Accident damages mirror on telescope slated for dark energy camera

Accident damages mirror on telescope slated for dark energy camera
Cracks in the secondary mirror on the Blanco telescope in Chile after an accident on February 20, 2012. Credit: Cerro Tololo Inter-American Observatory

An accident at the Blanco 4m telescope at Chile’s Cerro Tololo Inter-American Observatory has severely damaged a secondary mirror. The telescope is currently shut down for installation of the highly anticipated Dark Energy Survey Camera, and on February 20, 2012, the telescope’s f/8 secondary mirror was dropped during testing, resulting in fractures in the glass in the center of the mirror. Officials at the telescope said they are analyzing the extent of the damage to the mirror, and whether it extends beyond the visible cracks on the surface. They are also reviewing how the accident might affect the installation of the “DECam.”

Two staff members were injured during the incident, but are expected to fully recover. According to a post on the CTIO website, the f/8 had been removed for the installation of the DECam, and the f/8 was on the dome floor to test the focus mechanism. “The mirror and its back end assembly were being transferred to a handling cart to enable the tests. Unfortunately, the mirror was improperly installed on the cart and when the mirror was being rotated on the cart, the entire cart/mirror assembly toppled over injuring two of our technical staff,” said the report.

The mirror itself impacted the dome floor, causing the fractures, pictured above.

At this time, officials say it is not clear if the mirror is repairable or not and are reviewing what needs to be done to stabilize the cracks in the mirror. The accident is being investigated and initially, officials said they didn’t expect the incident delay the installation and commissioning of Camera as the f/8 is not required for the installation or operation of the Dark Energy Camera system. However, a later update said the DECam installation schedule was being modified to allow for the absence of the f/8 mirror.

The Dark Energy Camera will map 300 million galaxies with an extremely red sensitive 500 Megapixel camera, with a 1 meter diameter, 2.2 degree field of view prime focus corrector, and a data acquisition system fast enough to take images in 17 seconds.

The CTIO website said they would be providing future updates on the status of the and the DECam installation.

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Source: Universe Today
Citation: Accident damages mirror on telescope slated for dark energy camera (2012, February 27) retrieved 17 July 2019 from
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User comments

Feb 27, 2012
Wow that sucks. These mirrors can take years to manufacture.

Feb 28, 2012
Breaking mirrors like breaking windows and war are good for the economy, just as outsourcing manufacturing to get cheaper imports is good for the economy.

Well, at least according to our Libertarian Friends.

The effect (broken window fallacy) you are describing is an outflow of Keynsian economics. Unfortunately for your thesis, Libertarians (big L) tend to be followers of Hayek, not Keynes. The difference is not insignificant: http://www.youtub...ERTFo-Sk
Furthermore, the broken window fallacy is completely disconnected from whether imports are good for the economy or not, so your entire thesis is non sequitur.

Feb 28, 2012
The astronomers should have studied physics too. Then they would have been able to predict that this will happen when you turn that dolly around too quickly. Angular momentum, you see. tsk..

Feb 28, 2012
Oooh that's a nasty looking crack. I would be very surprised if they could fix it

What size is this mirror? How much are they worth?

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