6 ms·

Maybe this is something which cheaper space-launch could solve. If it were economical to send maintenance robots to fix dead satellites, then perhaps these tiny

by gnode 9y ago

Maybe this is something which cheaper space-launch could solve. If it were economical to send maintenance robots to fix dead satellites, then perhaps these tiny satellites could be allowed to self-track (using GPS). In the event that the satellite fails it could be repaired / collected / de-orbited before its orbit deviates too far from nominal.

djrogers 9y ago
> perhaps these tiny satellites could be allowed to self-track (using GPS) Not so sure GPS would work well up in space, given that the signals are aimed down at the planet's surface.
- baobrien 9y ago
  GPS Satellites are in MEO, so AFAIK, it's possible to get a GPS track in LEO -- assuming the receiver isn't artificially altitude and speed capped.
  - cbanek 9y ago
    You can get GPS in LEO, but there are altitude and speed limits on non-military applications / chips. "In GPS technology, the term "COCOM Limits" also refers to a limit placed on GPS tracking devices that disables tracking when the device calculates that it is moving faster than 1,000 knots (1,900 km/h; 1,200 mph) at an altitude higher than 18,000 m (59,000 ft).[2] This was intended to prevent the use of GPS in intercontinental ballistic missile-like applications. Some manufacturers apply this limit only when both speed and altitude limits are reached, while other manufacturers disable tracking when either limit is reached. In the latter case, this causes some devices to refuse to operate in very high altitude balloons.[3]" https://en.wikipedia.org/wiki/Coordinating_Committee_for_Multilateral_Export_Controls https://en.wikipedia.org/wiki/Coordinating_Committee_for_Mul...
- mirashii 9y ago
  For what it's worth, GPS does work, and can indeed work very well. Applications like GNSS-RO have been done on research and commercial LEO satellites and use GPS to get orbit position estimates down to 10s of centimeters.

by gnode 9y ago

djrogers 9y ago

> perhaps these tiny satellites could be allowed to self-track (using GPS) Not so sure GPS would work well up in space, given that the signals are aimed down at the planet's surface.

baobrien 9y ago
GPS Satellites are in MEO, so AFAIK, it's possible to get a GPS track in LEO -- assuming the receiver isn't artificially altitude and speed capped.
- cbanek 9y ago
  You can get GPS in LEO, but there are altitude and speed limits on non-military applications / chips. "In GPS technology, the term "COCOM Limits" also refers to a limit placed on GPS tracking devices that disables tracking when the device calculates that it is moving faster than 1,000 knots (1,900 km/h; 1,200 mph) at an altitude higher than 18,000 m (59,000 ft).[2] This was intended to prevent the use of GPS in intercontinental ballistic missile-like applications. Some manufacturers apply this limit only when both speed and altitude limits are reached, while other manufacturers disable tracking when either limit is reached. In the latter case, this causes some devices to refuse to operate in very high altitude balloons.[3]" https://en.wikipedia.org/wiki/Coordinating_Committee_for_Multilateral_Export_Controls https://en.wikipedia.org/wiki/Coordinating_Committee_for_Mul...
mirashii 9y ago
For what it's worth, GPS does work, and can indeed work very well. Applications like GNSS-RO have been done on research and commercial LEO satellites and use GPS to get orbit position estimates down to 10s of centimeters.