# Explorer S-45

> NASA artificial satellite lost in a launch failure

**Wikidata**: [Q7387042](https://www.wikidata.org/wiki/Q7387042)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Explorer_S-45_(satellite))  
**Source**: https://4ort.xyz/entity/explorer-s-45

## Summary
Explorer S-45 was a NASA artificial satellite that was lost during a launch failure on February 25, 1961. As part of the Explorers Program, it was intended to be deployed into space using a Juno II rocket but did not reach orbit.

## Key Facts
- **Entity Type:** NASA artificial satellite (classified structurally as a space probe).
- **Launch Date:** February 25, 1961.
- **Launch Vehicle:** Juno II (an American space launch vehicle used during the late 1950s and early 1960s).
- **Launch Site:** Cape Canaveral Launch Complex 26.
- **Program:** Part of the Explorers Program.
- **Alternate Name:** S-45.
- **Mission Outcome:** Lost in a launch failure.
- **Identifier:** NSSDCA ID EXS-451.
- **Image Resource:** Available via Wikimedia Commons (S-45 1.jpg).

## FAQs
### Q: What was Explorer S-45?
A: Explorer S-45 was a NASA artificial satellite designed for the Explorers Program. It is most notable for being lost due to a failure during its rocket launch.

### Q: When and how did Explorer S-45 launch?
A: The launch attempt occurred on February 25, 1961. The satellite was launched aboard a Juno II rocket from Cape Canaveral Launch Complex 26.

### Q: What distinguishes Explorer S-45 from other satellites?
A: While part of the successful Explorers Program, Explorer S-45 is specifically distinct because it failed to reach orbit. It is also associated with the Juno II launch vehicle, a booster active in the early 1960s.

## Why It Matters
Explorer S-45 represents a specific historical data point in the early American space race, illustrating the high frequency of launch failures during the late 1950s and early 1960s. As a component of the broader Explorers Program, this mission highlights the experimental nature of early orbital science and the challenges faced by NASA in deploying unmanned robotic spacecraft.

While the mission itself resulted in the loss of the satellite, the entry serves as a record of the Juno II launch vehicle's history and the operational timeline of Cape Canaveral Launch Complex 26. Understanding failed missions like Explorer S-45 is essential for a complete historical analysis of space exploration reliability and the evolution of launch vehicle technology.

## Notable For
- Being a lost NASA artificial satellite due to launch failure.
- Utilizing the **Juno II** rocket, a prominent American booster of the early 1960s.
- Launching from **Cape Canaveral Launch Complex 26**.
- Being part of the long-running **Explorers Program**.
- Possessing a dual classification in records as both a "satellite" and a "space probe."

## Body
### Mission Overview
Explorer S-45 was an unmanned spacecraft developed by NASA. Structured as a space probe in technical classification, the Wikidata description defines it specifically as an artificial satellite. The primary significant event for this entity was the rocket launch on February 25, 1961, which was declared a failure, resulting in the loss of the craft.

### Launch Details
The launch operation was conducted at **Cape Canaveral Launch Complex 26**. The vehicle assigned to carry the payload was the **Juno II**, a four-stage American booster rocket derived from the Jupiter IRBM and used by NASA during the late 1950s and early 1960s.

### Program Context
Explorer S-45 was a constituent of the **Explorers Program**. This program has been a long-running United States effort to launch scientific spacecraft. While many Explorer missions were successful, S-45 serves as an example of the risks associated with early spaceflight.

### Identifiers and Records
- **NSSDCA ID:** EXS-451
- **Aliases:** S-45
- **Wikimedia Commons Category:** Explorer S-45

## References

1. Jonathan's Space Report