The phase is defined by a set of fields in the object catalog entry.
|Parent||P||EJCAT/Body||the parent can be an extended JCAT ID (EJCAT) or a body name.|
|SDate||t1||VagueDate||the phase start time. This can be the time the object separated from the parent EJCAT or the time the object departed the parent body's gravitational sphere of influence (SOI)|
|Primary||C||Body||the name of the central body for this phase|
|DDate||t2||VagueDate||the phase end time|
|Status||S||Phase Status Code||a code describing the event that ends the phase|
|Dest||D||Location/Body/JCAT||`destination', a string whose definition depends on the Status value. It can be empty, a Location, a body, or a JCAT.|
The symbols in the table above are used in the discussion below for conciseness. A location can be expressed as a string (uncontrolled text, e.g. 'W Atlantic') or as longitude/latitude coordinates (e.g. 74W 22S). The Dest field may be blank if reentry location is unknown.
The different kinds of phases are defined by the Status field. They are given in a somewhat arbitrary order that makes sense to me, and grouped by what kind of Dest field is used. The state of an object includes its `externality' - is it free, attached to a parent object externally, or is it inside its parent object. This externality is also described in the following table defining the different Status codes. The table assumes (in the interpretation of t1 and t2) that P is a EJCAT rather than a body. If P is a body then t1 represents the time the object went from P's SOI to C's SOI; if D is a body then t2 represents the time the object went from C's SOI to D's SOI.
|Cases with t2 and Dest both empty|
|O||In orbit||Sep from P at t1, still in free flight||Free|
|AO||Attached in orbit||Attached to P from t1 to present||External|
|AO IN||Attached inside||Inside P from t1 to present||Internal|
|UDK||Undocked||Docked to P from t1 to t2, sep from P at t2||External to free|
|REL||Released||Attached to P from t1 to t2, sep from P at t2||External to free|
|DEP||Deployed||Same as REL but for objects on planetary surface||External to free|
|LO||Liftoff||Launch from C surface (C is not Earth)||Free|
|ALO||Attached at liftoff||Attached to P from t1 to t2 including at launch from C surface.||External|
|Dest is always blank but t2 is not|
|E||Exploded||Sep from P at t1, free in orbit until breakup at t2. Next phase of this object is a debris fragment.||Free|
|N||Renamed||In orbit from t1 to t2, name or owner changed at t2. Next phase reflects new name and owner||Free|
|LEASE||Lease||Temporary lease from main owner from t1 to t2. SatType code is PA.||Free|
|Dest is a location on C, or C itself, or blank|
|R||Reentered||Sep from P at t1, destroyed in C's atmosphere at t2 after natural decay||Free|
|D||Deorbited||Sep from P at t1, destroyed in C's atmosphere at t2 via active deorbit maneuver||Free|
|L||Landed||Sep from P at t1, landed or splashed down on C's surface at t2||Free|
|AR||Reentered attached||Attached to P from t1 to t2 when P reentered||External|
|AR IN||Reentered inside||Inside P from t1 to t2 when P reentered||Internal|
|AL||Landed attached||Attached to P from t1 to t2 when P landed||External|
|AL IN||Landed inside||Inside P from t1 to t2 when P landed||Internal|
|TX||Transmission ended||Operated on C's surface from t1 to t2||Free|
|Dest is a JCAT from D catalog (deep space). JCAT ID used in deep space catalog for this object is given by the Dest value.|
|DSO||Deep space||Sep from P at t1, passed deep space boundary at t2.||Free|
|DSA||Deep space attached||Attached to P since t1, passed deep space boundary at t2.||External|
|DSA IN||Deep space inside||Inside P since t1, passed deep space boundary at t2.||Internal|
|Dest is a JCAT not from D catalog|
|DK||Docked||Sep from P at t1, docked with D at t2||Free to External|
|GRP||Grappled||Sep from P at t1, docked with D at t2||Free to External|
|ATT||Attached||Was attached to P at t1, then attached to D at t2||External.|
|TFR||Transfer||Inside P at t1, moved inside D at t2||Internal|
|TFR E||Transfer external||Inside P at t1, moved to exterior of D at t2||Internal to External|
|RET||Retrieved||Attached to P at t1, moved inside D at t2||External to Internal|
|EVA||Spacewalk||Moved outside P at t1, returned inside D at t2||Internal to tethered or free to Internal|
|Dest is a body name|
|EO||Escape||Left P's SOI at t1, In C's SOI from t1 to t2, entered D's SOI at t2||Free|
|EAO||Escape attached||Attached to P from t1 to t2. In C's SOI till t2, then in D's SOI||External|
For cases R, D, AR, AR IN: if C has no atmosphere, t2 is the time of impact on C's surface. Natural decay includes orbit perturbation due to mascons, and direct impact without first entering bound orbit.
For cases DSO, DSA, DSA IN; the object is considered to have left the main part of GCAT at t2. Its old JCAT ID no longer applies and the Deep Space Catalog JCAT ID is used for further phases of its history.
The cases EO and EAO are only used in the Deep Space Catalog and the heliocentric and lunar-planetary registers.