Inside the Institute for Manufacturing at Cambridge: A revolution in space propulsion
As part of our series of articles exploring the Institute for Manufacturing - part of the University of Cambridge’s Department of Engineering - we talk to Nadeem Gabbani inside its Centre for Industrial Photonics.
PhD student Nadeem Gabbani works in the IfM’s Centre for Industrial Photonics, directed by Prof Bill O’Neill.
“We deal with lots of laser-based or laser-assisted processes,” he explains. “We are very industry-focused. If we can’t find a real-life application for the technology, it’s probably not worth doing.”
Useful in precision manufacturing and advanced materials processing, photonics has applications across multiple industries, from aerospace and transport to electronics and communications.
“We have some of the most precise laser machine platforms in the world, which are very versatile,” continues Nadeem. “We have lasers that are pulsed, which are special because you can perform lots of interesting processes like machining materials without damaging them.
“The cool thing about pulse lasers is that while they only have an average power of about 30 watts, all that energy is compressed into that picosecond pulse, so the peak power if very high. So you can remove material very efficiently, or machine large areas very quickly.”
Explaining how the IfM’s most advanced laser platform operates, he adds: “This has some diagnostic tools that go in-line with the machining process.
“We have microscopes, we have optical coherence tomography, so you can get a picture of the layers or surface that we are machining.
“We also have a Raman spectrometer that looks at the signature of the emission from the laser process. Often you can use this fingerprint to see if it has gone right or wrong.
“The idea here is we incorporate this into a big feedback and control system so we can process faster and more precisely than any other machine in the world.
“What we are trying to compete with is photolithography – the kind of process where they pattern silicon wafers. That is a very expensive and time-consuming process. If we can do it with a laser like this, we can save the industry a lot of money.”
Ongoing PhD projects include work on super-conducting materials that do not require quite such a low temperature as usual, and high-frequency terahertz devices that can be used for communications.
Another student is using a pulse laser to machine away thousands of ultra thin layers of a seed, and taking an image each time, building up a unique picture for biological applications.
Most striking of all is a project in which Nadeem is heavily involved.
“I come from a space propulsion background and there are a number of space activities going on in the IfM. We have formed a new research group,” he explains. “We have applied for a launch for a satellite.”
In February, the group hopes to launch a class of nano-satellite called a CubeSat.
“It weighs about 3kg and is the size of a shoebox,” says Nadeem. “There has been a huge explosion in the small satellite industry. People use them with consumer electronics.It makes them as capable as much bigger, more expensive satellites.
“For this mission we are going to be working on a novel type of propulsion system that another PhD student is working on. If it works, it’s going to revolutionise the space industry because of how efficient it is and how scalable it is.”
The group still needs another £26,000 towards the £250,000 cost of the launch, which will send the CubeSat into a low orbit at about 300km, on a nearly pole-to-pole, or Sun-synchronous path.
“A lot of people do Earth observations, or track ships or aircraft. They’ve been doing that in swarms,” says Nadeem.
“Instead of spending £20million-£40million on a single large satellite, you could have a whole fleet of these. This would cost something in the order of hundreds of thousands of pounds per spacecraft – certainly under £1million – and we can get ground resolution of a couple of metres.
“We have deployable panels that stabilises it as we come out of the deployer and increases the drag. The mission is going to be two to four weeks, which is very short. That helps us with the licensing and registration.”