Prisma’s role is one of providing Swedish companies with an opportunity to present themselves within a high profile project. As a result the project can pave the way for other, international commissions. Prisma and Nanospace are therefore made for each other.
 
One of the many innovative companies involved in the Prisma-project is the Uppsala-based Nanospace. They manufacture, as the name suggests, tiny components for aerospace use. With Prisma, Nanospace will test a complete miniaturised attitude control system. It is this type of system that ensures that satellites are correctly oriented in space so that they don’t point in the wrong direction.
 
Prisma has given the Swedish Space Corporation, Sweden and Nanospace a leading role within miniaturised propulsion systems.
 
”Our technology is completely unique within Europe”, says Tor-Arne Grönland, managing director for Nanospace. 
 
Importance of a first flight
Regarding Prisma and the technology the project will demonstrate, attitude control involves even the maintenance of sub-satellites in exactly the correct formation. In this instance Nanospace are not responsible for the alignment control of Prisma itself, but have instead an experimental site for testing their innovative system.
 
”This gives us the opportunity of carrying out our desired experiments and tests without the system being at the same time critical for the mission”, says Tor-Arne Grönland.
 
Nanospace’s status as experimental on Prisma is one way of circumventing a chicken-and-egg problem within aerospace technology.
 
“When competing for a commission it is of enormous advantage to have flown with one’s system”, informs Tor-Arne Grönland. “Therefore it is difficult to secure a commission before a system has flown for the first time”.

This is why Prisma is such a unique opportunity for Nanospace.

"The Swedish National Space Board has the courage"
To offer this type of possibility is one of the main aims of Prisma.
”It is fantastic that The Swedish National Space Board has had the courage and the strength to initiate its own satellite project of this variety, which gives Sweden and Swedish companies the opportunity of presenting new technologies and demonstrating that we can cope with advanced formation flight”, says Tor-Arne Grönland.
 
Even for the Swedish Space Corporation this is a unique opportunity. They have the chance to show that they can take the responsibility for and run a complicated satellite project with contributions from a number of countries.
 
”It demonstrates the worth of being willing to venture at the national level”.
 
Interest from ESA is continually increasing
The European Space Agency, ESA, was not involved in the project at the beginning. ESA has its own similar project, Proba-3, and wanted to concentrate on that.
 
”Prisma is at a more advanced stage than Proba-3 so ESA are naturally incredibly interested”, says Tor-Arne Grönland.
 
Nanospace are happy about Prisma’s advantage, as ESA is a potentially huge customer. The organisation is involved, amongst other things, in the planning stages of the space telescope Darwin, which will search for planets around other suns and for life on these planets. Darwin will be comprised of several large mirror telescopes that, using the interferometer principle, can function as one telescope with a resolution equating to the distance between the mirrors being the diameter of the mirror.
 
For this to function however, these must fly in an extremely exact formation. It is here that the Nanospace micro-motor may come in.
 
Hundreds of process steps
The Nanospace mini-motor doesn’t look like much. It is a golf ball-sized metal sphere on a metal pedestal. If one looks closely enough at the sphere however, there are small holes there. Four of them to be exact, one at each cardinal point. Behind these holes sits a barely millimetre sized rocket thruster-nozzle, and in the inside of the sphere there are four very tiny combustion chambers. There are there also valves and additional support equipment for the rocket motors.
 
The hearts of the spheres are six precision manufactured silicon discs.
 
“Each silicon disc involves several hundred process steps where we pattern, coat and etch”, says Tor-Arne Grönland. “It is difficult and expensive and we have ten or so patents on the process”.
 
When these discs are then brought together you get all of the functionality – valves, filters, heaters, combustion chambers and thruster-nozzles. There then remains the problem of the interface with the rest of the world and getting the motors to work in a system.
There are no possibilities for testing parts of the system during manufacture. If a part doesn’t function after assembly there is no option but to start from the beginning again. It is another one of the major challenges with this type of system.

Before and after Prisma
For Nanospace there is an era before Prisma and one after. After Prisma the market is wide open.
 
“Then it is much easier to choose our technology”, says Tor-Arne Grönland and laughs. “Until then we will expand at a moderate pace and oversee our technology development and process development”.
 
Although the attitude control and micro-propulsion system is the first Nanospace system to be released, Tor-Arne Grönland believes that they have other products that can be even greater. The xenon-measurement system for satellites with electrical ion-motors belongs to this category, something that will probably continue to become more common. Even here Sweden lies in the absolute front line with the technology demonstrator SMART-1, which became the first European satellite to reach the moon. There is even an extensive market for the tank measurement system that Nanospace are working on, as well as valves and sensors. The applications are not either limited to aerospace, but can be found also in other areas.
 
Nanospace has its origin within the Ångström Space Technology Centre at Uppsala University. Now it is a fully owned subsidiary of the Swedish Space Corporation.

Kim Bergström
November 2007

Images: © NanoSpace

Read more about NanoSpace on www.nanospace.se