Alexander Gliese 1, Carolyn Lake 2, Kohar Malkastian 3, Kirstin Moore4, Adam Stambouli 4, Eric Sturm 5

Mentors: Nerses Armani 6 , Giulio Rosanova 6

1University of Maryland Baltimore County - College of Engineering and Information Technology2College of Southern Maryland - Department of Mathematics, Physics, and Engineering

3Montgomery College, Department of Science, Engineering, and Technology4University of Maryland - A. James Clark School of Engineering

5University of Michigan - College of Engineering6Mechanical Engineering Branch - NASA Goddard Space Flight Center

Wide-Field Infrared Survey Telescope (WFIRST) Scale Model

Abstract Design

Takeaways

Acknowledgments

A five percent scale model of the Wide Field Infrared Survey Telescope (WFIRST) is needed to showcase the functionality of the current design. WFIRST’s mission is to perform Wide Field imaging and surveys of the near infrared sky as well as to detect exoplanets in other solar systems. WFIRST is currently in Phase A of the design process, where the observatory requirements are chosen and the single best approach is decided upon. WFIRST project managers have requested a small scale model to be able to physically display the current proposed design. The model needs to be lightweight and durable, therefore it will be made out of aluminium alloy 6061 and composite material. The actual observatory has modular subsystems that have to be included in our design, such as the avionics modules located in the Spacecraft (SC) and both Wide-Field and Coronagraph Instruments (WFI & CGI) located in the Instrument Carrier (IC). Since the observatory will have different configurations between launch and orbit, our model requires the Outer Barrel Assembly (OBA) door, the Solar Array Sun Shield (SASS) solar panels, and the High Gain Antenna System (HGAS) to be deployable. In addition, all subsystems will be removable and replaceable since the project is iterating the design.

Methodology

The most immediate lesson was learning to model parts using CAD software, more specifically Creo Parametric 3.0 and Solidworks. Once familiar with these programs, we realized that not every feature has the ability to be machined. With help from our machinist, we learned how to design parts for machinability. After all parts were designed, the observatory was assembled in CAD. Through this assembly, we discovered that many pieces needed to be redesigned to incorporate additional assembly features. Despite the time our design process took, the skills learned are invaluable.

Figure 1. Relative size of actual observatory to 6 foot human

Figure 2. Relative size of scale model to 6 foot human

Figure 3. Cross-section of scale model

We would first like to thank our mentors, Giulio Rosanova, Todd Colangelo, and Nerses Armani, for all the time and effort they’ve invested in our project. We would also like to send our gratitude to Chris Kolos for the many hours he dedicated. Lastly, thank you to the following people who helped make this project a success: Sheri Thorn, Todd Purser, Matthew Nelson, Charles English, Wellington Abhilashi, Robin Penn, Bobby Nanan, and everyone in the 547 fabrication shop.

6FT

6 FT

• Decided on a scaling factor for our modelo Rough estimates of size and weight at various scaling factorso We considered the size of features in the model

• Took measurements of full size model in Creo View• Designed preliminary scaled parts in Solidworks and Creo

Parametric 3.0• Consulted a machinist and our mentors• Used recommendations and requests from our machinist and

mentors to improve model• Continued consulting and improving until we reached a final

design• Prepared isometric drawings and step files to send to the

machine shop• We had most of our model made out of aluminumo Truss pieces were made out of carbon fiber compositeo We had the HGAS dish rapid prototyped

• We choose a color scheme that highlighted important parts of our model and were similar to the colors of the satellite

• After manufacturing, we grouped the aluminum pieces into sets that would be anodized the same color

• Sets were sent to the plating lab• We assembled the model using screws and epoxy

Outer Barrel Assembly (OBA)

Solar Array Sun Shield (SASS)

Telescope

Wide-Field Instrument (WFI)

Coronagraph Instrument

(CGI) Instrument Carrier (IC)

Spacecraft (SC)

High Gain Antenna System (HGAS)