> ## Documentation Index
> Fetch the complete documentation index at: https://docs.valar.space/llms.txt
> Use this file to discover all available pages before exploring further.

# Inclination Change

> Plan chemical or electric inclination changes within an explicit deadline and propellant constraints

The finite inclination planner is available through **Operations → Planner → New
Plan** for enabled accounts. Its initial rollout is internal-only. Accounts without
access retain their existing chemical inclination workflow.

## Configure a plan

1. Select the spacecraft, an available chemical or electric thruster, and
   **Inclination Change** in Overview.
2. Choose the initial orbit and mass source using the existing Initial State step.
3. Set the earliest start and **Completion deadline (UTC)**. The optimizer must
   complete within this interval; it cannot place a burn before the start.
4. Enter the **Target mean inclination (GCRF)** and its tolerance. Mean inclination
   removes the periodic variation present in instantaneous orbital elements.
5. Set the propellant cap, required reserve, maximum duty fraction, minimum coast
   between burns, sunlight restriction and any UTC blackout intervals.
6. Review the configuration and create the plan. Computation produces a proposal
   for the existing review/approval workflow.

Blank maximum propellant uses the selected initial state's available propellant
after dry mass and reserve. The selected device's uninterrupted-burn limit applies
independently of duty and coast settings. Duty is measured over one initial orbital
period. Blackouts include their start and exclude their end.

## Read the result

**Inclination plan verification** shows the target and achieved mean inclination,
instantaneous inclination, propellant, remaining reserve, firing time, elapsed time,
deadline and actual achieved epoch. The search disclosure records the selected
node-window policy, reference cost, evaluation count and assumptions.

The context plot shows instantaneous inclination. Its periodic oscillations are
not the mean-target achievement test. Firing time includes only thrust intervals;
elapsed time includes waiting and coasting.

The result is the best verified feasible schedule found within the reported search,
not proof of a global optimum. An unfinished or unverified trajectory is not presented
as a completed plan. Changing physical inputs or burn segments requires recomputing
the plan so its verification remains associated with the actual saved schedule.

## Applicability

The current method supports near-circular LEO: mean eccentricity at most 0.01,
mean perigee at least 200 km, mean semi-major axis below 7378.137 km, and corrections
up to 5°. It does not deliberately raise or lower the orbit to reduce plane-change
cost. Natural perturbations continue to act.

The model uses the frozen spacecraft's isotropic cross-sections and does not infer
missing battery, thermal or slew-propellant behavior. Review the assumptions and
the actual finite-burn sequence for the selected spacecraft. Existing approval
and orbit-freshness requirements still apply; computation does not approve burns.

See [Planner](/features/planner) for the shared workflow and
[Burn Plan](/features/burn-plan) for reviewing individual operational maneuvers.