Sending a satellite balloon in to the stratosphere

text text SCIENCE AND TECHNOLOGY

A 1.6kg helium filled balloon which soared 36km above Mount Barker to the edge of space, has returned to Earth with a payload of thousands of images capturing the agricultural landscape below and the curvature of the planet itself.

The successful balloon launch was the culmination of intense team work undertaken by 31 students participating in this year’s Southern Hemisphere Summer Space Programme (SHSSP), which UniSA is hosting in partnership with the International Space University (ISU).

Over the course of a single week students split into teams charged with specific tasks including the design and building of the balloon’s payloads, the tracking of its telemetry during flight, the recovery of payloads after its descent and the analysis of what data was collected.

Launch day was attended by the Mayor of Mount Barker, Ann Ferguson, and presided over by former NASA Chief Exploration Scientist and ISU SHSSP director John Connolly, who welcomed and spoke to assembled onlookers about the purpose of the venture, thanking sponsors of the project.

At 9.30am air traffic was diverted away from the Murray Bridge region, leaving only a patch of cirrocumulus clouds peppering the skyline as a ten second countdown gave way to the balloon’s release. It ascended at a speed of 5 metres per second until it reached the Earth’s stratosphere and its target altitude of around 36,000 metres – four times the height of Mt Everest.

As atmospheric pressure increased the balloon burst, bringing the satellite payload back to Earth at an area 96km away from the launch site.

Infra-red images of local South Australian agricultural areas.Student Bruce Clarke, who was responsible for the build and design of the camera payload attached to the balloon, explained that the purpose of the project was to collect and analyse visible and near infra-red images of local South Australian agricultural areas, to develop a greater understanding of the health of crops in the area.

“We used a Raspberry Pi computer – it’s a small inexpensive computer, a versatile bit of technology often used for hobby electronics that you can hook up to a monitor, which we did and we programmed it to take pictures,” Bruce says.

With two cameras facing down and a camera attached to the side of the payload, more than 8000 images were captured and stored on a USB drive during the balloon’s flight, as well as video footage of the journey.

“Pictures were taken in near infra-red and we can compare them with frames from the video footage which helps us determine how green certain crops in the region are – this tells us about the level of chlorophyll in the plants and how healthy they are,” Bruce says.

“It is technology that could equally be applied by small agricultural-based communities in more remote parts of the world; enabling them to have some way to monitor the growth of their crops and determine which areas need greater maintenance.”

View of space.Student Lisa Stojanovski, who led the video production team, was also part of the recovery group who travelled through mallee scrub to retrieve the payload after the balloon came down to earth.

“We did a live webcast of the balloon launch and filmed the project as it developed,” Lisa said.

“It’s important to have documentation of the whole process and it serves as a template for anyone wants to do this kind of project in future. Our team had a week to do this and we worked hard to get it done but it shows what can be achieved by working collaboratively.”

“The launch was amazing – it went without a hitch and knowing the balloon had been 36km up in the air and then seeing it back on the ground was kind of like seeing an old friend again, it was a joyful experience.”

Program Co-Director, Michael Davis, congratulated the team following their success.

“This is a great illustration of how a group of enthusiastic participants from diverse backgrounds and cultures can work together to design and test a new solution to a global problem.”

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