Rendez Vous in Space hp50g

Use arrows to produce a small impulsion in this direction. Dock to Soyuz. "Docking is completed" when Apollo Soyuz distance is less than 1 (noted D<1) and when velocity is less than 2 (written U<2 on the screen). Caution, you have only 100 units of propellant. (written prop=100). At each level, "w" the angular velocity increases. At first, there is no rotation! So it is easy: you can go straight ahead! ALPHA allows to do the same level again (no lives lost). ON to quit. You have 3 lives, at each success full docking you gain one more. A life is lost at each collision (not in the axis and/or to large velocity). The score is computed with the number of propellant units left times the number of the level.

What does the program? It reads the touched arrow and this gives the impulsion px or py which is -1, 0 or 1 so the force is: fx=3*omega*omega*(x-x0)+2*(omega)*v+px; fy=                    -2*(omega)*u+py; The velocity is then recomputed using a simple Euler explicit scheme u=u+dt*fx; v=v+dt*fy; The position is then updated: x=x+dt*u; y=y+dt*v; t=t+dt;