Hohmann Transfer Budget
Compute both coplanar Hohmann burn magnitudes, total impulse, and half-period coast time for circular endpoints.
Description
A Hohmann transfer joins coplanar circular orbits through an ellipse tangent at both endpoints.
A Hohmann transfer joins coplanar circular orbits through an ellipse tangent at both endpoints. Its two impulsive burns change between circular and transfer speeds, with a half-ellipse coast between them.1
Compute both coplanar Hohmann burn magnitudes, total impulse, and half-period coast time for circular endpoints.
When to use Hohmann Transfer Budget
Use this tool to compute both coplanar Hohmann burn magnitudes, total impulse, and half-period coast time for circular endpoints.
Prepare the orbital state or model parameters in one reference frame. Confirm compatible distance/time units and the stated angular and gravitational-parameter conventions.
How to use Hohmann Transfer Budget and understand its results
- Prepare the orbital state or model parameters in one reference frame. Confirm compatible distance/time units and the stated angular and gravitational-parameter conventions.
- Enter mu, initialRadius, finalRadius using the field table and calculation rules, then run the tool.
- Read burnMagnitudes, totalDeltaV, transferCoastTime. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| mu | Gravitational parameter, using the same distance and time units throughout; km³/s² for km and seconds. | number | Required |
| initialRadius | Initial radius | number | Required |
| finalRadius | Final radius | number | Required |
Enter positive μ and circular endpoint radii in compatible units. The tool computes both burn magnitudes using vis-viva, sums them and returns half the transfer ellipse's period. Inward and outward transfers are accepted; equal radii give zero burns but retain a half-period coast value.
aTransfer = (rInitial+rFinal)/2; totalDeltaV = |vTransfer1−vCircular1|+|vCircular2−vTransfer2| Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| burnMagnitudes | Burn magnitudes | list of number |
| totalDeltaV | Total delta v | number |
| transferCoastTime | Transfer coast time | number |
{
"input": {
"mu": 1,
"initialRadius": 1,
"finalRadius": 4
},
"output": {
"burnMagnitudes": [
0.26491106406735176,
0.18377223398316211
],
"totalDeltaV": 0.4486832980505139,
"transferCoastTime": 12.418235332245125
}
}Limitations and assumptions
This does not schedule departure phase or handle eccentric endpoints, plane changes, finite burns or obstacles. Burn outputs are magnitudes, not signed thrust directions.
Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use Bielliptic Transfer Budget: Budget all three bielliptic burns and transfer coast time for coplanar circular endpoints in consistent km/s units. For a complementary task, use Combined Plane Change Savings: Compare a combined speed/plane-change impulse with speed change plus a plane change at the lower endpoint speed; geometry must be co-located.
References
-
Hohmann Transfer Budget — tool.io
Similar or alternative tools
- Bielliptic Transfer Budget
Budget all three bielliptic burns and transfer coast time for coplanar circular endpoints in consistent km/s units.
- Combined Plane Change Savings
Compare a combined speed/plane-change impulse with speed change plus a plane change at the lower endpoint speed; geometry must be co-located.