In the LaunchCode field of the launch lists, I take a rather old-fashioned view of
success and failure. Nowadays, if a commercial satellite launch vehicle fails to
deliver all its customer payloads to the correct orbit in working order,
the launch is considered a total failure. In the 1950s, however,
a US government launch that got only a few metres off the pad might still be considered a `partial success',
for example because it demonstrated the correct functioning of the engine ignition
system and the ability of the rocket to fly in vaguely the right direction.
When you're assessing the capability of launch vehicles over decades and comparing
those from new space players and established spacefarers, this older approach is
actually helpful. In 2012 I introduced the following scheme.
For pass/fail purposes I consider a score of less than 0.75 to be a failure; one could argue for
lowering that boundary a little bit.
For launches with a single payload, or multiple equal-priority payloads, I give:
| - full success | 1.00 | |
| - orbit usable but not nominal | 0.75 | |
| - orbit but not a usable one | 0.40 | |
| - payload failed to separate or fatally damaged by LV | 0.25 | (even if good orbit) |
| - orbit not reached | 0.00 | (or reentry after circa 1 orbit) |
For missions with primary (P) and secondary (S) payloads, a rough scaling
to give the P 3 times the weight of S -
| - full success | 1.00 |
| - S off-nominal orbit | 0.95 |
| - S unusable orbit | 0.85 |
| - S failed to sep | 0.75 |
| - P off-nominal orbit | 0.55 |
| - P unusable orbit | 0.30 |
| - P failed to separate | 0.10 |
There's still some subjectivity here, and I've allowed myself to assign intermediate values,
e.g. when an orbit is only slightly off-nominal. Now obviously scores of 0.40 or less
are going to mean an unhappy customer, but I think it's still worth distinguishing from complete
failure to orbit a it usually indicates a vehicle which is 'close' to working in contrast
to some vehicles which never make it beyond first or second stage burn.
In my initial implementation in 2012, the scores assigned that differ from 0.0 and 1.0 were:
| Score | LaunchCode | Launch (Launch desig, vehicle) |
|---|---|---|
| 0.25 | OF25 | 96-061 Pegasus |
| 0.40 | OF40 | 63-021 Thor Agena, 67-032 Proton. 76-062,76-088, 80-031, 86-075,90-055 Molniya, 78-119, 95-052 Kosmos, 84-120, 04-052 Tsiklon, 91-051 Pegasus, 95-U01 Mu-3S-II, 96-048 CZ-3, 80-043 Atlas, 99-017, 99-023 Titan, 99-024 Delta 3, 06-006, 08-011, 11-045, 12-044 Proton/Briz, 11-005 Rokot |
| 0.45 | OF45 | 04-050 Delta 4H (primary payload medium-bad orbit, secondary failed to orbit) |
| 0.50 | OF50 | 01-029 Ariane 5/V142 |
| 0.75 | OS75 | 97-057 PSLV, 97-066 Ariane 502, 07-027 Atlas V/NROL-30, 09-029 Soyuz/Meridian |
| 0.80 | OS80 | 00-048 Delta 3, 01-015 GSLV (somewhat off-nominal orbit) |
| 0.85 | OS85 | 12-054 Falcon 9 (primary perfect, secondary unusable) |
In some orbital launches, the launch vehicle targets a suborbital trajectory
and the payload has its own engine to perform orbit insertion. This can lead
to a situation where the LV is fully successful but the payload does not reach orbit
due to a malfunction of its own (cases PG, PI, PP).
sAn asterisk at the end of the code (e.g. S2P*) indiicates that despite the failure, subsequent
stages continued to operate and fired correctly except for being on the wrong trajectory.
| - AD | Accidental destruct (erroneous range safety or onboard destruct or termination) |
| - AL | Accidental launch or ignition (Discoverer 0, Tianlong-3 S1). |
| - FF | Fairing related failure (no fairing sep, or MaxQ failure, fairing destroyed) |
| - FS | Structure failure other than fairing and other than due to previous loss of control |
| - PA | Payload failed to separate from payload adapter |
| - PE | Exploded on pad prior to lifting off |
| - PG | Payload orbit insertion system, attitude or guidance problem |
| - PI | Payload orbit insertion system, ignition problem. |
| - PP | Payload orbit insertion system, propulsion problem |
| - Sn | Failure in stage n, e.g S2 is failure in stage 2 |
| - SnB | Boom - Exploded or RUD during stage n |
| - SnE | Electrical or power systems failure during stage n. |
| - SnG | Guidance or attitude control failure during stage n, including software error |
| - SnGm | Guidance, attitude control failure during burn m of stage n, including software error |
| - SnI | Failure in stage n, engine did not ignite or did not reach full thrust |
| - SnP | Propulsion failure in stage n, early shutdown including lack of propellant |
| - SnPm | Propulsion failure in burn m (m=2 or more) of stage n, early shutdown including lack of propellant |
| - SnR | Failure of stage n to restart for burn 2 or later |
| - SnS | Separation failure or bad separation between stage n and stage n+1 |
| - SnU | Underperformance during stage n |
| - U | Failure, all details unknown |
| - UX | Unconfirmed failure (may not have launched, or reaching orbit may not have been intended). |
| - WX | Weather (lightning strike or other) |