Introduction to Space Missions INTRODUCTION TO SPACE MISSIONS Space Missions Types of missions: some examples Which orbit for which mission? Launchers Frequencies: fuel for communications mission Space environment Ground segment Actors in the Space System value chain Conclusion INTRODUCTION TO SPACE MISSIONS Space Mission: why do we send satellites to Space, why do we go to Space? Space Missions: what are the motivations? Overview of Space Missions Some important steps in the Space development history From Sputnik to large telecommunications satellites Korea and Space What are the elements of a Space Mission?

Space Mission: why do we send satellites to Space, why do we go to Space?

It is risky, costly, long to develop, with limited life duration, • But Man has always wanted to go beyond the known frontier, and

Space offers unique features: • Escape from Earth to discover new worlds  exploration • Global Earth view  observation and telecommunication • Absence of gravity  research • Ability to go round the Earth in approximately one hour  observation, global communication

Space Missions: what are the motivations?

Instrument of Public Policy: • National Sovereignty: independence from other countries for communication and observation • Defense and Security: secured communications, monitoring of treaties • Environment policy: resource management, pollution control, climate monitoring • Research and Exploration: national prestige, inspiration for youth, education • Government services: e-government, mapping

Economic development and commercial use of Space: • Services for all: tele-medecine, e-education, development aid • Meteo, exploitation of resources • Telecommunications (TV, telephone, VSAT, internet) • Navigation • Space tourism

Overview of Space Missions

Earth Observation: Navigation • Optical Imaging • Positioning • Radar imaging • Mobility planning • Meteorology Services Science missions: • Refuelling • Earth science • Repair in orbit • Solar System Others • Deep Space exploration • Early Warning • Man in Space • SIGINT, ELINT Telecommunications • M2M/IoT • Broadcast • AIS • Mobile • Tourism • Broadband (internet) • Secure Communications

Some important steps in the Space development history

• 1957: launch of Sputnik, first artificial satellite • 1960’s: Man in Space, Man on the Moon. Start of telecom and observation missions, scientific observation • 1970’s-1980’s: Russian Space Station (Mir), Space Shuttle, scientific exploration • 1990’s: International Space Station, constellations for navigation (GPS and GLONASS), telephony (Iridium and Globalstar) • Around 2000’s: development of telecom missions, privatisation of Telecom operators, creation of regional operators, numerous Earth observation systems, manned flights, exploration and science • 2010 ’s: emergence of « New Space », new actors, such as OneWeb, SpaceX, Blue Origin, new budget/financing • December 2017:ArianeGroup starts the production of Ariane 6 • February 2018:lauch of Falcon Heavy From Sputnik to large telecommunications satellites

60 years between those two pictures!

Korea and Space: Koreasat (Mugunghwa) 1 and 2 built by Martin Marietta and Matra Marconi Space, launched respectively in 1995 and 1996 Khalifasat for EIAST/MBRSC

KOMPSAT6: Radar payload for Koreasat-1: international design team Korea What are the elements of a Space Mission?

Space System design Satellite design is an optimisation process which involves many components, resources and constraints

Environment Programmatics Launcher, vacuum, Budget, planning, radiations industrial cooperation

Regulations Frequencies, Space Satellite design law Mission • Payload: antennas, repeater, Payload performances instrument Orbit, lifetime, … • Platform: mechanical, thermal, avionics, power, propulsion Infrastructure Ground segment, Control and Users What are the elements of a Space Mission?

Types of missions Earth Observation LEO observation, Meteo Science and Exploration Columbus and Rosetta Telecommunications Broadcasting, Broadband, MSS, Secure Communications, IFC Navigation Services ATV, debris removal, servicing Other types of mission Early warning, SIGINT, ELINT M2M/IoT Space System architecture: Earth observation system

Observing the Earth: Principles in Low Earth Orbit (LEO) Sun Synchronous Orbit: • All Earth can be imaged, with stable sun/scene/satellite angle, from a “short” distance • Pass-by on scenes is NOT continuous… Optical imaging: mostly Push broom • No snapshot principle, but “combing” the surface in harvesting data. Radar missions: active sensing • Illumination of scene, capturing reflection

Ideal balance : coverage vs resolution

Pléiades 20 x 20 km

Pléiades Pléiades : Very High Resolution over 20km swath

SPOT 6 60 km swath

SPOT 6

SPOT 6 : High Resolution over 60km swath Radar vs. Optical

Mission and Satellite Key Features - System engineering

Video (EO System, Orbit, Resolution)

GOCI (07: 16 UTC 26 Jan. 2011)

Earth observation: Meteo instrument

The GOCI instrument, flying on the Korean COMS satellite is offering, since June 2010, unprecedented real time imaging of the water composition and aerosols data

GOCI image: Sinmo volcano in Japan

GOCI image: Yellow dust over the East China Sea before hitting Korea (Nov. 12, 2010)

GOCI under testing GOCI image: Chlorophyll => Detection of biological weak variation Science and Exploration

• Earth / sun science • Astronomy • Solar System exploration Juice

Solar Obiter

Gaia Rosetta Bepi Colombo Columbus: celebrating 10 years for the European laboratory

Title

Contents

Rosetta: long voyage to comet encounter

Rosetta programme Rosetta (total cost: 1100 M€) • ESA : project authority • CNES : responsible for the French part of the payload Philae (total cost: 250 M€) : • CNES : sub-system provider, provider of the Science Operations and Navigation Center Mission Better knowledge of the material of the primitive solar system and its formation Checking if : • Comets have provided an important part of Earth oceans water • Comets have provided compounds required for the birth of life on Earth (complex organic molecules)

Rosetta: long voyage to comet encounter

And a selfie from space!

Telecommunications missions

Broadcast and fixed services Mobile

Broadband Secure communications Broadcasting satellites One way services

Wide coverage – Hot Bird superbeam

ARABSAT BADR-6 Broadcasting coverage Broadband: Example of Ka-Sat

Eutelsat Tooway service • 100% European coverage for broadband User access • 20 Mbps (homes) • 50 Mbps (businesses)

Ka-Sat satellite • Eurostar E3000 satellite providing bidirectional access in Ka-band • Four-colour scheme for efficient frequency re-use • 90 Gbps throughput satellite • In service since 2012

Couverture à quatre couleurs Mobile Satellite Services (MSS)

• Inmarsat-4 cellular network at global scale with three multibeam geo • Alphasat satellites

Secured communications

• Global and steerable spot beams • Skynet 5 system coverage • Four satellites launched from 2007 to 2012

Secure Communications

Secure Communications: « on the pause »

Secure Communications: « on the move »

A new market for telecom satellites: In-Flight Connectivity

Provides connectivity via satellite to aircraft • Cockpit data • Entertainment for passenger

The system must be capable to follow air routes distribution with high flexibility: • Daily basis • New routes

Navigation systems GPS, Galileo, Beidou, Glonass, Gagan, and augmentation Systems (SBAS): WAAS, EGNOS

Services: exemples of ATV, removedebris, servicing missions

ATV (5 models have flown): • Supply the ISS with liquids, gas and cargo • Provides Delta-V to ISS for orbit raising • Performs avoidance maneuvers • Bring back ISS garbage and burn it • Video

Servicer: • What type of services can we imagine for an in-orbit servicer?

Removedebris mission: • Video

Other type of missions: M2M/IoT (for connected objects), AIS

Market projections: billions of connected objects in the next years

LEO constellations for Communications Several constellations have been developed in LEO, to take advantage of low latency, easier access to space, smaller satellites MobileTelephony: interconnection at global level with handheld terminals • Iridium: 66 satellites at 780 km altitude, in operation since 2002, with a new generation (Iridium Next) being deployed • Globalstar: 48 satellites at 1400 km altitude, in operation since 2000, and a new generation of 24 since 2013 Messaging: Machine to Machine interconnection with low cost terminals • OrbComm: 35 satellites at 720 km altitude, in operation since 1995, and a new generation of 24 satellites since 2015

LEO constellations for Communications: Iridium

Iridium: • 66 satellites at 780 km altitude (and not 77) • 1.5 kW, 860 kg

LEO constellations for Communications: OneWeb

OneWeb constellation • Fleet of LEO microsatellites to deliver Internet globally with low latency • Initial constellation: 648 satellites + spares = 900 satellites to be built, reduced to 600 • 150 kg satellites, 1,200-kilometer orbit • Very high production rate

What are the elements of a Space Mission?

Which orbit for which mission? Where to send the satellites: trajectories in Space

Orbit parameters

Different types of orbit

Which orbit for which mission?

The case of 2 special orbits

2 interesting points: the Lagrangian points L1 and L2

Where to send the satellites: trajectories in Space

General case: one body is attracting the satellite This is the general case for Earth orbits The ideal satellite trajectory is defined by theory The real trajectory takes into accounts several disturbing elements: • Earth is not « perfect » • Atmospheric drag (mainly in LEO) • solar wind (radiation pressure)

Specific cases: two or more attracting bodies It is the case of a System with Earth and Sun, or Moon This leads to complex trajectories, which are mission specific • Interesting property of Lagrange libration points, where the attraction of the two bodies are equal and opposite: sun observation (SOHO), parking for interplanetary mission

Orbit parameters S' S (satellite)

r E v Apogee Perigee

rp

a MAT 9178

a 3 orbit period: T = 2 

(µ = 3.986 x 1014 m3 s-2)

Different types of orbit

Orbit LEO MEO GEO HEO

Orbital plan Equatorial, inclined Equatorial, inclined Equatorial Molnia type: or near polar or near polar Inclination: 63.4°

Altitude 200 – 800 km Around 2000 35786 km 1000 – 40000 km or 25000 km

Access time to 15 – 20 mn 45 – 240 mn Continuous > 6h satellite

Pros and Cons . Short signal delay Intermediate . Large Specific . Small path loss between LEO and signal delay utilisation for . Low launch cost MEO for signal (latency) northern regions per delay, path loss . Large path loss with 8 satellites satellite, but many and launch cost . Large launch cost in 4 Molnia satellites for per satellite per satellite orbits continuous access But 1 satellite covers 1/3 of Earth Which orbit for which mission?

Which orbit for which mission? The case of 2 special orbits

Geostationnary orbit « Invented » by Arthur C. Clarke in 1945 Using the property of angular velocity for a point on the equator and a satellite at #36000km altitude: the satellite « does not move when seen from Earth » Application for telecommunications : 3 satellites cover the whole Earth

Which orbit for which mission? The case of 2 special orbits

Polar or near-polar orbits The satellite goes over the poles at each orbit, and sees a different slice of the Earth at each orbit Generally located around 700 km

2 interesting points: the Lagrangian points L1 and L2

• At L1 and L2 Lagrangian point, the attraction of Earth and Sun are in equilibrium • L1 and L2 are used for astronomical observation missions • Example of SOHO, launched in 1995, • embarking 12 experiments • ESA/NASA cooperation

A very special trajectory: rendez-vous with a comet

Video

What are the elements of a Space Missions?

Launch segment The launch segment: selection of launch sites

Launching environment: impact on the satellites

Launcher selection criteria

The launch segment: selection of launch sites

There are a few launch sites over the Earth. The following selection criteria are use to determine the location: • Large area for assembly halls and launch pads • Free zone under the early trajectory • No constraints towards East (for launches to Geo Stationnary) • As close as possible from Equator (Earth rotation effect) • Accessibility (land, sea, air) • Political situation (unrest, export)

Launching environment: impact on the satellites

During the launch, the satellite has to withstand several types of constraints, which will drive its design: Mechanical and acoustic: • Acoustic noise of the launcher engines (mainly on large surfaces) • Mechanical vibration on structural parts (primary and secondary structures) • Shocks when the fairing is separated in 2 parts • Shocks at spacecraft separation

Thermal: • Aerothermal drag during ascent, due to launcher speed • Thermal environment when the launcher is above atmosphere (Sun orientation)

Depressurization/ venting during launch • going from ambient pressure on earth to vacuum when in space

Launcher selection criteria Technical: • Launcher performances (delta-V, orbit parameter at separation) • Launcher environment (vibration, shocks, noise, thermal) • Physical compatibility between the spacecraft and the fairing • Reliability (mission success) • Telecom satellites are generally designed to be compatible with all “heavy launchers”, such as Ariane 5, Proton M, Falcon 9, Falcon Heavy, Ariane 6 (to come) Financial: • Price • Including insurance (linked to reliability) • And induced costs: transport, launch campaign Programmatics: • Availability for the required launch date, with sufficient margin • Flexibility • Alternative launcher Political and strategic: • Export issues • Sovereignty What are the elements of a Space Mission?

Frequencies: Fuel for communications mission

Frequency bands used in Space:

Need for coordination

Overall coordination process: a 3-step process for GEO satellites

Frequencies: fuel for communications mission

Spectrum is a scarce resource: Access to spectrum is key for Telecom mission implementation Spectrum is shared amongst various services, such as: • Fixed Satellite Service (FSS) • Mobile Satellite Service • Broadcasting Satellite Service (BSS) • Earth exploration satellite service • Space research service • Amateur satellite service • Inter-satellite service

Frequencies: fuel for communications mission

Radio frequency spectrum • Limited natural resource that must be used and shared equitably, rationally, efficiently and economically. • Common resource (United Nations non-appropriation treaty - 1967). • To be regulated at international level: the Radio Regulations managed by the ITU - International Telecommunication Union. • the international regulations are complemented by national regulations (sovereign right of each State to regulate its telecommunication (ITU Constitution).

ITU - International Telecommunication Union • United Nations specialized agency, headquartered in Geneva (Switzerland) and responsible for regulations of Telecommunications. • Organization within which governments and the private sector coordinate global telecom networks and services through International Regulations.

Frequency bands used in Space:

• Limited bandwidth

• Cheaper terminals • Good foliage penetration • Good support for mobiles • Wide beamwidths, so frequency re-use difficult • Easy to intercept and jam

• More Bandwidth • Absorption losses increase • Narrow beams allow frequency re-use • Better spot beam support for small terminals • Robust protection • Better pointing accuracy needed • = (more complex/more expensive terminals) A perfect world Frequencies: need for coordination

Purpose of coordination: • Guarantee a minimum signal to noise ratio • Minimize interference level from other networks

Techniques: • Frequency isolation The real world • Polarization isolation • Coverage isolation • User terminal antenna diameter increase, to reduce gain towards adjacent satellite Overall coordination process: a 3-step process for GEO satellites

Advance Publication Information • Outline of Administration intention to use frequency and orbital resources in the future • Opportunity for discussion with other interested administrations Request for Coordination • Technical information about future satellite network based on Appendix • Negotiations to co-ordinate with other networks • Framework for negotiations detailed by RR • Advantage to first-comers who often have large staff dedicated to co-ordination activities Notification • Occurs after successful completion of coordination and demonstration of acceptance levels of interference • Bring into Use, 3-year suspension

What are the elements of a Space Mission?

Space environment

Natural space environment

Micrometeorids

From 1957 to 2015: orbital debris are generated by the activity of man in space

The space environment interacts with the satellite

Natural space environment Coronal mass ejections: • huge bubbles of gas ejected from the Sun Solar flares: • huge explosions on the surface of the Sun. Flares are very fast processes with time scales of only a few minutes. They only occur during maximum solar activity period (11-year cycle). Solar wind: • Flux of particles (electrons, protons, Helium) escaping from the Sun The geomagnetic field: • The geomagnetic field acts as a shield. It protects the earth from certain particles. On the other hand, it creates the radiation belts by trapping the electrons and protons.

Micrometeorids

Micrometeroids • The micrometeoroids are of natural origins (comets, asteroids, etc.). • The meteoroids arriving on Earth generally come from the asteroids (99.4%). The meteoroids coming from comets are less fragile and do not cross the atmosphere. They are seen as shooting stars (Perseides, in August).

• Some 15 000/20 000 tonnes / year penetrate into the atmosphere (6 tonnes arrive on Earth) X

Meteoroids smaller than 0.1mm are called micrometeoroids. • Their speed is 11 to 72 km/s, with an average of 20 km/s. • Order of magnitude: a particle of 1 mm radius at 70 km/s has as much energy as a bowling bowl of 4kg at 130 km/h….

From 1957 to 2018: orbital debris are generated by the activity of man in space. • Satellites (4700 of which 1800 in use) and stages of rockets, products from explosion, collision, operational debris (tools, separation belts, bolts, instrument covers, propulsion products ) • 20 000 objects > 10 cm, • More than 700 000 objects from 1 to 10 cm, • 100 000 000 objects from 1 mm to 1 cm. US Surveillance network (radars + telescope) operated by NORAD tracks objects above 10 cm in LEO and objects above 1 m in GEO. Europe is currently implementing some means of space surveillance = Radar Graves (France) that fills a database of 2000 objects (operational and non-operational).

From 1957 to 2018: orbital debris are generated by the activity of man in space. • Satellites (4700 of which 1800 in use) and stages of rockets, products from explosion, collision, operational debris (tools, separation belts, bolts, instrument covers, propulsion products ) • 20 000 objects > 10 cm,

The space environment interacts with the satellite

Atmosphere: • Drag, disturbing torque • Erosion Charged particles (electrons, protons, heavy ions): • electrostatic discharge • Degradation of electronic components, SEE • Degradation external materials, optical instruments due to cumulated dose • Degradation of solar cells, opto-electronic components… Magnetic field: • satellite / magneto-coupler coupling Solar radiation: • Thermal effects • Solar pressure Micrometeorids / Debris: • physical damage What are the elements of a Space Missions?

Ground Segment Control segment Spacecraft configuration Payload and platform health monitoring

Mission segment Mission preparation and management Payload configuration Gateway

User Segment Data processing, archiving, distribution User terminals: TV reception, VSAT, mobile phones, military terminals

Space System architecture: Earth observation system

Space System architecture: Telecommunications system

What are the elements of a Space Missions?

Space Law

Space Liability: the 1967 Outer Space Treaty (107 rat., 23 sig.) Provides basic legal framework for International Governance of Outer Space • Benefit to all the peoples, peaceful use of space Provides legal framework for international liability of States party to the Treaty Space Liability: the 1972 Liability Convention (92 rat., 21 have sign.) Expands on the liability rules created in the 1967 Outer Space Treaty • Introduction of the term “Launching State”: a State which launches or procures the launching of a space object, or from where it is launched • Introduction of the liability regimes applicable to Launching States: Absolute liability for damage caused on the surface of the earth or to an aircraft in flight, Liability for fault for damage caused elsewhere than on the surface of the earth The 1975 Convention of Registration of space objects (64 rat.) • Mandatory central registration of objects launched into outer space • Launching States shall provide all information to Secretary General of the UN

Actors in the Space System value chain

Manufacturers Telecom main players: Airbus, SSL, Boeing, TAS, Lockheed Martin, Orbital ATK Telecom challengers: CAST, Melco, ISS Reshetnev, OHB Observation main players: Airbus, IAI, Satrec Initiative, TAS, NEC Observation challengers: CAST, Elecnor, Lockheed Martin, Ball Aerospace And a lot of new entrants Telecom operators, Space Agencies Global (Intelsat, Eutelsat, SES, Telesat) and regional operators (KT, Arabsat, Nilesat, ABS, Turksat), with fleets from 1 to 50 satellites National Agencies: NASA, ESA, ROSCOSMOS, CNSA, JAXA, CNES, DLR, ASI, BNSC, ISRO, CSA, South Korea (KARI), Netherlands, Ukrain, Israel, Brasil, North Korea, Taiwan, Iran, Algeria,…United Arab Emirates Dedicated Agencies: Eumetsat, NOAA New Space GAFA, SpaceX: entrepreneurs, huge investment capacity, privately funded programmes, dreams and ambitions. They can be in any place of the value chain

Conclusion

Through this module, we have seen all the types of Mission that can be fulfilled by a Space System , and all the elements that have to be taken into account for designing it

In the next module, we will see how the mission drives the System and Subsytem design, at Platform and Payload level, how this design can be validated before launch, by focusing on Telecommunications Satellites.