Example
For example, to transfer from circular low earth orbit with km to a new circular orbit with km using Hohmann transfer orbit requires delta-v of 2824.34+1308.38=4132.72 m/s. However if spaceship first accelerates 3060.31 m/s, thus getting in elliptic orbit with apogee at km, then in apogee accelerates another 608.679 m/s, which places it in new orbit with perigee at, and, finally, in perigee slows down by 447.554 m/s, placing itself in final circular orbit, then total delta-v will be only 4116.54, which is 16.18 m/s less.
| Burn | Hohmann ΔV (m/s) | Bi-elliptic ΔV (m/s) | |
|---|---|---|---|
| 1 | 2824.34 | 3060.31 | |
| 2 | 1308.38 | 608.679 | |
| 3 | - | 447.554 | |
| Total | 4132.72 | 4116.54 |
- Forward applied ΔV
- Reverse applied ΔV
Evidently, the bi-elliptic orbit spends more of its delta-V early on (in the first burn). This yields a higher contribution to the specific orbital energy and, due to the Oberth effect, is responsible for the net reduction in required delta-V.
Read more about this topic: Bi-elliptic Transfer
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