““Optical Telescopes.”Optical Telescopes.”Dyer Teacher Workshop

June, 2009 C. R. O’Dell

Vanderbilt University

GalileanTelescope

GalileoSustermans

InventorRotated

GalileoGalilii’s

Telescopes

Refracting Telescope

HeveliusTelescope

Telescopes-History

ChromaticAberration

AchromaticDoublet

YerkesTelescope

Telescopes-History

NewtonianTelescopeSchematic

Newton’s Reflector

Herschel’s Biggest Telescope

Lord Rosse

Telescopes-History

Ritchey24-inch

Mt. Wilson60-inch

100-inch

200-inch

Keck 10-m

Canary Island

Telescope

SALT

LBT-Schematic

Telescopes-History

Mona Kea

YerkesAerialView

Reasons for going into Space

Earth’s Atmosphere Blurs Out our View even when it is perfectly clear. This means that our view of the heavens is like that from a small telescope.

Usually a bigger telescope produces a sharper image. The HST images are 20X better than what is allowed by our Atmosphere.

The atmosphere also limits the energies of the photons that we can see.

19231923 Hermann Oberth publishes “Die Rakete Hermann Oberth publishes “Die Rakete

zu den Planetenraumen”zu den Planetenraumen” In this small book he elucidates most of In this small book he elucidates most of

the modern reasons for putting the modern reasons for putting telescopes in space.telescopes in space.

The ability to exploit space for The ability to exploit space for astronomy was and continues to be astronomy was and continues to be closely dependent upon transportation.closely dependent upon transportation.

Space Travel in 1930.Space Travel in 1930.

The V2The V2

19451945“Army Surplus” V-2 Rockets “Army Surplus” V-2 Rockets

come to the US.come to the US.

19461946 The first “Think-Tank”, the RAND corporation The first “Think-Tank”, the RAND corporation

commissions a study of potential uses of rockets.commissions a study of potential uses of rockets. Lyman Spitzer, then a 32 year old professor at Lyman Spitzer, then a 32 year old professor at

Yale performs this study.Yale performs this study. In this study he proposes building space In this study he proposes building space

observatories, leading up to something very observatories, leading up to something very similar to today’s HST.similar to today’s HST.

Soon after its creation in 1958 NASA established Soon after its creation in 1958 NASA established building the HST as a long-term goal.building the HST as a long-term goal.

1971-72 NASA begins to 1971-72 NASA begins to consider the HST.consider the HST.

One of the first things NASA did was to establish One of the first things NASA did was to establish if the project was feasible (a Phase-A Study).if the project was feasible (a Phase-A Study).

In parallel with studies by multiple contractors a In parallel with studies by multiple contractors a group of scientists was convened at NASA HQ group of scientists was convened at NASA HQ by Nancy G. Roman to provide feedback.by Nancy G. Roman to provide feedback.

At the end of this study I was nominated by At the end of this study I was nominated by Lyman Spitzer to become the Project Scientist Lyman Spitzer to become the Project Scientist (September 1972).(September 1972).

ResolutionResolutionversus Timeversus Time

Originally the design was for a 3-m aperture.

1972-3mCrossSection1972-3mCrossSection

1972-3mConfiguration1972-3mConfiguration

We had $$ problems from the We had $$ problems from the beginning.beginning.

The original $300M price-tag was a The original $300M price-tag was a dictated price. dictated price.

Different configurations were considered.Different configurations were considered. Different sizes (1.8-m, 2.4-m, 3.0-m) were Different sizes (1.8-m, 2.4-m, 3.0-m) were

considered.considered. The 2.4-m configuration was chosen in The 2.4-m configuration was chosen in

June, 1975.June, 1975. ESA became a 15% partner in late 1976.ESA became a 15% partner in late 1976.

A Skeleton Sketch.A Skeleton Sketch.

HST CutawayHST CutawayCroppedCropped

This was the first spacecraft to be designed for maintenance.

NBSNBSAxial SI ReplacementAxial SI Replacement

Primary Mirror.

Primary MirrorPrimary MirrorAfter Aluminizing After Aluminizing

The telescope structure.The telescope structure.

Focal Plane Assembly.Focal Plane Assembly.

WF/PC PrelaunchWF/PC Prelaunch

Transporting the Telescope to California.

OTA Development ProblemsOTA Development Problems

The manufacture of a light-weight, highly precise The manufacture of a light-weight, highly precise mirror was considered to be an established mirror was considered to be an established technology by the project managers.technology by the project managers.

As the primary mirror was being tested and As the primary mirror was being tested and finished, the FGS was shown to be inadequate.finished, the FGS was shown to be inadequate.

This all occurred as a new Project Manager This all occurred as a new Project Manager came on-board, whose mandate was to control came on-board, whose mandate was to control the escalating costs.the escalating costs.

Spherical AberrationSpherical Aberration

This was discovered as the first images This was discovered as the first images were made.were made.

The cause was a misaligned optical device The cause was a misaligned optical device used to measure the shape of the primary used to measure the shape of the primary mirror.mirror.

This device made the mirror appear to be This device made the mirror appear to be flat when it was of the right shape.flat when it was of the right shape.

The Reflective The Reflective Null CorrectorNull Corrector

The Direct The Direct MistakeMistake

Contributing FactorsContributing Factors

The primary mirror was not considered the most The primary mirror was not considered the most demanding part of the HST.demanding part of the HST.

The method of testing had become routine.The method of testing had become routine. Management was concentrating on a redesign of Management was concentrating on a redesign of

the FGS, which WAS new.the FGS, which WAS new. The resident MSFC QA person had not been The resident MSFC QA person had not been

changed.changed. The report on the anomaly with the alignment The report on the anomaly with the alignment

was not forwarded to MSFC.was not forwarded to MSFC.

The Assembled HST is Moved.The Assembled HST is Moved.

Schedule HistorySchedule History

JAW CartoonJAW Cartoon

LaunchLaunch

HST in OrbitHST in Orbit

Servicing MissionsServicing Missions

SM1-12/93 COSTAR, WFPC2,Solar ArraysSM1-12/93 COSTAR, WFPC2,Solar Arrays SM2-02/97 STIS,NICMOS,FGSSM2-02/97 STIS,NICMOS,FGS SM3A-12/99 FGS,Gyros,ComputerSM3A-12/99 FGS,Gyros,Computer SM3B-03/02 ACS,Solar Arrays,CryoCoolerSM3B-03/02 ACS,Solar Arrays,CryoCooler SM4-06/09 WFC3,COS,(STIS+ACS SM4-06/09 WFC3,COS,(STIS+ACS

Repairs),Batteries,Gyros, etc.Repairs),Batteries,Gyros, etc.

The construction crane operator.

SM1SM1Axial SI ReplacementAxial SI Replacement

NBSNBSAxial SI ReplacementAxial SI Replacement

SM4-Crew

Scientific ProductivityScientific Productivity

OrionNebula

OrionNebula1996

The Hubble Ultra Deep Field.

Reading MaterialReading Material ““Who Invented the Telescope” by Albert Van Who Invented the Telescope” by Albert Van

Helden, pp. 64-69, July, 2009 issue of “Sky Helden, pp. 64-69, July, 2009 issue of “Sky and Telescope.”and Telescope.”

““The Space Telescope” by Robert W. Smith. The Space Telescope” by Robert W. Smith. Cambridge University Press, 1989(pre-Cambridge University Press, 1989(pre-launch) & 1993(post-launch).launch) & 1993(post-launch).

““The Orion Nebula” by C. Robert O’Dell, The Orion Nebula” by C. Robert O’Dell, Harvard University Press, 2003 (Chapter 7).Harvard University Press, 2003 (Chapter 7).