Tool 9 · Maneuver & Mission Design

Multi-Burn Transfer Planner

Compare a direct Hohmann transfer with a staged multi-burn strategy using one intermediate circular orbit. This tool introduces optimization thinking: sometimes an intermediate orbit is useful for mission design, even when it is not the lowest theoretical Δv solution.

What this tool computes

A basic Hohmann transfer moves directly from one circular orbit to another using two burns. A multi-burn plan breaks the maneuver into two transfer legs through an intermediate orbit. This page compares both strategies side by side.

  • Direct two-burn Hohmann transfer cost
  • Leg 1 transfer: initial orbit to intermediate orbit
  • Leg 2 transfer: intermediate orbit to final orbit
  • Total staged Δv and total transfer time
  • Simple sweep over intermediate altitude to find low-cost options
  • Orbit sketch and Δv trade curve

Core maneuver model

Each leg uses the same Hohmann transfer equations. For one transfer between radii \(r_a\) and \(r_b\):

\[ a_t = \frac{r_a+r_b}{2} \] \[ v_c = \sqrt{\frac{\mu}{r}}, \qquad v_t = \sqrt{\mu\left(\frac{2}{r}-\frac{1}{a_t}\right)} \]

The staged transfer is treated as two connected Hohmann-style legs:

\[ r_1 \rightarrow r_m \rightarrow r_2 \] \[ \Delta v_{multi} = \Delta v_{1m}+\Delta v_{m2} \]

Why multi-burn planning matters

A direct transfer is not always the whole story. Real mission planning may include intermediate parking orbits, operational waiting time, phasing needs, visibility constraints, launch-window constraints, or staged checkout.

  • Intermediate orbits can support payload checkout or rendezvous timing.
  • Higher intermediate orbits may be used for mission geometry, not only Δv.
  • Sweeping the intermediate orbit teaches trade-space thinking.
  • The lowest Δv solution may not be the most operationally useful plan.

How to interpret the result

  • If multi-burn Δv is higher than direct Hohmann, that is expected for many simple circular cases.
  • If the intermediate altitude is close to the initial or final orbit, one leg becomes small.
  • The sweep plot shows how sensitive total Δv is to the chosen intermediate orbit.
  • The tool is best read as a mission-design comparison, not only a calculator.

Important limitation

This educational planner does not solve a true optimal-control problem. It compares ideal impulsive coplanar transfer legs.

Interactive transfer planner

Choose a preset, then adjust the intermediate orbit manually.

Results

Direct Hohmann Δv

Direct transfer time

Multi-burn total Δv

Multi-burn transfer time

Δv difference

Best sweep altitude

Interpretation

Run the planner to compare direct and staged transfer options.

Burn / LegΔvTime
Leg 1
Leg 2
Orbit layout
Intermediate altitude sweep

Assumptions and limitations

This tool assumes:

  • Circular initial, intermediate, and final orbits
  • Coplanar impulsive Hohmann-style transfer legs
  • No plane change, drag, J2, finite-burn losses, or phasing wait time
  • Intermediate orbit is selected by the user, not optimized by a full trajectory optimizer