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Constellation Management


Controlled Uniform Constellation

The simulation on this page shows that it is possible to control the geometry of a global constellation using an underactuated and bounded control system. We utilize the same initial network of 100 balloons, but we apply an algorithm called "Paired North-South Zonal Control," which is described as follows:

  • Zones are defined as -90 to -45, -45 to 0, 0 to 45, 45 to 90 latitude.
  • Define the target number of balloons in each zone as 15, 35, 35, and 15, respectively.
  • Every four hours, count the number of balloons in each zone.
  • If the actual number differs from the target, specify balloons to be moved from nearby zones, give them the appropriate control instructions, and remove them from paired North-South control.
  • Continue moving these balloons that are under zonal control until the destination zone is reached.
  • For those balloons not under zonal control and whose nearest neighbors are not under zonal control, apply paired north-south control.


Paired north-south control is defined as follows:

  • Only apply control when a StratoSat is closer than 2000 km from its nearest neighbor
  • The control direction (when applied) is either north or south, nothing else.
  • If a StratoSat is north of it's nearest neighbor, it is commanded north.
  • If a StratoSat is south of it's nearest neighbor, it is commanded south.
  • Re-evaluate control for each StratoSat every 4 hours.

This movie goes for 120 days like the free-floating movie.




Note that QuickTime® is required to view these simulations.
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