Delta-v budget
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Delta-v budget (or velocity change budget) is a term used in astrodynamics and aerospace industry for velocity change (or delta-v) requirements for the various propulsive tasks and orbital maneuvers over phases of the space mission.
Sample delta-v budget will enumerate various classes of manoeuvres, delta-v per manoeuvre, number of manoeuvres required over the time of the mission.
In the absence of an atmosphere and landings where the ground is hit with some speed, the delta-v is the same for changes in orbit the other way around: gaining and losing speed cost an equal effort.
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[edit] Launch/landing budget
- Launch to LEO — this not only requires an increase of velocity from 0 to 7.8 km/s, but also typically 1.5–2 km/s for atmospheric drag and gravity drag
- Re-entry from LEO
[edit] Stationkeeping budget
| Maneuver | Altitude | Average delta-v per year |
Maximum m/s per year |
||||
|---|---|---|---|---|---|---|---|
| [km] | [m/s] | [m/s] | |||||
| station-keeping | 50–55 | ||||||
| Drag compensation | 400–500 | <25 | <100 | ||||
| Drag compensation | 500–600 | < 5 | < 25 | ||||
| Drag compensation | >600 | < 7.5 | |||||
| Attitude control (3-axis) | 2– 6 | ||||||
| Spin-up or despin | 5–10 | ||||||
| Stage booster separation | 5–10 | ||||||
| Momentum wheel unloading | 2– 6 | ||||||
[edit] Interplanetary budget
| Maneuver | Delta-v required |
|||
|---|---|---|---|---|
| From: | To: | [m/s] | ||
| Earth surface | Low Earth Orbit | 9300-10000 | ||
| Low Earth Orbit | Geostationary Transfer Orbit | 2500 | ||
| Geostationary Transfer Orbit | Geostationary Orbit | 1500 | ||
| Geostationary Transfer Orbit (perigee) | Earth escape orbit | 700 | ||
| Earth escape orbit | Low Lunar Orbit | 700 | ||
| Earth escape orbit | Mars Transfer Orbit | 600 | ||
| Low Earth Orbit | Mars surface | 4800 | ||
| Low Earth Orbit | Solar escape | 8700 | ||
| Low Lunar Orbit | Lunar surface | 1600 | ||
| Mars surface | Low Mars Orbit | 4100 | ||
| Mars capture orbit | Mars low-energy transfer orbit | 900 | ||
| Low Mars Orbit | Phobos Transfer Orbit | 900 | ||
| Phobos Transfer Orbit | Deimos Transfer Orbit | 300 | ||
| Deimos Transfer Orbit | Deimos surface | 700 | ||
| Phobos Transfer Orbit | Phobos surface | 500 | ||
