Thursday, November 05, 2015
Sailing in SPAAACE - marks and lines
A couple of ideas spring to mind, but its worth noting that space sailing is likely to be more like America's Cup racing with its virtual course borders, using electronic aids galore. In this case you could (for example) define locations with respect to an Earth Centred Inertial (ECI) coordinate frame.
Other ideas could be to use stations or satellites as marks, together with additional geometric constraints.
One such would be to define a sphere around a point or satellite. For example a race could have start to be the volume within 10 km of the International Space Station (ISS). This is simple to define but could end up with all solar sails clumped at the same, advantageous sector, most likely the point of the sphere furthest from the Earth.
Marks could be define also as sphere - for example, the figure above shows the various Earth-Sun Lagrange points, and you could imagine a race between them, such as:
- Start within 10 km of the ISS
- Pass within 100 km of L4
- Pass within 100 km of L3
- Pass within 100 km of L5
- Finish within 10 km of the ISS
This would allow solar sail craft to slightly cut the corners as they could be within 100 km while not actually going round the mark.
Alternatively the mark could be defined using a combination of distance from point or satellite plus at least as far from the central object (e.g. the Sun in these cases) as the point or satellite. More advanced ones could define solid angles using the line from the relevant central gravitational body to the mark point or satellite.
Therefore it is doable, there are ways to define such as race.
So let your imaginations go, look up at the sky, and imagine the windjammers of the future, tacking their way around the solar system.
Just keep an eye out for solar storms and those pesky space pirates!