Relativistic Rocket Travel

Ship time vs. Earth time for constant proper-acceleration interstellar travel.

Destination Distance

Proper Acceleration — 1.00g (9.807 m/s²)

Thrust fraction — 100% of trip under thrust (accel to midpoint, decel to dest)

0% (coast only)50% (accel + decel)100% (accel+decel no coast)

Ship time (proper)3.58 yr

Earth time (coordinate)6.00 yr

Peak velocity95.1656% c

Peak γ (Lorentz factor)3.2556

Time dilation factor1.6756

Distance4.3700 ly

Earth ages 2.42 yr more than the crew during this trip.

How it works

Uses exact special-relativistic kinematics for constant proper acceleration. "Ship time" (τ) is what clocks aboard experience. "Earth time" (t) is coordinate time in the departure frame. Thrust fraction splits the trip into accel / coast / decel phases. No fuel or propulsion system is modeled — this is purely kinematic.