# SOLRAD 11A

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

**Wikidata**: [Q111857335](https://www.wikidata.org/wiki/Q111857335)  
**Source**: https://4ort.xyz/entity/solrad-11a

## Summary
SOLRAD 11A was one of a pair of identical satellites placed in a circular equatorial orbit at 20 Earth radii. It was launched on March 15, 1976, aboard a Titan IIIC launch vehicle as part of the SOLRAD program. The satellite carried the designation 08748 and was also known by several aliases including SOLRAD HI-TRIP and SRD-11A.

## Key Facts
- Launched on March 15, 1976, aboard a Titan IIIC launch vehicle
- One of a pair of identical satellites placed in a circular equatorial orbit at 20 Earth radii
- Designated as spacecraft 08748 with aliases including SOLRAD HI-TRIP, SRD-11A, and P74-1C
- Had COSPAR ID 1976-023C and NSSDCA ID 1976-023C
- Part of the SOLRAD (Solar Radiation) program for solar observation
- Also known as SESP NO. NRL-111-0264 and NRL-111

## FAQs
### Q: What was the purpose of SOLRAD 11A?
A: SOLRAD 11A was part of the SOLRAD program designed to study solar radiation from Earth orbit. As one of a pair of identical satellites, it operated in a circular equatorial orbit at 20 Earth radii to monitor solar activity.

### Q: When and how was SOLRAD 11A launched?
A: SOLRAD 11A was launched on March 15, 1976, aboard a Titan IIIC launch vehicle. It was one of two identical satellites launched together as part of the same mission.

### Q: What orbit did SOLRAD 11A occupy?
A: SOLRAD 11A was placed in a circular equatorial orbit at a distance of 20 Earth radii from Earth's center, making it part of a specialized satellite pair for solar observation.

## Why It Matters
SOLRAD 11A represented an important advancement in solar observation capabilities during the 1970s. As part of the SOLRAD program, it contributed to our understanding of solar radiation and its effects on Earth's environment. The satellite's unique equatorial orbit at 20 Earth radii allowed for continuous monitoring of solar activity from a stable vantage point. This mission built upon earlier SOLRAD satellites and helped establish the foundation for modern solar observation programs. The data collected by SOLRAD 11A and its twin satellite would have been valuable for both scientific research and practical applications related to space weather forecasting and understanding the Sun's influence on Earth's magnetosphere.

## Notable For
- One of a pair of identical satellites operating in a specialized equatorial orbit at 20 Earth radii
- Launched as part of the long-running SOLRAD program for solar radiation studies
- Operated in a unique circular equatorial orbit that provided stable solar observation conditions
- Carried multiple designations and aliases reflecting its various program affiliations
- Represented continued advancement in solar observation technology during the 1970s

## Body
### Technical Specifications
SOLRAD 11A was designed as part of a satellite pair, with both units being identical in construction and purpose. The satellites operated in a circular equatorial orbit at a distance of 20 Earth radii, which is approximately 127,600 kilometers from Earth's center. This orbit type was specifically chosen to provide optimal conditions for solar observation.

### Mission Details
The satellite was launched on March 15, 1976, as part of a coordinated mission that included its twin satellite. Both were carried into orbit aboard a Titan IIIC launch vehicle, a heavy-lift rocket capable of placing multiple payloads into orbit simultaneously. The mission designation included several identifiers: 08748, SOLRAD HI-TRIP, and P74-1C.

### Program Context
SOLRAD 11A was part of the broader SOLRAD (Solar Radiation) program, which had been ongoing since the late 1950s. The program focused on monitoring solar X-ray and ultraviolet emissions, which are important for understanding space weather and the Sun's impact on Earth's upper atmosphere. The "11A" designation indicates this was part of the SOLRAD 11 series, with the "A" likely denoting the first of the twin satellites launched together.

### Identification and Documentation
The satellite was cataloged under multiple identification systems for tracking and documentation purposes. Its COSPAR ID (1976-023C) and NSSDCA ID (1976-023C) both use the same designation, indicating standardized international tracking. Additional aliases including SESP NO. NRL-111-0264 and NRL-111 suggest connections to Naval Research Laboratory programs and the Space Environment Services Center.

## References

1. Jonathan's Space Report