PRE2018 4 Group9

Group members

Member	ID number
Rob de Mooij	1017797
Ilja van Oort	1001232
Sara Tjon	1247050
Thomas Pilaet	0999458
Joris Zandeberge	1231962

Problem statement

The amount of collisions between satellites and space debris increases exponentially, due to the growing amount of space debris.
Chance that a satellite collides with a piece of debris bigger than 1 cm in a year:
2007: 17-20%, 2010: 50%
Consequences: no internet, no gps, costs a lot of money, space travel may become more difficult/impossible

Objectives

• Analyzing the available methods to remove space debris
  
• Find methods on how to prevent new space debris (governance)
  
• Further develop a promising method
  

Users and their requirements

Users:

• Satellite owners (governments, space associations)
  

Requirements:

• re-usable
  
• quick to implement
  
• hard to abuse
  
• versatile (for both smaller and larger debris)
  
• autonomous
  
• durable
  
• affordable
  

Approach, milestone and deliverables

Approach:
Reading papers to get a good picture of the current problem and the state-of-the-art technology
Analyzing and comparing possible methods for space debris removal by looking at their pros and cons
Further development of a (combination of) promising technique(s) with a model or prototype.

Milestones:
Week 2: Determined subject; defined plan
Week 3: Find state of the art methods; finished literature search
Week 4: Determine promising method(s)
Week 5: Basic model
Week 6: Final model
Week 7: Results model, implement model in USE, finalized wiki
Week 8: Presentation

Deliverables

• Wiki page
  
• Presentation
  
• Model/prototype
  

Who is doing what?

What	Who
Literature study	All
Literature analysis	All
Modelling	Rob/Ilja/Sara
Prototyping	Rob/Ilja/Sara
Updating wiki	All
Implementation USE	Joris/Thomas
Visualizing data/results	Joris/Thomas
Presentation	Joris/Thomas

Summary 25 scientific articles

• Dubanchet, V., Saussié, D., Alazard, D., Bérard, C., & Peuvédic, C. Le. (2015). Modeling and control of a space robot for active debris removal. CEAS Space Journal, 7(2), 203–218. https://doi.org/10.1007/s12567-015-0082-4
  

This paper focusses on the technical aspects of using a robotic arm on a ‘chaser’ satellite to capture large debris. This approach is considered to be the most realistic to actually be employed in the upcoming years. In the introduction, several efforts in achieving the modeling and control of such a system (in space) are outlined. In the second section, the main issues in achieving this are described. In the third and fourth section, an algorithm used to model and simulate the dynamics of this satellite and the method of controlling it are described. The resulting system is then simulated using Matlab (the code is provided in the paper).

• Flegel, S., Krisko, P., Gelhaus, J., Wiedemann, C., Möckel, M., Vörsmann, P., … Matney, M. (2010). Modeling the Space Debris Environment with MASTER2009 and ORDEM2010. Proceedings of the 38th COSPAR Scientific Assembly, (January).
  

This paper describes and compares two software tools (MASTER-2009 and ORDEM2010 developed by ESA and NASA respectively) used to describe debris orbiting the earth. The main goal of these tools is to estimate the object flux onto a specified target object and is therefore useful in achieving safe space travel. In MASTER, debris is simulated based on lists of known historical events responsible for scattering debris in earth’s orbit. Results are also validated using historical telescope/radar data. ORDEM is designed to reliably estimate orbital debris flux on spacecraft using telescope or radar fields-of-view. Therefore, both programs make heavy use of empirical data for their predictions. Results of the program deviate particularly in debris with a size of 1 mm to 1 cm. These bits of debris are particularly difficult to model, as the amount of measurement data is very small. Reasons for the deviation of the results for these small debris are described in the paper.

• Klinkrad, H. (2006). Space debris : models and risk analysis. Springer.
  

This book extensively covers space debris in general and describes the technical aspects of this debris in detail. In chapters 2 to 6, it is outlined how the space debris environment can be characterized and modelled using measurement data. Furthermore, it is explained how the future of space debris orbiting earth can be predicted and how this could be influenced by mitigation measures. Chapters 7 to 9 describe aspects of risk assessment and prevention within on-orbit shielding, collision avoidance and re-entry risk management. Chapter 10 gives an overview of the risks associated with natural meteoroids and meteorites. Lastly, chapter 11 overviews the importance of space debris research and international policy and standardization issues.
Understanding the causes and controlling its sources is essential to allow for safe space flight in the future. This can only be achieved through international cooperation. This has been done through international information exchange and international cooperation at a technical level. Furthermore, steps have already been taken in establishing space debris mitigation standards, guidelines, codes of conduct and policies by several space agencies, governmental bodies and international space operators.

• Yazdkhasti, S., & Sasiadek, J. Z. (2017). Space Robot Relative Navigation for Debris Removal. IFAC-PapersOnLine, 50(1), 7929–7934. https://doi.org/10.1016/j.ifacol.2017.08.767
  

In order for a ‘chaser’ (spacecraft capable of removing space debris) to properly navigate towards its target, it must be able to estimate the pose and motion of the target. In the introduction, several works addressing this problem are outlined. This paper presents a method to estimate the relative position, linear and angular velocity and the attitude of space debris using vision measurements (using stereo cameras). In order to estimate the relative states between spacecraft, the Multiplicative Extended Kalman Filter and Unscented Kalman Filter were applied. The methodology is described by first outlining the coordinate systems used. Afterwards, the estimation algorithm is described (in which a set of feature points tracked by a stereo camera are key). Then, the described algorithms are validated using a simulation experiment. This paper could be very interesting for our model. Perhaps we could translate the presented algorithm into a script and further build on it.

• Colmenarejo, P., Avilés, M., & di Sotto, E. (2015). Active debris removal GNC challenges over design and required ground validation. CEAS Space Journal, 7(2), 187–201. https://doi.org/10.1007/s12567-015-0088-y
  

In this paper, proposed techniques for active debris removal (ADR) are categorized as follows:
- Contactless techniques (e.g. an ion beam), which can mostly build on existing techniques as opposed to using new ones
- Techniques requiring rigid contact (e.g. through a robotic arm), in which de-orbiting can be achieved by directly transmitting a force/torque to the debris
- Techniques requiring non-rigid contact (e.g. using flexible tentacles), which can entail intricate dynamics
A list of the proposed techniques can be retrieved from table 1 in the paper. As of yet, the most technologically advanced methods are the use of a robotic arm and capture through a tethered net.
Additionally, the main operational phases of active debris removal are outlined:
1. Ground controlled phase: In this phase, the “chaser” is brought closer to the target, usually not autonomously.
2. Fine orbit synchronization phase: The chaser moves to the (approximate) orbit of the target, which can be autonomous or partially using ground support
3. Short range phase: the final (passive) approach toward the target. Challenges here (which we could also address) are:
- Necessity to determine debris angular velocity and shape using optical observation, which most likely requires image processing techniques
- Necessity to synchronize the chaser with the angular motion of the debris
- In case of contact, necessity to de-tumble/control the resulting composite satellite
4. Terminal approach/capture
5. De-orbiting
Clearly, the fourth and fifth phase are very specific to the technique chosen for debris removal. Furthermore, the following aspects are discussed in the paper in detail:
1. Terminal approach using visual-based navigation
2. Ground validation of guidance, navigation and control systems based on hardware-in-the-loop test facilities

• Chen, S. (2011). The Space Debris Problem. Asian Perspective, 35(4), 537–558. https://doi.org/10.1353/apr.2011.0023
  

Near-Earth orbits are becoming congested as a result of an increase in the number of objects in space—operational satellites as well as orbital space debris. The risk of collisions between satellites and space debris is also growing. Suggested concepts for active removal of space debris: small-debris collection, ground-based lasers, trash tenders, dual-use orbit transfer vehicles, space-based lasers, and space tethers. There are two separate areas of concentration: small-debris elimination and individual large-object collection.

• Nishida, S.-I., Kawamoto, S., Okawa, Y., Terui, F., & Kitamura, S. (2009). Space debris removal system using a small satellite. Acta Astronautica, 65(1–2), 95–102. https://doi.org/10.1016/j.actaastro.2009.01.041
  

Electro-dynamic tether (EDT) technology, a possible high efficiency orbital transfer system, could provide a possible means for lowering the orbits of objects without the need for propellant.

• Ruggiero, A., Pergola, P., & Andrenucci, M. (2015). Small Electric Propulsion Platform for Active Space Debris Removal. IEEE Transactions on Plasma Science, 43(12), 4200–4209. https://doi.org/10.1109/TPS.2015.2491649
  

A deorbiting platform is in charge of approaching a target debris, bringing it to a lower altitude orbit and, in the case of a multiple target mission, releasing it and chasing a second one. Electric propulsion plays a key role in reducing the propellant mass consumption required for each maneuver and thus increasing the mass available to deorbit a relevant number of debris per mission.

• Huang, P., Zhang, F., Meng, Z., & Liu, Z. (2016). Adaptive control for space debris removal with uncertain kinematics, dynamics and states. Acta Astronautica, 128, 416–430. https://doi.org/10.1016/j.actaastro.2016.07.043
  

Tethered Space Robots are a promising solution for the space debris problem. Kinematics and dynamics parameters of the debris are unknown and parts of the states are unmeasurable according to the specifics of tether, which is a tough problem for the target retrieval/de-orbiting. Models and simulations can be used to get proposed parameters and their expected performances.

• Lampariello, R. (2013). On Grasping a Tumbling Debris Object with a Free-Flying Robot. IFAC Proceedings Volumes, 46(19), 161–166. https://doi.org/10.3182/20130902-5-DE-2040.00118
  

The grasping and stabilization of a tumbling, non-cooperative target satellite by means of a free-flying robot is a challenging control problem. A novel method for computing robot trajectories for grasping a tumbling target is presented. The problem is solved as a motion planning problem with nonlinear optimization. The resulting solution includes a first maneuver of the Servicer satellite which carries the robot arm, taking account of typical satellite control inputs. An analysis of the characteristics of the motion of a grasping point on a tumbling body is used to motivate this grasping method, which is argued to be useful for grasping targets of larger size.

• Klima, R., Bloemenbergen, D. (2016) Space debris removal: a game theoretical analysis https://www.mdpi.com/2073-4336/7/3/20

Space debris are a threat to operational spacecraft. Debris removal mission have been investigated by several space agencies to protect the satellites in the orbital environments. This costs a lot of money, but it has positive effect for all the satellites in the same orbital. A drawback is the agencies can all financially contribute to the debris removal or wait for others to do it. The risk of the latter is that the debris will be catastrophic. A game-theoretical analysis is presented where a realistic model of the orbit environment including all space objects are implemented. The experiments confirmed the predicted exponential growth of space debris near the Earth orbits. Active object removal are necessary.

• Liou, J.-C., Johnson, N. L. (2006). Risks in space from orbiting debris https://science.sciencemag.org/content/311/5759/340?casa_token=eKETqH8PDB4AAAAA:F0c9mUOMMHFELTaZbWngoc5wcDTKOkO0Ke0enr3v5kST6L-BQAsv6JItvTKWMiUkH2xrm2XAz7wm2Q

Since the launch of Sputnik I, an orbital debris environment has been created which has a risk on the space systems, including human space flight and robotic missions. More than 9000 orbiting objects with a total mass larger than 5 milion kg are tracked by the U.S. Space Surveillance Network. Three collision have been occurred. There is a potential increase in Earth satellite population which results from the collisions of the space objects.

The current debris environment in the Low earth orbit (LEO) region is unstable and the collisions will become dominant in the future even without new launches. The collisions will happen between 900- and 1000 km over the next 200 years, which results in debris increase. Because undoubtedly new spacecraft will be launched in the future, the situation is even worse.

• Marco M. Castronuovo (2011)., Active space debris removal —A preliminary mission analysis and design, Pages 848-859, ISSN 0094-5765, https://doi.org/10.1016/j.actaastro.2011.04.017 .

(http://www.sciencedirect.com/science/article/pii/S0094576511001287 )

The removal of 5 to 10 objects per year from the LEO can prevent the debris collisions from cascading. There are three oribtal regions near the Earth where the collision occur and the sun-synchronous condition is the one we should target for debris removal. For this removal, a space mission has been designed with the goal to remove 5 rockets per year from this orbital environment. This space mission includes the launch of a satellite which contains de-oribitng devices. This satellite chooses an objects and grabs it with a robotic arm. A second arm puts a de-orbiting device to the object. Then the next target can be done. An active debris removal mission can de-orbit 35 large objects in 7 years and the mass budget is compatible.

• Shin-Ichiro Nishida, Satomi Kawamoto, (2011). Strategy for capturing of a tumbling space debris,Pages 113-120,ISSN 0094-5765,

https://doi.org/10.1016/j.actaastro.2010.06.045 . (http://www.sciencedirect.com/science/article/pii/S0094576510002365 )

The capture of space debris objects are not favorable, because tracking errors lead to loaindg and momentum transfer occur during the capturing. Because the exact mass and inertial characteristics of the target are unknown due to unavailability or damage, it is harder to use the capture arm to capture the object. A “joint virtual depth control”algorithm for a force controlled robot arm control is used which tries to stop the rotation of the target with a brush type contactor. As a result, a new active space debris removal system is becoming more achievable.

• Vladimir Aslanov, Vadim Yudintsev, (2013). Dynamics of large space debris removal using tethered space tug, Pages 149-156, ISSN 0094-5765,

https://doi.org/10.1016/j.actaastro.2013.05.020 . (http://www.sciencedirect.com/science/article/pii/S0094576513001811 )

Tethered systems are promising technology to reduce the space debris. This is possible in different ways: through momentum transfer or electrodynamic effects. Another way is using a tethered space tug which is attached to the space debris. Large space debris can cause a loss of control of the tethered space tug, so the problem of the removal of this large space debris is studied. The transportation system consists of a space debris and a space tug which are connected by the tether. The properties of this system on the motion of the system are studied, which includes the moments of inertia, the length and properties of tether, thruster force and initial condition of motion. The transportation process is possible when the space tug force is in de same direction as the tether and the tether is tensioned. There is minimal height of safe transportation below which the space tug can come into collision with the space debris.