Directv 1R (110W) is scheduled for end of life deorbit and has been removed from the SatMaps! database. Directv 1R Deorbit Documentation
Directv 1R Deorbit
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Iceberg said:so does it go to that big stud satellite farm in heaven?
Going to get thick up there. They call it "deorbit" and in the process they increase the elevation a hundred miles or so. This puts it on an escape velocity but really slow movement. If they moved It even a little distance closer to the earth, it would slowly start descent over many many years.
That's not actually a wondeful idea...
Communications sattelites in geosynchronous orbit don't carry enough propellant to lose enough velocity to achieve an orbit low enough to noticably increase their drag and accelerate their inevitable fall to earth. The stationkeeping thrusters only have enough energy to change their orbital by a few hundred km. It doesn't matter if you use the thrusters to increase the velocity and raise the orbit or decrease the velocity and lower the orbit. The energy available is only a tiny fraction, less than one percent, of the energy required to manoevre to either dip into the atmosphere and crash or achieve escape velocity and leave earth orbit.
The statement that implied the payload vehicle would continue to slowly drift further away from earth was mistaken. Increasing orbital height requires increasing velocity and that requires an ongoing energy input. The solar pressure from the sun averages out to nil over the long term and there's no appreciable atmospheric drag as there is in low earth orbit.
The statement preferring pushing dead satellites down rather than up ignores some practical considerations. If you push the thing downward, then everything ascending to geosynchronous orbit has to avoid it until it crashes, on a timescale marked in centuries. Unfortunately, there are a lot of upper stages left over from the launch vehicles that put these sattelites in orbit already there in highly eccentric orbits (highly eccentric implies their velocity at the peak is much lower than an object in circulr orbit at the same altitude). If the satellite is pushed downward its likely to eventually impact one or more of these eccentric orbits with a considerablly different velocity and produce a lot of small debris that can't be tracked and avoided.
So, the preference is to park the dead satellite up and out of the way. They also intentionally vent the remaining propellants, flatten the batteries, and so on to remove all onboard energy sources that might one day explode and spread debris.
There's nothing special about geosynchronous orbit other than that the obital period matches the planet's rotation, but since its kind of handy to not need tracking motors on satellite TV dishes, they're trying to minimize debris to keep the orbit useful for as long as possible. It won't last forvever, but maybe by then we won't need it anyway.
Let it descend!! Everybody else seems to "lose" communication with their satellites and they come crashing down to earth, why not let another one?
Communications sattelites in geosynchronous orbit don't carry enough propellant to lose enough velocity to achieve an orbit low enough to noticably increase their drag and accelerate their inevitable fall to earth. The stationkeeping thrusters only have enough energy to change their orbital by a few hundred km. It doesn't matter if you use the thrusters to increase the velocity and raise the orbit or decrease the velocity and lower the orbit. The energy available is only a tiny fraction, less than one percent, of the energy required to manoevre to either dip into the atmosphere and crash or achieve escape velocity and leave earth orbit.
The statement that implied the payload vehicle would continue to slowly drift further away from earth was mistaken. Increasing orbital height requires increasing velocity and that requires an ongoing energy input. The solar pressure from the sun averages out to nil over the long term and there's no appreciable atmospheric drag as there is in low earth orbit.
The statement preferring pushing dead satellites down rather than up ignores some practical considerations. If you push the thing downward, then everything ascending to geosynchronous orbit has to avoid it until it crashes, on a timescale marked in centuries. Unfortunately, there are a lot of upper stages left over from the launch vehicles that put these sattelites in orbit already there in highly eccentric orbits (highly eccentric implies their velocity at the peak is much lower than an object in circulr orbit at the same altitude). If the satellite is pushed downward its likely to eventually impact one or more of these eccentric orbits with a considerablly different velocity and produce a lot of small debris that can't be tracked and avoided.
So, the preference is to park the dead satellite up and out of the way. They also intentionally vent the remaining propellants, flatten the batteries, and so on to remove all onboard energy sources that might one day explode and spread debris.
There's nothing special about geosynchronous orbit other than that the obital period matches the planet's rotation, but since its kind of handy to not need tracking motors on satellite TV dishes, they're trying to minimize debris to keep the orbit useful for as long as possible. It won't last forvever, but maybe by then we won't need it anyway.
polychromeuganda said:
Let me get this straight. When old satellites get decommissioned they just use maneuvering thrusters to push them a few hundred km higher and the same thing is done with most other satellites too?
Why are they Turning it off if it still works and has fuel. I say still works because a few days ago I checked somebodies signal on 110 and it was good. Is it because it's about to lose fuel and they want to park the satelite up higher with the last bit of fuel it has?
Thanks for imparting us with your knowledge, i think it's weird how many satelitte techs I know (me included) who know so little about how our satelites actually work.
Ps we talking about directv sattelite here or dish?
The spacecraft in question has been "off" for some time. Orbital position has multiple occupancy
DirecTV 1R, the spacecraft in question has been "off" for some time. What you're receving from the area in the sky must coming be from a different spacecraft. The referenced FCC application narrative discusses extending permission for the platform command, control, and telemetry transmitters. These are low data rate, low bandwidth, low power, radios used to control the spacecraft and monitor its operating condition and position. The application says the major functions of the spacecraft (the wideband uplink/downlink transponders) are powered down, and the application promises to keep them that way. Permission to operate the high power transmitters must have expired some time ago, probably by reassigning it to another spacecraft, but I haven't researched which spacecraft is providing the signals you're receiving.
The basic position increment for geosynchronous orbit is 0.2°, or about 112km, but improved stationkeeping has made it possible to have more than one spacecraft in a given position. (Orbital position may have multiple occupancy.) The angular resolution of your DBS antenna is comparatively wide. You don't get any indication of the change when downlink frequencies have been reassigned to transponders on another spacecraft also in your antenna pattern's main lobe. I also don't know if the DirecTV diagnostic you use was remapped and the frequencies changed.
I don't know the details of why DirecTV wants to remove 1R from geosyncronous orbit, but I could tell you some of the more common end-of-life problems. This bird has been flying more than a decade, which makes it a geriatric case in the satellite business. (I started describing the problems that usually occur, but it got long, so the short version is that...) As it ages the available electrical power is declining and forces the operator to turn off transponders, while radiation damage is causing degradation and failures that slowly increase the risk of losing control of the spacecraft. (Even if there's plenty of propellant left) Eventually the risk of having a dead bird permanently occupying prime real estate outweighs the value of its diminishing capacity.
DirecTV 1R, the spacecraft in question has been "off" for some time. What you're receving from the area in the sky must coming be from a different spacecraft. The referenced FCC application narrative discusses extending permission for the platform command, control, and telemetry transmitters. These are low data rate, low bandwidth, low power, radios used to control the spacecraft and monitor its operating condition and position. The application says the major functions of the spacecraft (the wideband uplink/downlink transponders) are powered down, and the application promises to keep them that way. Permission to operate the high power transmitters must have expired some time ago, probably by reassigning it to another spacecraft, but I haven't researched which spacecraft is providing the signals you're receiving.
The basic position increment for geosynchronous orbit is 0.2°, or about 112km, but improved stationkeeping has made it possible to have more than one spacecraft in a given position. (Orbital position may have multiple occupancy.) The angular resolution of your DBS antenna is comparatively wide. You don't get any indication of the change when downlink frequencies have been reassigned to transponders on another spacecraft also in your antenna pattern's main lobe. I also don't know if the DirecTV diagnostic you use was remapped and the frequencies changed.
I don't know the details of why DirecTV wants to remove 1R from geosyncronous orbit, but I could tell you some of the more common end-of-life problems. This bird has been flying more than a decade, which makes it a geriatric case in the satellite business. (I started describing the problems that usually occur, but it got long, so the short version is that...) As it ages the available electrical power is declining and forces the operator to turn off transponders, while radiation damage is causing degradation and failures that slowly increase the risk of losing control of the spacecraft. (Even if there's plenty of propellant left) Eventually the risk of having a dead bird permanently occupying prime real estate outweighs the value of its diminishing capacity.
Lyngsat has useful signal information but doesn't appear to be a perfect catalog of spacecraft. According to satsig satbeams and needlebase the inventory around 110°W includes DirecTV-1R at 109.8°W, EchoStar-10 at 110.0°W, EchoStar-11 at 110.1°W, and DirecTV-5 (originally built as Tempo-1) at 110.1°W. These all are currently operational except for DirecTV-1R which is in a low power stationkeeping mode pending a final burn to move it up out of geosynchronous orbit into a stable higher orbit in July, after which it will be shut down.
As noted above, DirecTV-5 is already in that position and DirecTV-1R has already been retired as a DBS transponder.
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