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L‘Garde Programs - POWER ANTENNA
Power Antenna
The Power Antenna is a space based inflatable solar concentrator that can be used to provide:
- Electrical Power
- A High Gain Communications
- A Heat Source For Spacecraft Thermal Management
The power antenna concept was conceived as a low cost and environmentally friendly alternative to the Radio-isotope Thermal Generators (RTG) which are
widely used for deep space missions. RTGs use decaying radioactive plutonium as an electrical power source. While very energetic the plutonium presents
some very unique issues. The processing of plutonium in today's post cold war environment is becoming increasingly expensive. The environmental hazards
in the event of a launch failure are a concern.
The Power Antenna generates electrical energy by concentrating the available ambient solar energy onto solar cells. During this process most of the
energy can provide heating for the spacecraft to aid in thermal management. The antenna can act concurrently as an optical concentrator and as a high
gain antenna through the use of a beam splitter. The figure below shows the basic concept and the function and location of the beam splitter.
The beam splitter concept consists of an RF grid mounted in the path of the concentrated RF energy and deflects it toward a lateral RF feed. Optical
energy can pass through the grid allowing simultaneous use of the antenna as a solar concentrator.
The solar concentrator is sized to provide the optimum amount of light at the portion of the mission farthest from the Sun. However, the array may
be required to provide power throughout the mission to provide energy much closer to the Sun. Nearer the Sun the concentrator can provide more energy
than the solar cells can physically withstand. An optical attenuator is provided to reduce the amount of light concentrated to acceptable levels.
The optical filter is made up of a long sheet of transparent material of varying opacity. The filter is wound onto motor driven rollers which can
in effect control how much light reaches the array.
Various studies have been undertaken to refine this concept. Some early results are shown below. These weights are based on providing 75 Watts of usable electric power.
The weights include the inflation system and enough make-up gas to overcome any expected meteoroid leaks for 5 years. There are certain optical benefits at the higher
F/Ds but the support struts become longer.
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Power Antenna Mission Studies
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Power Antenna Stowed Volumes
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 You can view a simulation of the deployment of the Power Antenna.
And you don't have to wait for anything to download. This link requires at least a 56K connection and RealPlayer. There are some other
system requirements to play this video. If this link does not work for you, download the free RealPlayer by clicking in this button:
This minute-long computer animation shows the deployment of the Power Antenna on a simulated mission near Jupiter.
Play animationright now
Download animation to disk for later. (284 K)
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L'Garde completed a Phase II SBIR study of the Power Antenna Concept. Design features affecting performance, weight, and volume have been identified and
are being refined. There are many details effecting weight and performance such as pointing accuracy, frequency response, mission duration, to name just a few.
Should you wish to learn more about the Power Antenna concept or seek assistance in designing a system meeting your requirements,
please contact the Power Antenna Design Team.
Don't leave Earth without one!
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