High-Level Project Summary
We developed a low shock, hold down-release mechanism. The design encompasses several components including a 8W linear actuator encased in housing, two-piece threaded bolt sleeve, and a piston cup. Initially, the actuator engages the motion of the piston cup. The piston cup, once engaged, restricts motion of the threaded bolt sleeve. When the actuator is disengaged, the threaded bolt grips releases, allowing the bolt to separate. This separation causes no debris formation, with the motor-gear system eliminating the need for pyrotechnics. The design also withstands the temperature constraints as it utilizes materials already in use in existing spacecrafts.
Link to Project "Demo"
Link to Final Project
Detailed Project Description
How It Works
This device uses an 8-Watt cryogenic electromechanical linear actuator to drive a piston cup down into a cylindrical housing. The piston cup, once engaged, restricts motion of the threaded bolt sleeves. This ensures security of the bolt. When the actuator is disengaged, the threaded bolt grips releases by sliding apart, freeing the bolt.
Dimensions
Our design was based around a 0.5inch (12.7mm) bolt. This was decided due to available space grade bolt supplier data, but can be scaled to required dimensions - limited to the size of actuator. The stainless steel threaded bolt sleeves have an outer diameter of 15mm and fit into the extruded cut of the aluminum piston cup. The outer diameter of the housing is 1.4inch (35.56mm), the same as the sourced linear actuator. The housing is 2mm thick and made of titanium. The length of the device is 205mm and weighs 0.986kg.
How It Looks
What Its Made Of
In the search for materials, the effects of space temperatures and the strengths needed were considered. We decided to choose materials already commonly used in space, as well as ensuring the components were made of differing materials to avoid cold welding.
When designing the housing for the launch lock design, common space applications were considered, as well as the need for a stronger base. Titanium is commonly used in space, and can be seen in applications during some Apollo missions, as well as the international space station. Given these points, titanium was decided to be the best option. After consideration of the different types of alloys, Ti-6Al-4V was most suitable given its current application for frames.
Another common material used in aerospace application is aluminum. In our design, the piston cup required to be of a strong material. Considering the application of the cup is placed inside the mechanism, corrosion resistance was not of the greatest importance. Aluminum 2014 alloy was chosen as the best fit.
For the last main component, the sleeve was decided to be made of stainless steel. Having investigated current steels used in sleeve-like components, Fe-18Cr-10Ni-Ti was decided on. This is due to it's current application in aircraft structural tubing.
Space Agency Data
The majority of the data we used was collected from NASA-operated websites and databases. The information obtained was utilized as standard guidelines for our design. Additionally, we collected data from reputable journals and articles. This data varied from mechanical mechanism testing, to articles containing numerical values for material properties. The data was able to make our design constraints more realistic and aided our overall brainstorming process.
Hackathon Journey
We found the “Let It Go (Without A Bang)” challenge to be an ideal fit for our team as it encompassed each team member's interests. Everybody was able to bring something to the table and provide meaningful ideas and feedback. Our team’s collective interest in the space industry is the common factor which tied this challenge together. We approached this challenge by dividing up the roles in accordance with each member's strengths and expertise. Our team communicated ideas freely throughout multiple brainstorming sessions, and resolved conflicts or disagreements respectfully, while providing constructive criticism. One design challenge we faced was having to work around the limitations associated with the size of the overall mechanism. We were able to partially overcome this setback by reducing the size significantly while prioritizing the overall functionality of the mechanism.
Throughout the research process, we learned about failures of past techniques and the reasons they failed, as well as general space technologies. We weighed and compared multiple different approaches, and created the most suitable design. Emphasizing incorporating past successful designs and enhancing them with more modern technology was our end goal. Overall, this challenge provided us all with a creative outlet to brainstorm and learn about the different applications of engineering principles. We were able to utilize the knowledge we obtained during our three years of undergraduate courses and apply it to real-world concepts.
References
Tools Used
- Solidworks
Resources & References
- https://directory.eoportal.org/web/eoportal/satellite-missions/s/space-tethers
- https://ntrs.nasa.gov/api/citations/20190026519/downloads/20190026519.pdf
- https://cdn.glenair.com/datasheets/pdf/non-pyrotechnic-space-mechanisms-hdrms-pin-pullers-and-pushers.pdf
- https://core.ac.uk/download/pdf/76423819.pdf
- https://www.techbriefs.com/component/content/article/tb/pub/techbriefs/mechanics-and-machinery/20036
- https://www.youtube.com/watch?v=PFABKpqWG9Q
- https://www.moog.com/content/dam/moog/literature/Space_Defense/spaceliterature/spacecraft_mechanisms/moog-cryogenic-fine-positioning-linear-actuator-datasheet.pdf
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6694310/
- https://ntrs.nasa.gov/api/citations/19950024937/downloads/19950024937.pdf
- https://www.aluminum.org/product-markets/aircraft-aerospace
- https://www.nasa.gov/sites/default/files/atoms/files/nasa-std-5020a_w-chg_1_nasa_fastener_standards.pdf
- https://www.aerospacemanufacturinganddesign.com/article/aluminum-alloys-for-aerospace/
- https://www.researchgate.net/publication/326632223_Studies_on_Titanium_Alloys_for_Aerospace_Application
- https://www.researchgate.net/publication/245190388_Machining_of_aerospace_titanium_alloys
- https://www.altempalloys.com/space-and-rockets.html
- https://nickelinstitute.org/media/1699/high_temperaturecharacteristicsofstainlesssteel_9004_.pdf
- https://ntrs.nasa.gov/api/citations/20180001137/downloads/20180001137.pdf
Tags
#design #solidworks #teamwork #collaboration #actuator #piston #space #canada #alberta #edmonton
Global Judging
This project has been submitted for consideration during the Judging process.