Designations of U.S. Space Force Weapon Systems

1 The Designation System

In October 2023, the U.S. Space Force established a new designation system for its weapon systems, which are primarily, but not exclusively, satellites and other spacecraft. The system is defined by the latest version of Space Force Instruction (SPFI) 16-403 Space Force Weapon System Naming and Designations, dated 24 July 2024. SPFI 16-403 not only covers the designation system, but also some of the bureaucratic red tape to be followed for actually assigning a name or a designation to a USSF system.

The designation system is similar in concept to the MDS (Mission-Design-Series) system for aerospace vehicles (see aircraft designations). Specific designations look like this (notional examples):

Examples:		M	L	-	1	A
	Y	N	M	-	2	F
	(3)	(1)	(2)		(4)	(5)

In the following section, each of the five elements is explained in detail.

(1) Basic Mission: The letter to the left of the environment symbol designates the basic mission of the system. The following basic mission symbols are defined:

A - Attack
B - Battle Management
C - Communications
D - Defend
E - Electromagnetic Warfare
K - Support
M - Meteorological
N - Navigation Warfare
P - Pursuit (see note 1)
R - Reconnaissance
S - Surveillance
W - Warning & Tracking

Notes for Basic Mission Symbol:

"Pursuit" means active interception of targets is space to support offensive and defensive operations.

(2) Environment: This letter describes the operational environment of the system. As can be seen from the definitions, the designation system applies mainly to satellites, but also covers ground-based systems and even cyber warfare systems. The following environment symbols are defined:

C - Cyberspace Domain
D - Deep Space (see note 1)
G - Geosynchronous/stationary Orbit (GEO)
H - Highly Elliptical Orbit (HEO) (see note 2)
L - Low Earth Orbit (LEO) (see note 3)
M - Medium Earth Orbit (MEO) (see note 4)
T - Terrestrial
V - Various (see note 5)

Notes for Environment Symbol:

"Deep Space" is defined as orbits beyond the cislunar regime.
HEO are e.g. "Tundra" and "Molniya" orbits, with a perigee at LEO altitudes and an apogee at GEO altitudes.
LEO is defined as an orbital altitude of not more than about 2000 km.
MEO is an orbit between LEO and GEO.
"V" can be applied to space systems, which can either be deployed in differnt types of orbit, or which can actively change their orbital regime.

(3) Modified Mission: The modified mission prefix is optional, and can be used to designate a special configuration of a system. The following modified mission symbols are defined:

T - Test/Training/Range
X - Experimental
Y - Prototype
Z - Scientific/Calibration

(4) Design Number: Separately for each basic mission symbol, numbers are assigned sequentially starting from 1.

(5) Block Letter: Variants (a.k.a. blocks) of a basic system are designated by a suffix letter. The first block always receives suffix "A", and subsequent blocks letters are to be assigned in alphabetical sequence, when the system's configuration has been significantly changed.

2 Designation Listings

For each basic mission type, a list of assigned designations is going to be provided. However, the nomenclature system is quite new, and at the time of this writing, only a single concrete designation has been made public.

M - Meteorological Systems

Designation	Prime Contractor	Name (Remarks)
ML-1A	BAE Systems	WSF-M (Weather System Follow-on - Microwave)

3 Sources

[1] SPFI 16-403: Space Force Weapon System Naming and Designations, July 2024

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Last Updated: 17 June 2025