# Explorer 17

> former NASA research satellite

**Wikidata**: [Q49874](https://www.wikidata.org/wiki/Q49874)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Explorer_17)  
**Source**: https://4ort.xyz/entity/explorer-17

## Summary
Explorer 17 was a NASA research satellite launched in 1963 to study Earth's upper atmosphere, focusing on atmospheric density and composition. Operated by NASA as part of the Atmosphere Explorer series, it decayed from orbit in 1966. The satellite provided critical data on atmospheric conditions despite experiencing battery failure during its mission.

## Key Facts
- **Launch Date**: April 3, 1963, at 02:00:02 UTC from Cape Canaveral Space Launch Complex 17A.
- **Operator**: National Aeronautics and Space Administration (NASA).
- **COSPAR ID**: 1963-009A.
- **Mission Duration**: Operated until battery failure on July 10, 1963; decayed on November 24, 1966.
- **Launch Vehicle**: Delta B (serial number 357/D017).
- **Aliases**: Atmosphere Explorer-A.
- ** Decay Date**: Reentered Earth's atmosphere on November 24, 1966.

## FAQs
### Q: What was the primary mission of Explorer 17?
A: Explorer 17 was designed to study Earth's upper atmosphere, measuring atmospheric density, temperature, and composition to improve understanding of atmospheric dynamics.

### Q: Why did Explorer 17 stop functioning?
A: The satellite experienced a battery failure on July 10, 1963, which ended its operational mission, though it remained in orbit until 1966.

### Q: How long did Explorer 17 stay in orbit?
A: It remained in orbit for approximately 3 years and 7 months, decaying on November 24, 1966.

## Why It Matters
Explorer 17 played a key role in early atmospheric science research, contributing to NASA's efforts to characterize Earth's upper atmosphere during the Space Age. As part of the Atmosphere Explorer program, it gathered data critical for modeling atmospheric behavior, which supported both scientific research and spacecraft design. Despite its relatively short operational lifespan due to battery failure, the mission demonstrated the feasibility of satellite-based atmospheric studies, paving the way for future Earth observation missions. Its findings helped scientists better understand atmospheric density variations and their impact on satellite trajectories, addressing challenges in space exploration and orbital mechanics.

## Notable For
- First satellite in the Atmosphere Explorer series dedicated to studying atmospheric density and composition.
- Experienced a battery failure just 3 months into its mission, limiting data collection.
- Provided early insights into upper atmospheric conditions, contributing to the development of orbital decay models.
- Operated during a pivotal period in space science, bridging early satellite technology with later Earth observation missions.

## Body
### Launch and Mission Overview
Explorer 17 launched on April 3, 1963, aboard a Delta B rocket from Cape Canaveral Space Launch Complex 17A. The satellite, also known as Atmosphere Explorer-A, was designed to conduct detailed measurements of Earth's upper atmosphere. It operated until a battery failure on July 10, 1963, which halted data transmission. The spacecraft remained in orbit until November 24, 1966, when it decayed due to atmospheric drag.

### Mission Objectives
The primary goal of Explorer 17 was to study atmospheric density, temperature, and composition at high altitudes. Its instruments focused on measuring these parameters to improve scientific understanding of atmospheric dynamics and their effects on spacecraft performance. The mission aimed to address gaps in knowledge about the upper atmosphere's structure and variability.

### Technical Details
- **Launch Vehicle**: Delta B (serial number 357/D017), an American expendable launch system.
- **Failure Cause**: Battery malfunction on July 10, 1963, ending the satellite's ability to collect and transmit data.
- **Orbital Decay**: Reentered Earth's atmosphere on November 24, 1966, after completing 14,118 orbits.

### Legacy
Despite its operational limitations, Explorer 17 contributed valuable data to atmospheric science and spacecraft engineering. Its mission highlighted the importance of reliable power systems for satellite longevity and informed the design of subsequent Atmosphere Explorer satellites. The spacecraft's findings supported the development of more accurate atmospheric models, which remain relevant for modern space operations and climate research.

## References

1. Jonathan's Space Report
2. [Source](https://www.n2yo.com/satellite/?s=00564)
3. Freebase Data Dumps. 2013