Guide to the SATCAT columns
The latest SATCAT is at
The columns are as follows:
- Satcat number. This is the number in the NORAD/STRATCOM catalog,
prefixed with 'S'. (Elsewhere on this site you may see catalog
numbers with other prefixes, .e.g F000341 - these are auxiliary catalogs that
I use internally, and hope to publish when they are in better shape.
The auxiliary catalog numbers are likely to change when that happens.)
- COSPAR (International) Designation.
Post 1963, these are of the form YYYY-NNNCCC where YYYY is the year
of launch, NNN is the number of the launch within that year, and CCC
is a serial letter for objects within that launch. Thus,
2013-014C is the third object (satellite) cataloged for the 14th launch
of 2013. The serial letters go A to Z omitting I and O, then
continue AA, AB... to ZZ, then AAA.., again always omitting the letters I and O.
Often, A is the payload, B is the rocket stage and C onwards are debris,
but this is not always true.
- Official name. This is, when possible, the name as used by the satellite owner,
generally but not strictly the name used in press materials or
in UN registration.
- After the offical name, in byte 58, there may be a "?" character.
This indicates that although the listed satellite was one of the objects
from that launch, it may not be the specific object whose orbital data are
associated with the catalog number. In the current era of mass small satellite
deployments from a single rocket, often we know which satellites went up, and the
right number of objects are tracked, but we don't know which satellite is which.
I find it convenient to arbitrarily assign each missing satellite to one of
the `unknown object' catalog numbers from that launch, and then reassign them
later if the true match is found.
- Secondary name or prelaunch name. This can be the name the satellite
had before succcessful launch, or the secretly used internal program
name for military satellites, when known.
- Owner/Operator. The agency or organization which operates or owns the satellite.
Not necessarily the legal owner; I have used my judgement to determine
who is the 'effective owner' in a loose practical sense. Abbreviations
- Launch Date (Gregorian calendar, UTC/GMT)
- Current Status. This column is a bit messy; the notation
'Reentered Att' is short for Reentered Attached, and refers to the
existence of an associated object which the satellite was attached to,
and which has an entry in my auxiliary catalogs. Thus, S00004 Explorer I
was attached throughout its time in space to the Explorer I Baby Sergeant rocket
stage, Cluster 4 Assembly 4, which is entry A00002 in my auxiliary A catalog.
Since I'm not ready to publish the A catalog, the "Att" notation is just
confusing and I apologize for that.
- Date of Status. Usually, reentry date, if not blank.
- Date of orbit epoch. The date for which the orbital parameters apply.
- Orbit class. Calculated from the orbital parameters; a gross description
of the orbit. See
- Orbit period, minutes
- Perigee x Apogee height, relative to 6378 km spherical Earth, km.
- Inclination, deg relative to the Earth's equator (nominally J2000, but I haven't
done calculations to the required accuracy to worry).