HYPSO-2 satellite monitors harmful algae from space

It’s slightly larger than a 5-liter water bottle, and is whizzing around the Earth at a speed of 7.5 kilometers per second. The satellite has two cameras built into its body, and can be controlled quickly and turned smoothly in all directions.

HYPSO-2 has a special job, monitoring algae. Large algae blooms can cause major damage, poison drinking water and mass fish deaths.

“The new satellite means about a 10-fold increase in the capacity to monitor water quality, algae blooms, and other important ocean phenomena,” says Bjørn Egil Asbjørnslett, a professor and director of NTNU’s Ocean and Coast strategic research area.

“Another advantage of letting satellites capture data is that it means less emissions into the sea from research ships and other marine vessels,” he said.

One of HYPSO-2’s cameras is hyperspectral. That means that it can detect 120 shades of color in visible light. In comparison, our eyes and a regular camera only see a mixture of red, green and blue. This allows the small satellite to obtain very detailed images. One image taken from the sky can cover as much as 25,000 square kilometers on Earth.

“NTNU’s small satellites mean many new things for us,” says Geir Johnsen, a professor at NTNU’s Department of Biology.

“The fact that we can now determine exactly where they can make observations is completely new, and worth their weight in gold. Since the satellites can pass over the same fjord up to three times in the same day, we can plan our surveys much more thoroughly. If we are in the Arctic, for example, we have information about whether there is sea ice in the fjord or not,” says Johnsen.

Johnsen has been involved with the NTNU AMOS (Center for Autonomous Marine Operations and Systems) initiative on what is called an observation pyramid. In Svalbard, the researchers tested how one area could be mapped by connecting simultaneous data from a small satellite, a drone, and unmanned vessels on and under water.

Two satellites = ten times as much data

HYPSO-2 gives researchers sharper images than HYPSO-1.

“In addition, we can now use both satellites and obtain up to 10 times as much data. This is valuable,” Johnsen said.

The researchers have used HYPSO-1 to see the quality of sea ice in fjords, whether it is frozen, has snow on top and whether it is breaking up. Johnsen says this helps them to assess details in operations, what kind of boats they need, whether they can use snowmobiles, and so on.

“Better quality of the images also means that we can discover several new things of interest. Such as plankton algae, organic material and turbid water from river runoff, flood-sized rivers and glacial rivers. This gives us a lot of information about processes related to climate,” Johnsen said.

On August 16 this year, HYPSO-2 and just over a hundred other small satellites hitchhiked into space with Elon Musk’s Falcon 9 rocket.

At NTNU, the ground crew, composed of researcher Roger Birkeland, and Ph.D. student and operations manager Simen Berg, watched with their hearts in their throats.

You can see the launch from SpaceX here: HYPSO-2 leaves the rocket at 2:31:36.

In the evening, just under half an hour after the satellite was placed in orbit, they made contact. The researchers could hardly believe it was true that it went so quickly and painlessly.

“We got a great hyperspectral image already in the test. And the quality of the images continues to be great,” Berg said.

Early in November, the test phase ended, and NTNU took over the operation of HYPSO-2.

Now the low-orbit satellite is now in full swing with its five-year working day.

So far, everything is going well, according to Birkeland and Berg.

Berg checks HYPSO-2’s telemetry (i.e., automatic transmission of scientific data or other measurable variables over large distances using telecommunications), or health data, several times a day. This includes checking the battery level, that the satellite stays warm enough, is pointing in the right direction, and takes the images it’s told to.

And its health is good. HYPSO-2 seems full of energy and enthusiasm for work.

This is the second small satellite designed and built by researchers, master’s and doctoral students at NTNU. It’s big sister, HYPSO-1, was launched in January 2022, as one of the first hyperspectral satellites in the world.

The two small satellites are Norway’s only pure research satellites.

At the time of writing, HYPSO-2 is at an altitude of approximately 580 kilometers and passes over the North Pole 14 times a day. Several thousand satellites orbit the Earth, so NTNU’s small satellites are not alone in sending great snapshots home.

“But they have many advantages,” Birkeland said.

They can deliver images and fill information gaps in observations from other satellites. They can contribute to extra-efficient ocean monitoring through the observation pyramid, in interaction with other sensor systems. When something suddenly happens, the researchers can adjust the camera angles and quickly download images. It takes less than half a second from when they give a command to when the satellite listens.

After HYPSO-1 and 2, which are aimed primarily at ocean research, HYPSO-3, which is under construction, will follow.

With it comes the big win, Birkeland and Berg said. The satellite will get a more powerful computer, more instruments, and probably more cameras. It will see even more details, and will especially focus on lakes, rivers and waterways.

A prototype of the instruments could be ready in the spring of 2025. The road ahead is all about money. Berg and Birkeland believe HYPSO-3, at best, will be ready in two to three years.

Norway has great ambitions for small satellites and NTNU would like to help the business community gain a position in the rapidly growing space industry. According to Birkeland, Norwegian players have long been content to be subcontractors to large, international projects. Now he sees that more are trying to run projects on their own.

“We at NTNU are trying to figure out how we fit in with these players. The most obvious thing is that our students can go into jobs in this industry. But we are also trying to find out how we can collaborate more with the industry on research that drives technology forward,” Birkeland said.