Australia has just flown its own ‘vomit comet’. It’s a big deal for space research without gravity

Last Saturday, a two-seater SIAI-Marchetti S.211 jet took off from Essendon Fields Airport in Melbourne with an expert aerobatic pilot at the checkpoint and a suitcase full of scientific experiments in the passenger seat.

Pilot Steve Gale took the jet on Australia’s first commercial “parabolic flight”, where the plane flies along the path of a free-falling object, creating a brief period of weightlessness for everyone and everything inside.

Satellite flights are often a test run for space zero-gravity conditions. This was operated by the Australian space company Beings Systems, which plans to run regular commercial flights in the coming years.

As Australia’s space program begins to take off, flights like these will be in high demand.

What was on the plane?

The experiments on board the flight were small packages developed by space science students at RMIT University. As a program manager for RMIT’s space science degree, I have been teaching these students for the past three years and preparing them for a career in the Australian space industry.

The experiments investigate the effect of zero gravity on plant growth, crystal growth, heat transfer, particle agglomeration, foam and magnetism.

RMIT University science payload designed for satellite dish flying.
Gail Iles

Scientific phenomena behave differently in zero gravity than in laboratories on Earth. This is important for two main reasons.

First, zero gravity, or “microgravity”, provides a very “pure” environment to perform experiments in. By removing gravity from the system, we can study a phenomenon in a more “pure” state and thus understand it better.

Second, micro-gravity platforms such as satellite dishes, probe rockets and fall towers provide testing facilities for equipment and science before being sent into space.

Read more: To create a niche in the space industry, Australia should focus on microgravity research rockets

Lab on a plane: a mini ISS

Last Saturday’s flight was a success, with the six experiments recording a series of data and images.

The plant experiment observed broccoli seedlings throughout the flight and found no adverse reactions to hyper- or micro-gravity.

Another experiment formed a crystal of sodium acetate trihydrate in microgravity, which grew much larger than its counterpart on earth.

Insulin crystals grown at standard gravity (left) are smaller than those grown at micro gravity (right).

The largest zero-gravity laboratory is, of course, the International Space Station (ISS), where studies of plant growth, crystal growth, and physical scientific phenomena are common. At any given time, 300 experiments are taking place on the ISS.

It is not easy to transform an experiment on the bench into an independent scientific payload for space. Each one must be thoroughly tested before launch to ensure that it will work when it gets there, using satellite dishes or other test platforms.

Go ‘zero-g’

There is a common misconception that you have to go out into space to experience microgravity. In fact, it is the state of free fall that makes things seem weightless, and which can also be experienced here on Earth.

If you throw a ball to a friend, it tracks an arc as it flies through the air. From the moment it leaves your hand, it is in free fall – yes, even on the way up – and it’s exactly the same arc that the plane flies. Instead of a hand, it has an engine that gives it the “push” it needs to travel and fall through the air, and track a parabolic arc as it goes.

Diagram showing the speed, acceleration and direction of flight of an aircraft in parabolic flight.
The flight path during the parabolic maneuver.
Van Ombergen et al., Scientific Reports (2017)

Even the International Space Station experiences the same free fall as the ball or plane. The only difference for the ISS is that it has enough speed to “miss the ground” and move forward. The combination of forward velocity and pull toward Earth keeps it going in circles and orbiting the planet.

Human spaceflight

Satellite flights in the United States and Europe take place every two or three months. On the flights, scientists perform science, companies test technologies, and astronauts receive training in preparation for spaceflight missions.

As a researcher at the European Space Agency and former astronaut instructor, I am a veteran of five parabolic campaigns in Europe. I have completed over 500 parabolas on board the Novespace Airbus A300.

Although I have never been sick on these flights, up to 25% of people on board throw up under zero-g conditions. This is why they are sometimes called “break meters”.

Why now?

So why does Australia just suddenly need satellite dishes? Since the Australian Space Agency was established in 2018, several space projects have received support, including a lunar spacecraft, four Earth observation satellites and a space suit.

For these projects to succeed, all their various systems and components must be tested. This is where satellite flights come in.

The plane flies over Melbourne (top left), with students (bottom left) and getting ready for flight (right).
Being systems

As demand increases, so will Australian aircraft. Beings Systems plans to offer a larger aircraft – such as a Lear jet – by 2023, so scientists and companies can test their equipment, large and small, without leaving the country.

In addition to reading intriguing scientific articles on the latest phenomena observed in micro-gravity, we will begin to see footage of satellites testing the insertion of their antennas and people taking and taking space suits aboard satellite flights.

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