Machining for space applications21st Nov 2022
Satellites, and all components that are destined for space travel, experience a unique set of conditions that necessitate careful design and manufacture.
Components of a satellite and indeed all components for space are exposed to cosmic and solar radiation and extreme temperatures. They have to be lightweight, yet durable, and of course, it’s not possible to nip up into space and do a quick repair. They must not fail.
The satellite itself, be it a conventional, large satellite or a nanosatellite (aka CubeSat), will house a payload of high-end electronics, a power system and a communication link back to earth. CubeSats offer the benefit of being highly modular, from 1U (single unit CubeSats) right up to 6U (six units joined together), and have a much lower launch cost – they are designed so that they can ‘piggyback’ securely into a larger launch vehicle, via a dispenser.
How to design a CubeSat
If you’re designing a CubeSat or some other component that will be rocketing into space, there are some very important manufacturing decisions that you should take into account.
One of the most important points is that it must conform to the standards of the dispenser, ensuring that it will fit securely and can be cleanly released into space at the right time. Therefore, when it comes to design and manufacture, tight tolerances are crucial.
Another critical consideration is choosing a suitably space-resistant material.
What material is best for components going into space?
It’s a big ask for a material to be radiation-proof, vacuum-proof, able to operate in extreme temperatures (both very cold and very hot), as well as offering exceptional robustness, and weighing as little as possible. But all of this is crucial for a CubeSat frame and other machined components for space.
Mostly, components for space are manufactured out of aluminium 7075, 6082T6, various grades of titanium (often Ti-6Al-4V or Grade 5), or ceramics. All of these materials offer a good balance between strength and weight.
So which one should you choose? It is important to be aware that there can be issues with ceramics giving off toxic dust when machined, so finding a machining company for ceramic components may be more challenging. It is possible to machine ceramics safely, but it requires specialist processes and equipment.
A note about aluminium 6061
If you’re looking online about space-resistant materials, you will also see reference to aluminium 6061 being used for components for space applications. Aluminium 6061 is an American-wrought grade of aluminium which has similar properties to aluminium 6082. In the UK, 6061 can be hard to source and expensive. We recommend using aluminium 6082 as a more cost-effective and readily available alternative in the UK, with no compromise on performance.
Coatings for space components
It’s not just the material that helps to make a component suitable for space. In many instances a component for space can be made better, or more suitable, by adding some kind of protective coating. For example, coating or plating a component makes it possible to improve conductivity, manage temperature fluctuations or resist corrosion. Often a component will have multiple finishing processes applied to it to make it suitable for space missions.
For example, many componets are hard clear anodised. Clear anodising gives a champagne colour to this grade of aluminium. The hard anodising also provides a protective, corrosion-proof outer to the components. However, anodising is a dip process – the components are dipped into an acid electrolyte solution – which means that specific areas of the component can’t be easily masked or left un-anodised.
Therefore, to allow for any necessary electrical conductivity and to ensure that a FIP gasket (form-in-place gasket) can be applied, components are machined again post-anodising. A final layer may then be applied, such as an iridite coating. This is a very thin, invisible film which provides further corrosion protection without impacting the seal of a FIP gasket.
For more information about different finishing processes, take a look here.
If you are designing a CubeSat or any space applications or components and need to find a reliable machining partner with extensive experience in this highly demanding industry, get in touch with one of our estimators today to discuss your project.