Questions tagged [collision-avoidance]
Should be used for questions related to preventing collisions in orbit. This includes risk assesment, evasive manuevors, avoidance althorithims, and other safety measures.
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Ready-made tool for satellite maneuver detection
I am looking for a tool to detect satellite maneuvers from TLE data. The tool should be easy-to- apply (not my field at all) to many satellites, i.e., not rely on visual inspection or similar.
Shorten ...
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Round number bias in selecting operating altitude of satellites?
With more and more satellites in orbit and increasing risk of collisions, should satellite owners not select satellite altitudes more diligently or even at "random"? Is there a specific ...
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Inter-constellation Low Earth Orbit (LEO) Satellite collision risks - mitigation is some "relayed AIS" in use?
I saw some news about Starlink satellites often having the do maneuvers to avoid collisions. I don't know what % of the maneuvers were related to collisions between 2 Starlink ones (I guess their ...
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Mean motion as indication for satellite (evasion) maneuvers
I am interested in detecting satellite maneuvers, e.g., to avoid collissions.
As far as I understand the best publicly available data comes from TLEs although they have their own problems.
What is the ...
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What kind of propulsion did/does the Raytheon EKV vehicle use?
Raytheon has developed an Exoatmospheric Kill Vehicle, designed to intercept an ICBM and destroy it through a collision. Here are some related links:
Wikipedia page
YouTube video about the project, ...
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Does SpaceX expect 1 collision involving one of their Starlink satellites every 2 years?
I read on https://gizmodo.com/spacex-starlink-satellites-dodge-137-objects-daily-1850616506
by Passant Rabie:
A new report revealed that Starlink satellites had to make 25,000 collision avoidance ...
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Does a space elevator ruin most satellite orbits?
A space elevator would offer a direct connection between the surface of the Earth and geosynchronous orbits. While the concept has several severe problems, according to my understanding of orbital ...
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How do satellite operators negotiate when a collision avoidance measure is necessary?
In another question I asked How often do active satellites have to change course to avoid other active satellites?.
The idea behind the question was to understand which party is actively avoiding ...
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How often do active satellites have to change course to avoid other active satellites?
I'm only aware of the ESA and SpaceX incident in 2019. Does this happen more regularly especially now with more active Starlink satellites and other constellations?
More importantly, are there efforts ...
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Which is the primary spacecraft in a conjunction?
I ask the question in the title because I cannot find a clear answer.
It seems that in collision avoidance, the primary spacecraft is always more accurately known then the secondary. But I think this ...
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Does Privateer's tracking software Crow's Nest actually offer users something better than the previous state of the art?
CNN's Steve Wozniak's new venture takes aim at space junk discusses a project with Wozniak, Alex Fielding and Moriba Jah:
But the money, according to Wozniak's co-founder in this new venture, couldn'...
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Has a cubesat ever caused a problem for another spacecraft? Examples? Close calls?
Cubesats can pose some unique challenges; they are small and so potentially a little harder to track, have larger area/mass so more subject to forces that can change their trajectories, are often less ...
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How close were Starlink-1095 and Starlink-2305 to the Tiangong Chinese Space Station?
Various news outlets reported on the Chinese government complaining about SpaceX Starlink satellites (#1095 and #2305) getting so close to their Tiangong Space Station that they had to initiate ...
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How can we get rid of space debris? [closed]
It's known that space debris can do harm to satellites. I have 2 questions:
How do satellites avoid them?
Are there any ways to get rid of it?
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Is it possible to detect if orbits intersect or not and positions where they intersect if you know Keplerian elements (2D)?
I have two orbits and I know their Keplerian elements. Is it possible to find positions where two orbits are crossing if those positions exist?
Is it possible to do it if spacecrafts are on orbits of ...
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Has there ever been a non-negligible probability of conjunction between spacecrafts in Lunar orbit?
Apparently ISRO's Chandrayaan-2 orbiter and NASA's LRO narrowly avoided a possible conjunction event in Lunar orbit due to timely assessment and action of both agencies.
https://www.isro.gov.in/update/...
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How can we avoid collisions when moving from one orbit to another?
Imagine that my ship is parked in LEO and needs to transfer to a higher orbit. It makes a Hohmann transfer and flies to the needed orbit by an elliptical trajectory. But this trajectory is crossing a ...
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Apparent close encounter of Inspiration4: Is the airspace cleared for returning spacecraft?
In the recording of the SpaceX live-stream covering the return of the Inspiration4 crew one can see an aircraft cross path with the capsule at 22:59:58. This image is a frame grab of the scene seen ...
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International SSA/STM 3-Layer Model
I'm working on a paper outlining an International SSA/STM1 approach for Civil SSA/STM and have read and referenced many publications. I believe it was an IDA documents such as https://www.ida.org/-/...
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How much could a full-blown Starlink constellation contribute to a future Kessler scenario? What would be the worst-case scenario?
Discussions in comments below this answer to What is the biggest satellite constellation in space right now? have touched on risk vs reward and the Kessler Syndrome in the context of full-blown ...
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Why are we not seeing probability curves for space junk collision prediction?
Since many specific space junk collision risks have been assessed, why haven't we combined the data and graphed it? The trendlines could be very instructive. Like mapping climate change, the curve ...
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What are the chances that a spacecraft is hit by space junk?
If a rocket flies into space there is a possibility that it will encounter a piece of space garbage; even a small screw can be fatal.
What are the chances that such a collision really takes place? ...
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Is it normal for the US Space Force to warn companies about a possible collision (conjunction)?
I've read a German news article today (Golem.de) stating that there was a conjunction between a Oneweb satellite on its ascension course and a SpaceX satellite.
The US Space Force warned Oneweb that ...
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What are the Basics of CubeSat Power Supplies and Systems?
I am going to go ahead and apologize for my ignorance surrounding this topic, as my background is Aerodynamics, and not Electrical Engineering. From what I understand, CubeSats typically generate ...
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Any official size for the ISS pizza box?
I still haven't found the official size of the ISS pizza box[1] and a search on the WEB doesn't help:
"30 miles deep and 30 miles long around the space station": https://www.vice.com/en_us/...
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Starlink's autonomous collision avoidance
On their website, SpaceX claims that Starlink satellites are able to conduct autonomous collision avoidance manoeuvres using alerts from the US Department of Defence. This seems very reasonable, given ...
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Determine if two orbits cross paths
I'm trying to determine which orbital object will have the most close calls with another object. I've gotten the full TLE catalog from Space-Track.org, and using poliastro python package have ...
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How quickly can the Starlink spacecraft respond to an impending collision?
update: The word "refused" might be inaccurate:
CNET: ESA's near collision with SpaceX Starlink satellite blamed on a 'bug'
Ars Technica: SpaceX satellite was on “collision course” until ...
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Calculation of collision probability based on TLE
I have to calculate the probability of collision at moment $t$ with space debris. I am using JSPOC algorythm described in https://www.space-track.org/documents/...
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Covariance matrix of a satellite position
In order to estimate the probability of collision with space debris, the covariance matrix of the primary and secondary objects should be calculated (JSPoC paper). I'm going to calculate the matrix ...
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Use of thrusters for Collision Avoidance Maneuver
I'm building an orbit propagator that gives the position of two satellites at time T. The position are expressed in ECI and after that are being transformed in LVLH frame (as mentioned ECI to LVLH ...
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SGP4: the accumulation of error in radial, in-track and cross-track
I'm propagating the trajectories of 2 LEO satellites (altitude 700 km) in 7 days and calculating the radial, in-track and cross-track distances to determine the risk of collision.
JSPoC states that ...
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What prevents all these man-made objects flying in space from colliding with each other?
Does NASA know the location of every object in orbit and they calculate satellite and shuttle launches around not hitting these objects or are they just rolling the dice that the probability of ...
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Feasible way to detect masses without natural light in deep space?
While I was perusing the entries here on energy sources for interstellar travel, it occurred to me that a problem accompanying a low energy density in space distant from stars is darkness. Is there a ...
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How to determine an orbit of a satellite for a collision detection?
I'm trying to validate an collision detector, and for that I'm starting from a pair of initial conditions for a satellite. After that I will use an RK method to integrate. How can I determine a pair ...
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Whats the protocol if two satellites collide?
If two satellites from two different nations were to collide together due to poor planning on the behalf of one of the nations what would be the protocol? For instance, Russia launches a probe into ...
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Will the Tesla Roadster/Falcon 9H 2nd stage ever be a navigation hazard to cis-lunar space?
The saying "What goes around, comes around" can apply to spacecraft on ballistic trajectories that are launched from Earth into bound heliocentric orbits. Since the Tesla Roadster/Falcon 9H 2nd stage'...
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How predictable is one asteroid's trajectory?
If one fictitious probe mission was to impact an asteroid fast enough to destroy it using its kinetic energy, could the asteroid's trajectory be predicted accurately enough (plumes or emanations or ...
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How might one approach using AI (convolutional neural network) to predict collisions in orbit?
CNN's Tomorrow's Hero profile Meet Amber Yang. She's trying to prevent a space debris catastrophe describes an investigation into the use of a convolutional neural network (CNN) to predict possible ...
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ISS - Tiangong 2 minimum safe distance
Using the SGP4 propagator, I calculated the minimum distance between ISS and Tiangong-2 for this year.
I obtained 12.32 km for 2017-09-27 17:29:36.376 UTC (which ...
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Could we prevent a disaster if someone tried to send a rocket in retrograde GEO?
Let's say an evil dictator decide to deliver a payload to a retrograde "GEO" orbit.
I suspect the first inevitable collision would quickly produce a Kessler syndrome.
Is there anything that would ...
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How much can static cling be used to move things in space? Tractor Beam
Can static cling occurs in space? Can a static charge be amplified laterally to move objects in space similar to Star Trek's tractor beam? Can a static charge could be carried by a sustained particle ...
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Which two satellites had a 44% probability of collision at 2017-01-07 21:53 UTC?
I saw this message on space-track.org:
The JSpOC has identified a close approach between two non-maneuverable satellites in a sun-synchronous orbit (approximately 800km altitude) with a time of ...
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Is 75 meters an exceptionally close distance for two satellites to pass at >6,000 m/s?
While researching for this question I ran across something called Celestrak Socrates. I requested the ten closest predicted approaches, and saw distances of closest approach of the order of 100 ...
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Is 45 km unusually close to pass the ISS and deploy a microsatellite without warning?
Eight years ago, on September 27, 2008, the Shenzhou-7 carying three taikonauts deployed the microsatellite Banxing-1 for testing maneuvers and external imaging. A few hours later at 15:07 UTC the ...
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Are most Earth polar satellites launched to the South or to the North? And why?
Almost all satellites in LEO have been launched to the east, to take advantage of the Earth's surface rotational speed of about 5% of required orbital speed (Israel being a small exception for ...
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Why are space probes and satellites not destroyed by meteor showers such as the Perseid?
What are the mechanisms used to avoid destruction of space probes and satellites during meteor showers? Are they affected by them?
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What actions are performed to prevent i.e. ISS from getting hit by space junk? [duplicate]
When thinking about velocity I could imagine that the ISS getting hit by some space junk (let it be just a plate of 1 meter in span) with a velocity of some 100 meters per second could be quite fatal.
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How would an interstellar probe navigate the pull of gravity from stars and other large objects on the way?
Refer to the ambitious probe sent by Yuri Milner, Stephen Hawking and Mark Zuckerberg to Alpha Centauri:
Yuri Milner is spending $100 million on a probe that could travel to
Alpha Centauri within ...
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How does a spacecraft such as Soyuz detect when it's on collision course with an object?
Today Roscosmos reported (in Russian, here's a machine translation into English) that the Soyuz vehicle on its way to the ISS avoided collision with a piece of Japanese rocket body, allegedly launched ...
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