This field encodes the target orbit type (LEO, GEO etc.), the upper
stage(s) disposal mode, and the number of launch vehicle related debris
objects generated during the launch phase (later stage breakups are not
included). Note that the data in this field represent the intended
result of the launch, not the actual result. It can be used to track the
evolution of space debris mitigation practices used by launch agencies.
The format of the launch profile code is:
Sat XXX CC N
where XXX is the orbit code for the target orbit, CC encodes the planned
upper stage(s) disposal mode, and N is the number of other debris
objects planned to be left in orbit from the launch vehicle (not
counting objects released by the payload, although there is some
ambiguity in that).
The target orbit codes are:
Orbit code | Meaning |
---|---|
DSO | Deep space orbit (Earth orbit with apogee beyond 150,000 km) |
EEO | Earth escape orbit |
GEO | Direct geosync insertion |
GTO | Geosync transfer orbit |
HEO | Highly elliptical orbit (except MTO, MOL, DSO) |
ISS | International Space Station |
LEO | Low Earth Orbit (other than SSO, LSS, ISS) |
LSS | LEO space station other than ISS |
MEO | Medium Earth Orbit |
MOL | Molniya orbit |
MTO | MEO transfer orbit (with payload performing MEO circularization) |
SSO | Sun-sync orbit |
STO | Supersync transfer orbit (apogee more than 45000 km) |
XO | Extraterrestrial launch (e.g. launch from lunar surface) |
The next part of the launch profile code indicates what measures are taken to dispose of each
upper stage which reaches orbit, or is close to reaching orbit. This section has one,two or
three letters, depending on the number of upper stages reaching orbit.
Disposal codes are not included for extraterrestrial launches.
For example, OL means that one upper stage was left in orbit with no orbit change, and a second
one was left in orbit with a perigee lowering burn carried out after payload deployment.
Disposal code | Meaning |
---|---|
A | Stage left in Earth orbit, but remains attached to payload by design. |
B | Stage made depletion burn which boosted it to higher Earth orbit. |
D | Actively deorbited to destructive reentry |
E | Stage placed in Earth escape orbit |
L | Small perigee lowering burn to reduce orbit lifetime (but not meeting criterion for P) |
O | Left in Earth orbit for later uncontrolled reentry |
P | Perigee lowered to 180 km or less for rapid decay, or stage left in orbit with that low a perigee to start with. |
R | Recovered intact for possible reuse (so far, space shuttles only, considered as upper stages). |
S | Stage left in marginally suborbital trajectory for targeted reentry on first orbit. Stages with perigees above -1000 km are included. |
The S cases are typically ones involving disposing of a large core stage by leaving it slightly suborbital and
making the payload or a small insertion stage complete the orbit insertion (for this purpose, the Shuttle
External Tank is counted as a stage). This is a standard way of avoiding leaving a big stage with a non-restartable
engine in low orbit, and is included to highlight this responsible strategy (and as a contrast to cases such as the CZ-5B).
Finally the number of other launch vehicle-related intentional debris objects is listed. Accidental debris, such
as from upper stage breakups, is not included here. Typically the objects noted are tumble weights, multi-payload
adapters such as Ariane Sylda5, or payload release hardware such as Starlink tension rods.
For example, 'Sat GTO SO 1' indicates that the launch was targeted for geotransfer orbit, that one stage was marginally
suborbital and another was left in orbit for uncontrolled decay, and one additional debris object was left in orbit.