Amateur astronomers listen to Iranian satellites

The US military wants to dismiss the launch of the first Iranian military satellite as a trivial matter. This is nothing but a „tumbling webcam in space“, said a general. But amateur astronomers speak of a success.

Robert Simmon has already been quite stunned once in his life. That was in the summer of 2007, when the then Nasa employee had just bought his first iPhone. On the lock screen he saw a view he knew very well: It was a visualization of Earth that he had created as part of his job at the U.S. Space Agency.

The picture was called „Blue marble“ and was a bit too beautiful to be real. That’s how he recognized it. Simmons’s work was funded by U.S. tax dollars, so anyone can use the material for free. Until today. Apple hasn’t paid a cent despite millions of uses.

„Never expected that a picture of me would grace the tip of an Iranian missile“
Last week brought a similarly big surprise for Simmon, who now works for satellite operator Planet: When the Iranian Revolutionary Guards launched a rocket into space on Wednesday from the Shahud launch site, a logo was clearly visible on it. It showed the satellite „only“ on board, i.e. light, with an image of the Earth in the background.

It was a work that Simmon once again knew well: „When I started with remote sensing and data visualization, I never expected that an image of me would adorn the tip of an Iranian rocket.“

As of last Wednesday, „Only“ is now orbiting the Earth, the first Iranian military satellite It’s listed in the US Sky Catalogue under the number 45529. For the regime in Tehran, which is currently struggling with a particularly severe corona eruption, it is a prestigious success. The USA, on the other hand, is trying to talk the matter down. „It’s a tumbling webcam in space; it’s unlikely to provide information,“ said Jay Raymond, the responsible general of the U.S. Space Force.

Marco Langbroek is one of the people who sees things a little differently. The archaeologist and amateur astronomer regularly looks out for interesting things in the sky from his home in Leiden, Netherlands. Even an asteroid is named after him. The stargazer regularly observes secret spy satellites and takes high-resolution photos of space capsules. Immediately before the telephone call with the SPIEGEL on Monday morning, as he says, he has just taken another photo of the International Space Station from the ground.

„There is nothing staggering about it. The launch was a success.“
Marco Langbroek, Dutch amateur astronomer
On Sunday, says Langbroek, he also registered interesting radio pulses. He was sure that they came from the Iranian „only“ satellite. „It emits a strong signal at a frequency of 401.5 megahertz, which can be detected even with relatively simple technology.“ Every ten seconds the missile, whose orbit is known, sends a data packet to Earth.

If you take a closer look at the information from the satellite, says Langbroek, there is no evidence that it is rolling disoriented through space. No matter what the Americans claimed: „We don’t see any variations in the signal, there’s nothing staggering. The launch was a success.“

But there is one important question that the amateur astronomer is not yet able to answer: What is „only“ doing in its orbit at an altitude of 430 kilometers? After the launch, the Iranians declared that it was a „multifunctional satellite“. The assumption is that it has a camera on board, but there is no hard evidence of this.

Apparently commercially available components were used.
The satellite passes the same point on the ground about every four days, says Langbroek, but not always at the same position of the sun. The different lighting conditions in each case could therefore make it difficult to compare the images taken. The inclination of the orbit reveals that „only“ the earth is flown over between 60 degrees north and 60 degrees south.

According to Langbroek, there are about 20 degrees of latitude between the individual satellite orbits; at the equator this corresponds to a distance of 2220 kilometres. It is possible that he will send the data he has collected over Iranian territory to Earth. There is a ground station in the city of Tabriz, among other places.

US amateur astronomers explained over the weekend that they could even decode the telemetry data from the Iranian satellite. According to them, the Iranians had used commercial components for so-called cubesats for the construction. These are comparatively inexpensive mini-satellites, which are particularly popular in the higher education sector. However, commercial providers also use the technology to make money by marketing satellite data.

There is no question that „only“ is a comparatively small satellite. According to US General Raymond, it would be about 34 by 10 by 10 centimetres. However, US astronomer Jonathan McDowell of the Harvard-Smithsonian Center for Astrophysics considers it twice as large, i.e. 34 by 22 by 10 centimeters. This is the size that can be reconstructed from the logo on the rocket, for which Simmons‘ picture was also used.

Using an optical telescope, amateur astronomer Langbroek says he has already been able to observe the Iranians‘ third rocket stage as a bright spot in the night sky. He has not yet seen the satellite itself. But he believes it is possible that he will be able to do so.

Rocket is strategically more important than the satellite
The fact that the satellite is so small does not say much about its possible applications, says the Dutchman. „Even if it contains only simple technology, it can easily be adapted to its tasks.“ If you just want to take pictures, a device of this size is sufficient. „A lot of countries do interesting things with simple technology,“ concludes Langbroek.

Anyway, the strategic significance of Wednesday’s launch is probably more to do with the rocket. The new development of the Revolutionary Guards is based on a first stage with liquid propulsion, which can be traced back to a North Korean „Nodong“ type rocket. The upper stages, on the other hand, are powered by solid fuel. The Iranian paramilitaries declared that they were working on models completely equipped with solid fuel propulsion.

Such long-range missiles could be fired quickly and without refuelling from mobile launch vehicles. They would also have a high military value. After all, at the top of their class, not only could satellites be transported. But also warheads.