| Hitchhiker 2 | |
| Mission Type: | Technology |
| Operator: | USAF |
| Cospar Id: | 1963-042B[1] |
| Satcat: | 682 |
| Spacecraft Bus: | P-11 |
| Manufacturer: | Lockheed MartinMIT |
| Launch Mass: | 60kg (130lb) |
| Launch Date: | UTC[2] |
| Launch Rocket: | Thor SLV-2A Agena D 386 |
| Launch Site: | Vandenberg SLC-1W |
| Orbit Reference: | Geocentric |
| Orbit Regime: | Low Earth |
| Orbit Periapsis: | 285km (177miles) |
| Orbit Apoapsis: | 585km (364miles) |
| Orbit Inclination: | 89.9° |
| Orbit Eccentricity: | 0.02201 |
| Orbit Period: | 93.4 minutes |
| Apsis: | gee |
Hitchhiker 2 (or P-11 4202, P-11 AS and OPS 3316) was a satellite launched by U.S. Air Force. It was launched with the aim of studying and measuring cosmic radiation. The satellite was the second successful satellite of the P-11 program, following the failure of the first Hitchhiker satellite in March 1963. It was launched on October 29, 1963 from Vandenberg Air Force Base, California, on a Thor-Agena launch vehicle.
On May 23, 1965, the satellite re-entered the Earth's atmosphere.