mars gang| Let's Connect
Let's Connect
Active Probe and Drogue Assembly System (APDAS)
Summary
The APDAS is a probe-and-drogue style docking system intended to facilitate the rapid mating or assembly of structures and components in space.The drogue is able to perform passive soft-capture of the probe, while the active hard-capture and release are performed on the probe's side. The idea behind this system is that multiple corresponding male and female ends are present on either component. Proper alignment is achieved by whatever machine or vehicle is manipulating the structure to be mated, as there are only a handful of positions in which the probes and drogues would be inline. The two parts click together in soft-capture, with hard-capture being actuated after.
How I Addressed This Challenge
What did you develop, and why is it important?
I developed a docking system to expedite construction and assembly in space.
After the first bases are established on the moon and Mars, large space stations and spacecraft might not be too far in the future. Especially for space stations, space assembly is crucial - they cannot be launched in one piece from earth, and construction in space allows for much larger structures.
Parts and components launched from earth would need to be assembled, and for this it is necessary to have a docking system that allows to do that quickly, and easily.
What does it do, and how does it work?
The APDAS does three things:
- Passive soft-capture
- Active hard-capture
- Active release
In addition, it can correct misalignments (to a certain degree) thanks to the drogue.
Please see the demo presentation for visualizations and additional explanations
Soft capture works by simply pushing the probe through the drogue. The petals of the drogue are spring-loaded and pivot back into place behind the probe, preventing undocking. This connection however, is still loose.
Hard capture is established by retracting the probe with an electromechanical linear actuator (EMLA) fixed to the parent component which engages with the threaded probe housing. This pulls the two parts flush against each other and creates a strong link between them.
A capture can be released through the use of an active system inside the probe. The probe is first released from hard capture by driving it forward, at which point the release EMLA retracts the release plunger. The release plunger is a threaded rod with mounts at the forward end that several arms connect to. When the plunger is pulled back, the arms extend out and forward as a slot engages with a pin on the probe housing. The arms push apart the drogue petals and allow an undock.
What do you hope to achieve?
My goal would be to allow for large assemblies so that humans can retain a permanent presence in space. I think it's important that we colonize other planets, and to get there we need large space stations and spacecraft that can carry cargo and passengers.
How I Developed This Project
I'm studying aerospace engineering in university, so a hardware engineering challenge like Let's Connect was really interesting to me. I used Fusion360 to develop the design and Photoshop for some of the images.
A major problem I ran into was the simulation of interaction between parts. My original plan was to create a 30-second video, but I couldn't animate it because the contact sets and joints on my model weren't working properly.
To make the animations in the demo I manually took pictures of the moving components and made those into a gif.
How I Used Space Agency Data in This Project
I used information on docking systems from NASA to help design my project.
- CSM11 Docking Subsystem - helped when deciding on type of docking mechanism to use
- NASA Docking System Block 1 - influenced the choice of how to actuate the probe and release rod