In summary, TCS technology is important to world balloon programs because it
simplifies missions by mitigating overflight and safety concerns, expands flight
termination options, and minimizes payload recovery logistics.
3.5.2 GAC TCS Technology
Over twenty years ago, Global Aerospace Corporation in Irwindale, CA created a
unique system to control the trajectory of a stratospheric balloon. They developed
a flight prototype of a wing assembly called the StratoSail TCS which exploits the
natural difference in wind speed at different altitudes to produce a horizontal force
on a balloon to:
• Avoid regions of high population density.
• Minimize flights over geopolitically sensitive areas.
• Enter regions of high scientific value.
• Maintain the geometry of multiple balloon constellations.
• Other options for trajectory control were also investigated, for example
station-keeping.
The flight segment uses a wing assembly, a tether, a gondola interface package,
and software. The gondola interface package remains physically attached to the
gondola of the balloon. A winch system reels out a very long tether that carries the
wing assembly. The wing assembly is stowed compactly with the gondola at
launch, and the tether is rolled on a very large spool. The package also includes
interface hardware and software to accept commands from and relay data to the
balloon payload. The wing assembly is lowered by the tether. The main element
of this assembly is the wing that generates the aerodynamic forces that alter the
flight path. The wing assembly includes a rudder to control the direction of the
wing’s pull. An electronics module in the wing assembly uses solar power and
batteries to control the rudder, to process data from various sensors, and also to
communicate with the package by radio link.
Tests verified the expected behavior, but further development was not pursued
owing to the acceptance of the current capabilities to control altitude, especially
by the techniques used by Loon and others. Nevertheless, it remains a potential
technology that could be developed in the future. See Section 5.10 for details.
3.5.3 Parachute Technology
Balloon parachutes have been tested many times over the decades. Some of the problems in opening a parachute have resulted in excessive shock to the payload and its
sensitive and valuable instruments. Some of these problems were solved by the development of the rip-stich technology. At flight termination there is the risk of contacting
the collapsing balloon. Another is the need to rapidly separate from the payload and
collapse the chute at landing to preclude dragging it across the ground and damaging
it. Separate technologies were developed to solve these potential problems.
3.5 Technology Examples 61
simplifies missions by mitigating overflight and safety concerns, expands flight
termination options, and minimizes payload recovery logistics.
3.5.2 GAC TCS Technology
Over twenty years ago, Global Aerospace Corporation in Irwindale, CA created a
unique system to control the trajectory of a stratospheric balloon. They developed
a flight prototype of a wing assembly called the StratoSail TCS which exploits the
natural difference in wind speed at different altitudes to produce a horizontal force
on a balloon to:
• Avoid regions of high population density.
• Minimize flights over geopolitically sensitive areas.
• Enter regions of high scientific value.
• Maintain the geometry of multiple balloon constellations.
• Other options for trajectory control were also investigated, for example
station-keeping.
The flight segment uses a wing assembly, a tether, a gondola interface package,
and software. The gondola interface package remains physically attached to the
gondola of the balloon. A winch system reels out a very long tether that carries the
wing assembly. The wing assembly is stowed compactly with the gondola at
launch, and the tether is rolled on a very large spool. The package also includes
interface hardware and software to accept commands from and relay data to the
balloon payload. The wing assembly is lowered by the tether. The main element
of this assembly is the wing that generates the aerodynamic forces that alter the
flight path. The wing assembly includes a rudder to control the direction of the
wing’s pull. An electronics module in the wing assembly uses solar power and
batteries to control the rudder, to process data from various sensors, and also to
communicate with the package by radio link.
Tests verified the expected behavior, but further development was not pursued
owing to the acceptance of the current capabilities to control altitude, especially
by the techniques used by Loon and others. Nevertheless, it remains a potential
technology that could be developed in the future. See Section 5.10 for details.
3.5.3 Parachute Technology
Balloon parachutes have been tested many times over the decades. Some of the problems in opening a parachute have resulted in excessive shock to the payload and its
sensitive and valuable instruments. Some of these problems were solved by the development of the rip-stich technology. At flight termination there is the risk of contacting
the collapsing balloon. Another is the need to rapidly separate from the payload and
collapse the chute at landing to preclude dragging it across the ground and damaging
it. Separate technologies were developed to solve these potential problems.
3.5 Technology Examples 61