Students at Finland’s Aalto University are carefully piecing together their country’s first satellite.
The Aalto-1, a bit taller than a milk carton, will come in at around a tenth the cost of one of its larger counterparts. The miniature device, which only weighs 3kg, is an example of a nanosatellite, or nanosat, and is one of many being assembled right now in Europe.
But why are they suddenly taking off?
“Mainly because they circumvent one of the biggest impediments to space exploration: the launch cost,” said Antti Kestilä, a system engineer and doctoral student in Aalto University.
Conventional satellites are heavier and much larger than nanosats and more expensive to fire into space. “As a general rule of thumb, every 1kg of satellite adds €50,000 to the launch cost,” says Kestilä.
“All nations have a right to explore space but it’s been a privilege for rich countries so far,” said Jaan Praks, professor of space technology with Aalto.
As an example of how nanosatellites are opening up space research, the EU-funded project QB50, managed by the von Karman Institute for Fluid Dynamics in Belgium aims to launch a constellation of 50 nanosats up to a 400 kilometre altitude. This will allow the study of what researchers say is the least explored layer of the atmosphere.
With the nanosat, which was first developed in the late 90s by a Stanford University graduate, it is cheaper than ever to get to space. The final cost of Aalto’s sprite, which has been assembled over the last five years by a core team of 20 students, will be around €1 million.
Eventually, many expect nanosats will become affordable for science classes in secondary schools, or hobbyists who want to perform their own experiments in space, as they draw on constant improvements in price and performance being achieved by the consumer electronics industry.
What began as a tiny cardboard design now keeps students from five different departments in Aalto busy. “One company has spun out already; there will be more in the future,” said Kestilä.
In addition to Aalto, students from the University of Helsinki and the University of Turku, researchers from VTT Technical Research Centre and the Finnish Meteorological Institute and scientists from companies including Aboa Space Research Oy, a spin out from Turku University, and Oxford Instruments Analytical Oy, are all involved in the field.
Small satellite developers and manufacturers are springing up all around Europe. The best known is probably Surrey Satellite Technology, a spinoff of Surrey University, which is part of the European Airbus group.
Before November 2013, only 75 nanosats had ever been launched. This leapt to 170 launches in 2014, and more than 1,000 are projected to be spinning around low-Earth by 2020.
Size not a problem
The Aalto-1, due for launch sometime in the beginning of 2016, will carry out several conventional roles in space. It will carry a spectrometer instrument, which designers are calling novel due to its small size, a radiation detector and a solar sail.
The spectrometer was built and developed by VTT, and weighs only 500 grams. Despite being equipped with a tiny lens, it will be strong enough to pinpoint algae blooms and trees in the forests, said Tuomas Tikka, the project’s quality manager and a doctoral candidate with Aalto. This will allow the device to perform a role in tracking environmental conditions in seas and illegal tree-felling.
The second application will test a device invented by researchers at the Finnish Meteorological Institute. According to Praks, the tiny satellite will reel out a hair-thin 100 metre aluminium wire to create a “solar sail”. The theory goes that a stream of electrons and protons from the sun - the solar wind - will push on the sail, allowing the satellite to ride along without the need for any sort of fuel or propellant. If it works, scientists on the ground will learn that space missions can be run at an even lower cost.
A third application will study fluxes in space radiation caused by the interaction of the earth's magnetic field with charged particles from the sun.
All this means Aalto-1, “can comfortably outperform Sputnik”, the first man-made satellite launched by Russia in 1957, said Praks.
Admittedly however, there are some limitations to a device 30cm in height. “Common sense says the smaller you go, the more you limit your applications in a way,” said Kestilä.
Beaming a television or GPS signal down to earth is beyond these tiny gadgets. Propulsion also remains an issue. While satellites have rockets to keep them in position, nanosats do not.Second and third satellites
Aalto-1 is being held up by problems with the launch. The university has a contract with SpaceX, the private US spaceflight company founded by Elon Musk, which has experienced trouble with its Falcon 9 rocket. The company had a run of 17 successful launches with the Falcon until 28 June, when its rocket disintegrated shortly after lift-off.
Not that Praks is too worried. “In the space business, delays aren’t uncommon,” he shrugs.
A third nanosat, Finland 100, is planned for 2017, to mark the centenary of Finnish independence. Again, it will be built by students and will contain cameras and a radio receiver that will record images of the earth, space, the Aurora Borealis, and Finland.
Of course all these nanosats could mean an increase in the volume of space junk – floating debris that can pose a collision hazard to other satellites.
“There’s a rule which says satellites have to come back to Earth after 25 years. The likely lifecycle of the nanosat is 2-5 years, so it shouldn’t be a big problem,” said Tikka. With nanosats operating in low-Earth orbit, they burn up on re-entry after a year or so anyway, he added.