PRE2018 3 Group1: Difference between revisions

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=== Preferences ===
=== Preferences ===
 
* The robot should be able to propel itself as fast as possible.
* It should have a sufficient reacting time.
* The detection range should be as large as possible.
* The robot should detect and clean as much orbital debris as possible in a given time period.
* The robot needs to be efficient, it should not waste energy when cleaning space.
* It should be operational for as long as possible.
* The costs need to be as low as possible.


=== Constraints ===
=== Constraints ===

Revision as of 20:46, 16 February 2019

Group members

Name Student ID Major
Max van Mulken 1006576 Software Science
Mart Hagedoorn 1021524 Software Science
Niels Verstappen 0999624 Software Science
Rani van Hoof 1026024 Biomedical Engineering
Kees Voorintholt 1005136 Software Science

Introduction

This wiki is an information page about a study on a huge problem that is known as the Kessler Syndrome. This Kessler Syndrome is basically a form of cascade failure. It starts with for example two satellites colliding, this collision will cause a lot of debris to fly around in orbital space. This debris will then again collide with other debris, space stations or satellites, which can eventually lead to a shield of debris around the planet earth.

The importance of this problem will be further explained and several solutions will be considered and discussed.

The study is done for a TU Eindhoven course: Robots Everywhere (0LAUK0). While studying this problem and its possible solutions, it is made sure that the 3 USE aspects: User, Society and Enterprise, are central.

Problem definition

As mentioned in the introduction the problem that will be studied is the Kessler Syndrome. In the long term this shield of debris around the earth can have disastrous consequences. Starting with the consequence of not being able to send any new satellites into orbital space as they would get smashed by orbital debris immediately. At the speed of which these objects travel they will just shatter in tons of smaller objects and travel straight ahead. This means that now all these smaller pieces make a cloud of debris of which the total area is bigger than it was before it crashed. This cloud will destroy everything it encounters, only making the cloud of debris bigger and bigger.

But why would this affect the ordinary human being living his life on planet earth, the orbital debris is in space right why would we care? Well at the point where we have no more satellites in orbital space there will be quite some changes to our way of life. How would we make the important business call to a CEO on the other side of the world? How would we know what the weather will be for the coming weeks? All these things will become impossible without satellites.

Also it might seem like a future problem that we could maybe still prevent, however that is not true, in fact it has already started a long time ago. There are numerous reports of orbital debris colliding with satellites or space stations, the US government logged 308.984 close calls and 665 emergency alerts in 2017 alone [1]. Furthermore, on average a satellite crashes to the earth once every week which causes a rain of space junk that will burn up on the way to the earth. However some of this space junk may stay in orbit, which means the amount of orbital debris keeps increasing.

To have some kind of visualization of how much orbital debris is already out there, there are about 650.000 objects between the size of a softball and a fingernail. Next to that there exist approximately 170 million pieces of space junk that are smaller than the tip of a pencil [1]. All of this together with the roughly 23.000 satellites, rocket bodies and other human made objects, make a huge amount of objects flying around in orbit.

So if you had the impression that this problem was not very relevant, think again because it will change our ways of living drastically


Objectives

While studying the subject we have set several objectives for ourselves:

  • We will do literature study and based on these studies we will choose the best solution for the Kessler Syndrome.
    • The best solution should be based on several criteria like: safety, cost, effectiveness.
  • We want to make a clear design on how such a robot should be created.
  • After this design is created we want to model this solution to be able to run simulations on it.
    • Using these simulations we want to make visual representations in the form of graphs.
  • To support the feasibility of the best solution we will also use a simulation.

USE aspects

While the problem described above is a very ambitious one to solve entirely, we believe the work we can do in 8 weeks is more than enough to impact multiple stakeholders. We will identify stakeholder groups and look at what our project can do for these groups.

Society

The product aims to prevent or even solve the problem that the Kessler Syndrome poses, in the extent to which that is still possible. If prevention of or a solution to this problem is no longer possible, it will at least attempt to reduce the consequences and growth of the problem. The Kessler Syndrome poses multiple complications that will influence society in a major way.

Since the Kessler Syndrome will cause everything in orbit to be in danger of being damaged and/or destroyed, it will be very hard for humans to launch and maintain satellites into orbit. This has a number of consequences, since satellites are very important for society today. First of all, they allow us to do a lot of research of the entire solar system and even beyond the solar system, expanding our knowledge of our place between the stars. Perhaps even more important to some people, satellites have allowed us to be way more accurate when predicting weather forecasts and potential storms, which is not only nice when you are planning a camping trip but can also be a lifesaver when it concerns a hurricane prediction. Also, since communication over large distances works in straight lines, satellites have greatly increased the distance over which communication can work correctly, along with increasing quality of communication. Instead of having a direct communication channel between two points which can be blocked by a large building or a mountain, communication via a satellites allow the communication to avoid large obstacles. Society has prospered and greatly benefitted from these communication channels, delivering the Internet, modern television and even radio stations to millions of people around the world. Finally, satellites play a key role in navigation. The GPS (Global Positioning System), which is used by every piece of modern navigation technology, has not only allowed individuals to find their way around but is also used by giant infrastructures like air traffic control, and is used by corporations like Google to provide society with an all-inclusive map of the entire world. It is safe to say that satellites are key to modern society, meaning development of the Kessler Syndrome to disallow satellites would be disastrous.

While the project and product themselves do not entail a lot of direct consequences for the people, if something were to go wrong while disposing of orbital debris and a large piece of metal would, for example, come crashing down on a residential area, people would suddenly have a huge stake in the project as well. Society would be outraged. Thus, it is very important that if a orbital cleaning were to be put into practice, that it is done right.

Later stages of the Kessler Syndrome could form a cloud of space debris in orbit that would make it too dangerous to send any spacecraft either into or past orbit. This not only limits satellites, but we would no longer be able to send out missions to other planets or moons because of a fear of the spacecraft getting destroyed. We as a society would be forever stuck on Earth, unable to accomplish the dreams science-fiction has set out for us.

Enterprise

Enterprises that would suffer from this problem, were it not to be addressed, would be both enterprises that focus on space exploration and any enterprise that benefits from sending satellites into orbit. As discussed above, there are a lot of enterprises which would suffer from a lack of satellites since communication methods would suffer severely. Next to these indirect consequences, more direct consequences are suffered by enterprises like SpaceX and Orbital. These enterprises focus on space exploration and flight research to bring multiple benefits and large chunks of knowledge to the general public. Both of these tasks, especially space exploration, will become a lot harder were the close Earth orbit to be home to huge amounts of debris. It would greatly increase the risk of crafts being damaged when send into or beyond orbit. Thus, it is in these enterprise’s best interest that the Kessler Syndrome’s effect is reduced.

State of the Art

One of the most important things to do at the start of this project is to understand the state of the art of the current technology. The literature study is divided in two relevant topics: How to track space debris? How to remove space debris?

The first will cover the state of the art in finding and tracking debris in space. Where the second will focus on the methods on how to remove pieces of debris from space. We will divide the topic on how to remove space debris in several parts, such that all parts focus on the state of the art of one method.

Literature study on tracking space debris:

There is already a lot of information available on debris that is in orbit around the earth.[2] The sources of this debris are normal launch operations, certain operations in space, fragmentations as a result of explosions and collisions in space, firings of satellite solidrocket motors, material ageing effects, and leaking thermal-control systems.[3] To track those pieces of debris several techniques are developed. At this moment the pieces of debris that are bigger than 10 cm can be tracked. Nowadays, space-object tracking is done with radar technology. To track debris, a radar beam is aimed to a predetermined position in space. When a piece of debris is observed, this piece will be tracked and the motion of the debris is saved. With the motion data of the debris the orbit can be calculated.[3] With this technology we can track pieces of at least 10 cm, but pieces of debris greater than 1 cm can seriously damage satellites. At this moment tracking of debris that is smaller than 1 cm is extremely hard because of the size, but also the reduced orbital stability. Also the total number of objects we have to track when we reduce the size threshold exponentially increase.[4]

In July/August and April/May 2013 a new technique for space debris tracking was tested.[5] Here a laser was fired and the reflected signal was received. Then the time between the laser that was fired and the received signal can be used to calculate the distance. These techniques of tracking space debris can be used for tracking satellites with reflectors, but not yet to track smaller pieces of debris. To be able to track smaller pieces of debris, we need to upgrade the laser power, laser irradiance and efficiency.[4]

Literature study on removing space debris:

  • RemoveDebris

An experimental satellite called RemoveDebris was launched by the International Space Station in 2018. This satellite will perform three experiments with regard to remove space debris. The first experiment was performed in October 2018, RemoveDebris captured a dummy satellite with a net in low orbit. The research group says: “Our small team of engineers and technicians have done an amazing job moving us one step closer to clearing up low Earth orbit”. The idea of this technique is that satellites in the future can identify pieces of space debris and capture them with a net that is tethered to the satellite. Once such an object is captured small rockets can be used to drag the satellite and object back in the atmosphere. There is all a danger to this technique, it is possible that the captured space debris and the satellite collide and increase the space debris problem instead of solving it. [6]

The second experiment will be with the use of a harpoon, soon in early 2019 RemoveDebris will shoot a pen-sized harpoon at a composite target that will be deployed by the International Space Station. This technique is similar to that of the capture with a net, capture a piece of space debris and return it to the atmosphere, a harpoon can be used to capture larger objects that can’t be captured with a net. However a harpoon could also break an object in two which makes the overall space debris problem worse. [7]

In the third experiment RemoveDebris will deploy a drag sail that would speed up the deorbiting process of the satellite. A drag sail will be deployed so the satellite can re-enter the atmosphere and this will be the final experiment of RemoveDebris.

  • Ion beam

Ion-beams can be used to remove debris from space. An ion beam is a type of charged particle beam consisting of ions, this can be used in space to transmit a force to a nearby piece of debris. This force can change the course of the debris, but it can also be used to slow down the debris such that it will crash towards the earth. Depending on the size and material the debris will (partly) burn up in the atmosphere. In the literature study of PRE2016 3 Group19, we found more information about the ion beam. The most advanced technology that uses an ion beam is the ion beam shepherd (IBS)[8]. The concept of IBS is that the spacecraft is located not too far from the debris and is pointing his ion thruster towards the debris. The ions with a high velocity will transmit their velocity to the asteroid and the asteroid will change it direction and possibly slow down. There is another thruster that will cancel out the motion caused by pushing the debris.

  • Laser

The idea is simple, take a laser and gradually evaporate space debris till it doesn’t exist anymore or it changes of orbit. A lot of research has been done into this solution, it has been estimated that with a ground based laser it would be possible that under the right circumstances an object could be slowed down by 1 millimeter a second. [9] For most objects it would still take a long time before they are slowed down enough for them to break up in the atmosphere, but with this technique it would be possible to avoid major collisions. A downside is that a ground-based laser can only be used when the conditions are right, a laser wouldn’t be able to penetrate clouds. Another danger is that when the laser is aimed at a wrong part of a piece of space debris such a piece might explode of break apart. [10]

  • Gecko-inspired robot

Another technique on removing space debris is inspired from a gecko, the gripper that is used can be compared with the fingers and toes of the gecko. A gecko can hang upside down by their toes, since the toes are covered in a kind of bristles that stick when moved in one way and can easily be removed when moved in the other way. The grabber used the same adhesion technique, when the grabber is moved in the right direction, the debris will stick to it. The robot was tested in a zero gravity environment and could grab debris in a shape of a cube or an beach ball. This technique is not yet fully developed, next steps could be to develop sensors that could help monitor adhesion and the robot still needs to be tested outside the space station in a more extreme environment.[11]

  • Magnets

The last technique we will cover is using magnets to deorbit pieces of debris. This solution does not require contact with the debris, because magnetic fields can influence each other without contact. Therefore it is safer for the robot to use magnets, since no contact is required. The technique is based on magnetic field, these fields can attract or repel pieces of debris, to change the orbit or to completely deorbit it.[12] To create a magnetic field, superconducting wires are used that are cooled to extreme low temperatures. These field can then influence the orbit of multiple pieces of debris at once. A disadvantage of using magnets, is that they will not influence pieces of glass or aluminium and therefore the robots using magnets are only useful for debris that is made from elements that react to magnetic fields.

Best solution:

From the work done by PRE2016 3 Group19, they concluded the the ion beam technology is the best solution for the space debris problem. We will discuss the solution shortly and then draw our own conclusion. The experimental satellite RemoveDebris uses harpoons and nets to catch pieces of debris to remove them, therefore it needs physical contact with the debris for these techniques. There is a disadvantage to physical contact, since there is a risk that the piece of debris is not caught and it will drift away. Furthermore when the net or harpoon is stuck to a piece of debris it might not be functional anymore. Like RemoveDebris, the gecko solution also tries to grab the debris and collect it. The biggest difference between those techniques is that there is almost no force needed for the gecko solution to grab the debris and thus the chance on pushing it away is smaller. We think that using this technique is the most desirable technique using physical contact.

The next possible solution is to use a laser to evaporate the debris. This will be safer for the earth, but it takes a lot of time to completely remove the debris. To use the laser it takes loads of energy, so it is almost not possible from space and a laser from the ground can only be used in the right conditions. Using a laser is not the only technique that does not use physical contact, we can also use magnets to change the orbit of debris. The biggest advantage of using magnets is that it can handle multiple pieces of debris at the same time and thus cleaning can be a lot faster. But it is only able to remove pieces of metal, thus glass and other debris will not be affected by magnets. The last, we think the best, solution is the ion beam. Since it is more precise than magnets and can easier be charged than an robot that uses a laser, the ion beam method seems like the best method.

Additional resources:

A lot of additional research has already been done in this field of research. In the following section we will show the separate papers:

  • There are over 500.000 pieces of space debris that are currently tracked, these pieces move with speeds up to 17.000 miles/hour. [13]
  • General overview of the problem, with the addition of why the general public should care about the problem. [14]
  • The Kessler Syndrome explained. [15]
  • Threat of the Kessler Syndrome. [16]
  • Some possible solutions to the Kessler Syndrome. [17]

Getting rid of orbital debris

Solution Criteria

We assessed the following requirements, preferences and constraints for the robot design.

Requirements

The robot:

  • Needs appropriate fuel tanks such that it can get in orbit.
  • Should be able to move around in space by changing its direction and speed.
  • Needs to reach a minimal speed of ...
  • Should be able to precisely detect orbital debris within a range of at least … km.
  • Has to push the debris it detects into to atmosphere where it will burn up.
  • Has to contain two ion beams that can target objects in 360 degree space together.
    • One beam is used to move space debris and the other is necessary to keep the robot in the same position relative to the debris.
    • The robot also uses these ion beams to propel itself forward and to adjust its trajectory
    • Electromagnetic tether?
  • Needs an energy source to charge the ion beams.
    • Solar panels.
    • Other options?
  • Should get a continuous stream of data from the earth on where the orbital debris currently is.
  • Should be able to avoid satellites if it encounters one.
    • SPACETRACK is the current program for worldwide Space Surveillance Network (SSN). It consists of multiple, dedicated, electro-optical, passive, radio frequency and radar sensors. The purpose of the SSN is not only space debris cataloging and identification but also satellite attack warning and space treaty monitoring. In total the SSN tracked 39,000 space objects.
  • Should be able to handle certain circumstances, it should be able to withstand:
    • Extreme temperatures.
    • Lots of friction and supplementary heat.
    • No gravity situations.
    • Harsh-radiation.
    • Heat flux: thermal energy absorbed by the debris.
  • Should be able to operate for at least 10 years.

Preferences

  • The robot should be able to propel itself as fast as possible.
  • It should have a sufficient reacting time.
  • The detection range should be as large as possible.
  • The robot should detect and clean as much orbital debris as possible in a given time period.
  • The robot needs to be efficient, it should not waste energy when cleaning space.
  • It should be operational for as long as possible.
  • The costs need to be as low as possible.

Constraints

General design

Approach

First of all, a literature study is performed to assess the state of the art regarding space debris orbiting the Earth and the Kessler Syndrome. To prevent the occurence of the Kessler Syndrome, the space debris should be removed from orbit before it can collide with other debris. The literature study resulted in multiple possible solutions for cleaning space debris. These solutions are compared with each other based on ... , leading to the most promising solution. Afterwards, the best solution will be developed. First, requirements, preferences and constraints for this design have to be defined. Then the robot design will be specified based on these requirements, preferences and constraints. This design will be tested by simulating the robot during its task to track and clean orbital debris. This simulation … The robot will be put to the test by conducting simulation experiments to assess the … of the robot. Finally, conclusions … and recommendations for further research will be provided.

Planning and division of work

Week Concern Responsible member(s)
1
  • Define subject
  • Work plan
  • Literature study (10 references per member)
  • Introduction, problem definition and objectives (wiki)
  • USE aspects (wiki)
  • State of the art (wiki)
  • Approach, planning, deliverables, milestones and work division (wiki)
  • Update wiki page
  • Prepare tutor meeting 1
  • All
  • All
  • All
  • Niels
  • Max
  • Kees & Mart
  • Rani & Max
  • All
  • All
2
  • Tutor meeting 1
  • Process tutor meeting 1
  • Review of previous week
  • Literature study
  • References in APA style
  • Update objectives
  • Completed state of the art and selection of best solution
  • Add details to planning
  • Requirements, preferences and constraints for design
  • Update wiki page
  • Prepare tutor meeting 2
  • All
  • All
  • All
  • Mart
  • Max
  • Niels
  • Kees
  • Rani
  • Niels & Rani
  • All
  • All
3
  • Tutor meeting 2
  • Process tutor meeting 2
  • Review of previous week
  • Work on robot design
  • Update wiki page
  • Prepare tutor meeting 3
  • All
  • All
  • All
  • All
  • All
4
  • Tutor meeting 3
  • Process tutor meeting 3
  • Review of previous week
  • Work on robot design
  • Start working on simulation
  • Update wiki page
  • Prepare tutor meeting 4
  • All
  • All
  • All
  • All
  • All
5
  • Tutor meeting 4
  • Process tutor meeting 4
  • Review of previous week
  • Work on simulation
  • Update wiki page
  • Prepare tutor meeting 5
  • All
  • All
  • All
  • All
  • All
6
  • Tutor meeting 5
  • Process tutor meeting 5
  • Review of previous week
  • Simulation experiments
  • Update wiki page
  • Prepare tutor meeting 6
  • All
  • All
  • All
  • All
  • All
7
  • Tutor meeting 6
  • Process tutor meeting 6
  • Review of previous week
  • Finish simulation experiments
  • Finalise wiki page
  • Prepare presentation
  • All
  • All
  • All
8
  • Presentation

Milestones

Week Milestone Remarks
1
  • Determine subject for the project
  • Subject chosen: Cleaning up orbital debris
2
  • Selection of best solution
  • Finish literature study
  • Finish state of the art analysis
  • Requirements, preferences and constraints for design
  • Best orbital debris cleaning method: Ion beam
3
4
  • Robot design
5
  • Finalised simulation
6
7
  • Finish simulation experiments
  • Completed wiki page
  • Finish preparation of presentation
 -
8
  • Completed presentation

Deliverables

The deliverables are as follows:

  • Wiki page

This wiki page will describe the project progress in detail and will be updated weekly. It will contain all relevant information about the project and links to the end products.

  • Robot design

The literature study will result in the most promising idea that might aid in a solution to the Kessler Syndrome. A robot design of this solution will be provided.

  • Simulation

The designs of the robot will be put to the test in simulations that sketch the practical workings of the robot.

  • Presentation

This presentation will be held during week 8 of the project and includes an introduction of the Kessler Syndrome and the possible solutions. The best solution is considered further by providing the robot design and a simulation of this robot.

References

  1. ↑ 1.0 1.1 Mosher, D. (2018, april 15). The US government logged 308,984 potential space-junk collisions in 2017 — and the problem could get much worse. Retrieved february 7, 2019, from https://www.businessinsider.com/space-junk-collision-statistics-government-tracking-2017-2018-4?international=true&r=US&IR=T
  2. ↑ http://stuffin.space/
  3. ↑ 3.0 3.1 Mehrholz, D., Leushacke, L., Flury, W., Jehn, R., Klinkrad, H., & Landgraf, M. (2002). Detecting, Tracking and Imaging Space Debris. Retrieved from http://www.pacaspacedebris.com/wp-content/uploads/2013/05/Detecting-space.pdf Cite error: Invalid <ref> tag; name "paca" defined multiple times with different content
  4. ↑ 4.0 4.1 Greene, B. (n.d.). Laser Tracking of Space Debris. Retrieved from https://cddis.nasa.gov/lw13/docs/papers/adv_greene_1m.pdf
  5. ↑ Latifi, J. (2017). Literature Review: Space Debris, Track methods and the Danger of the Future Debris Environment. Retrieved from https://jblati14.files.wordpress.com/2017/03/gis636-space-debris-literature-review_latifi-jorida.pdf
  6. ↑ University of Surrey. (2018, September 19). Net successfully snares space debris | University of Surrey. Retrieved February 9, 2019, from https://www.surrey.ac.uk/news/net-successfully-snares-space-debris
  7. ↑ Pultarova, T. (2018, June 22). 1st Satellite Built to Harpoon Space Junk for Disposal Begins Test Flight. Retrieved February 9, 2019, from https://www.space.com/40960-removedebris-space-junk-cleanup-test-flight.html
  8. ↑ Bombardelli, C., & Peláez, J. (2011a, July 1). Ion Beam Shepherd for Asteroid Deflection. Retrieved February 14, 2019, from http://sdg.aero.upm.es/PUBLICATIONS/PDF/2011/AIAA-51640-157.pdf
  9. ↑ Mann, A. (2011, October 26). Space Junk Crisis: Time to Bring in the Lasers. Retrieved February 9, 2019, from https://www.wired.com/2011/10/space-junk-laser/
  10. ↑ Bates, D. (2011, March 16). Nasa to shoot lasers at space junk around Earth to prevent collisions with satellites. Retrieved February 9, 2019, from https://www.dailymail.co.uk/sciencetech/article-1366838/Nasa-use-lasers-shoot-space-junk-Earth.html
  11. ↑ Choi, C. Q. (2017, June 28). Gecko-Inspired Robot Could Snag Space Junk. Retrieved February 9, 2019, from https://www.space.com/37335-robotic-gecko-gripper-microgravity-space-junk.html
  12. ↑ Williams, M. (2017, June 21). Let's Clean up the Space Junk with Magnetic Space Tugs - Universe Today. Retrieved February 9, 2019, from https://www.universetoday.com/136142/lets-clean-space-junk-magnetic-space-tugs/
  13. ↑ Garcia, M. (2013, September 27). Space Debris and Human Spacecraft. Retrieved February 10, 2019, from https://www.nasa.gov/mission_pages/station/news/orbital_debris.html
  14. ↑ Hull, S. (2015, October 30). Is the Sky Really Falling? An Overview of Orbital Debris. Retrieved February 10, 2019, from https://ntrs.nasa.gov/search.jsp?R=20150023281
  15. ↑ La Vone, M. (n.d.). The Kessler Syndrome Explained. Retrieved February 10, 2019, from http://www.spacesafetymagazine.com/space-debris/kessler-syndrome/
  16. ↑ Pelton, J. N. (2013). The Space Debris Threat and the Kessler Syndrome. In J. N. Pelton (Ed.), Space Debris and Other Threats from Outer Space (pp. 17–23). https://doi.org/10.1007/978-1-4614-6714-4_2
  17. ↑ David, L. (2013, January 25). Space Junk Menace: How to Deal with Orbital Debris. Retrieved February 10, 2019, from https://www.space.com/19445-space-junk-threat-orbital-debris-cleanup.html

Other (not yet used) references

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