PSAS/ RocketNames

PSAS Naming Conventions

(There are ANSI standards, Y1.1-1972, Y10.5-1968, Y10.19-1969, can't find them)

The purpose of this page is to document a framework for consistent usage within the project. The goal is to make the project easier. There are no enforcement mechanisms beyond infrequent whining.


We have built a series of airframes of increasing size. The first was "LV0" for Launch Vehicle 0. The second "LV1", then "LV2". On occasion there have been multiple designs in the same size class, likewise there have occasionally been multiple copies of a single airframe design.

We encode this information as:


Where VV is the vehicle identifier, "LV" or Launch Vehicle, in the case of the airframe, N is a single decimal digit identifying the design sequence. A single lowercase letter r identifies the design revision, and C is a digit identifying the particular copy of a design.

For example, after crunching an LV2a airframe in Aug. 2005 (LV2b was destroyed in an earlier flight), the next airframe design was designated LV2c, meaning the 3rd design revision of the LV2 airframe. The 1st incarnation of this design would be called LV2c1

Historical Note: We previously used a different naming system for the launch vehicle. LV2a was called LV2.1 and LV2b was called LV2.2.

Avionics Packages

The avionics package is named in analogy to the airframe scheme.


Here PP is the component group designator, "AV" for avionics. The NrC is just as explained in the Airframe section.

For example the avionics package designation in 2006 was AV2b. The "2" refers to the major design revision. In this case targeting the LV2 size airframe. We intend to keep the N-major revision of the avionics in sync with the N-major revision of the airframe. The "b" refers to the 2nd generational revision of the LV2-targeted avionics.

As a final example the 2nd copy to the "b" avionics targeting the LV2 airframe, and installed into the LV2c1 airframe would be LV2c1-AV2b2. Dropping the "AV2" is allowable LV2c1-b2.


A very good feature to have is a unique designation for each part. Here is the basic form of a part number:


Where TTTT represents an alphanumeric type-code, and NNNN is a numeric part number. The FF field is the "extra" part number provided for special cases, normally this field is not used.

Sometimes a more elaborate scheme might be called for. Something like this:


This decodes as follows

Field Type Length Meaning Notes
PPPP alphanum 1 - 4 Project Code omit unless ambiguous
LL alpha 0 - 2 Launch Series use only if PPPP present
BBBBB alphanum 1 - 5 Board or Assembly Code omit unless ambiguous
VVV numeric 0 - 3 Integer Version Number omit unless ambiguous
SS alpha 0 - 2 Unit Build Sequence omit unless ambiguous
TTTT alpha 1 - 4 Part Type Code see table
NNNN numeric 1 - 4 Numeric Part Number
FF alpha 0 - 2 Extra Part Number special circumstances only
AA numeric 0 - 2 Actual Device Code special circumstances only


Diode number 204 on GPS board revision #1 of Launch Vehicle #2. The suffix `.2' refers to the 2nd part installed in this position. Normally a part is installed only once and no suffix is used.
Usually, the second component of a multi-part component called D204. Sometimes, undesirably, letter suffixes may be used to add distinct parts without re-numbering.
Maximum--style part code. Launch Vehicle #2, flight `a' (first flight), GPS board revision 3 (the `03' is the same as 3). Variable resistor number 204a (Could be entirely unrelated to VR204!). The `.1' refers to the 1st part installed on the board. Normally a part is only installed once, therefore most parts are implicitly designated `.1', the actual `.1' is almost always omitted. Presumably a part labeled `.1' has had a replacement contemplated at some point.
If there is no ambiguity, the simple form of the part number is used. In this case transistor number 101.


The major field separator is the `:' (colon), always used between major fields, such as between board designator and part designator. The `.' (dot) is an optional subfield separator to disambiguate difficult cases, e.g. 802.1:R1100

Project Code
For our purposes this will be of the form LV1, LV2, LV3, etc. This could be extended with a prefix like "PSAS:". Ground support equipment might use another designator such as "LTC" for Launch Tower Computer.

Launch Series
Flight sequence number. Follows the alphabetic sequence a, b, c,... z, aa, ab,... Note that this is a time sequence code as opposed to a serial number. Perhaps a date code could also be used here.

Board or Assembly Code
Board designation, alphanumeric, usually upper case.

Integer Version Number
Board-level version number. Numeric starting from `1'. Leading zeros are not significant.

Unit Build Sequence
Alphanumeric, lower case. a,... ab, ... Designates separate builds of the assembly. This is the serial "number" of the board.

Part Type Code
Designates what kind of part this is. For example `C' is for a capacitor, `R' for a resistor. The recommended codes are tabled below.

Component Type Designation Motivation
Power Diode CR Current Rectifier
Signal Diode D
Photo Diode, solar cell PD PhotoDiode
Photo Diode, solar cell DL Diode `Lite'
Zener Diode Z
Transistor Q No idea
Transistor Array QA
Photo Transistor QL
Resistor R
Variable Resistor VR
Resistor Array RA
Thermistor RT
PhotoResistor RL
Capacitor C
Variable Capacitor VC
Variable Capacitor Diode VCD
Capacitor Array CA
Crystal / Resonator X
Inductor L No idea
Variable Inductor LV VL sucks
Inductor Array LA
Strain Gage SG less generic
Switch SW
Integrated Circuit U Convention?
Light Emitting Diode LED
Transformer T
Test Point TP
Removable Jumper J
Male Connector CM
Female Connector CF
Generic Connector CN
Fuse F
Ferrite Bead E Convention?
Wire (also fixed jumper) W
Wire Bundle WB
Transient Voltage Suppressor TVS
EM Shield EMS
SCR K ???
other Thyristor Y ???
Motor, actuator M
Piezo element PZ
Battery B

Part Number NNNN

Never zero. Leading zeros are not significant. Part numbers need only be unique within a given board and revision, however, it is desirable that part numbers convey as much information as possible. We therefore try to keep them unique across a project, and to keep part numbers grouped by functional section.

Major subsystems have a common 4th digit, as in the case of the flight computer using 1xxx numbers, the GPS using 5xxx, etc. Current Nxxx subsystems are:

Function TLA numbers
Flight Computer FC 1xxx
Generic Node GFE 2xxx
Avionics Power System APS 3xxx
Inertial measurment IMU 4xxx
GPS GPS 5xxx
Telemetry (ATV, WiFI) TLM 6xxx
Pyro/Recovery PYR 7xxx
Fin Control FIN 8xxx

Future Nxxx series systems are proposed to be:

Function TLA numbers
Magnetometer MAG 9xxx
Pressure PRS 10xxx
Propulsion control PRP 11xxx
Backup uplink radio UPL 12xxx

Each major subsystem (Nxxxx) have application sections which have a common 3rd digit (xNxx). These are defined per major subsystem, but since some of the boards have commone components, some of the number range is reserved:

Function TLA numbers
Switching Power Supply SPS 000 - 099
High Availability Power Supply HAP 100 - 199
Microprocessor & Misc. UC 200 - 299
Application specific sections ??? 300 - 999

... which leaves 7 possible application section left per major subsystem.

Extra Part Number
This field is legitimately used when a single logical part has multiple physical components. For example when two resistors are placed in series to increase power handling capability or precision, each resistor might be designated R101a, R101b, etc. A less legitimate use for this field is as a quick and dirty way to wedge part numbers into a previous scheme without having to re-number everything.

Actual Device Code
This field distinguishes between parts installed on the same board in the same place at different times. The field should always be separated from the part number by a `.' dot. When a board is first assembled the parts are implicitly `.1' coded. If a part fails or is otherwise replaced, the replacement becomes a `.2' part. If the original part is reinstalled, it would again be the `.1' part.

Suggested schematic layer usage

This is mostly for xfigs, but may apply more broadly.

Components 100
Component Marks 90
Interface + Power 80
Labels 60
Values 40
Signals 0