A mission (spaceflight) may carry several astronauts. Traditionally each astronaut is identified with a specific `role' on that mission - Commander, Mission Specialist, etc. When more than one astronaut on the flight has the same basic role, they are numbered - Mission Specialist 1, Mission Specialist 2, etc.
I assign role tags which are abbreviated forms of the roles - for example `MS3' for 'Mission Specialist 3'. The general form of a role tag is a string of letters - the basic role tag - optionally followed by an integer. So 'MS3' is a role tag and its basic role tag is 'MS'.
The role tag is combined with a mission tag to form a role code. For example, the role code `A11/LMP' combines mission tag A11 (Apollo 11) with role tag LMP (Lunar Module Pilot) to identify Buzz Aldrin's role on the mission.
When a mission has more than one segment, the role of the astronaut often changes. For example, Anton Shkaplerov was Komandir (KDR) of the Soyuz TMA-22 spaceship (mission code TMA22) from its launch to docking with ISS, while Dan Burbank was Bortinzhener-2 (BI2). So, their full launch role codes are TMA22/KDR and TMA22/BI2. On reaching the ISS, they became part of ISS Expedition 29 (mission code EX29) then under the command of Mike Fossum, and got new segment role codes EX29/FE3 and EX29/FE5 (Flight Engineer 3 and 5). They later transferred to ISS Expedition 30 - and Burbank became EX30/CDR, commander of Expedition 30. As a final segment, they returned to Earth on Soyuz TMA-22 with their original role tags.
To distinguish different segments of a mission with the same mission code, I use a `phase number'. Phases are discussed in the General Catalog of Space Objects https://planet4589.org/space/gcat and split the flight history of a space object into consecutive periods, with breaks at events like docking and undocking. In general the phases of a spacecraft correspond to the segments of a human spaceflight mission.
The Soyuz TMA-22 mission had three phases: 1 - launch to docking; 2 - docked to ISS; 3 - undocking to landing. The mission code for Soyuz TMA-22 is `TMA22'; the code for phase 3 is `TMA22:3'. So, for the final segment of Burbank's flight he has the role `TMA22:3/BI2': Bortinzhener-2 on phase 3 of Soyuz TMA-22. It is not guaranteed that astronauts return on the same ship they launched on, or that they retain the same role.
The general segment role code, then, is of the form
M:p/Rwhere M is the mission tag, p is the phase number, and R is the role tag. The :p is omitted if p is 1 (launch phase). The /R may also be omitted in certain circumstances (see the discussion of the segments column in the Rides table; omitting it implies the role tag is the same as for the previous segment).
The role codes table lists all of the basic role tags used by the various space agencies. Some role tags are closely equivalent (BI `Bortinzhener' in Russian is just a translation of FE `Flight Engineer' in English) but not necessarily identical, and I retain the original language to be precise.
In the table I assign `role classes' to each tag to group together broadly-equivalent role tags, using one of the role tags in the class to label it. There are (as of now) six role classes.
The columns of the role tags table are:
For NASA and Roskosmos missions the roles have traditionally been explicitly announced. For recent suborbital tourist flights this is not always the case and I have had to make my best guess based on the statments of the flight operator.
special case. At the time Chinese annoucements used the ZZ, FZH and GCH roles but more recent Chinese descriptions of the mission retrospectively use ZZ, CS and SY roles which seem to have become standard on more recent flights. I retain the FZH and GCH designations used in the contemporary documents.
|FE||Flight engineer or mission specialist|
|P||Passenger, astronaut, generic space traveller.|
There is some slop between these classes; on a single-person spaceflight, the astronaut may be a PLT, or a CDR (even though there is no-one else for them to command, although I guess they can command the flight computer to do things). The distinction between FE and PS classes is that the PS operates research experiments being carried by the space vehicle but typically has no role in operating the space vehicle itself. Historically some astronauts with the FE role have also had MO duties while those with the MO role have also often performed FE duties. (The USSR had a whole separate MO astronaut corps at the Institute for Medical-Biological Problems, but only four ever flew.)