Trip Planner

Trip planner (VAB / SPH)

The flight Dashboard shows the mechanic while you fly; the planner lets you size a ship for it, in the editor, before you ever launch. From your vessel's ΔV and acceleration, a target distance, and a flight profile, it previews arrival time (mission + crew clocks) and resource use - using the same special-relativity physics the flight layer applies, so the plan and the flight agree.

Open it from the ApplicationLauncher button in the VAB/SPH.

What you set

• Target distance: a field that toggles between a slider and manual entry, with a ly / AU unit switch. If a planet pack is installed, an optional "pick a body" dropdown fills the distance from a chosen body. Manual entry always works, planet-pack or not.
• Flight profile:
  • Rendezvous: brake to rest at the destination. Your ΔV splits between accelerating and braking.
  • Flyby: one-way; all ΔV goes into accelerating, no braking budget.

What it reads from your ship

Input	From
ΔV	the stock ΔV readout
Max acceleration α	active-engine thrust ÷ vessel mass
Onboard resource amounts	ship part resources
Consumption rates	your installed life-support framework (or crew-count approximation)

How to read the output

┌─ TRIP PLANNER ──────────────── VAB ─┐
│ Distance  4.3 ly   ◀━━━━●━━━▶  [ly]  │
│ Profile   ( Rendezvous ) Flyby       │
│ Cruise    0.462 c   ▓▓▓▓░░░░│1c       │
│ Mission   10.1 yr    Crew  9.0 yr    │
│ Supplies  Food ✓  O₂ ✓  Water ⚠ −40kg│
└──────────────────────────────────────┘

• Cruise β: the speed this ship settles into, on a light-wall gauge. It comes from your ΔV via the relativistic-rocket shorthand β = tanh(ΔV/c) (flyby) or tanh(ΔV/2c) (rendezvous).
• Mission / Crew: how long the trip takes in outside time vs how much the crew ages.
• Supplies: for each life-support resource, whether it lasts or you are short by an amount. Because the crew only consumes for the time it experiences, the trip total is rate × crew_time.

Expert mode adds γ_cruise, the accel / coast / decel time-and-distance breakdown, the cruise consumption rate (×1/γ), and the dose ×1.00 contrast row.

Design lessons the planner teaches

ΔV	flyby β	rendezvous β
0.5 c	0.462	0.245
1.0 c	0.762	0.462
2.0 c	0.964	0.762
3.0 c	0.995	0.905

• A fast rendezvous costs roughly double the ΔV of a flyby: that's the direction-blind braking penalty (The Physics#1-thrust-falls-as-1γ3-the-light-wall) showing up at design time.
• A low-thrust ship spends longer getting up to cruise, which lengthens the trip and changes the resource total (the crew clock runs during the accel phase too).
• A longer mission means more radiation dose even though the crew ages less - the "radiation, not starvation" point, made before launch.

Caveats (it's a preview, not a promise)

• β = tanh(ΔV/c) treats KSP's Newtonian ΔV as rapidity; that is exact only for a relativistic exhaust, so it is mildly optimistic at high ΔV.
• A single α is a first-order approximation (mass drops during the burn), so the accel-phase distance can be off for a high mass-ratio stage.

The planner is editor-only and independent of the flight hooks, so it carries none of their timing risk - but treat its numbers as a close estimate, not a guarantee the in-flight value lands identically.

See also

• The Physics - the model behind the numbers.
• Dashboard - set a planner target and its ⚠ decel now cue becomes exact.