Summary (2) DSS Architecture 2 Free AV trajectories for collector spacecraft Minimum Av combiner spacecraft location Exploitation of conic sections Optical delay lines Delay lines to steer array 's los ZR(Cross Results Delay Length Vs Specific Impulse cross over point Space Systems Laboratory Massachusetts Institute of TechnologySpace Systems Laboratory Massachusetts Institute of Technology Summary (2) Summary (2) • DSS Architecture 2 – Free ∆V trajectories for collector spacecraft – Minimum ∆V combiner spacecraft location – Exploitation of conic sections • Results – Delay Length vs Specific Impulse cross over point • Optical Delay Lines – Delay lines to steer array’s LOS 100 200 300 400 500 600 700 800 900 1000 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 Specific Impulse (secs) D e l a y Length Convers ion ( kg/ m ) R o = 500 m R o = 50 m -1.2 -0.9 -0.6 -0.3 0 0.3 0.6 0.9 1.2 -0.6 -0.3 0 0.3 0.6 x1" x2" Imaginary Paraboloid Elliptical Trajectory D1 D2 Delay/Ro = |D1 - D2| φ = 0o, ψ = 162o Combiner (Focus) dtarget Cross Range (z/Ro) Zeni t h (x / R o ) -180 -90 0 90 180 0 30 60 90 120 150 180 (Rz = Ro) R z = 0 (Rz = ∞) R z = R o (Rz = 0) [Rz = -0.87Ro] R z = ∞ (Rz = -∞) [Rz = 0.87Ro] (Rz = -Ro) R z = -R o R z = -∞ LEO GEO ψ (deg r ees ) φ (degrees) -1.5 -1 -0.5 0 0.5 1 1.5 -1.5 -1 -0.5 0 0.5 1 1.5 -1 -0.5 0 0.5 1 y/Ro(velocity vector) Circular Paraboloid Ellipse ← Optimal Focus (p/Ro=2.2076) Projected Circle z/R o (Cross axis) Hyperbola (Foci) x/ R o (Z e n i th Na d i r )