# Spacelab 2 X-ray Telescope

> X-ray telescope flown on the STS-51-F Spacelab 2 mission

**Wikidata**: [Q105439418](https://www.wikidata.org/wiki/Q105439418)  
**Source**: https://4ort.xyz/entity/spacelab-2-x-ray-telescope

## Summary
The Spacelab 2 X-ray Telescope was an X-ray telescope launched aboard the Space Shuttle Challenger on the STS-51-F mission in 1985 to study high-energy astrophysical phenomena. It was part of the Spacelab 2 payload and operated for 8 days in orbit, conducting observations using grazing-incidence optics. The telescope is now housed at the Science Museum in London.

## Key Facts
- **Launch Date**: July 29, 1985, at 21:00:00 UTC from Kennedy Space Center Launch Complex 39A.
- **Mission Duration**: 8 days, concluding with a landing at Edwards Air Force Base on August 6, 1985.
- **Dimensions**: 1.0 m width, 2.2 m length, 8.2 m height.
- **Mass**: 326 kg.
- **Manufacturer**: University of Birmingham (United Kingdom).
- **Principal Investigator**: Peter Willmore.
- **Power Consumption**: 160 watts.
- **Current Location**: Science Museum, London (inventory number 2005-33/1).

## FAQs
### Q: What was the purpose of the Spacelab 2 X-ray Telescope?
A: The telescope was designed to observe X-ray emissions from celestial objects, focusing on high-energy astrophysics, including supernova remnants and the interstellar medium.

### Q: How long did the Spacelab 2 X-ray Telescope operate in space?
A: It conducted observations for 8 days during the STS-51-F mission, despite challenges from the Space Shuttle’s payload bay environment.

### Q: Where is the Spacelab 2 X-ray Telescope displayed today?
A: It is part of the Science Museum’s collection in London, cataloged under inventory number 2005-33/1.

## Why It Matters
The Spacelab 2 X-ray Telescope was a pioneering instrument for high-energy astrophysics, leveraging grazing-incidence optics to capture X-ray data that Earth’s atmosphere typically blocks. As part of the Spacelab 2 mission—the first to focus on astronomical observations—it tested technologies later used in orbital X-ray observatories like ROSAT and Chandra. Despite the mission’s shortened timeline due to the Space Shuttle’s payload bay issues, the telescope demonstrated the feasibility of large X-ray instruments in space, advancing our understanding of cosmic phenomena such as supernovae and black holes. Its legacy lies in both its scientific contributions and its role in validating experimental space-based X-ray astronomy techniques.

## Notable For
- First UK-built X-ray telescope launched into space.
- Utilized grazing-incidence mirrors to focus X-rays, a novel approach at the time.
- Operated despite the Space Shuttle’s payload bay thermal and mechanical challenges.
- Contributed to early studies of the X-ray background and interstellar medium.

## Body
### Mission Overview
The Spacelab 2 X-ray Telescope launched on July 29, 1985, aboard the Space Shuttle Challenger (STS-51-F). The mission, delayed by a launch abort on July 12, lasted 8 days, with the telescope conducting observations until August 6, 1985. It operated in the Shuttle’s payload bay, exposed to space, and focused on targets such as the supernova remnant Cassiopeia A and the Perseus Cluster.

### Technical Specifications
- **Optics**: Grazing-incidence mirrors with a 1.0 m diameter aperture.
- **Detector**: Position-sensitive proportional counter.
- **Power**: 160 W consumption during operations.
- **Size**: 2.2 m length, 8.2 m height ( deployed configuration).

### Legacy
After the mission, the telescope was retired and donated to the Science Museum in London in 2005. It remains a key artifact in the history of X-ray astronomy, illustrating 1980s space technology and international collaboration (led by the University of Birmingham with NASA support). The mission’s data informed later X-ray observatory designs, bridging early experiments and modern facilities like the Chandra X-ray Observatory.

## References

1. [Source](https://collection.sciencemuseumgroup.org.uk/objects/co8060768/spacelab-2-x-ray-telescope-xrt)
2. Jonathan's Space Report
3. [Source](https://nssdc.gsfc.nasa.gov/nmc/experiment/display.action?id=1985-063A-07)