Estimate how long an escaping spacecraft remains inside an instrument's useful distance window using a constant-speed screening model. Duty cycle then converts transit time into usable observation time.
Usable observation time equals transit time multiplied by duty cycle.
The result screens an observation campaign by distance window. A real hyperbolic trajectory slows as it climbs out of the gravity well, so constant average speed is an explicit planning assumption.
Replace average speed with a trajectory-derived value when navigation solutions are available.
From 10,000 km to 500,000 km at an average 11 km/s, transit time is about 12.37 hours. At a 60% duty cycle, usable observation time is about 7.42 hours.
No. Escape velocity is an ideal local speed; launch losses, staging, rotation, and the spacecraft's current speed change required delta-v.
No. The core escape calculation is a vacuum, two-body estimate. Add a mission margin or a separate loss estimate.
Yes. Enter that body's gravitational parameter and the distance from its center.
Gravitational potential becomes less negative with distance, so less kinetic energy is needed to reach a zero-energy escape path.
No. Use it for early trade studies, then verify with trajectory, propulsion, thermal, and operations analyses.
| Input | Role |
|---|---|
| Starting distance | Beginning of useful window |
| Maximum distance | End of useful window |
| Average speed | Constant screening assumption |
| Duty cycle | Fraction available to observe |