Science Fair Project Encyclopedia
Delta-v budget
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.
| Contents |
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
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 | ||||||
Interplanetary budget
| Maneuver | Delta-v required | |||
|---|---|---|---|---|
| From: | To: | [m/s] | ||
| Earth surface | Low Earth Orbit | 9700 | ||
| Low Earth Orbit | Geostationary Transfer Orbit | 2500 | ||
| Geostationary Transfer Orbit | Geostationary Orbit | 1500 | ||
| Geostationary Transfer Orbit (perigee) | Earth escape orbit | 700 | ||
| Low Lunar Orbit | Lunar surface | 1600 | ||
| Earth escape orbit | Low Lunar Orbit | 700 | ||
| Mars low-energy transfer orbit | Earth escape orbit | 600 | ||
| Mars low-energy transfer orbit | Mars capture orbit | 900 | ||
| Deimos transfer orbit | Phobos transfer orbit | 300 | ||
| Mars Escape Orbit | Deimos transfer orbit | 200 | ||
| Phobos transfer Orbit | Low Mars Orbit | 900 | ||
| Mars surface | Low Mars Orbit | 4100 | ||
| Deimos transfer orbit | Deimos surface | 700 | ||
| Phobos transfer orbit | Phobos surface | 500 | ||
See also
External link
10-26-2009 08:16:03
The contents of this article is licensed from www.wikipedia.org under the GNU Free Documentation License. Click here to see the transparent copy and copyright details
The contents of this article is licensed from www.wikipedia.org under the GNU Free Documentation License. Click here to see the transparent copy and copyright details