# Van Allen Probe B

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

**Wikidata**: [Q28473100](https://www.wikidata.org/wiki/Q28473100)  
**Source**: https://4ort.xyz/entity/van-allen-probe-b

## Summary
Van Allen Probe B (also known as RBSP-B) was a space probe designed to study Earth's Van Allen radiation belts. Launched in 2012 as part of the Van Allen Probes mission, it operated until 2019 to investigate the dynamic processes within Earth's magnetosphere.

## Key Facts
- **Launch Date**: August 30, 2012, at 08:05:27 from Cape Canaveral Space Launch Complex 41  
- **Retirement Date**: July 19, 2019, at 17:27 UTC  
- **Mass**: 610.6 kilograms (launch weight)  
- **Operator/Manufacturer**: Johns Hopkins University Applied Physics Laboratory  
- **Funding**: National Aeronautics and Space Administration (NASA)  
- **Orbit**: Highly elliptical with periapsis 219 km, apoapsis 28,441 km, inclination 10.2°, period 494.3 minutes  
- **Launch Vehicle**: Atlas V 401 (mission AV-032)  
- **Named After**: James A. Van Allen  
- **Aliases**: RBSP-B, VAP-B, Radiation Belt Storm Probe B  

## FAQs  
### Q: What was the primary mission of Van Allen Probe B?  
A: Van Allen Probe B was designed to study Earth's Van Allen radiation belts, focusing on the physical processes that accelerate, transport, and lose energetic particles trapped in Earth's magnetosphere.  

### Q: When did Van Allen Probe B cease operations?  
A: It ceased operations on July 19, 2019, after completing its extended mission to characterize the radiation belts.  

### Q: What organization managed Van Allen Probe B?  
A: The Johns Hopkins University Applied Physics Laboratory (JHU/APL) operated and manufactured the spacecraft under NASA's funding.  

### Q: Why was Van Allen Probe B named after James Van Allen?  
A: It honored James A. Van Allen, who discovered the Van Allen radiation belts in 1958, recognizing his foundational contributions to magnetospheric physics.  

## Why It Matters  
Van Allen Probe B fundamentally advanced space science by providing unprecedented detail on Earth's radiation belts. Its data revealed how solar storms accelerate and trap particles, directly informing spacecraft shielding design and space weather forecasting. The mission resolved long-standing debates about belt dynamics, revealing their extreme variability and the role of electromagnetic waves in particle acceleration. This knowledge protects satellites, astronauts, and terrestrial infrastructure from radiation hazards, making it a cornerstone of space environmental studies. The twin-probe approach also pioneered coordinated magnetospheric measurements, setting a precedent for future multi-spacecraft missions.  

## Notable For  
- **Dual-Probe Synergy**: Operated alongside Van Allen Probe A to enable simultaneous spatial comparisons across the radiation belts.  
- **High-Elliptical Orbit**: Engineered with a 219 km–28,441 km altitude range to directly sample inner and outer belt environments.  
- **Early Retirement**: Ceased operations in 2019 due to battery depletion, ending an era of dedicated radiation belt observation.  
- **NASA Funding**: Represented a significant NASA investment in heliophysics, with a total mission cost of over $1.1 billion.  

## Body  
### Mission Overview  
Van Allen Probe B (RBSP-B) was one of two identical spacecraft in the Van Allen Probes mission, tasked with characterizing Earth's Van Allen radiation belts. Its primary goals included understanding particle acceleration mechanisms, radiation belt variability, and their response to solar activity. As part of the mission, it coordinated with twin Probe A (RBSP-A) to create spatial maps of energetic particle distributions.  

### Launch and Operation  
Launched on August 30, 2012, aboard an Atlas V 401 rocket from Cape Canaveral, Van Allen Probe B entered a highly elliptical orbit. Managed by the Johns Hopkins University Applied Physics Laboratory (JHU/APL) with NASA funding, it operated for nearly seven years—far exceeding its initial two-year mission. The spacecraft ceased operations on July 19, 2019, after its batteries degraded beyond usable capacity.  

### Spacecraft Specifications  
- **Mass**: 610.6 kg (launch weight), built by JHU/APL.  
- **Power and Systems**: Solar-powered with redundant batteries; no specific payload details provided.  
- **Communication**: Operated as part of NASA's Deep Space Network.  
- **Name Origin**: Honored James A. Van Allen, discoverer of the radiation belts.  

### Orbital Characteristics  
- **Type**: Highly elliptical orbit around Earth.  
- **Periapsis**: 219 km (closest to Earth).  
- **Apoapsis**: 28,441 km (farthest from Earth).  
- **Inclination**: 10.2° relative to Earth's equator.  
- **Orbital Period**: 494.3 minutes.  
- **Eccentricity**: 0.6814291.  
- **Semi-Major Axis**: 20,708 km.  

### Retirement and Legacy  
Van Allen Probe B retired on July 19, 2019, alongside its twin (which ceased operations in 2019). Its data remains critical for space weather models, radiation hazard assessments, and understanding magnetospheric physics. The mission concluded with NASA's entry of the spacecraft into Earth's atmosphere for an uncontrolled reentry.

## 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.nasa.gov/feature/goddard/2019/first-of-two-van-allen-probes-spacecraft-ceases-operations)
5. [Source](https://heavens-above.com/orbit.aspx?satid=38753)
6. [Source](https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=2012-046B)
7. [Source](https://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/req/naif_ids.html)