S-Class Satellite Bus
Data current as of 2026-07-20.
The S-Class bus accounts for 33 cataloged objects, of which 32 are in orbit and 32 are active. 1 have reentered. Most are built by YORKSS. The largest operator on this bus is Space Development Agency. The first launched in 2019, the most recent in 2025.
32
In orbit
32
Active
33
Total launched
1
Reentered
S-Class launched per year
Still in orbit Since reentered Click a year to list its satellites.
Typical specifications
Most common values across cataloged S-Class satellites.
| Manufacturer | YORKSS |
|---|---|
| Purpose | Communications, laser |
| Launch mass | 300 kg |
| Dry mass | 300 kg |
| Length | 1.0 m |
| Diameter | 0.6 m |
| Span | 2.0 m |
| Shape | Box + panels |
| Power | 4 deployable fixed solar arrays, batteries |
| Propulsion | ? |
| Design life | 3 years |
| Equipment | ICEYE X3 X-band SAR, low-resolution optical camera |
| Typical orbit | 104 min period, 81° inclination |
Top operators
Top countries
US 33
S-Class satellites
Track any of them live in KeepTrack.
| Name | NORAD | COSPAR | Owner | Launched | Orbit | Status | Track |
|---|---|---|---|---|---|---|---|
| PRAETORIAN SDA_601 | 65585 | 2025-203X | SDA | Sep 10, 2025 | 104 min, 81.3° | Active | ◉ |
| PRAETORIAN SDA_621 | 65584 | 2025-203V | SDA | Sep 10, 2025 | 104 min, 81.3° | Active | ◉ |
| PRAETORIAN SDA_620 | 65583 | 2025-203U | SDA | Sep 10, 2025 | 104 min, 81.3° | Active | ◉ |
| PRAETORIAN SDA_619 | 65582 | 2025-203T | SDA | Sep 10, 2025 | 104 min, 81.3° | Active | ◉ |
| PRAETORIAN SDA_618 | 65581 | 2025-203S | SDA | Sep 10, 2025 | 104 min, 81.3° | Active | ◉ |
| PRAETORIAN SDA_617 | 65580 | 2025-203R | SDA | Sep 10, 2025 | 104 min, 81.3° | Active | ◉ |
| PRAETORIAN SDA_616 | 65579 | 2025-203Q | SDA | Sep 10, 2025 | 104 min, 81.3° | Active | ◉ |
| PRAETORIAN SDA_615 | 65578 | 2025-203P | SDA | Sep 10, 2025 | 104 min, 81.3° | Active | ◉ |
| PRAETORIAN SDA_614 | 65577 | 2025-203N | SDA | Sep 10, 2025 | 104 min, 81.3° | Active | ◉ |
| PRAETORIAN SDA_613 | 65576 | 2025-203M | SDA | Sep 10, 2025 | 104 min, 81.3° | Active | ◉ |
| PRAETORIAN SDA_612 | 65575 | 2025-203L | SDA | Sep 10, 2025 | 104 min, 81.3° | Active | ◉ |
| PRAETORIAN SDA_611 | 65574 | 2025-203K | SDA | Sep 10, 2025 | 104 min, 81.3° | Active | ◉ |
| PRAETORIAN SDA_610 | 65573 | 2025-203J | SDA | Sep 10, 2025 | 104 min, 81.3° | Active | ◉ |
| PRAETORIAN SDA_609 | 65572 | 2025-203H | SDA | Sep 10, 2025 | 104 min, 81.3° | Active | ◉ |
| PRAETORIAN SDA_608 | 65571 | 2025-203G | SDA | Sep 10, 2025 | 104 min, 81.3° | Active | ◉ |
| PRAETORIAN SDA_607 | 65570 | 2025-203F | SDA | Sep 10, 2025 | 104 min, 81.3° | Active | ◉ |
| PRAETORIAN SDA_606 | 65569 | 2025-203E | SDA | Sep 10, 2025 | 104 min, 81.3° | Active | ◉ |
| PRAETORIAN SDA_605 | 65568 | 2025-203D | SDA | Sep 10, 2025 | 104 min, 81.3° | Active | ◉ |
| PRAETORIAN SDA_604 | 65567 | 2025-203C | SDA | Sep 10, 2025 | 104 min, 81.3° | Active | ◉ |
| PRAETORIAN SDA_603 | 65566 | 2025-203B | SDA | Sep 10, 2025 | 104 min, 81.3° | Active | ◉ |
| PRAETORIAN SDA_602 | 65565 | 2025-203A | SDA | Sep 10, 2025 | 104 min, 81.3° | Active | ◉ |
| PEXT | 64874 | 2025-154F | APL/NASA | Jul 23, 2025 | 95 min, 97.4° | Active | ◉ |
| BANE Bane | 58465 | 2023-185D | YORKSS | Dec 1, 2023 | 87 min, 97.3° | Active | ◉ |
| CHECKMATE 10 Checkmate 10 | 57762 | 2023-133F | SDA | Sep 2, 2023 | 104 min, 81.0° | Active | ◉ |
| CHECKMATE 3 Checkmate 3 | 56169 | 2023-050H | SDA | Apr 2, 2023 | 104 min, 81.0° | Active | ◉ |
| CHECKMATE 1 Checkmate 1 | 56168 | 2023-050G | SDA | Apr 2, 2023 | 104 min, 81.0° | Active | ◉ |
| CHECKMATE 2 Checkmate 2 | 56167 | 2023-050F | SDA | Apr 2, 2023 | 104 min, 81.0° | Active | ◉ |
| CHECKMATE 7 Checkmate 7 | 56166 | 2023-050E | SDA | Apr 2, 2023 | 104 min, 81.0° | Active | ◉ |
| CHECKMATE 6 Checkmate 6 | 56165 | 2023-050D | SDA | Apr 2, 2023 | 104 min, 81.0° | Active | ◉ |
| CHECKMATE 4 Checkmate 4 | 56164 | 2023-050C | SDA | Apr 2, 2023 | 104 min, 81.0° | Active | ◉ |
| CHECKMATE 5 Checkmate 5 | 56163 | 2023-050B | SDA | Apr 2, 2023 | 104 min, 81.0° | Active | ◉ |
| CHECKMATE 8 Checkmate 8 | 56162 | 2023-050A | SDA | Apr 2, 2023 | 104 min, 81.0° | Active | ◉ |
| HARBINGER (ICEYE-X3) Harbinger | 44229 | 2019-026E | YORKSS | May 5, 2019 | 88 min, 40.0° | Reentered | ◉ |
Frequently asked questions
How many S-Class satellites are there?
The catalog lists 33 objects built on the S-Class bus. 32 are in orbit and 1 have reentered.
How many S-Class satellites are in orbit?
32 S-Class objects are currently in orbit, of which 32 carry an active status.
Who builds the S-Class bus?
The S-Class bus is most commonly built by YORKSS.
When did the first S-Class satellite launch?
The first cataloged S-Class satellite launched in 2019, and the most recent in 2025.