2021 SPACEPORT AMERICA CUP: SPACE DYNAMICS LABORATORY PAYLOAD CHALLENGE

Monash High Powered Rocketry (HPR) is a young team of students who aim to contribute to the development of the space industry in Australia and enable our members to become space engineering pioneers. We achieve this by developing sounding rockets capable of delivering scientific payloads to accurate altitudes as high as 30,000 feet. Through rigorous engineering development cycles, we design and manufacture each component that we fly! We compete in local and international competitions, and this year was our first entry in the Spaceport America Cup, the largest collegiate rocketry competition in the world, usually held at the Spaceport America Vertical Launch Area in the New Mexico desert. This year the competition continued in a virtual format, nevertheless, Monash HPR achieved outstanding results! 

Monash HPR members (L-R) Isaac Sims, Bryan Birchler, Callen Hardie and Rebecca Freeman presenting in the Space Dynamics Laboratory Payload Challenge (at 2 am Melbourne time!).

An overview of the payload and its position in the rocket

As part of the competition, teams are encouraged to develop scientifically interesting payloads to be flown in our rockets. The Space Dynamics Laboratory Payload Challenge offers prizes for such payloads, where scoring is based on the team's technical objectives, craftsmanship and operation. Due to the virtual nature of the competition, each team submitted a written application and the top ten payloads were selected to present their work at the competition’s conference sessions. Monash HPR was chosen for our Artificial Neurovestibular System experiment (a simulation of the inner ear) that would fly onboard our rocket, Project Icarus, to 10,000 feet. If you would like to find out more, the recordings of the competition can be found on the Experimental Sounding Rocket Association’s YouTube channel.

Otoliths and hair cells of the human neurovestibular system, on earth the accurate detection of our location in space relies on the force of gravity on these hairs, hence when humans are exposed to low gravitational fields our brain becomes confused as the signals it detects from the hairs is inconsistent with information from visual and kinesthetic cues (image retrieved from here).

Our payload has three main objectives that we hope to achieve. Firstly the payload will carry our novel neurovestibular system experiment and gather information about how humans perceive space flight. A second objective is to collect flight data, including both inertial and atmospheric measurements, allowing us to understand the conditions of rocket flight. Finally, this payload is our first that will be deployed from the rocket, meaning that it will return on its own separate parachute, using our student developed mechanical release system. This project allows us to explore a longer experimental time and expand our capabilities for future missions where exposure to the free airstream is advantageous.

The neurovestibular system is a series of structures within your inner ear that play an important role in determining our orientation and location in space. Paired with our visual and motor systems, we can accurately sense where and how our body is moving on earth. However, spaceflight exposes the human body to unique conditions mainly, high accelerations (or high G-forces) and low accelerations, including periods of microgravity. This can alter the body's neurosensory inputs, leading to severe disorientation, reduced coordination and difficulty processing information, all of which are crucial for a flight crew's optimal performance. This space motion sickness needs to be considered as more humans begin to access parabolic flight to ensure a comfortable and safe journey.

The Payload team is developing a functional prototype of the neurovestibular system, which aims to model this disorientation using a representation of the biological system. The team has chosen to use spring steel ‘hairs’ that are suspended in silicone gels. Each hair will have a pair of strain gauges that will measure how much each hair deflects during the flight. Through a series of physical tests and simulations, we can correlate the deflection of the hairs to the acceleration they are exposed to. Post flight, we can compare the deflection data to accelerometers on the payload and where there is a difference between the ‘perceived’ and actual acceleration, we suggest these are likely periods of disorientation for humans during flight.

We have developed customised circuit boards that take inputs from several accelerometers, gyroscopes, magnetometers, barometers and temperature sensors and collate this data for post flight analysis. The aptly named “Sensor Stack” has been vital for our Dynamics team to help verify their custom trajectory simulator SATURN, which was awarded first place in the Charles Hoult Award for Modelling and Simulation at the competition this year.

Some of the payload teams in-house developed electronics that collects flight data and atmospheric conditions

Our mechanical release gives us a unique competitive advantage by allowing the payload to descend under its own parachute, separately from the rocket. The main advantage of separating the payload from the rest of the rocket is that we are able to obtain more data with a longer descent time. The release consists of aluminium claws that lock into a ring attached to the bulkhead of the rocket. Following an event to separate the nose cone, the payload can undo the locking mechanism and fall away from the rocket. The release also allows for the easy installation of the payload into the rocket!

This is one of the many interdisciplinary projects that the Payload team at Monash HPR work on, other projects include modelling high g-force loading on the spine and determining the skin friction on the airframe during transonic flight. Our members work across mechanical, electrical, software and experimental design, while developing connections and strong transferable skills to take into future career opportunities.

Troubleshooting - it's a team effort!

Inspecting the integration of the payload in the body tube, pop the nose cone on top and she’s ready to fly!