A busy day at RamSat! The weather cooperated early in the morning and we were able to test the solar panels and sun sensors. Direct sunlight confirmed that each component is working as expected. Next we continued integration of the central stack. Mentors also continue software development for attitude determination and control, and ground station communication for telemetry and image transmission.

We have begun our final build. Each screw gets a dab of thread-locking fluid before being set into place. Tonight we have a great student turn out ranging from 7th to 12th grade! Students are taking turns placing components. We are also getting amazing archival pictures thanks to Tara Kneiser.

For more information on our launch, check out the Wikipedia page for our launch: https://en.wikipedia.org/wiki/SpaceX_CRS-22

Last week, we remotely commanded RamSat to take a photograph with each of the two cameras. The students took a moment to estimate the file size of the first image. As you can see here, their math was perfect! We were able to to transmit out first image and measure the resulting load on the battery. Over the next few days, we will begin modifying the ground station to convert the transmitted data back into a photograph. The modifications to the ground station are ongoing as well. This weekend will be dedicated to more assembly and testing.

We are making great progress with the rebuild and and should be ready for our vibration test in January. During the first few days in space, RamSat will gather telemetry data such as battery voltage and temperature. Once we establish contact, we will be able to download and analyze this data. We also were able to reattach the camera and antenna. Our goal is to test the camera at our next meeting.

We have been busy in the late days of summer and here is a long overdue update. First, we our launch date has been pushed back to 12 May 2021. This gives us a few more months to work through development and testing of RamSat. We will still launch on SpaceX-22 as part of a resupply mission to the International Space Station. Our goal is to complete the reassembly process, and schedule our vibration testing in December, and hand RamSat off to Huston in February.

We have begun testing each of the magnetorquers individually. Shown here, you can see what looks like a copper bar running from left to right, and another perpendicular to the first. These two interact with magnetic fields on the X and Y axis. On the bottom of the board, there is a 3rd copper loop for the Z axis. The stack is mounted on a development board where we can energize each axis and read the generated magnetic field with a field tester. These signals are strong enough to be seen with a common smart phone and compass application.

We have isolated the problem to a short somewhere on the main board for the flight computer. The manufacturer, Pumpkin Inc. was super helpful and offered to do some diagnostic assistance. We mailed the board to California on Friday June 26, and by Monday evening they had identified the problem as a short circuit inside the main processor chip. Here’s a thermal infrared image showing the high temperature on that chip when powered. The dark red spot indicates the short! The area of warm temperature in the lower left of that image is from the voltage regulator (on the other side of the board). It is going into a thermal shut-down mode as the result of the short circuit. Pumpkin is making repairs to the board and will return it to us soon.

After completely dissembling RamSat, we have determined that our processor module is the source of the problem. Tonight, the mentors met to review our options. New parts will be ordered immediately, and we will resume testing as soon as possible. Unfortunately, this will likely result in a delay to our launch date. But this gives us an opportunity to work with a new group of students this fall. Because we completely dissembled the "stack", we will need to perform another vibration test. We will post a new schedule when it is available.

On June 13, with the antenna deployed, we were testing the radio when we lost the ability to program the flight computer. After two days of troubleshooting, we determined that there is a power drain on the motherboard module that was preventing a connection to the programmer. Having exhausted all other options, we have begun the process of carefully dissembling RamSat. The problem appears to be the connector of the white cable shown here.

Antenna deployment test was a success! There are two UHF antennas, each are 44 cm. They will be used to transmit data back to the classroom ground station. The VHF antennas are 16.5 cm long and will receive data from the ground station. They are extremely delicate and sag under earth's gravity. Having the antennas deployed will allow us to build and test the communication systems.

Starting June 4th, we began the process of final testing and assembly of the RamSat components. This process will take students and mentors three days. Once the frame is fully assembled, it will be integrated with the Nanoracks deployment system for the final vibration test on June 9th. Once the frame is built and vibration tested, it can't be dissembled. These are some of the last pictures you will see of these components! Here are some highlights.

First step, battery! Today we shook the battery for 3 minutes at the test lab. Then, it's back to ORNL for another vacuum test to ensure the battery is not damaged. Next step is final assembly, starting June 4th.