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Two defunct satellites will narrowly avoid colliding on Wednesday evening, passing each other just fifteen to thirty meters apart while travelling at 14.7 kilometers per second
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- Title
- 2 satellites will narrowly avoid colliding at 32,800 mph over Pittsburgh on Thursday
- Authors
- Rafi Letzter
- Published
- Jan 28 2020
- Word count
- 518 words
Worth noting that there’s probably pretty decent error bars on the 15-30 metre estimate as it is. All of this information is based on TLE data, which the JSPoC collects on satellites in orbit for navigation and intelligence purposes—and these can have fairly low accuracy and precision. LeoLabs will then be “marking up” this baseline data with computer modelling or even complementing it with further observational data to sell to customers.
Given both satellites are defunct, it’s going to be a case of watch and pray. Nothing to be done here. Unfortunately, given the satellites orbit 900km high, well above an altitude where they’ll decay naturally, any debris field created will likely be permanent.
What’s worse is that the debris field will be in the highly valuable earth observing polar/sun synchronous orbit belts.
Good news update: the predicted miss is now 13-87 metres, which has lowered the probability of a collision to about 1 in 1000.
I don't really follow space related topics regularly other than whatever gets popular enough, but I was curious enough to look briefly into matters regarding space debris. My current knowledge of it goes about as far as a SciFi anime about corporate space debris janitors I once enjoyed called Planetes.
Haven't found any updated news yet but the first thing I found from NASA was the Spade Debris Elimination (SpaDE) system. Link to a Phase I Final Report with a date of December 2012: https://www.nasa.gov/directorates/spacetech/niac/2011_space_debris_elimination/
One user on Quora gave a list of some ideas being explored by various organizations around the world (https://www.quora.com/How-can-space-debris-be-reduced):
Click to expand
Snagging and Moving Space Junk
The European Space Agency is exploring several types of retrieval systems, including catching the satellite with a net.
The e.DeOrbit mission – first proposed publicly in early 2014 – would seek out satellite debris in a polar orbit at an altitude between 800 and 1,000 kilometers (500 to 620 miles). The European Space Agency is considering several kinds of "capture mechanisms" to pick up the debris, such as nets, harpoons, robotic arms and tentacles.
Pushing Debris Out of Space
The Switzerland-based Swiss Space Systems announced plans to launch a privately built SOAR unmanned space plane from an Airbus A300 jetliner by 2017 for small satellite launches.
CleanSpace One, a technology demonstration spacecraft, is expected to launch in 2018 from the back of a modified Airbus A300 jumbo jet. The Swiss Space Systems satellite would then meet up with a decommissioned SwissCube nanosatellite to move it out of orbit.
Using the Power of Electricity
The Japanese Aerospace Exploration Agency proposes to use an electrodynamic tether whose current would slow down the speed of satellites or space debris, according to an early 2014 report from Agence France Presse. Slowing the satellite speed would make it gradually fall closer to Earth, where it will burn up. A satellite using part of the system was expected to launch Feb. 28 (without capturing a satellite), with a tether test proposed for 2015.
A Space Debris Slingshot
To save on fuel, Texas A&M University's Sling-Sat Space Sweeper proposes swinging (capturing an object, swinging it towards Earth's atmosphere, and then using the momentum to sail on to the next piece of space debris for removal). The researchers were still examining design ideas as of early 2013.
Solar Sail
A British proposal called CubeSail would use the drag of a solar sail to push orbiting space debris down to lower orbits. Initially slated to fly in 2011, the proposal is still under design and is expected to build on more recent small satellite experience from its maker Surrey Space Centre, specifically the STRaND-1 nanosatellite that flew in February 2013.
Huffing and Puffing
Space Debris Elimination, or SpaDE would push satellites into a lower orbit by using air bursts within the atmosphere. A design proposal from Daniel Gregory of Raytheon BBN Technologies in Virginia would use a balloon or high-altitude plain to send the bursts out, which early studies in 2012 indicated could be enough to disturb the paths of low-Earth orbital debris.
Knock Junk Down with a Net
A network of nanosatellites, connected with a piece of electrically conducting tape that could be as long as 2 miles (3 kilometers), could knock satellites down as it passes through Earth's magnetic field and produces voltage. The solar-powered ElectroDynamic Debris Eliminator (proposed by Star Technology and Research, Inc.) could get rid of all large pieces of satellite debris in low-Earth orbit within a dozen years, its proponents said in 2011 (adding they needed more funding to make it a reality).
https://en.wikipedia.org/wiki/Space_debris#Dealing_with_debris
It'll take me some more time to look into the current status for each of those, but I believe some of them are active and on-going. That gives me some hope of humanity avoiding some final, absolute Kessler syndrome scenario where all future space exploration is forever cut-off (assuming we deal with the legalities of ownership and cost of removal of the debris).
A bit sensational considering there's zero risk to anyone on the ground even if they did collide.
Kessler syndrome is kinda scary, but wouldn't it only really affect mid-plane satellites? Debris in Ultra-low Earth orbit satellite planes like the new SpaceX swarm would decay pretty quickly and I would think the geostationary plane would be high enough to be untouched as well. Would the "sandpaper effect" be so powerful that we couldn't launch anything new past it at all, even with protective farings?