Ground Control

What is Ground Control?

Ground Control is the team that deals with testing data acquisition systems (aka DAQ), testing hardware, and any non-flight related electronics/hardware needed for SRL’s projects. Similar to Avionics, Ground Control is interested in creating robust, functional products that are easy to use and provide exactly what is needed for initial, intermediate, and final design testing. Be it thrust data, temperature sensing capabilities, chamber pressure measurements, and/or live-feed UIs for complicated processes, Ground Control’s work focuses on getting other teams the data they need to continue their groundbreaking engineering endeavors.

The Current System

Ground Control’s current DAQ consists of an Arduino Mega, an SD card shield, a custom PCB, 2 ADS1115 ADC boards, an HX711 load cell amplifier, and an ADC board made up of 2 MCP3428 chips. These components work in tandem across I2C and SPI channels to collect data from up to 8 pressure transducers, 6 thermocouples, and a load cell, which is then stored on the SD card via the SD card shield and displayed on a laptop screen via the Arduino IDE’s built in Serial Monitor. While this system works well for solid rocket motor tests, liquid engine tests require quite a bit more instrumentation and a much more “adrenaline-friendly” UI. Aside from pressure transducers, thermocouples, and a load cell, the liquid engine DAQ must also be capable of driving a number of servos that can open and close fluid valves. On top of that, this system is limited to a sample rate of about 10 Hz, which is not quite enough to see all the important aspects of a static fire. Therefore, we are currently developing a Raspberry Pi solution that can handle all of the liquid engine instrumentation and control requirements while providing an easy-to-interpret GUI through Tkinter, Python’s built-in GUI creation tool, and a sample rate of at or above 50 Hz. If you’re interested in helping out in this endeavor, feel free to join us!

Ground Control’s History

While Ground Control is a relatively new team, SRL has been doing data acquisition since its inception. From simply setting out a laptop covered by a cardboard box to radio controlled ignition systems, SRL’s DAQ solutions have seen numerous different forms. However, with the prospect of more complicated systems such as liquid engine turbopumps and gas generators, it quickly became apparent that these one-off solutions wouldn’t be able to cut it. Hence, it was determined that all DAQ development should be consolidated under one team, and Ground Control was born!