Satellite launches are all the rage these days.
Every couple of months, a new group seems to announce its own fleet of satellites, whether that be SpaceX's Starlink, Amazon's Project Kuiper or OneWeb, all are competing to create a global internet network using thousands of satellites in low Earth orbit (between 300 to 1000km above Earth's surface).
But what does it take to actually build a satellite and get it into space?
The first step is to design your satellite and build a prototype of it, ensuring that it does everything it is meant to.
Once you have built your satellite, you need to make sure it will be able to survive in the harsh environment of space.
There are many factors that conspire to make the journey in space a difficult one. Because of this, before launching the satellite, it needs to go through a process of space testing and qualification, ensuring it will survive the trip to, and it's time orbiting, in space.
At the Australian National University, we host the National Space Testing Facility (NSTF), where companies and engineers from all over Australia come to test their satellites before launching them.
As described in the previous Sunday Space article "How cold is space exactly", a satellite in low Earth orbit will experience temperatures ranging from -150 degrees to 120 degrees every hour or so.
To make sure that your satellite can handle these temperatures, we must first conduct thermal cycling tests.
This is where we put the satellite in a big oven and change the temperature rapidly, making sure any electronics and materials are able to cope with the temperature change.
The temperature is not the only danger to consider - space is a vacuum, which means that there is next to no atmosphere or pressure.
While you may not consider this a problem for a lifeless, metallic box, the lack of pressure leads to a phenomenon known as outgassing.
This is where liquids such as glues or grease vaporise, possibly coating your cameras with gunk or, even worse, causing your satellite to fall apart.
To get around this, engineers use special glues and materials that minimise outgassing, while also baking the satellite at a very high temperature in a vacuum to ensure very little outgassing will happen up in space.
Space engineers also have to consider a variety of other effects, from cosmic radiation damaging the electronics of your satellite to checking that the communications will function all the way in space.
One last test is then done to make sure the satellite will survive the trip on a rocket.
At the NSTF, we strap the satellite to a machine called the shaker table, which like the name suggests, is a table that shakes.
It vibrates the satellite as it would while on the rocket. This machine is so violent, it needs to be located away from the building's foundations or else the building may be shaken apart and slide down Mount Stromlo.
Assuming the satellite passes all of the tests, it is then good to go for launch: simply put it in a rocket and eject the satellite into its desired orbit.
The path to satellite launch is a long one, fraught with danger, but it's all worth it to see your little creation orbiting as a tiny speck of light in the night sky!
- Jonah Hansen is a PhD student specialising in space interferometry at Mount Stromlo Observatory, at the Australian National University.