PRE2019 1 Group1

Autonomous systems for space traffic management

Group Members

Name	Study	Student ID
Stijn Eeltink	Mechanical Engineering	1004290
Laura Kulter	Psychology & Technology	0851512
Annelies Severens	Biomedical Engineering	1232787

Planning

Each week will consist of two meetings. Prior to each meeting the team will work individually on the tasks they have been assigned for that meeting. During the meetings the results of these tasks will be discussed and finalized. L = Laura, S = Stijn, A = Annelies.

Week	Monday (morning)	Wednesday (afternoon)
1	ALL : choose topic	ALL : literary research problem definition make the planning define structure of the report
2	L : introduction/problem statement L : wiki page A : state of the art	ALL : PCR A: state of the art S : stakeholders L : introduction/problem statement L : edit planning in wiki
3	political aspects economical aspects technical aspects (state of the art) PCR	A: state of the art on wiki S: edit stakeholders L: RPC’s and update wiki A: air traffic management ALL: 2 questions for stakeholders (more is allowed)
4	political aspects economical aspects technical aspects (effects of the solution) Intermediate evaluation (peer review)	political aspects economical aspects technical aspects (effects of the solution)
5	concept discussion conclusion first draft	Hand in first version for feedback
6	discuss feedback	implement feedback
7	finalize report and wiki	Final evaluation (peer review) finalize report and wiki
8	Presentation Deadline : report and wiki

Introduction

Space debris often gets the most attention when one talks about threats that exist to active satellites and other spacecraft (previous 0LAUK0 groups have done extensive research on that topic before: PRE2016_3_Group19 , PRE2018_3_Group1 , PRE2018_4_Group9). However recent developments in the space industry present a ‘new’ threat to active satellites.

On Monday morning September 2nd the European Space Agency had to fire the thrusters of its Aeolus satellite to avoid a collision with satellite Starlink44.^[9]

Where traditionally space travel was government-driven, the privatization and commercialization of space activities have gained momentum and have developed different interests like faster and cheaper access to space. Currently there are several organizations that plan to launch thousands of satellites up into earth’s orbit in the next several years. These range from governments like the UK planning to launch 2000 satellites by 2030^[10] to large companies like SpaceX planning to launch 12000 satellites for its Starlink constellation.^[10] If we compare this to the currently 4987^[10] satellites in orbit, of which only 1957^[10] are still active and functional, one quickly sees how ‘full’ the currently quite ‘empty’ low orbit space around earth will become in the near future.

This could overwhelm current space flight safety processes. However, there are encouraging signs that the government, industry, and the space community are acting to address these issues. This project will look at a possible solution for managing these many thousands of satellites by using an autonomous system for space traffic management(STM).

Problem Statement

As stated on the introduction this project will focus on the need for an Autonomous Space Traffic Management System (henceforth called ASTM). The main reason for the need of such a system is the ever increasing presence of active satellites in low earth orbit, which will make it no longer feasible in the near future to avoid collisions by depending on human input. The goal of a good working ASTM system is to solve the following problems:

-Autonomous space flight and collision avoidance of all participating members. The group of members can run into the thousands, meaning that the system should be able to take into account large 3D flight models;

-Because there can be many different participating members, from small private owners to large constellations owned by governments or companies, the system will need to be able to easily adapt to different messaging structures and types of satellites. Rather than trying to enforce a single new program structure the system will have to be able to work with as many existing and future systems as possible;

-The system is meant to be an autonomous third party assistant, not an owner. For instance a company could develop and license this system to satellite owners who want access to easy STM. This would mean that the system needs to ensure that participating members are always able to take back control of their spacecraft should a license end or a conflict between parties arise;

-The system should be impartial. Meaning it should never sacrifice a satellite in favour of another satellite (government vs private owner). However the system should also be able to react to unavoidable situations(though these will be very unlikely to happen), in which case it might inquire human parties to negotiate which satellite(s) will be sacrificed;

Because of the international space treaties^[2] there are currently no rules in STM and no single entity is able to enforce whatever rules it creates. This means that ASTM systems will need to take several additional problems into account:

-An ASTM system will need to not just take participating members into account, but should also be able to react to non-participating members which it is has no control over;

-The system should be able to work with incomplete or not totally accurate information, this is especially likely with military satellites who might disclose false or incomplete information regarding the existence and manoeuvres of strategic satellites;

(Bonus) A nice additional feature would be if the ASTM system incorporates self-learning algorithms. Especially to predict future flight paths or future possible collisions and avoid them early on to perhaps decrease the risk of situations where the loss of satellites is unavoidable and to maybe even lower the needed amount of manoeuvres since the amount of times a satellite can manoeuvre is a very limited resource. (REQUIRES SOURCE)

State of the art

At the moment, there are no international or even national Space Traffic Management systems. However, because of the increasing amount of non-governmental organizations executing space activities, rules are needed to ensure safety in air space. Generally speaking, Space Traffic Management can be defined by the safety insurance of: 1. Safe access to outer space, 2. The conduction of operations in outer space, and 3. The return of space objects from outer space free from interference of any form.^[1]

Currently, the Outer Space Treaty forms a basis of international space law.^[2] The treaty was opened in 1967, when the United States, the United Kingdom and the Soviet Union signed the treaty. More countries followed in the coming years. As of 2019, 109 countries are parties of the treaty. This treaty focuses on the limitation of the use of celestial bodies and restricts nations from claiming sovereignty of outer space. It does not include any legal regulation of a Space Traffic Management. At the time that the treaty was set up, the STM concept was not considered a priority. In 2015, the UNCOPUOS committee had received approval to add STM as an agenda item in 2016.^[3]

The Cosmic Study from IAA created a definition for STM. It was the first step, but too premature to implement any regulations limiting freedom.^[4]

“The set of technical and regulatory provisions for promoting safe access into outer space, operations in outer space and return from outer space to Earth free from physical or radio-frequency interference” – Cosmic Study (IAA)

The 2016 “Orbital Traffic Management Study – Final Report” does not contain a definition for space traffic management. Instead, it provides a definition for Space Traffic Safety. Management would imply centralized command and control, which was seen as problematic.^[5]

“Freedom from those conditions in orbital space that may lead to incidents resulting in harm (death or injury to astronauts and spaceflight participants, damage to public welfare ,damage or loss of spacecraft, interference to spacecraft). Incidents of specific concern are collisions or orbital breakups.” – NASA

The 2017 German Aerospace Center (DLB) White paper on the “Implementation of a European Space Traffic Management System” defines STM as:^[6]

“Execution of all necessary managing and Monitoring and Control Operations (including routine and contingency scenarios) to ensure safe ballistic travel of manned and unmanned Suborbital Space Vehicles (SSVs) and spaceplanes through Near-Earth space and airspace under consideration of the existing European Air Traffic Management System and Infrastructure.”

According to [1] a national system will be most probably implemented before an international regime. This also has to do with data sharing between governmental and non-governmental organizations. Over the years, there have been different definitions and approaches to STM from the United States, European Space Agency (ESA) and the International Academy of Astronautics (IAA). However, they have some similar key operations, one of which is collision avoidance. This focuses on point 2. of Space Traffic Management: the conduction of operations in outer space. At the moment, ground operators make decisions, which might not always be optimal. The use of machine learning, artificial intelligence, is being explored to support ground operators when planning and implementing collision avoidance manoeuvres.^[7] This is one application that artificial intelligence can be used for. In ^[8] an initial architecture for a Space Traffic Management system is proposed, based on open Application Programming Interfaces (APIs). The use of machine learning in complete STM systems is being explored at the moment, a great step towards complete autonomous STMs.

Stake Holders

The last years have seen rapid growth and change in the space industry. Where traditionally space travel was government-driven and solely focused on security, political or scientific activities. The privatization and commercialization of space activities have gained momentum and have developed different interests like faster and cheaper access to space. This easier access to space has opened participation to many more participants than was historically possible. Private companies have proposed, funded and begun deployment of very large constellations of satellites.

These new activities could overwhelm current space flight safety processes. However, there are encouraging signs that the government, industry, and the space community are acting to address these issues. But is their effort enough, and is there a need for an Autonomous Space Traffic Management System?

Political

While space activity has democratized with many new players, the U.S. government is still the single largest actor and stakeholder in the lower earth orbit (LEO) operations environment. The U.S. government re-established the National Space Council in the summer of 2017. One of its first actions was to establish a working group to recommend a way forward on space traffic management. “National Space Traffic Management Policy” was issued on June 18, 2018, and outlines several steps changing how space traffic is managed and regulated. This paper addresses the need for improved space situational awareness (SSA), data sharing with other organizations, and space traffic management (STM).

The Department of Commerce wants to simplify the regulatory structure for licensing for commercial companies, which the industry has needed for a long time. It will also take the function of STM and SSA for the U.S. Air Force. By creating an open-architecture space data repository they will actively share information with and between operators, and encourage new technologies for SSA.

The Federal Communications Commission has been regulating practical orbital debris for commercial companies that operate in the U.S. market. The new rules would explicitly address the issue of large constellations and post-mission disposal reliability. These new rules also contemplate active SSA data sharing, transponders, enhanced signatures, and shared maneuver plans, which would greatly decrease the amount of space debris.

Space is however fundamentally an international concern since no nation owns or controls the environment. The foundational document for international space law is the Outer Space Treaty. Though this treaty is not enough. The United Nations Committee is considering new rules for topics like space debris management and creating guidelines for the long-term sustainability of space.

While these combined actions have mitigated some of the risks in the transition, further action is recommended. The best source of innovation and solutions are the organizations that are building new systems. Industry-driven norms and standards of behavior are among the most effective methods for preventing the new activity from contributing to space debris. The government should encourage these industry-driven, voluntary approaches.

Economics

This change in space activities, especially the very large LEO constellations, represents major investments by commercial companies like SpaceX. Every U.S. operator proposing a large constellation has stated the intention of following best practices and being ‘’good citizens’’ of space. These operators have a significant vested interest in maintaining the space environment, and in protecting their investments that will run into the billions of dollars. Some of the new operators are among the strongest proponents advocating for increased regulation and scrutiny. They intend to build in high reliability for post-mission disposals, like their intent to deploy satellites at a low altitude, and then raising the orbit once checkout is complete. While there are some disadvantages to this approach, when a satellite fails, drag can bring it down much earlier.

They are building in the capability of high-precision orbit knowledge and are actively willing, even seeking, to share position and maneuver data. Also, a high level of automated collision avoidance and automated deorbit of failed systems are being developed, much like the ASTM proposed by our group. To make sure the post-mission disposal plans are successful, companies are planning to deorbit on a fixed schedule, rather than maximizing mission life as is commonly done. Also, operators are adding grappling fixtures, reflectors, and other retrieval aids, even if they have no intent for on-orbit servicing or retrieval.

References

[1] (https://iislweb.org/docs/Diederiks2017.pdf)

[2] http://www.unoosa.org/pdf/publications/STSPACE11E.pdf

[3] UN General Assembly resolution A/RES/70/82, “International cooperation in the peaceful uses of outer space”, 21 December 2015 Online: http://www.unoosa.org/oosa/oosadoc/data/resolutio ns/2015/general_assembly_70th_session/ares7082. html, (accessed 06.09.2017);

[4] K.U. Schrogl, “Space Traffic Management: The new comprehensive approach for regulating the use of outer space – Results from the 2006 IAA cosmic study”, Acta Astronautica 62, 2008, pp. 272-276

[5] O.Brown et al.: “Orbital Traffic Management Study – Final Report”, prepared for National Aeronautics and Space Administration (NASA) Headquarters, prepared by Science applications InternationalCorporation(SAIC),21November 2016.

[6] R. Tüllmann et al.: “On the Implementation of a European Space Traffic Management System – Volume I. A White Paper; Volume II. The Safety and Reliability Strategy; Volume III. Technical Requirements”, conducted on behalf of European Space Agency (ESA) by German Aerospace Center (DLR) and partner Institutes and Companies, 27 April 2017.

[7] file:///C:/Users/20166004/Downloads/artificial-intelligence-support1.pdf : more explanation about collision maneuvers

[8] https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20180007349.pdf

[9] http://www.esa.int/Our_Activities/Space_Safety/ESA_spacecraft_dodges_large_constellation

[10] https://www.pixalytics.com/satellites-orbiting-earth-2019/

[11] https://www.space.com/spacex-starlink-satellites-launch-just-beginning.html

[12] https://www.eumetsat.int/website/home/Satellites/LaunchesandOrbits/SatelliteOrbits/Satellitemanoeuvres/index.html

[13]http://www.esa.int/Our_Activities/Space_Safety/ESA_spacecraft_dodges_large_constellation

[…] file:///C:/Users/20166004/Downloads/PREPRINT-DASC2011-AutomaticCollisionAvoidanceSystemDesignDevelopmentandFlighttests.pdf : automatic collision avoidance system