All these Sky Pixels Are All these Sky Pixels Are YoursYours

The evolution of telescopes The evolution of telescopes and CCD Arrays: The and CCD Arrays: The

Coming Data NightmareComing Data Nightmare

Once Upon a Time: Life Was Once Upon a Time: Life Was SimpleSimple

• One Big Telescope

• One Thick Mirror

• One Lousy Detector

Old School

• But No QE

Thick MirrorsThick Mirrors

Made the support structure of the Made the support structure of the telescopes very expensivetelescopes very expensive

Capital Cost scaled as ACapital Cost scaled as A33

Would be limiting factorWould be limiting factor Thermal IssuesThermal Issues 1948-1982 1948-1982

Solution: Develop Thin MirrorsSolution: Develop Thin Mirrors

Lower Cost for Support StructuresLower Cost for Support Structures Thermal Issues are lessThermal Issues are less

Next: Combine Individual Light Next: Combine Individual Light SourcesSources

First done at the Multiple Mirror Telescope First done at the Multiple Mirror Telescope which was commissioned in 1982which was commissioned in 1982

Thin to Segmented Thin to Segmented MirrorsMirrors

Thin Mirror Technology (including Thin Mirror Technology (including Hubble) would dominate from 1982 Hubble) would dominate from 1982 to about 1998to about 1998

Keck 10 meter segmented mirrorKeck 10 meter segmented mirror

What about Detectors?

Photographic/Film is horrible non linear and no QE

Need a digital detectorBoyle and Smith 1969 CCD Nobel

Prize

Scalability of CCD Construction

335 Million Pixels335 Million Pixels

Optical InterferometerOptical Interferometer

• Can it work at short wavelengths to combine the light from many mirrors?

Real Life ComplicationsReal Life Complications

Towards a Full Sky Assault

Europeans Do BetterEuropeans Do Better

2x8.4 = 11.5 meters2x8.4 = 11.5 meters

World’s Biggest Single ApertureWorld’s Biggest Single Aperture

24.5 Meter Telescope Coming

Giant Magellan Telescope7 x 8.4 mirrors

The Next Big ThingThe Next Big Thing

A 33 GigaPixel Digital CameraA 33 GigaPixel Digital Camera

But is Big Aperture = Big ScienceBut is Big Aperture = Big Science

Historically not – Historically its survey Historically not – Historically its survey instruments that advance the field.instruments that advance the field.

Here comes the LSST Here comes the LSST

Site finalized in 2009Site finalized in 2009

LSST Concept

Single 8.4 M mirror3 degree FOV (!)80% encircled energy = 0.2” (Like HST)10s integration equivalent to 10hr

integration with 200 inch telescope.There are 40,000 square degrees in the

skySo …

WOW!

Relentless Image Acquisition

Lots of Hardware

Lots of Design Issues

Focal Plane Is curved

But Can this Work?

Each image = 132 Gbyte

240 Images per hour = 32 Terrabytes

10 hours = 320 TB

4 Day Survey = 1.28 PB

Rinse and repeat and each pixel contains information!