Related Experiment Video
Updated: Jun 9, 2026
10:35
Bringing the Visible Universe into Focus with Robo-AO
Published on: February 12, 2013
Reflective correctors for the Hubble Space Telescope axial instruments
Applied Optics
|September 8, 2010
Summary
New reflective correctors fixed the Hubble Space Telescope's spherical aberration. These optical elements restored camera resolution and spectrograph capabilities for improved astronomical observations.
Area of Science:
- Astronomy and Astrophysics
- Optical Engineering
- Space Science
Background:
- The Hubble Space Telescope (HST) suffered from spherical aberration, significantly degrading its optical performance.
- This aberration limited the clarity and resolution of scientific instruments, impacting observational data quality.
Purpose of the Study:
- To design and implement optical correctors to compensate for the HST's spherical aberration.
- To restore and enhance the performance of key scientific instruments, including cameras and spectrographs.
Main Methods:
- Development and deployment of five reflective correctors, each comprising a field mirror and an aspherical reimaging mirror.
- Integration of these correctors into a new module replacing an existing axial instrument during a refurbishment mission.
Main Results:
- Restoration of angular resolution capability in the HST's camera, albeit within reduced fields of view.
- Regained potential for observations in crowded fields and effective light collection at spectrograph slits.
Conclusions:
- The successful implementation of reflective correctors effectively corrected spherical aberration in the HST.
- Instrument performance was significantly improved, enabling higher quality astronomical data acquisition.
Related Concept Videos
01:16Focusing of Light in the Eye
Light rays enter the eye through the cornea, a transparent dome-shaped tissue that is the eye's outermost layer. The cornea bends or refracts, light rays traveling to the pupil. The shape of the cornea determines how much of the light is bent and whether the image will be focused correctly on the retina at the back of the eye. Once the light has passed through both refraction layers, it converges into a single focal point onto a small area. This is where photoreceptors start transforming...
01:17Common Leveling Mistakes and Errors
A survey team is tasked with determining the elevation difference between points Point A and Point B, separated by uneven terrain. They use a leveling instrument and a leveling rod.Common MistakesMisreading the Rod: During a backsight reading at Point A, the instrumentman observes the rod partially obscured by tall grass. Instead of reading 1.135 m, they mistakenly record 1.735 m due to the misalignment of the crosshair with the wrong graduation. This error adds 0.600 m to all subsequent...
01:15Distance Corrections
To achieve precise distance measurements, especially in surveying and construction, certain corrections must be applied to account for potential sources of error like the standardization errors, temperature variations, and slope adjustments.Standardization error emerges when measurement equipment undergoes changes, such as wear, repairs, or weather impacts. To address this, surveyors compare the equipment’s readings to a standard. This process identifies any deviation that might lead to...
01:05Total Internal Reflection Fluorescence Microscopy
Total internal reflection fluorescence microscopy or TIRF is an advanced microscopic technique used to visualize fluorophores in samples close to a solid surface with a higher refractive index, such as a glass coverslip. TIRF only allows fluorophores in proximity to the solid surface to be excited. When light from a medium with a lower refractive index (such as air) hits the glass coverslip at a critical angle, the light undergoes total internal reflection stead of passing through the glass.