GPS and Other Satellites

[kato13]

Originally Posted by Targan

Correct. Real-World Relativity: The GPS Navigation System

When these quotes were posted the programmer in me was thinking, what engineer would allow that. The next paragraph radically changes the context of the quotes as far as this discussion goes.

The engineers who designed the GPS system included these relativistic effects when they designed and deployed the system. For example, to counteract the General Relativistic effect once on orbit, they slowed down the ticking frequency of the atomic clocks before they were launched so that once they were in their proper orbit stations their clocks would appear to tick at the correct rate as compared to the reference atomic clocks at the GPS ground stations. Further, each GPS receiver has built into it a microcomputer that, in addition to performing the calculation of position using 3D trilateration, will also compute any additional special relativistic timing calculations required

Also this

https://en.wikipedia.org/wiki/GPS_satellite_blocks

The Block IIA satellites were slightly improved versions of the Block II series, designed to provide 180 days of operation without contact from the control segment.

Given how important the GPS system is I could see MILGOV sacrificing quite a bit to make sure they can update them twice a year. Don't know how long they could keep them working but they would sure try.

In my world the GPS system would be some where between useless (If ASATs or EMP were really effective), to only being able to provide accurate time (if say 3 or 4 are alive) , to the least likely option partially functional (with like 8 sats working properly, like during the deployment for "desert shield").

If you say you can only get a link for 4 hours every 4 days that could be a useful plot device. You could even have a few sats giving out erroneous information so if you check during other times you get totally wrong information.

[Targan]

Originally Posted by kato13

The next paragraph radically changes the context of the quotes as far as this discussion goes.

Whoops

Originally Posted by kato13

Given how important the GPS system is I could see MILGOV sacrificing quite a bit to make sure they can update them twice a year. Don't know how long they could keep them working but they would sure try.

In my world the GPS system would be some where between useless (If ASATs or EMP were really effective), to only being able to provide accurate time (if say 3 or 4 are alive) , to the least likely option partially functional (with like 8 sats working properly, like during the deployment for "desert shield").

If you say you can only get a link for 4 hours every 4 days that could be a useful plot device. You could even have a few sats giving out erroneous information so if you check during other times you get totally wrong information.

Sounds reasonable.

[Olefin]

Keep in mind that even a catastrophic Kessler scenario in LEO (low earth orbit) poses a minimal risk for launches of craft that are going past LEO - or for satellites and craft above LEO. Also even in the worst case scenario what you get is an increase in the number of collisions, not a physically impassable barrier to space exploration or a barrier that prevents craft to getting to higher orbits.

After all the Soviet weather satellite did survive to re-enter - if the debris had been so bad that LEO was impassible then it would been destroyed long before.

Also the debris in LEO will eventually decay and re-enter just due to residual air drag at those orbital heights - meaning that in a couple of decades at most the increase in collision risks will significantly be reduced.

And France has one big advantage in that they may very well have an intact satellite manufacturer - i.e. Cannes Mandelieu Space Center in Cannes has been making satellites for quite a while - i.e. the satellite division of Aerospatiale - so that would give the French most likely the last intact satellite manufacturing plant in the world and a launch facility that they could use as well - the question is how much of their facilities are still in one piece along with engineers and technicians

[RN7]

Originally Posted by Olefin

Keep in mind that even a catastrophic Kessler scenario in LEO (low earth orbit) poses a minimal risk for launches of craft that are going past LEO - or for satellites and craft above LEO. Also even in the worst case scenario what you get is an increase in the number of collisions, not a physically impassable barrier to space exploration or a barrier that prevents craft to getting to higher orbits.

After all the Soviet weather satellite did survive to re-enter - if the debris had been so bad that LEO was impassible then it would been destroyed long before.

Also the debris in LEO will eventually decay and re-enter just due to residual air drag at those orbital heights - meaning that in a couple of decades at most the increase in collision risks will significantly be reduced.

And France has one big advantage in that they may very well have an intact satellite manufacturer - i.e. Cannes Mandelieu Space Center in Cannes has been making satellites for quite a while - i.e. the satellite division of Aerospatiale - so that would give the French most likely the last intact satellite manufacturing plant in the world and a launch facility that they could use as well - the question is how much of their facilities are still in one piece along with engineers and technicians

I think higher orbits were for example the French would place an INTEL satellite would be at lest risk from debris due to their being less junk at that altitude.

[.45cultist]

The impact of EMP would be felt more among the younger digital generations. Something to stress in role-playing T2013 or later timelines. If I run a game for my nephews again, I'll have to have my map protractor as an aid.

[rcaf_777]

Well since no one is going to ask, I going too. Why is it that the intro in Satellite down contradict the downing of DP 201?

And why dose the downing of DP 201 contradict the rest of the Twilight 2000 Version 1 Timeline?

[Legbreaker]

Originally Posted by rcaf_777

Well since no one is going to ask, I going too. Why is it that the intro in Satellite down contradict the downing of DP 201?

And why dose the downing of DP 201 contradict the rest of the Twilight 2000 Version 1 Timeline?

How does it do that?