This weekend, a Chinese rocket booster, weighing around 23 tons, came back to Earth after spending more than a week in space – with some critics, including NASA Administrator Bill Nelson, responsible for the poor planning by China Is held. Pieces of rockets called Long March 5B are believed to have fallen into the Indian Ocean near the Maldives, and no one was injured.
But the incident has shown the potential dangers that come from humanity’s increasing presence in space, said Hanspeter Schaub, a professor at the Ann and HJ Smid Department of Aerospace Engineering Sciences.
Schaub is an engineer with an eye for the myriad pieces of garbage that surrounds our planet – from meteors to the size of dust grains to man-made rocket stages as large as school buses.
As humans launch more objects into space, he said, this debris can become a threat to the safety of satellites and human astronauts in orbit. In 2009, an inactive Russian satellite called Iridium 33 crashed into an active satellite, sending a cloud of shrapnel around the planet.
He sat down with CU Boulder Today to talk about whether you should be concerned about objects falling from space- and emerging science fiction-esque technologies could soon play a role in removing space debris from orbit. Huh.
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How normal is this rocket booster-like object crashing back to Earth?
Satellites and other objects in space come down after launching, sometimes within months, sometimes years or decades. Most are designed to burn in the atmosphere so that very few parts make it to the ground. But it is really rare that the size of this Chinese rocket comes down.
Many experts have also expressed concern about this phenomenon – saying that, in general, this should not happen in space exploration. Why is it like this?
There is increasing awareness around the world that when you launch a vehicle you must be a good citizen, but also when you have a vehicle that is nearing the end of its life. For example, if you have energy left in your satellite’s battery, you should eliminate it. Otherwise, it can cause an explosion, and an explosion means that you create a lot of small debris.
Still, the average person probably isn’t going to get hurt by objects falling from space, right? As far as we know, no one has died from the space debris till date.
The chances of being hit by space debris are really low. There are many other things that we should be worried about these days.
What we are looking for is that there are many events where these large, upper-stage rocket bodies actually get very close to each other in low Earth orbit – hundreds of meters or so. They do not collide, which is very good. They just pass quietly at night.
But we have realized that this happens more often than we thought years ago.
What happens if two of them collide
If two of those big objects hit each other, they would make so much shrapnel. One of those collisions can suddenly create thousands or thousands of pieces of space debris. You are looking at objects that are about an inch in size, but at that speed, they will destroy your satellites. This is a big, big concern.
We are launching a lot more objects into space every year. How can we prevent such accidents from happening?
My group, in particular, is trying to figure out how we can move these large bodies out of the way and prevent collisions.
We are looking at technology that can pull an object or stop falling. If you are trying to use a robotic spacecraft that docks a satellite to fix it or remove it from the path, and it is rotating, it is really difficult. Once they are inactive, the spacecraft can rotate in orbit. Think of an object the size of a school bus that completes one revolution every six seconds.
Your solution involves electrostatic forces – such as clothes sticking together in the dryer. How does that work?
You will fly to an object, then aim an electron gun at it to charge a negative charge and charge that object up. This allows you to create an electrostatic attractive force.
If you modify the beam at the right time to make it stronger or weaker, you can actually unspin that object. This may take a few weeks, but you can slow down the spin rate in such a way that it becomes very easy to dock.