# SOLRAD 11B

> SOLRAD 11B was one of a pair of identical satellites that were placed in a circular equatorial orbit of 20 earth radii

**Wikidata**: [Q111857642](https://www.wikidata.org/wiki/Q111857642)  
**Source**: https://4ort.xyz/entity/solrad-11b

## Summary
SOLRAD 11B was a spacecraft launched on March 15, 1976, designed to operate in a circular equatorial orbit at a distance of 20 Earth radii. It was one of a pair of identical satellites boosted into space by a Titan IIIC launch vehicle. The mission is also identified by the aliases SOLRAD HI-TRIP and SRD-11B.

## Key Facts
- **Launch Date:** March 15, 1976
- **Classification:** Spacecraft
- **Launch Vehicle:** Titan IIIC
- **Orbital Profile:** Circular equatorial orbit at 20 Earth radii
- **COSPAR ID:** 1976-023D
- **NSSDCA ID:** 1976-023D
- **Satellite Catalog Number (SCN):** 08749
- **Mission Configuration:** One of a pair of identical satellites
- **Alternate Names:** SP74-1D, SESP NO. NRL-111-0264, SOLRAD HI-TRIP, SESP P74-1D, SRD-11B, SOLRAD11B

## FAQs
### Q: When was SOLRAD 11B launched?
A: SOLRAD 11B was launched on March 15, 1976.

### Q: What rocket was used to launch SOLRAD 11B?
A: The satellite was launched using a Titan IIIC launch vehicle.

### Q: What was the orbital path of SOLRAD 11B?
A: SOLRAD 11B was placed into a circular equatorial orbit located 20 Earth radii from the planet.

## Why It Matters
SOLRAD 11B represents a specific configuration of space technology deployed in the mid-1970s. Its primary distinction lies in its deployment as one half of a pair of identical satellites, suggesting a mission design focused on redundancy or coordinated data collection. The mission utilized the Titan IIIC, a heavy-lift launch vehicle, indicating the satellite's significant mass or the requirement to reach a high-energy orbit.

The orbital specification is a critical differentiator for this entity; placing a satellite in a circular equatorial orbit at 20 Earth radii (approximately 127,420 km) positions the spacecraft well beyond low Earth orbit, distinct from standard shuttle or station deployments. This specific orbital insertion suggests the vehicle was designed for deep-space monitoring or specialized scientific observation rather than standard telecommunications or low-altitude reconnaissance.

## Notable For
- Being one of a pair of identical satellites launched simultaneously.
- Operating in a high-altitude circular equatorial orbit (20 Earth radii).
- Utilizing the Titan IIIC launch platform.
- Possessing multiple designators and aliases, including SOLRAD HI-TRIP and SESP P74-1D.

## Body
### Mission Overview
SOLRAD 11B is classified as a spacecraft and was one of two identical units launched during this mission. The existence of a "twin" satellite implies a dual-body system, likely connected or deployed in tandem to achieve mission objectives.

### Launch and Deployment
The launch took place on March 15, 1976. The vehicle responsible for placing the payload into space was the Titan IIIC, a model of the Titan III family known for its capability to lift substantial payloads into various orbits.

### Orbital Characteristics
The defining technical characteristic of SOLRAD 11B is its orbit. It was inserted into a circular equatorial orbit at a distance of 20 Earth radii. An equatorial orbit implies the satellite traveled along the plane of the Earth's equator, while the 20 Earth radii distance places it in a region of deep space, far outside the Earth's immediate atmospheric influence.

### Identification and Aliases
The spacecraft is cataloged in international databases under specific identifiers. The COSPAR ID is 1976-023D, and the NSSDCA ID is 1976-023D. It is also tracked under Satellite Catalog Number 08749.

Historically, the mission and hardware have been referred to by several different names and designators, including:
*   SP74-1D
*   SESP NO. NRL-111-0264
*   SOLRAD HI-TRIP
*   SESP P74-1D
*   SRD-11B
*   SOLRAD11B

## References

1. Jonathan's Space Report