describe the launch of a satellite from the ISS as the crew opening a window and tossing the satellite out. But, in fact, there is a very carefully planned direction to which the crew "toss" the satellites. I believe it's to the rear and below of the ISS, such that when the orbits cross in the future there is no danger that the two will collide.
If, for example, they were to push the satellites to the side of the ISS, then an orbit later the two would meet again as the satellite's orbit would be oscillating to one side and then the other of the ISS. Going to the rear, making the satellite's orbital velocity slightly slower than the ISS, would put the satellite in a lower orbit. But that lower orbit makes the satellite complete its trip around the Earth faster than the ISS, so should put it ahead of the ISS when they meet again. If launched behind and below, then by the time it gets around to the ISS again, it should be far enough away that there would be no possible danger of a collision.
Or, something like that. I forget the details, but it's been discussed here a while ago.
Greg KO6TH
Peter Pauly wrote:
Anyone know the details? I assume they would want to release them
"towards
earth" and not in the other direction so that they would have a lower
orbit
than the station and not run into them at some point. Do they just toss them out?
Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
"On purpose" is a multiply faceted thing. It's high enough that it can stay in orbit, but low enough that the Shuttle and other launch vehicles can get to it. That orbit happens to be low enough that stuff does tend to decay fairly rapidly, but I think access was more the driving factor for how high to put it.
Anything in a higher orbit will necessarily cross through the ISS's orbit on their way to decay. So, putting the ISS higher would have been better from a debris perspective, and also would reduce the need for reboosting. But if you can't get to the ISS with the available launch vehicles, that would kind of defeat the whole purpose of the space laboratory.
Greg KO6TH
Patrick Green wrote:
It's my belief that ISS sits in a decaying orbit on purpose so other debris is limited. They constantly have to keep pushing up their orbit to stay in space and not fall back to earth.
73 de KA9SCF
FYI, interesting article in the current Air&Space magazine about the extent of debris and trash in orbit. It is a real trash heap out there.
73, Ted K7TRK
-----Original Message----- From: AMSAT-BB [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Patrick Green Sent: Wednesday, August 16, 2017 12:54 PM To: Amsat BB Subject: Re: [amsat-bb] Hand deployed satellites
It's my belief that ISS sits in a decaying orbit on purpose so other debris is limited. They constantly have to keep pushing up their orbit to stay in space and not fall back to earth.
73 de KA9SCF
On Wed, Aug 16, 2017 at 2:12 PM, Greg D ko6th.greg@gmail.com wrote:
I jokingly describe the launch of a satellite from the ISS as the crew opening a window and tossing the satellite out. But, in fact, there is a very carefully planned direction to which the crew "toss" the satellites. I believe it's to the rear and below of the ISS, such that when the orbits cross in the future there is no danger that the two will collide.
If, for example, they were to push the satellites to the side of the ISS, then an orbit later the two would meet again as the satellite's orbit would be oscillating to one side and then the other of the ISS. Going to the rear, making the satellite's orbital velocity slightly slower than the ISS, would put the satellite in a lower orbit. But that lower orbit makes the satellite complete its trip around the Earth faster than the ISS, so should put it ahead of the ISS when they meet again. If launched behind and below, then by the time it gets around to the ISS again, it should be far enough away that there would be no possible danger of a collision.
Or, something like that. I forget the details, but it's been discussed here a while ago.
Greg KO6TH
Peter Pauly wrote:
Anyone know the details? I assume they would want to release them
"towards
earth" and not in the other direction so that they would have a lower
orbit
than the station and not run into them at some point. Do they just toss them out?
Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
-- Best regards,
Patrick Green _______________________________________________ Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Oh yeah
It amazes me how the ISS is not going ting ting ting
Sent from my iPhone
On 17 Aug 2017, at 9:36 am, Ted k7trkradio@charter.net wrote:
FYI, interesting article in the current Air&Space magazine about the extent of debris and trash in orbit. It is a real trash heap out there.
73, Ted K7TRK
-----Original Message----- From: AMSAT-BB [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Patrick Green Sent: Wednesday, August 16, 2017 12:54 PM To: Amsat BB Subject: Re: [amsat-bb] Hand deployed satellites
It's my belief that ISS sits in a decaying orbit on purpose so other debris is limited. They constantly have to keep pushing up their orbit to stay in space and not fall back to earth.
73 de KA9SCF
On Wed, Aug 16, 2017 at 2:12 PM, Greg D ko6th.greg@gmail.com wrote:
I jokingly describe the launch of a satellite from the ISS as the crew opening a window and tossing the satellite out. But, in fact, there is a very carefully planned direction to which the crew "toss" the satellites. I believe it's to the rear and below of the ISS, such that when the orbits cross in the future there is no danger that the two will collide.
If, for example, they were to push the satellites to the side of the ISS, then an orbit later the two would meet again as the satellite's orbit would be oscillating to one side and then the other of the ISS. Going to the rear, making the satellite's orbital velocity slightly slower than the ISS, would put the satellite in a lower orbit. But that lower orbit makes the satellite complete its trip around the Earth faster than the ISS, so should put it ahead of the ISS when they meet again. If launched behind and below, then by the time it gets around to the ISS again, it should be far enough away that there would be no possible danger of a collision.
Or, something like that. I forget the details, but it's been discussed here a while ago.
Greg KO6TH
Peter Pauly wrote:
Anyone know the details? I assume they would want to release them
"towards
earth" and not in the other direction so that they would have a lower
orbit
than the station and not run into them at some point. Do they just toss them out?
Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
-- Best regards,
Patrick Green _______________________________________________ Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
participants (5)
-
Andrew Rich -
Greg D -
Patrick Green -
Peter Pauly -
Ted