Two satellites almost ran into me. How they managed to avoid the crash?

The first alarm was received on January 27. Two small satellite circling around the Earth in low orbits, are in a situation of possible contact. Satellites, one of which belonged to Capella Space, and the other Spire Global, might encounter. The alarm about possible clashes filed 18th space control squadron of the U.S. air force — office does this every time he considers the event a collision is quite likely. The probability of collision can be either very small, or frightening. The squadron estimated the probability between 0.2 and 10% for the 72-hour period. But this is guesswork.

If the satellites collided, fragments of satellites (the years of work, a lot of money), too, would fly in space. Then they would become even more rubbish, which flies around the Earth, threatening other orbiting vehicles.

Spire, which has around 60 small satellites that monitor ships and weather, not particularly worried by this warning.

But Capella, with only one companion, worried.

What happens if you have companions?

Given the fact that the squadron monitors more than 24,000 space objects, such messages ultimately come as often as junk e-mail. In 2016, the unit sent almost 4 million of these messages of a possible collision, the severity of which varies from “note” to “consider evasion”. But some of the smaller satellites, including Sputnik Spire, Dodge do not know: they have no propulsion systems, so they can’t get away from danger. Such potential impacts have to move the other side. But if none of the moons can’t go off course, the situation is more complicated.

Capella has only recently launched its first satellite, named Denali after the national Park on Board the rocket Express SmallSat, which in December launched into space from 60 satellites. Primary in 2016, the company originates also from the crash. The founder Shares Banazadeh, like everyone else in 2014, was puzzled by the disappearance of Malaysian airlines flight 370, which disappeared on the way to China. “We asked ourselves: why can’t we find a huge 777-y plane on the planet that you call home?”, says Banazadeh, a former engineer at the jet propulsion Laboratory of NASA. “We may not observe our planet.”

But this is only part of the answer. According to his reasoning, satellites that can see visible light cannot penetrate clouds or the darkness of the night. Most of the world, most of the time are lost to them. Instead of passively collecting light Capella sends to earth the radio waves. They bounce back, changing depending on what I face and the satellite picks up their ball, creating space radar system. “We send out energy and signals from our own satellite, not waiting for the light to come to us, says Bayside. We will carry their own flashlight”.

Using this system it is possible to observe the ships, monitor the crop, to detect floods, even to exercise a kind of espionage. You might be able to find the missing plane. In any case, Denali was a demonstration satellite, and not part of a fully functional Park of the dozens of satellites that will be launched in the coming years. But he was the first.

So when Capella received a warning, the mood in California at the mission control center was tense. Over time, the company announced that the probability of collision is increased. To think about what will happen after the accident at that speed (about 50 000 km/), it made no sense, so they decided to remove the satellite from the road.

Meanwhile, the engineers at Spire, preparing the data: satellites of the company which collect the GPS signals passing through the atmosphere, just understand their position, even better than the BBC. “So when someone connects and says: Hey, there is a convergence; the contact in four days”, we turn into attention and begin to load the data,” says Nick Allen, head of the brand in Spire. For him this routine. The company receives several messages of this kind every week for its more than 60 satellites.

Satellites, Spire can’t move by themselves, so the data collection is the most important thing a company can do. In a difficult situation, Spire can tilt the solar panels of the satellite to change its resistance, hoping to get him off the course.

The avoidance of a dangerous collision, however, went to Denali, who had engines on Board, but have not tested it. So on Tuesday, 29 January, the system has been activated. To the relief of all, it worked. The engines activated four times, raising the orbit of Denali at 50 meters with each thrust. “If we had not been able to maneuver, the situation would have been very scary,” says Bansode.

No one knew for sure what happens. On 29 January the team has been hard watching whether there will be a collision. And after dinner, the air force “confirmed that the event was nominal and the satellites separated safely.”

The growing population of objects orbiting the Earth, many of whom are unable to leave the road, leads to increase the risk. No Spire, which is one of the largest private accumulations of satellites in orbit, no Planet, which are more likely, not placing the motors on their small companions. Both companies have passive ways to change routes, but their use in order to avoid collision may require more advance notice. In addition, small satellites are less likely to collide than large.

But there is a chance. How are we going to resolve this growing problem — is not yet clear. Space is big, but not so much that the wreckage of the satellites just vanished.