Shaded region shows where the sail eventually reaches rest in the lab frame, as a function of 4 fixed variables and two floating variables, which are plotted. Parameters are the size of the beam optics (D_c), the radius and mass of the sail r_s and m_s, the wavelength λ of the laser, the laser power P, and the spacecraft velocity β relative to the lab frame. Criterion:
(2π√(2π))/λ · (P·Dc·rs)/(msc³) ≥ Φ(βc)Φ(β)=⅓u³−u+⅔, u=√[(1+β)/(1−β)]Large‑sail limit: rs ≫ w0≈Dc/2
Controls
Fixed Parameters (those NOT on axes)
Tip: If an axis includes βc, keep it in linear scale (0–0.99). Other positive quantities often benefit from log scales.