# LUVOIR-B

> proposed UV-optical-NIR space telescope

**Wikidata**: [Q3935024](https://www.wikidata.org/wiki/Q3935024)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Advanced_Technology_Large-Aperture_Space_Telescope)  
**Source**: https://4ort.xyz/entity/luvoir-b

## Summary
LUVOIR-B is a proposed 8-m ultraviolet-to-near-infrared space telescope designed to operate from the Sun-Earth L2 Lagrange point; it is the smaller of two architectures studied for NASA’s Large Ultraviolet Optical Infrared Surveyor (LUVOIR) concept and is currently targeted for launch in 2039.

## Key Facts
- **Primary mirror diameter**: 8 m (26 ft)
- **Wavelength coverage**: ultraviolet, optical, near-infrared (UV-optical-NIR)
- **Orbit**: Sun-Earth L2 Lagrange point
- **Launch readiness target**: 2039 (expected, not yet approved)
- **Alternate names**: ATLAST, Advanced Technology Large-Aperture Space Telescope, ATLAS telescopio, Telescopio atlas
- **Instance of**: space telescope, proposed entity
- **Part of**: Large Ultraviolet Optical Infrared Surveyor (LUVOIR) study
- **Freebase ID**: /m/04cszy0
- **Wikipedia sitelinks**: 10 across 9 languages plus Commons
- **Commons image**: LUVOIR-B_transparent.png

## FAQs
### Q: Is LUVOIR-B already approved and funded?
A: No. It remains a proposed architecture within NASA’s LUVOIR study; no launch contract or budget line exists yet.

### Q: How does LUVOIR-B differ from LUVOIR-A?
A: LUVOIR-B is the 8-m mirror “moderate” architecture, whereas LUVOIR-A envisions a 15-m mirror; both were studied to explore cost-vs-capability trades.

### Q: Why place the telescope at L2?
A: The Sun-Earth L2 point provides a thermally stable, unobstructed view of the sky, allowing the sensitive UV/optical instruments to operate continuously without Earth’s glare or atmospheric interference.

## Why It Matters
LUVOIR-B is one of NASA’s flagship-class mission concepts designed to answer the highest-priority astrophysics questions of the coming decades. With an 8-m primary mirror—four times the light-collecting area of the Hubble Space Telescope—it would deliver unprecedented angular resolution and sensitivity from the ultraviolet through the near-infrared. This capability would let astronomers directly image dozens of potentially habitable exoplanets, search their atmospheres for biosignatures, trace the flow of matter into and out of galaxies, and map the large-scale structure of the cosmos with extraordinary detail. Because it is optimized to be smaller and presumably less expensive than the 15-m LUVOIR-A, LUVOIR-B represents a pragmatic path to achieving revolutionary science while fitting within plausible budget envelopes. If selected after the 2020 Decadal Survey, it would become the scientific successor to both Hubble and James Webb, shaping the direction of space-based astronomy for the 2040s and beyond.

## Notable For
- **Flagship-scale mirror in a compact 8-m package**, balancing cost and performance
- **Broad wavelength coverage** (UV through NIR) in a single observatory, something neither JWST nor Roman Space Telescope provides
- **L2 operations** enabling continuous, uninterrupted observations free from Earth-occultation and thermal cycling
- **Direct imaging of Earth-like exoplanets** as a core science requirement, driving ultra-low wavefront-error optics and starlight-suppression technologies

## Body
### Mission Concept
LUVOIR-B emerged from the 2016–2018 NASA-sponsored LUVOIR Science and Technology Definition Team as one of two point designs. The study examined how a large-aperture, general-purpose observatory could address the Astrophysics Decadal Survey’s science goals for the 2030s. The 8-m architecture was chosen to fit within projected flagship-mission cost profiles while still delivering transformative science.

### Optical Design
The telescope is conceived as a segmented, on-axis, obscured design with an 8-m primary mirror. The mirror’s precise figure and active wavefront control would yield diffraction-limited images down to at least 500 nm, a factor of 5–10 better than Hubble’s resolution. A suite of internal coronagraphs or starshades would provide starlight suppression at the 10⁻¹⁰ level, enabling direct spectroscopy of habitable-zone exoplanets.

### Instrument Package
Although instruments are not yet selected, concept studies assume:
- High-resolution UV spectrograph (R ≥ 100 000) for circumgalactic-medium science
- Wide-field optical/NIR imager covering ≥ 2 × 2 arc-min with Nyquist sampling at 400 nm
- Multi-band coronagraphic camera working from 200 nm to 2 µm
- High-contrast integral-field spectrograph for exoplanet characterization

### Launch and Operations
LUVOIR-B is sized for launch on a single heavy-lift vehicle (Falcon Heavy or SLS-class) without in-space assembly. After injection to a halo orbit around Sun-Earth L2, the observatory would undergo a 6-month commissioning period, followed by a minimum five-year prime mission, with consumables sized for 10+ years of operations.

### Status and Next Steps
The 2020 Astrophysics Decadal Survey ranked the overall LUVOIR concept as a top priority, but recommended further cost and risk reduction before implementation. NASA continues technology-development investments in large-aperture wavefront sensing, high-contrast coronagraphy, and large-format UV detectors that would be required by LUVOIR-B should it proceed to flight.

## References

1. Freebase Data Dumps. 2013