# Van Allen Probe A

> space probe used to study Earth's Van Allen radiation belts

**Wikidata**: [Q28473093](https://www.wikidata.org/wiki/Q28473093)  
**Source**: https://4ort.xyz/entity/van-allen-probe-a

## Summary
Van Allen Probe A was a United States space probe and geomagnetic satellite designed to study Earth's Van Allen radiation belts. Launched on August 30, 2012, as part of the twin-spacecraft Van Allen Probes mission, it was manufactured and operated by the Johns Hopkins University Applied Physics Laboratory. The probe operated in a highly elliptical orbit until its service retirement on October 18, 2019.

## Key Facts
- **Classification:** Geomagnetic satellite (space probe).
- **Launch Date:** August 30, 2012, at 08:05:27 UTC.
- **Launch Vehicle:** Atlas V 401 (AV-032).
- **Launch Site:** Cape Canaveral Space Launch Complex 41, United States.
- **Operator & Manufacturer:** Johns Hopkins University Applied Physics Laboratory.
- **Funder:** National Aeronautics and Space Administration (NASA).
- **Mass:** 591.6 kilograms (launch weight).
- **Orbit Type:** Highly elliptical orbit around Earth.
- **Retirement Date:** October 18, 2019, at 16:30 UTC.
- **Namesakes:** Also known as Radiation Belt Storm Probe A (RBSP-A), VAP-A, and VAP A; named after physicist James A. Van Allen.

## FAQs
### Q: What was the primary purpose of Van Allen Probe A?
A: Van Allen Probe A was designed to monitor Earth's magnetosphere and study the Van Allen radiation belts. It gathered data to help scientists understand the dynamics of these radiation regions.

### Q: How long was Van Allen Probe A operational?
A: The probe was launched on August 30, 2012, and was retired from service on October 18, 2019, operating for just over seven years.

### Q: Who built and managed Van Allen Probe A?
A: The spacecraft was built and operated by the Johns Hopkins University Applied Physics Laboratory, with funding provided by NASA.

## Why It Matters
Van Allen Probe A served a critical role in advancing the understanding of space weather and the hazardous radiation environment surrounding Earth. As one of two identical probes in the mission (alongside Van Allen Probe B), it provided stereoscopic views of the radiation belts, allowing researchers to distinguish between spatial and temporal changes in the magnetosphere. This data is essential for protecting satellites and astronauts from the dangers of space radiation. By characterizing the behavior of relativistic electrons and ions, the mission contributed significantly to heliophysics and the predictive modeling of space environment conditions.

## Notable For
- Being part of the Van Allen Probes mission, a twin-spacecraft system dedicated to studying the radiation belts.
- Operating in a highly elliptical orbit with a high apoapsis of 28,050 km, allowing it to traverse the entire radiation belt zone.
- Being named after James A. Van Allen, the discoverer of the radiation belts.
- Utilizing the Atlas V 401 launch vehicle for its deployment.
- Covering a distinct orbital path (Period: 487.6 minutes) to measure magnetic and electric fields and particle populations.

## Body
### Mission Overview
Van Allen Probe A was a geomagnetic satellite and space probe that functioned as a component of the broader Van Allen Probes mission. Its primary directive was the study of Earth's Van Allen radiation belts. The spacecraft was identified by the COSPAR ID 2012-046A and the NSSDCA ID 2012-046A. It held the NAIF ID -362 and the SCN (Satellite Catalog Number) 38752.

### Development and Specifications
The probe was manufactured by the Johns Hopkins University Applied Physics Laboratory, which also served as the operator. The project was funded by the National Aeronautics and Space Administration (NASA). The spacecraft had a launch mass of 591.6 kilograms.

### Launch and Orbital Parameters
Van Allen Probe A launched successfully on August 30, 2012, at 08:05:27 UTC from Cape Canaveral Space Launch Complex 41. The launch was facilitated by an Atlas V 401 rocket (serial AV-032). Upon deployment, the probe entered a highly elliptical orbit around Earth characterized by the following parameters:
- **Apoapsis:** 28,050 kilometres
- **Periapsis:** 235 kilometres
- **Semi-major Axis:** 20,520 kilometres
- **Orbital Period:** 487.6 minutes
- **Inclination:** 10.1024 degrees
- **Eccentricity:** 0.6777209

The orbital epoch was noted as April 25, 2022 (likely referring to data referencing), though the active operational life concluded earlier.

### Mission Conclusion
The probe's operational phase concluded with a "service retirement" event. This significant event took place on October 18, 2019, at 16:30 UTC. Prior to retirement, the probe contributed extensive data regarding the Earth's magnetosphere and related regions.

## References

1. [Source](https://spaceflightnow.com/news/n0605/25lwsradiation/)
2. [Source](https://spaceflightnow.com/news/n1211/09vanallen/)
3. Jonathan's Space Report
4. [Source](https://www.space.com/space-exploration/satellites/incoming-1-300-pound-nasa-satellite-will-crash-to-earth-on-march-10)
5. [Source](https://www.space.com/van-allen-radiation-probes-end-mission.html)
6. [Source](https://heavens-above.com/orbit.aspx?satid=38752)
7. [Source](https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=2012-046A)
8. [Source](https://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/req/naif_ids.html)