Estimate one-way light time, free-space path loss, and received carrier power for a spacecraft receding on an escape trajectory. It is a transparent first-pass link budget with user-entered gains and system losses.
Received dBW = transmitter dBW + transmit gain + receive gain − FSPL − other losses.
Received carrier power is the power at the receiver input before noise and implementation details. Link margin still requires noise temperature, bandwidth, data rate, and required Eb/N₀.
Pointing loss, polarization loss, atmosphere, rain, hardware loss, and coding performance should be included explicitly for a complete budget.
At 1,000,000 km and 8.4 GHz, free-space path loss is about 230.94 dB. With 20 W, 25 dBi transmit gain, 55 dBi receive gain, and 3 dB other losses, received power is about −140.93 dBW.
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.
| Term | Budget sign |
|---|---|
| Transmit power | + |
| Transmit antenna gain | + |
| Receive antenna gain | + |
| Free-space and other losses | − |