We received the following question from one of our readers:
There are two answers to this question. Yes GPS works in space. And no, GPS doesn’t work in space.
The ISS uses GPS satellites to determine its position and orientation in space. There are 4 GPS antennas on the S0 Truss truss (circular objects inside the red rectangle in the picture below.
The antennas are connected to two GPS receivers located in the American laboratory on the ISS. Each antenna can receive signals from four or more satellites, which is necessary to determine the position of the station in space.
The signal from each satellite will not reach each of the antennas at the same time, depending on the location of the satellites and the tilt angle of the station. The difference is measured in nanoseconds, but modern equipment is sensitive enough to record this difference and use it to calculate both the height of the station and its exact orientation in space.
GPS is also used to correct information about the exact position of spacecraft approaching the ISS.
The answer is «No»
If an astronaut takes out a GPS device or turns on GPS on his mobile phone, then the GPS functionality of these devices will not work. Any modern GPS equipment contains built-in hardware limitations that prevent devices from functioning at high altitudes and high speeds.
This is to prevent attackers from using GPS to create guided missiles, high-speed projectiles, etc. The GPS receivers on board the ISS are specially designed without this limitation.