CSIRO, Space Machines to test Flexible Solar Panels in Space

Space Machines Company (SMC) who last year announced they would be Gilmour Spaces’ first customer to utilise Eris rocket have reported that they will deploy and test flexible solar cells that have been developed by Australia’s national science agency, CSIRO.  

SMC are obtaining the CSIRO technology so that the solar panels can be tested in space and will be deployed alongside more traditional solar panels so that their relative performance can be assessed. This payload will be alongside HEO Robotics’ “Potoroo” camera that SMC announced earlier this year. 

“This is a fantastic example of collaboration between a privately funded space company and a government agency to develop the Australian sovereign capability in space,” said Rajat Kulshrestha, CEO and Co-founder of SMC. 

“[We wanted to know] can we take their existing panels and flight test them in space and really understand how they perform across a number of situations and environments?”

Printable solar cells are usually less efficient than rigid versions but in the future, they could be an order of magnitude cheaper than traditional space-grade solar cells and exceptionally volume efficient. 

Although the initial test will use static printed cells that are fixed to the spacecraft's surface, the goal is to use solar films that are deployed with light and compact dispensers, which will minimise stowage volume on satellites.

Flexible solar panels are not a new idea, there have been many attempts at developing solar panels that can provide a flexible surface and efficiencies similar to traditional panels. However, what CSIRO are aiming to do is develop solar panels that are not only printed but also lightweight, thin and semi-transparent, bringing down the cost of solar panels using a low-cost manufacturing process.  

The panels already have an endless array of potential applications, due to their lightweight and flexibility including being made into fabrics for camping or sailing and emergency power deployment systems. The printable “solar inks” are deposited onto flexible plastic films that can then be connected to make solar panels of significant size and are ideal for places where traditional solar panels are too heavy or bulky. 

This will be the first time that CSIRO’s printed solar panels will have been tested in space. 

"We will collect data from this mission to explore new applications of our technology", said CSIRO Principal Research Scientist, Dr Mei Gao. "Solar films are about making solar energy more accessible, on Earth and in space." 

“We are flying traditional [solar panels], but we will be taking CSIRO panels as payloads to ensure that we can test them and actually also get a benchmark across existing performance compared to traditional solar panels. I think this will be great telemetry to get, to be able to then go to the next step and really start to work more closely in the future with CSIRO,” said Kulshrestha.

Developing Australian in-space solar technology is crucial for the country's sovereign space capability and the growth of the local space industry. Solar is the primary energy source in space, but space-graded rigid and foldable solar panels, the main alternatives today, are heavy and extremely expensive. CSIRO are hoping this new technology will reduce not only the cost of solar panels but also the barriers to entry for manufacturers, creating new job opportunities within Australia. 

“Solar panels, in general, are very expensive and they're hard to obtain because some of them are still under international regulatory regimes especially out of the US and so our view has been how to easily and cost-effectively access technology that allows us to put solar panels on our spacecraft.” 

“In addition, traditionally solar panels have been quite heavy, and so the Watts per kilo has been a real issue and also the volume that it takes up. Especially as rideshare becomes the way a lot of the satellites get into space.” 

“The envelopes are pretty tight in terms of volume, our view has been how do we get a very, very optimized mass volume power ratio to the way we generate power in space. So, part of that exploration was working together with CSIRO to understand the technology they're developing,” said Kulshrestha. 

CSIRO has developed the technology with funding from the Victorian State Government and the Australian Government through the Australian Renewable Energy Agency, and have been supported by a number of industry partners. It is hoped that this technology will lead to new solar manufacturing industry in Australia. 

In addition to the cost, the current space solar technology is dominated by countries with a well-developed space industry, such as the USA, China and a small group of European nations. This means Australian space companies depend on suppliers that are thousands of kilometres away and are largely committed to the demands of their local markets.  

“Especially now [with the challenges of COVID] it is important to have local supply chains and part of what we're trying to do with CSIRO is exactly that. Establish a supply chain that allows us to access a critical part of our spacecraft locally,” said Kulshrestha.

It is technologies like this that could really revolutionise the smallsat market, with Kulshrestha suggesting that this is one of many technologies that are currently being made smaller and cheaper. 

The current CubeSat market provides many off the shelf options that have reduced the barriers to entry, and Kulshrestha believes that is what is happening with the next segment up which is still dominated by larger companies with large budgets. 

“I think anything in the smallsat space still is very bespoke so it's very hard to acquire components that are cost-effective whilst delivering the performance you need to support larger satellites. Our view is that I think technologies like these really go a long way in starting to make such systems more accessible and cost-effective,” said Kulshrestha.

With the Optimus-1 launch planned for next year, SMC are ramping up the qualification and development of their vehicle systems but it is central to their business model that they support a local supply chain. 

“The only way we can establish a local supply chain and a pipeline of customers is to help companies get space qualified. That's been our objective from day one and so I think our view is that with this first flight the more technology, more Australian technology we can test, the faster the path to creating a healthy chain of suppliers, partners and customers that can work with us,” he concluded.