hello,


I would like to point you onto my Solar Sail Launch System
http://solar-thruster-sailor.info/figs/fig19-21d.html .
The system sail could be used to transport landers to NEO-asteroids for ore collection and bringing them back with their load to a space station like the ISS.
Another purpose would be performing low thrust satellite tasks.

It´s roller reefing technique could be seen in addition to Bong Wie´s works about steering and station keeping of solar sails, since reefing and unreefing of the solar sails moves both, the center of mass AND the center of solar light pressure while displacing the weight in Wie´s proposal does move only the center of mass.

The solar sail launch system design uses (besides the sail foil) also SEP thrusters as propulsion system.
AS it provides a large disk which uses almost the full launcher area for an Inner Ring Construction
(docking station) and surrounding solar cell ring it is best fitted to power SEP thrusters which may serve as main propulsion while the solar sail features serve for fuel less station keeping and steering.

The fuel less system
is based onto the roller reefing technique
http://solar-thruster-sailor.info/figs/fig13.html
which was primarily thought for larger solar sails but can get used for the launch system sail also.

The sail panels in this case are transported into space on rolls
http://solar-thruster-sailor.info/figs/fig14-15.html
which allow to steer the sail through roller reefing.

For the fuel less steering and station keeping technique take a look on
http://solar-thruster-sailor.info/figs/fig18.html


To get such a system into space with one single launch
take a look at
http://solar-thruster-sailor.info/figs/fig19-21d.html
The Solar sail launch and self enlargement system (SSLS) would enable to launch an operation ready solar sail which carries a central payload and docking station as well as ample solar cell arrays - for year long space usage directly without further construction tasks into space.

Unlike a heliogyro sail this sail does not have to spin for structure stability since it is based on a stiff inner ring construction with also stiff sail panel roll telescope brackets which can enlarge through extracting it´s telescope segments through rotation which stops after the segments are drawn out.

The drawback of the design would be the heavy weight penalty through the stiff construction parts.
Though for instance for Sun observing satellites the solar sail propulsion is only needed for steering and station keeping purposes to keep that sail serving for years once it has reached the designated orbit.

The sail can reach that destination with a strong launcher like the Ariane and it´s own ion thrusters thanks to the large solar cell arrays which enable power strong solar electric units.

But it would be also possible to do a low cost LEO-launch, for instance with a cheap ICBM launcher and drive the spacecraft to it´s destination with solar electric propulsion and use the solar sail later when it has arrived as a means to keep station.

Since the craft features also a docking station carrying mobile docking able add-on thruster units even combining with other types of propulsion like chemical or steam propulsion would be feasible
http://solar-thruster-sailor.info/figs/fig16.html (Mobile Docking able Thruster Unit).

I would be interested about your opinion on this design.


Best wishes


Frank