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Idea: I-2022-01817

TYCHO: Supporting Permanently Crewed Lunar Exploration with High-Speed Optical Communication from Everywhere

This idea has been archived

Dear idea/use case provider,

 

We would like to inform you that your submission has been considered of interest and a potential candidate for future augmentation of the Cislunar Communications and Navigation services.

The Moonlight Programme proposed for decision at the upcoming ESA Ministerial Council (CMIN 22) in November 2022 is also planned to support related Technologies and industry initiated Products/ Services Activities.

Hence, the activity you proposed could potentially be supported by the Moonlight Programme, pending also subscription levels achieved at CM22.

Your submissions will be forwarded to ESA team that is working on the Moonlight programme preparation and we invite you to follow up through the email contact point: moonlight@esa.int.

Thank you again for applying.

 

Kind regards,

ESA Evaluation Team

Sep 15, 2022
All Authors
In the current wake of mission plans to the Moon and to Earth–Moon Libration points (EML) by several agencies and organizations, TYCHO identifies the key role of telecommunication
provision for the future path of lunar exploration. It demonstrates an interesting extension to existing communication methods to the Moon and beyond by combining innovative technology with a next frontier location and the commercial space communication sector.
It is evident that all communication systems will rely on direct communication to Earth
ground stations. In case of EML-2 missions around HALO orbits or bases on the far side of the Moon, it has to be extended by communication links via relay stations. The innovative approach is that TYCHO provides this relay communication to those out-of-sight lunar missions as a service. TYCHO will establish a new infrastructure for future missions and even create a new market for add-on relay services. The TMA-0 satellite is TYCHO's first phase and a proposed demonstrator mission to the Earth–Moon Libration point EML-4. It demonstrates relay services needed for automated exploratory and manned missions (Moon bases) on the rim (>90°E and >90°W)  and far side surface, to lunar orbits and even to EML-2 halo orbits (satellites and space stations). Its main advantage is the permanent availability of communication coverage. This will provide full access to scientific and telemetry data and furthermore to crucial medical monitoring and safety. The communication subsystem is a platform for conventional communication but also a test-bed for optical communication with high data-rate LASER links to serve the future needs of manned bases and periodic burst data-transfer from lunar poles. The operational TMA-1 satellite is a stand-alone mission integrated into existing space communication networks to provide open communication service to external lunar missions.

In the current wake of mission plans to the Moon and to Earth–Moon Libration points (EML) by several agencies and organizations, TYCHO identifies the key role of telecommunication
provision for the future path of lunar exploration. It demonstrates an interesting extension to existing communication methods to the Moon and beyond by combining innovative technology with a next frontier location and the commercial space communication sector.

Fig. 2.: TYCHO satellite relay servicing between Earth and the Moon (near and far sides) via EML-4 with KA-band and laser-comms. EML-system is co-rotating leading to the EML-4 and EML-5 positions to be similar to Earth GEO position and allowing to be seen on the same relative position on Moon's sky. Allowing permanent-on comm-links is the key point in TYCHO.

 

It is evident that all communication systems will rely on direct communication to Earth
ground stations. In case of EML-2 missions around HALO orbits or bases on the far side of the Moon, it has to be extended by communication links via relay stations. The innovative approach is that TYCHO provides this relay communication to those out-of-sight lunar missions as a service. TYCHO will establish a new infrastructure for future missions and even create a new market for add-on relay services. The TMA-0 satellite is TYCHO's first phase and a proposed demonstrator mission to the Earth–Moon Libration point EML-4. It demonstrates relay services needed for automated exploratory and manned missions (Moon bases) on the rim (>90°E and >90°W) and far side surface, to lunar orbits and even to EML-2 halo orbits (satellites and space stations). Its main advantage is the permanent availability of communication coverage. This will provide full access to scientific and telemetry data and furthermore to crucial medical monitoring and safety. The communication subsystem is a platform for conventional communication but also a test-bed for optical communication with high data-rate LASER links to serve the future needs of manned bases and periodic burst data-transfer from lunar poles. The operational TMA-1 satellite is a stand-alone mission integrated into existing space communication networks to provide open communication service to external lunar missions.

The TYCHO mission is a concept study[0] by Andreas HORNIG conducted for the Institute for Space Systems (IRS)[1] at the University of Stuttgart, Germany and at OHB-Systems Bremen. It is a phase 0/A study for a demonstrator and operational communication relay satellite and covers the mission goals and use cases for the optical and rf-comm-links, the full satellite systems design and the business case situations from 2013.

For the 2022 MoonLight constellation, the focus lies on the specific aspect of the caller. It is describing the "user terminals and connectivity" on the TYCHO baseline and the "universal access and integration into further networks” aspects.

The TYCHO idea won the "innovative mission to the moon" call from OHB-Systems for the Space Generation Congress by the SGAC for IAC2011 Cape Town (ZA). The idea was developed into said concept study as a thesis at the University of Stuttgart in 2013 and presented to the space community at IAC2013 in Beijing and peer-reviewed in the Astro Astronautica journal in 2015[3].

AerospaceResearch.net
Yes

Within the overall perspective of ESA’s MoonLight initiative, the TYCHO mission shall become for the moon, what Eutelsat became for Earth, a satellite communication service from a quasi stationary position in the sky that started a European industry in the operation of lunar satellites[11,12].

Out of this ambition in the 1970s, there are now many privately owned and operated geostationary telecommunication satellites connecting our every lives on Earth. TYCHO transfers this to the Moon and shall replicate this success by integration into the MoonLight system and beyond to provide telecommunication services via classical radio frequency links as well as optical laser links.

 

And this one aspect of high speed and secure laser links is the core in this call for ideas. We will provide the base of the business case, the benefit factor for all users within the MoonLight network and who these users are.

 

TYCHO mission statement

  • The TYCHO mission provides communication relay services between the Earth and the Moon via the Earth–Moon Libration point EML-4.

  • Its service is mainly based on Laser Communication Terminals with small terminals for the user segment eg. on moon’s surface.

  • It serves as a long-term infrastructure for different Moon missions on lunar surface, lunar orbit, and to the EML-1 and EML-2 points.

  • It shall enable inter-connectivity between other services like MoonLight, EDRS, TDRS and more.

  • An interference free/minimized communication service shall be provided to ITU shielded zone[7] on the far side of the moon.

  • It enables rover based manned geological exploration missions of the moon's surface due to exceptional availability.

  • The mission is divided into a demonstrator satellite TMA-0 proving that it is possible with the use of today's technology and the operational satellite TMA-1, which provides the longterm communication service.

  • The mission will open up new scientific knowledge and market opportunities.

Video 1.: TYCHO presentation during IAC2013 in Beijing.

Earth–Moon-Libration point 4

Properties

The TYCHO satellites utilize the special properties provided by the libration point EML-4. In this point in the co-rotating frame the combined gravity forces on the satellite by Earth and Moon are equal to the centrifugal force of the satellites. The EML-4 provides two useful effects for space

applications. If the satellite leaves this point due to perturbation (solar pressure, etc.) a restoring force acts on the satellite resulting in a bean-shaped orbit with a long-term stability. This is advantageous for AOCS and the propellant mass. Furthermore, all five EML points have fixed positions in the co-rotating frame and the same orbit period as the Moon. This feature is advantageous for the communication service (Fig. 1).


Coverage of high priority landing sites and EML-2

From the position in EML-4 the satellite can establish permanent communication links to the surface of the Moon and also to EML-2 in the Moon shielded zone[7]. The rotation of the Moon is tidally locked and always facing the Earth with the same side and thus also EML-4. Additionally, the fixed positions of EML points also allow fixed communication between EML-4 and EML-2.

For the user requirement elicitations, high-priority landing sites from the NASA Exploration Systems Architecture Study (ESAS) [4-6] for possible future missions and the formerly planned Apollo 18–20 landing sites are analyzed with AGI Satellite Tool Kit (STK). The coverage times to these 13 locations from different locations (EML-2, EML-4, Deep Space Network (DSN)) showed that 10 out of 13 sites are accessible from EML-4 (20°E–140°W, 85°N–85°S) (Fig. 4, Table 1). The comparison revealed an exclusive zone at the edge of the near and far side of the Moon (80°W–100°W, 85°N–85°S) with best coverage time for the Orientale Basin Floor landing site (10).

 

Fig. 4.: Lunar coverage map with EML-4 (top) and with EML-2 and Deep-Space-Network (DSN) Madrid (bottom). The colours indicate the access to the different satellites in percentage of time. The red 100% indicates the permanent availability of link access to the position on lunar surface and thus the best availability. The user can estimate how often a connection can be established and kept during a period of a lunar month. Also showing EML-4 exclusive zone (minimum 5° elevation).

 

Table 1: (extends Fig. 4)

The analysis shows that the unique selling proposition is servicing lunar missions in the exclusive zone with an emphasis on far side missions in that region because no direct-to-Earth communication is possible and communication is only possible via a relay satellite in EML-4. The region on the far side but in close proximity to the near side is interesting for astronomy missions. The Moon shielded zone[7] allows radio astronomy as well as high energy particle science without interfering noise propagating from Earth. It is also an interesting region for mobile manned missions for geological exploration of the Mare Orientale impact crater and furthermore attractive due to the possibility of reaching the near side for communication and safety reasons. Additionally, the coverage zone includes the lunar maria area compound of Mare Imbrium, Oceanus Procellarum, Mare Cognitum and Mare Humorum with the landing sites 4, 5, 6, 9 and 11. This wide area is completely on the near side and interesting for geology and the evolution of the Moon.

So TYCHO permanently covers most of the high-priority landing sites and the EML-2 for possible future autonomous and manned lunar missions. Prime clients would be radio astronomers from the shielded zone due to the need to transmit big-data and the requirement to have no interfering disturbance from any radio frequency source during these transmissions to their radioscope antennas. Laser links with TYCHO would be their prime choice.

The business case lies on the client side, to provide the terminal hardware and the service to the user to connect to TYCHO’s and any other optical network. This is currently in progress for Earth laser comms systems, and it will be new for the Moon.

No

The application is open for starting or joining a consortium.

During several projects for Tesat-Spacecom and the EDRS project.

And directly for ESA Summer of Code in Space campaigns with AerospaceResearch.net[2]

Use Case #1: NAV - Positional Knowledge of all Nodes

With such a tight beam like optical beams, positional knowledge of the client and the targeted entry point into the communication network becomes essential. In contrast to radio-frequency based systems optical systems have tiny beam diameters so that targeting the other node becomes a challenge. The client on the lunar surface needs to know precisely both positions, the own position and the satellite in orbit. With the a priori knowledge of the satellite in orbit the laser terminal can be targeted towards the satellite and the remaining searching time of the other terminal can be minimized. The TYCHO mission is in the Earth-Moon-Libration point 4 (EML-4), so the client needs to have the targeting information for the time of call and his own position to be able to move the laser terminal into the right azimuth and elevation position. Without both positions, it becomes almost impossible/impractical to establish such a connection.

 

Use Case #2: COMS - Automatization and Integration

With the use case #1, communication between one client and one orbital terminal is already possible but incomplete. It would still require further steps to deliver the data to the goal on another lunar destination, into the lunar gateway station or back to earth. So ESA's Scylight can enable the client on the lunar surface to forward the data to the final address. Within Scylight wake-up-on-light[9,10,13] features are being implemented into the EDRS and follow-on networks. With such gnostic systems similar to IP-package based networks (Internet), the terminal wakes up when it sends an incoming call, opens up the line, and forwards the data to the address the client attached to the data.

It also allows the essential handover between MoonLight constellation, TYCHO, EDRS and other networks. The integration into many networks allows the final scalability of the overall service and the long term use as a permanent infrastructure.

In the scope of ESA's Moonlight initiative, the TYCHO mission is a perfect representative of how Moonlight enables the optical communication between lunar ground and a satellite in lunar orbit and beyond. Here two aspects become important, the positioning of all nodes of the communicating network and the full automatization of the services. Only this allows first of all the communication of high bandwidth data rate communication and the scalability of the system including an integration into other networks like the European Data-Relay Satellite System (EDRS).

Services used for Use Case #1 - positional knowledge:

The client on ground needs to have an onboard GNSS to provide its own position on the lunar surface. For that a GPS/GALILEO like GNSS service for the moon provided by MoonLight is required.

Also the satellite in its orbit  needs to be known. The orbit determination can be achieved by several services. Either by classicale orbit determination by observation of the satellite. Or more advanced by the GPS/GALILEO like GNSS service by MoonLight. GNSS is confirmed to be usable also in different orbits. With MoonLight's GNSS, TYCHO can position itself with an onboard receiver. The data is used to create a set of orbit parameters, a so-called two-line-element (TLE) set. And this is broadcasted to the many clients to be used to call the satellite.

 

Services used for Use Case #2 - Automatization and Integration

Also here the orbital parameters (TLEs) of all the satellites are required to be determined and distributed. Moonlight's positioning and communication systems for all terminals are required.

Another service to be used by TYCHO is the standardized network layer of MoonLight. Interoperability is key to reliable, secure and sustainable communication and navigation systems around the moon.

 

For optical communication networks like EDRS the infrastructures exist that are inputs to the process flow of operations.

Some but not all are…

  • Tracking services of satellites by NORAD, ESTRACK and LeoLabs

  • Operation Centers for planning by the German Space Operations Center (GSOC)[8]

  • Communication services to upload instructions from GSOC to the satellite and telemetry back by GSOC

 

For the moon based application infrastructure like these needs to be extended or established.

Especially users with demand for high data rates and secure communication benefit from TYCHO integration into MoonLight.

Similarly to the internet on earth, the network layer is not directly seen by the clients. The client who wants to send data via high speed optical links can be enabled to do so completely with simply the entry points satellites and its own position. But who are the users that will require optical links and cannot use classical RF links?

Within TYCHO mission, the users are identified to use it for high data rate, backhaul purposes, like scientific data of radio astronomers secure channels due to the point-to-point aspects that only allows one user at a time and the very narrow beam with practically no other user within it disturbance free environment, also radio astronomers.

The TYCHO mission is a good example for all these aspects. The EML-4 position allows communication to the far side of the moon. This shielded zone (ITU) is important for radio astronomy where any other rf-communication would interfere to great effect and even make observation impossible. So satellites in lunar orbit and EML-2 would send out radio waves during the passover flights over the lunar bases on the far side. Optical communication solves this problem and would limit light interference to a very limited point on the lunar surface like a few hundred meters which is acceptable even by optical astronomers. Further the radio astronomer user would like to backhaul the data from the farer side to earth, so the EML-4 position would allow such a GEO like relais communication with permanent contact time to the client and high data rate. Lunar orbit satellites would not provide this always-on feature because they would move away from the line-of-sight during the orbit. Only delay times would be higher for connections via an EML4 satellite but for big-data application Delay Tolerant Network (DTN) features solve this.



Current state of the art optical networks via satellite are not constellation agnostic. The satellites as well as the client terminals within the constellation do not know each other. Parameters for aiming towards the target terminal, the schedule and routing are provided to each terminal before the actual link. Otherwise communication would not be possible.

  • With the novel wake-on-light feature the caller can access the TYCHO terminal.

  • The standardized IP based address feature will enable the TYCHO terminal to auto-route to the destination directly or via “hopping” the next nodes until it reaches the destination.

  • Determination of the TYCHO satellite orbit parameters will be able by onboard determination via MoonLight's GNSS and directly broadcasting it to others.

The laser terminals working according to the constellation agnostic method shall be standardized. Only in this way the user base will be big enough and an optical communication service will be viable and sustainable for lunar exploration activities. Another aspect is interoperability through standardization. If different users can just choose between several communication and navigation services from different providers supplementing each other there is no need, that every mission provides its own DTO or relay system. This leads to less missions around the moon, less rocket launches and most importantly, less debris on the moon's surface from completed missions.

Two technical showstoppers are identified.

The first is the availability of the GNSS system that is used for the orbit determination for the satellites the user wants to target and the GNSS system that is used for positioning the user’s location.

The second is the distribution of the satellite orbit parameters to the users via any other second communication channel. Without targeting knowledge, finding the satellite with the user’s terminal changes from seconds to hours and becomes impractical. With a typical ~10murad divergence angle laser beam, an uncertainty search area of ~6 degrees would take several hours to scan with a current state of the art spiral method. The user terminal needs to have a certain apriori knowledge of the targets' position for the scheduled transmission time.

 

Andreas HORNIG holds a diploma (Diplom-FH) as in mechanical engineering from the University of Applied Sciences Bremen and in aerospace engineering from the University of Stuttgart with a specialization in space systems and space applications. He specialized in concept studies for small satellites and the TYCHO mission is his diploma thesis.

He worked as a mission analyst for laser communication terminals at Tesat-Spacecom and as an operator for the TOAGS optical groundstation at Tenerife, Spain. He is now a project manager and systems engineer at Jena-Optronik for Star Trackers.

He is conducting an external doctoral research at the Institute for Photogrammetry with Prof. Dr-Ing. Fritsch at the University of Stuttgart in the field of tracking smallsats and cubesats with a distributed ground station network. He is a keen supporter of the open-source movement and his organization AerospaceResearch.net was selected several time by Google and ESA for their Summer of Code campaigns (GSOC and ESA SOCIS).

 

Ulrich BEYERMANN holds a diploma degree in aerospace engineering.

In his four years as a research assistant at the Institute of Space Systems at the University of Stuttgart his focus was on development of innovative communication systems. Besides his activities in system engineering of a flexible and full digital communication system he was in charge of building up the ground station.

After university he worked seven years at Tesat Spacecom in Backnang, world's leading supplier for high data rate communication systems, especially optical systems. Among other things he was project manager for several high data rate modulators for customers all over the world, including James Webb Space Telescope and development project for gbps modulator in cooperation with ESA. Therefore he has a deep knowledge in the space industry as well as ESA projects, systems engineering of space systems, especially communication systems, and excellent skills in organizing and managing projects.

Since 2021 he is working as an independent project manager, lean coach and consultant.

 

The business model is split into hardware and service.

The user terminals need to be designed and built using the TYCHO system for updating the pointing knowledge and auto-scheduling. Here engineering and licensing (including open-sourcing and open-standards) will be services that can be provided. The goal is to scale up the user base and cellphone as well asIoT standards are a plan. 

Providing the orbit parameters of all satellites within the network as a service is the most prosperable case. In the sketches you find this "at the moon base" and as a comparison this is similar to the DNS services in the internet, or space situational awareness services like from LeoLabs. Providing services to be able to access all nodes from user terminals and to allow optimal routing between satellites will be valuable. It also allows further expansions to provide high-precision orbit determination, collision avoidance between lunar satellites and spectrum sharing.

A research for possible users for such a mission was conducted in [0]. A regular update of new MoonLight participants is needed.

  • Wake-on-light features (for Scylight[9,10,13] and MoonLight)

  • Automation of user terminals by implementing the position knowledge database/almanach

  • We would like to analyze the stake holders to standardize the universal access to MoonLight and similar systems…

    • Integration to EDRS, TDRS and others

    • GALILEO adaption to lunar-navigational-satellite-service (lnss)

    • Scylight implementation into MoonLight

      • wake-on-light

      • auto-routing


    Furthermore the ESA roadmaps to related systems for orbit determination and SSA for the moon should be studied with respect to capabilities and private and public space services


    A demonstration should be conducted 

    • demonstrator mission for testing availability of GALILEO and other GNSS for satellite applications in lunar orbit


    And lastly, go-to-market strategies shall be developed like

    • government contract

    • technology demonstrator mission

[0] Hornig, A., "TYCHO: conceptual design of a satellite demonstrator mission to Earth-Moon-libration point EML-4 as preparation for a communication relay service", Supervisor: Prof. Dr. rer. nat. H.-P. Röser, Institute of Space Systems (IRS), University of Stuttgart, Stuttgart, Germany, 2013. [online]

[1] Institute of Space Systems (IRS), University of Stuttgart, Germany, www.irs.uni-stuttgart.de

[2] AerospaceResearch.net, https://aerospaceresearch.net

[3] Hornig, A., Homeister, M. "TYCHO: Demonstrator and operational satellite mission to Earth–Moon-Libration point EML-4 for communication relay provision as a service," in Acta Astronautica Volume 108, March–April 2015, Pages 156-170, https://doi.org/10.1016/j.actaastro.2014.10.016 

[4] Bhasin,K. B. , Warner,J. D. and Anderson, L. M., "Lunar Communication Terminals for NASA Exploration Missions: Needs, Operations Concept and Architectures," in 26th AIAA ICSSC Conference, San Diego, California, June 2008.

[5] NASA, "ESAS - Section 4H - Lunar Surface Outpost Communication Strategy," [Online].
Available: http://www.hq.nasa.gov/pao/FOIA/ESAS/ESAS_Appendix_4H.pdf. [Accessed 2013-03-13].

[6] NASA, "NASA's Exploration Systems Architecture Study - Final Report," 2005.

[7] ITU, "RECOMMENDATION ITU-R RA.479-5*: Protection of frequencies for radioastronomical measurements in the shielded zone of the Moon," 2003, https://www.itu.int/rec/R-REC-RA.479-5-200305-I.

[8] Göttfert, T., Wörle, M.-T., Prüfer, S. and Lenzen, C. (2018) "Operating and Evolving the EDRS Payload and Link Management System". In: 15th International Conference on Space Operations, SpaceOps 2018. 15th International Conference on Space Operations (SpaceOps 2018), 28 Mai - 01. Jun. 2018, Marseille, France. doi: 10.2514/6.2018-2688. ISBN 978-162410562-3.

[9] ARTES 4.0 Strategic Programme Line – Optical Communication  - ScyLight with the activity reference 5G.006/SL.022

[10] Chelkowski, S., Kröber, F., Treichel, K., Hornig, A. (Jena-Optronik GmbH) "AUTO-TDS: Enabling laser communication networks to auto detect incoming links, securing connection and auto-routing the data" IAC2022, Paris (accepted) IAC-22,B2,5,3,x69327

[11] ESA, "Historical overview" [Online]. Available:  https://www.esa.int/Applications/Telecommunications_Integrated_Applications/Historical_overview [accessed 2022-04-29] 

[12] Eutelsat, "Our History - 40 years of innovation at the heart of a global satellite industry and vibrant digital economy" [Online]. Available: https://www.eutelsat.com/en/group/our-history.html [accessed 2022-04-29] 

[13] CCSDS, "Optical Comunications Physical Layer" 141.0-P-1.1 (Pink Sheets) July 2020

 

Video 2.: TYCHO transfer phases animation. (1) Transfer from Earth to EML-4. (2) EML-4 operational orbit. (3) End-of-Life transfer to Moon with on surface disposal.

 

 

Video 3.: Example of trajectory and orbit station keeping strategy finding for EML-4 with NASA GMAT. Providing an estimate how big the area is where the TYCHO satellite will be as seen from the moon. This "bean shaped" orbit will have to be scanned fully from the moon leading to very loon, impracticle scanning times before connection can be establied. A good orbital knowledge of the satellite is required to reduce scanning and thus connection time for a terminal on the moon and also from other locations.

 

Fig.: The moon, earth and the EML-4 within the Earth-Moon system. The TYCHO orbit within the EML-4 area is a radius of about 45000km around the EML-4 point. This is the area a user needs to "scan" from the moon to find TYCHO without any apriori knowledge where it is. This takes hours in best cases and is impracticle for normal use cases. 

 

Fig.: Station keeping orbit after injection within a distance to EML-4. (0) transfer, (1) injection to 12,000 km distance, (2)–(4) “expansion and shrinking of orbit” within allowed 45,000 km distance.

 

TYCHO mission

 

Andreas HORNIG

 

Ulrich BEYERMANN

 

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Francesco Liucci

Dear idea/use case provider,

 

We would like to inform you that your submission has been considered of interest and a potential candidate for future augmentation of the Cislunar Communications and Navigation services.

The Moonlight Programme proposed for decision at the upcoming ESA Ministerial Council (CMIN 22) in November 2022 is also planned to support related Technologies and industry initiated Products/ Services Activities.

Hence, the activity you proposed could potentially be supported by the Moonlight Programme, pending also subscription levels achieved at CM22.

Your submissions will be forwarded to ESA team that is working on the Moonlight programme preparation and we invite you to follow up through the email contact point: moonlight@esa.int.

Thank you again for applying.

 

Kind regards,

ESA Evaluation Team