Vanguard Satellite Bus
Data current as of 2026-07-20.
The Vanguard bus accounts for 3 cataloged objects, of which 3 are in orbit and 0 are active. Most are built by Naval Research Laboratory. The largest operator on this bus is Naval Research Laboratory. The first launched in 1958, the most recent in 1959.
3
In orbit
0
Active
3
Total launched
0
Reentered
Vanguard launched per year
Still in orbit Click a year to list its satellites.
Typical specifications
Most common values across cataloged Vanguard satellites.
| Manufacturer | Naval Research Laboratory |
|---|---|
| Purpose | Science |
| Launch mass | 1.47 kg |
| Dry mass | 1.47 kg |
| Length | 0.165 m |
| Diameter | 0.508 m |
| Span | 0.508 m |
| Shape | Spherical |
| Power | Mercury batteries |
| Propulsion | None |
| Design life | The battery-powered transmitter operated for about 20 days, while the solar-powered transmitter functioned for over six years, with the last signals received in May 1964. |
| Equipment | Equipped with two radio transmitters: a 10 mW, 108 MHz telemetry transmitter powered by mercury batteries, and a 5 mW, 108.03 MHz Minitrack beacon transmitter powered by six solar cells. |
| Typical orbit | 121 min period, 33° inclination |
Top operators
Naval Research Laboratory 3
Top countries
US 3
Vanguard satellites
Track any of them live in KeepTrack.
| Name | NORAD | COSPAR | Owner | Launched | Orbit | Status | Track |
|---|---|---|---|---|---|---|---|
| Vanguard 3 Vanguard III | 00020 | 1959-007A | Naval Research Laboratory | Sep 18, 1959 | 124 min, 33.3° | Inactive | ◉ |
| Vanguard 2 Vanguard II | 00011 | 1959-001A | Naval Research Laboratory | Feb 17, 1959 | 121 min, 32.9° | Inactive | ◉ |
| Vanguard 1 Vanguard I | 00005 | 1958-002B | Naval Research Laboratory | Mar 17, 1958 | 133 min, 34.3° | Inactive | ◉ |
Frequently asked questions
How many Vanguard satellites are there?
The catalog lists 3 objects built on the Vanguard bus. 3 are in orbit and 0 have reentered.
How many Vanguard satellites are in orbit?
3 Vanguard objects are currently in orbit, of which 0 carry an active status.
Who builds the Vanguard bus?
The Vanguard bus is most commonly built by Naval Research Laboratory.
When did the first Vanguard satellite launch?
The first cataloged Vanguard satellite launched in 1958, and the most recent in 1959.