The form of the lander will be similar to that of Philae – only the payload housing will be a square frame made out of aluminium struts welded together (Right now we are considering a 15X15X15cm housing), and there will be 4 legs (as oppsed to 3) positioned at the edges of the cube (currently planned to be 20 cm long) – the current plan for the suspension is as follows:
4 Legs with springs that can actaute relative to the frame of the payload bay and each other and 2 shock absorbers (1 per 2 legs). The idea with this design is that the shock absorbers weight quite a bit, they will be attached to a rail that is attached to 2 legs – this rail will be able to move side to side relative to the legs its attached to – this way we ensure that if the lander touches down on 1 leg – its adjacent one wont also contract and therefore offer no shock absortion – we plan to use 2 60N shock absorbers for this design.
This is a very poor explanation I know but soon we plan to have a 3D scetch of the whole lander – it will be easy to understand then.
Now the parachute:
We considered various forms of landing systems – raging from controlled decent using rotor blades (quad copter- like), wings on the side of the lander with control surfaces to provide steering, solid rocket boosters (god knows how we would get ahold of those) to parachutes (which we ultimately decided to go with). A parachute with a surface area of 2.2m will (in theory) bring us down with 4m/s. The parachute will be made in the next few days and thrown from the top of an 8 story building – updates will follow