XSAS Ground Testing Rig and Prototype Fabrication

Welcome back to the XSAS blog!

In this post I will explain my work on the payload/structures team building the ground testing rig for XSAS. I will also talk about the progress we are making on the XSAS prototype, the results of the thermal vac testing, and the rover structure we started building for the outreach program.

Before our microgravity flight we want to test the deployment of XSAS on the ground. The best way to do this is to have it extend horizontally on some kind of moving platform. The platform I designed is supported by ball bearing rollers and has a plate that clamps down on each end of XSAS. I recently machined both bottom plates and assembled the majority of these rolling platforms.

Progress continues on the XSAS prototype. The project's critical design review is this Thursday, and we want to show off the prototype to our faculty and peers. A majority of the parts have been machined and assembly will begin earlier this week.

Results from the thermal vacuum testing are in, and it's all good news. The hinges and scissors structure were tested in a vacuum at 100 degrees Celsius. The scissors structure successfully deployed, and the dyneema burn to release the structure occurred 5 seconds sooner. We concluded that there are no negative effects of thermal expansion on the hinges or scissors structure and that the dyneema likely melted faster due to the high temperature.

The outreach team has also started work on the rovers to be used for the "Build Your Own Rover" workshop series. We played around with our supplies and came up with the basic structure design for the rover chassis. The rovers will be made out of PVC pipes and use servos to control tires for movement and searing. The payload we will likely have the kids build will support a camera for a reconnaissance mission.

Thanks for reading and stay tuned for next weeks blog post.

Nathan McKay
Structures/Payload Team
Outreach Team
Systems Team

XSAS Thermal Testing and Prototype Fabrication

Hey XSAS followers, in this entry I'm going to be talking about what we've been up to this week on the Payload subsystem.

We recently completed a test rig of our scissor structure that will be used on XSAS.  Since this is only a test, we didn't use anything fancy, we made the panels out of polycarbonate and mounted the setup to a scrap aluminum plate.  This rig allows us to study the deployment of our scissor.  We wrap a line of dyneema around the scissor to compress it, which is shown below:

To deploy the scissor, we stuck a resistor on the wire and ran current through it to heat it up.  This melts the wire and allows the structure to open up.  We end up with the deployed configuration shown below:

We're currently in the process of running this test in an oven at 100°C to see if thermal expansion affects the deployment (i.e. if the hinges get stuck).

We also started fabrication of the XSAS microgravity prototype this week.  So far we've completed the panels, which are identical to the ones seen in the pictures above in the test rig, and we should be done with the scissor pieces very soon (also similar to what is shown above). 

We have a long way to go with fabrication, but we should have completed something that looks like this by the end of this month:

 

  

 That's what's new this week for XSAS!

Joshua Robinson

XSAS Payload Team Lead

Electrical and Power Systems & Command and Data Handling

In this post, I'll be explaining what's going on in the electrical and power systems & command and data handling subsystem (EPS&CDH).

The EPS&CDH subsystem is in charge of wiring, power, and data collection for XSAS.  In essence, anything that uses electricity. 

In our last post, Clark talked about using PCB boards as placeholders for the solar panels on the experimental XSAS flight.  He also mentioned the use of accelerometers and strain gauges on these boards to monitor how the boards react when XSAS is released.  These strain gauges and accelerometers are going to record all the data measurements to a microSD card.  That’s where we come in.

This week, the members of EPS&CDH have been finalizing the list of components we need on these boards.  Recording data from a sensor like an accelerometer or a strain gauge is a process that requires many parts.  In addition, we’re trying to save as much space as possible, so some of these parts are really small.  The accelerometers we’re planning on using are 4mm x 4mm in size!

Stay tuned for a new blog post next week!

Arun Dutta

EPS&CDH Team Member