Solar Sail Space Craft with automatic furl and unfurl devices and central Docking and Payload Ring structure
- © Frank Ellinghaus -
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Inner Ring -
Flying Ring -
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Fig.13 -
Fig.14-15 -
Fig.16 Mobile Thruster Unit -
Fig.17 -
Fig.18 Fuelless Steering -
Fig.19-21d Solar Sail Launch System
Fig. 13 - Solar Thruster Sailor (STS) with roller reefing devices
Fig. 13 shows a Solar Sail Spacecraft based on the Solar Thruster Sailor design with an Outer Thruster Ring and an Inner Ring structure, stuffed with devices for furling and unfurling the sail panels 2.9.
This gives several advantages espacially for large solar sails.
The zone less than 900 km above Earth ground is dangerous for solar sails ( the ISS is about 400 km above ground) because the athmospheric rests are developing stronger forces than the solar sail.
For the Solar Thruster Sailor assembling, fixed to a space station (like the ISS) in a pretty close Earth orbit, becomes possible without having to fear that the craft crashes down to Earth.
The sail panels are furled on their rolls as long as the sail craft is in the atmospheric drag zone. The STS won´t unfurl them before the construction phase is completed and the craft has left the dangerous zone with the help of it´s thrusters. When an STS would return off a mission it furls it´s panels again and is able to get back to the station with it´s ion thrusters.
Also there is no folding of the sail since it comes on rolls. There is no unfolding and setting of a large breakage prone sail in space, just putting those rolls into it´s brackets. The size of the sail is not limited to the carriage capacity of a single launcher, so pretty large sails made off a lot of those panels can be used.
Moreover, the solar sail could steer though altering the size of sail panels at the appropriate locations which enables completely fuel less cruising mode without needing steering vanes.
But the most important feature of the Solar Thruster Sailor is the central docking and payload station in form of the Inner Ring construction 5. It enables transporting and handling of spacecrat fleets, objects and flying material containers in an efficient and economical way. It also has an inbuilt solar cell ring which can serve as a mobile solar power station. Which other solar sail designs can provide all this features together?
Before getting to the design I would like to quote from the not longer active project of the Carnegie Mellon University : "The primary difficulty with solar sails has been the need for great sail surface area relative to the payload mass. Also, the cost associated with manufacturing very large sails and the risks of deploying such structures in space has hindered their development. "
The Solar Thruster Sailor design avoids deployment and enables in orbit construction of very large solar sails which could be done mainly by remote control and robotics.
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For a larger high quality pdf of Fig.13 click here!
The figure shows the STS with the sail panels unfurled.
The brackets holding the panel rolls are located at the Outer Thruster Ring.
On the Inner Ring Structure are winches located which pull the panels to the plane center when unfurling. At least one of the two panel roll brackets is stuffed with an electric motor which pulls the panels back when roller reefing.
The Inner Ring Structure 5 consists of 3 Rings 5.a - 5.c which are held together with ring connecting pipes 5.9. The area between rings 5.b and 5.c is used up through solar panels 5.11, the area in the innerst ring 5.a is free for payload or daughter units. Those ring connecting pipes can go up and down off the ring plane also to form a volume for the docking and payload station.
The Inner Ring Structure 5 is held through (CNT-) threads into the Outer Ring. This holding structure is separate off the Sail and show´n in Fig. 17.
The sail panels itself are separate shown on Fig´s 14 and 15 and are similar to the panels designed for the solar sail Mars race through the Johns Hopkins University (JHU). It has two CNT-lines at the long edges which take the load off the sail cloth and has also rip stops to prevent the panel from tearing.
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The sail panels are looking similar like those the Johns Hopkins University (JHU) has designed for the solar sail Mars race.
The main difference is that they wanted to put the panels INTO tubes getting pulled out when the whole structure of the JHU solar sail was unfolding.
A very stressing procedure for the delicate extremly thin sail foils. I think smoothly rolling them off the roll is a lot better.
The concept for unrolling and rolling back is that every second panel is located above and every second panel is located under every second panel.
We now have the possibility to let the panels just in the two planes or lowering the upper panels after sail setting or reefing with adjustable brackets.
The sail design above is thought for really big solar sail structures which have to be built in space, because they are not launchable. For a launchable solar sail which uses also roller reefing for fuelless steering, station keeping and attitude control take a look on the Solar Sail Launch and self enlargement System (SSLS). For more informations on steering for both sail designs with roller reefing and ballast sail panels take a look at Fig.18 Fuelless Steering.
to the next Fig.`s 14-15 (single sail panel and panel shown on a roll)
Fig.1 -
Fig.2a-2b -
Fig.2c -
Fig.2d -
Fig.3a-3b -
Fig.4a-4c -
Fig.5 -
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Fig.7 -
Inner Ring -
Flying Ring -
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Fig.11 -
Fig.10 -
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Fig.13 -
Fig.14-15 -
Fig.16 Mobile Thruster Unit -
Fig.17 -
Fig.18 Fuelless Steering -
Fig.19-21d Solar Sail Launch System