24" Replacement Project - Proposal

Introduction

The following document outlines the details of the proposal to replace the current 24” scope in the main dome with a more modern and accessible telescope. It covers the requirements for a new scope, proposed equipment and  the rationale for the project.

The new telescope will allow the Hamilton Astronomical Society to:

  • Offer a better viewing experience to the public

  • Offer a better experience to school and community groups

  • Take great images of the sky which would be used to promote the society and educate the community

  • Improve the accessibility of the current dome configuration making it easier for more people to see the sky at a higher throughput

  • Provide a solid foundation for expanding the societies scope and reach into the Waikato community

  • Conduct limited research and contribute to astronomical knowledge

The committee and member base are working hard to expand the membership, community outreach and capabilities of the society. We aspire to provide the Waikato with a great experience and to provide public engagement and education to as many people as possible.

This proposal has been carefully considered. As much detail as possible has been provided to help our funding sources understand the project and what we hope to achieve with the funding provided. This proposal has already been submitted to the societies member base and we have collected their feedback to contribute to this document.

The society is open to questions, comments and suggested amends regarding this proposal. You can provide feedback on the proposal through the form below.

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What’s wrong with the current telescope?

While the current 24” has served the society well it has several issues that have spurred the society to seek funding for a more modern replacement:

  • The optics of the 24” are of low quality and provide only fuzzy small images of solar system and deep field objects.

  • The 24” has no capability for imaging.

  • Using the drive and pointing system for the 24” is complex and inaccessible for members.

  • The 24” is so difficult to use it is often not used in favor of smaller telescopes.

  • The structure of the telescope is deteriorating; the fiberglass it is made of is delaminating and falling apart

  • The computers running the motors are so old that they can not be replaced owing to their parts no longer being made

  • The 24” has a massive footprint compared to modern scopes reducing the space in the dome for visitors and members.

The planned replacement telescope has a mirror that is 7” smaller than the existing telescope. However the new scope will still be able to provide sharper and clearer images than the existing scope due to it’s more modern design and superior optics



Equipment required:

The society has compiled a list of equipment that will be required to upgrade the dome with a modern scope. This list includes not only the scope itself but the elements required to install it and operate it successfully.

The equipment listed has been vetted by multiple members of the society and experts in the field. We have selected the equipment below to provide the best balance between technology that will meet the following criteria:

  • Good viewing for a wide range of objects

  • Suitable for educational purposes

  • Easy to use to make it accessible to all members

  • Priced at a level where funding is achievable in the short term

  • Can be installed quickly with minimal support

  • Robust and easy to maintain

  • Allows limited research and investigations

  • Provides for limited astro photography

  • Expandable and upgrade-able in the future

Below is a list of the chosen equipment with a brief description of each item, why it is required and how it relates to the wider project:


Optical Tube Assembly

Planewave 17” Corrected Dall-Kirkham (CDK) OTA

The Optical Tube Assembly or “OTA” contains the mirrors required to focus the light through the eyepiece. We have chosen a CDK configuration, it offers excellent image quality at an affordable price, it is versatile for viewing a wide range of objects. The selected model is also light so as not to overload the dome pier, simple to use and most importantly robust.

http://planewave.com/products-page/telescopes/17-inch-cdk-optical-tube-assembly/


Mount

Planewave L-500 Direct Drive Mount - (Altazimuth Configuration)

As or even more important than the OTA is the mount that the OTA sits on. A good mount is critical to be able to accurately and reliably steer the telescope. A computer controlled “Go To” mount provides tracking at the press of the button increasing the accessibility of the instrument. The chosen mount also allows for expansion of the OTA in the future if needed. This mount also comes packaged with the software required to drive it.

http://planewave.com/products-page/mounts/l-500-mount/


Camera

CCD Sensor Camera - STXL-11002

This camera will serve 2 purposes, firstly it allows us to align the telescope using known star locations, this will mean that the mount is able to precision calibrate the position of the OTA. Secondly it will provide imaging capability for the telescope allowing us to capture imagery of objects to use for promotional and educational purposes.

http://diffractionlimited.com/product/stxl-11002/


Computer

Intel NUC - Mini Computer

In order to run the software that drives the mount the society will need to replace it’s 80s era controller with a new computer. We’ve chosen a simple NUC for this as it’s sufficiently powered, well priced and has a small footprint. A switch may be required for multiple ethernet IO, this is still being considered.

https://www.pbtech.co.nz/product/BPCINT3431466/Intel-NUC-BOXNUC7i3BNH-Mini-Computer-Kit-i3-7100U



Engineering and installation requirements:

In addition to acquiring the equipment the new scope requires some engineering work to be done to the existing dome. This work is required because the new scope is a different design and requires a different position and height within the dome.

To define the engineering requirements we have / will be consulting with:

  • The district council - Building consent

  • Structural engineer - For design and sign off of engineering work

  • Metal Fabricators - To establish what is involved in the fabrication of the work

  • Society members

  • The Hamilton Zoo

The council has been consulted and an agreement that we do not need a resource or building consent has been reached.  The work will be staged and the construction planned carefully to ensure that pre-commissioning engineering work is safe, correct and goes smoothly.

The following preparation work is required to prepare the dome for the new telescope:

  • Clear dome of existing equipment

  • Dismantle and remove existing telescope

  • Prepare pier for mounting of adapter

  • Crane in adapter

  • Fasten adapter

  • Safety check and floor repair where needed

  • Position check for mounting plate


Pricing

Pricing is currently being sought for all of the above components and engineering works, independent estimates are acquired funding will be sought. Information collected so far on pricing has been detailed below and includes some potential additional components :


CDK400 Package A$75,999-00 (contains IRF and EFA - See below)


CDK 17" OTA A$38,999-00

L500 Mount A$30,199-00

IRF 90 (rotating focuser) A$7,099-00

EFA (electronic focuser) A$1,299-00


Additions

Focal Reducer A$1,899-00

Light Shroud A$319-00

Delta T A$1049-00

OTA Counterweight A$319-00

STXL 11002 camera only A$11,399-00

STXL 11002 w/Self Guiding FW8G-STXL Filter Wheel A$15,499-00

STXL 11002 w/ Self-Guiding Filter Wheel Pro Package A$18,899-00


Alternatives

Software Bisque Paramount MEII w/ On Axis Encoders A$37,500-00

Software Bisque Paramount MEII A$27,299-00

STX 16803 A$15,299-00

STX 16802 w/ FW7 STX A$19,999-00

STX Guider A$1,799-00

STX Ultimate Package A$27,599-00 w/ FW7 STX, Self Guider, 50mm Square LRGBC and 50mm Square Narrowband Filter sets


Shipping

Shipping to Hamilton approx A$4,500-00


Dimensions

Shipping dimensions for the above are as follows:

The OTA crate is 150cm    X    100cm    x    80cm  and will weigh 120kg 

The L Mount crate is 150cm    x    100cm    x    80cm and will weigh  150kg

The Camera will be 50cm     x    50cm    x    50cm and will weigh  30kg


Timelines

Following receipt of funding we estimate the following timelines are required to reach commissioning of the new scope. If at any point we are able to partially fund the project to prepare an item ahead of full funding being obtained then we will do so. Items will be prioritised based on their staging.

Funding round

4-6 months (estimate variable)

Lead time on equipment

8-10 months

Purchase and shipping of equipment

6 weeks

Engineering adapter. In parallel.

4 weeks

Removal of existing scope and preparation of dome

2 weeks

Crane in / out

1 day

Assembly and commissioning

2 weeks


Feedback

Please provide feedback using the form above, all submissions will be considered by the committee and the proposal amended / updated based on member feedback.