Small and Thin Planet satellites: Development, State of the Art and EMC Issues.

1. Small and Thin Planet satellites: Development,State of the Art and EMC Issues. Jacob Gavan Fellow IEEE October 2013

2. Introduction • In the Beginning of the 17th Century KEPLER discovered the existence of Natural Satellites and their Orbit equations, but only in 1957 was Launched the First Russian (Artificial) Satellite SPUTNIK in a Low Earth Orbit(LEO) Due to the Advancements in the Development of Rockets. • In 1963 was Launched the first US Geostationary (GEO) Satellite due to the prediction of Arthur Clark in 1945 Inspired by the 3rd equation of KEPLER. • GEO satellites enable reliable long distance radio –communication with minimal interference • Satellite is an Interdisciplinary Field and the Subject of Satellite Radio Communication is One of the Most Importance.

3. Introduction: Main Satellite Orbits LEO: 300-2000 Km MEO:4000-8000,20000Km GEO: 36000 Km LPO :Moon ,Planets and future projects In 2013 are operating several Thousands LEO, more than 400 GEO and around 100 MEO satellites.

4. Classification of Satellites An Important part of the sat. cost is the salary of the specialist s and its space reliability tests.

5. Micro and Mini-satellites The extreme miniaturization of electronic systems predicted by Moore “doubling the number of elements on an IC each 18 months approximately” enable the building of reliable small sat. . These small sat. can provide good performance at low cost but, due to the limited place, redundancy is difficult to implement, which may limit sat. life time and performances.

6. Radio Amateur Satellites-OSCAR • (Orbital Satellites Carrying Amateurs) RadioOSCAR was founded in 1960.OSCAR1 the first non government Micro Satellite was launched in 12.61 transmitted Morse signals at 145MHz for 3 weeks. • GURWIN/OSCAR32 built in the TECHNION and launched the 7.98. The Satellite has a cubic form a=44.5cm and operated for more than 10 years at 145, 435 and 1270 MHz. P=20W . Nowadays radio amateurs from more than 24 countries and thousands of Engineering students all over the world are building hundreds of Pico and Nano-satellites . Each earth station is connected with a LEO small Satellite less than 15 minutes for each cycle and 97% of the time is not connected to the specific satellite . • Therefore is required a network of earth stations to control and operate properly LEO small satellites. Several amateur satellites failed in launch or operation.

7. Small Satellites Radio Frequencies • The LEO small satellites use often the VHF band from • (30-300)MHz which are significantly lower than the UHF and SHF Microwave bands used for bigger satellites. • The VHF are vulnerable because of the Faraday effect signal distortions from the Ionosphere layers. This effect can usually be neglected in case of narrow bandwidths up to 4.8kbps used generally for small satellites. • The terrestrial mutual interference are often higher in VHF. • The dispersion losses in VHF are significantly lower than for higher frequency bands which enable reduced transmitter power in the UP-LINK and especially in the power limited DOWN-LINK.

8. Advantages and disadvantages of small Satellites Advantages • Low price • Fast and low cost construction and replacement • Simple and lower cost launching with less pollution • Enhance the quantity and quality of students in space technology Disadvantages • Increase space junk • Limitations in power , redundancy and reliability • Less regulations and more interference

9. Thin Satellites Cube-Sat Stanford and Polytechnic California State U. have developed in 1999 an open source standard means for building and launching thin low cost nano and pico satellites. The Cube-sat. kit is a 10cm size cube weighting around 1 kg called the 1U. Are also available the pico-sat. 0.5U or for nano-sat. the 2 and 3U as shown in the figures. A P-POD Poly. Push Out and Deploy sub system is added The cost for academic students to build an 1U cube-sat. is less than $100k.

10. 5 Comments Cube-sat with many Very Thin FEMTO-SAT In the pictures the Cornell U. sprite 2cm x 2cm x 2mm. is printed on a small light wafer of silicon. The Microcontroller is a TI-MSP430. The sprite could include also miniature sensors such as mini cameras, magnetometers and GPS chips. The cube sat could carry hundreds of spring loaded sprites. The sprites could be positioned in orbit till 500km for radio communication by sailing on solar wind dip into space like cosmic dust, without onboard fuel supply.

11. The US Air Force Research Laboratory developed in 2004 the Modular Open Source ARCHitecture (MONARCH) for building small satellites using Plug and Play and 3D printing techniques.

12. NASA Special Nano-Satellite The high performance NASA’s nano-sat. Aercam was launched from a Space Shuttle (STS) in 2005 to inspect and protect SS and the ISS. The Aercam is just 19cm in diameter, weight only 4.5kg and include a Li Ion battery and propellant. An earlier Aercam could prevent the STS-107 disaster of 2003 and save the life of Ilan Ramon and his friends.

13. EMC Considerations for Small Satellites • The increasing number of sat., especially small and thin, enhance the magnitude and probability of noise and interference. • The threats are mostly from the great numbers of sat. built by students, which need to be regulated and controlled from the design steps by EMC experts. • Downlink Interference is more important due to the thin sat. limited output power and the strong level of terrestrial VHF interference which reduce S/N+I.

14. Main Mitigation Techniques to Reduce Small Sat. Interference. • The important mitigation measures are primary to keep the uplink and downlink Tx output spectrum clean from spurious and out of band noise in order not to disturb other users, especially Radio Astronomers .Secondary to protect the Rx from excessive noise and interference. • The main required mitigation techniques are: filtering in the F domain, spatial (nuling) and adaptive filtering for the downlink Rx, shielding and linearization especially for the output Tx stages. De orbit of space junk will also be useful. The leadership of an international regulation organization such as the ITU is a must in collaboration with regional and national institutions.

15. Israel main activities in Small Satellites • INSA Israel Nano-Sat Association was founded in 2006. • INSA cooperates with the Asher institute of the Technion in Haifa and with the IAI in the R&D of small satellites. The Technion is also collaborating with Cornell U. in this field. • The Technion has successfully operate the Gurvin mini–sat. Now is developed the INKLAJN nano-sat. that will execute 7 experiments at an altitude of 650km and a cluster of 3 sat. 6kg each for accurate positioning predicted for 2015. • The homeland security institute in BGU has received in 12.12 a $1M donation for launching 2 pico-sats carrying remote sensing, communication and GPS technologies. • Activities in small sat. at the high school scientific center in Hertzelia and at the international conferences in honor of Ilan Ramon.

16. Participation in the small satellite market (Euro consult) • 90% of the small sat. are for academic projects and the rest for government and commercial purposes, but only 10% of the budget are for academic projects. • The US has 30% share due to high-demand from NASA and the DOD. • Europe enjoys a 25% share, while Asia follows with 22% thanks to activities in China and Japan. • Russia has a 13% share of the market, while the Middle East and Africa tops 9% and the rest of the world follows with 5%.

17. Forecasting for Small Satellites • Development of complex small sat. clusters for home security and other applications. • Protection of important sat. by several small sat. sentinels. Modular open network architecture , Plug and Play and 3-D printing advanced techniques for fast design of small sat. • Operation of efficient techniques for reducing interference and de-orbit space junk. • Design of miniature smaller than Femto-sat. up to the level of Sat. on a chip (SOC). • Development of small sat. for the exploration of the moon and the planets. • National and International enhanced activities of students for improving their skills in STEM and in the design and building of small satellites.

18. Conclusions • The investing, development and operation of small satellites are increasing significantly due to their usefulness and several advantages over bigger sat. especially in low cost and fast productions • The applications of the interdisciplinary small sat. field are numerous from military to educational and the radio sub systems are of most importance. • The low cost, open source standards and short time required to build and launch small sat. will enhance the quantity and quality of needy space engineers and scientists. • EMC strict regulations and reduction of interference sources is a must for the development of thin sat. systems.

19. Selected References 1. pp(182-188)1 יעקב גוון "לוויינים קשר התקשורת" עיתון מדע של מכון וייצמן 4\984 2 .SO Keefe “Pioneering the Future” NASA Facts December 2002 pp(1-12). 3. E.Emma, and All; “Motivating Young Europeans for a future in Space” ESA Bulletin N135 August 2008 pp(27-35) 4. J.C.Lyke, J.Mac Neill; “Plug and Play Satellites” IEEE Spectrum Vol.49 8.12 pp(30-36) 5. A.Torkild ,and All; “Maritime Traffic Monitoring using a Space based AIS Receiver” ActaAstronautica Vol. 58 May 2006 pp(537-549). 6. R.R Milliron, “Enabling Space Access” Sat. Magazine: The Microsatellite market 1.11 7. R.R Milliron, “Insigth: Inter-orbital Fosters Small Satellite Surge ”Sat. Magazine 10.11 8. ComtechAeroastro, *Focus the Power of the Pico-satellites” Sat Magazine 1.11 9. H Page, R.Walker; “Flying Students Experiments to he Edge of Space” ESA Bulletin N 144 February 2012 pp(33-38). • J.Gavan,R.Perez,editor; “Handbook of Electro Magnetic Compatibility” Chapters 19,20; Academic Press, 1995.

20. References (2) 11. Casro, et All; “GENSO Pre-Operational Activities and Preparation for GEOID/HUMSAT Operations” ESA Bulletin N149 February 2012 PP(39-43 12. J.Foust, “Emerging opportunities for low cost small satellites in civil and commercial space” Futron report 2011 13. H.Helvasian, S.W. Janson Editors; ”Small Satellites : Past , Present and Future” The Aerospace Press AIIA. 8.09 14. T. Bekey; “ Advanced Space Systems Concepts and technologies:2010-2030” The Aerospace Press 2009. 15. J.A. Atchison,M.A.Peck ;“A Passive Sun-Pointing Millimeter-Scale Solar Sail” ActaAstronautico, Vol.67 ,7/8 2010, PP(108-121). 16. M.A. Peck; “How Sat. the Size of Chips Could Revolutionize the Way we Explore Space”;IEEE Spectrum August 2011, PP(39-43). 17. P.Fortescue, G.Swinerd, J.stark, Editors; “Spacecraft Systems Engineering”,4th edition, 2011, J. Wiley WWW.aiaa.orgWWW.insasite.comWWW.spacecraftresearch.com WWW.cubesat.wikidot.com WWW.nasa.gov/grail

21. Thin Planet satellites: Development,State of the Art and EMC IssuesHeadlines • Introduction • Classification of Satellites • Description of Small and Thin Satellites. • Radio Amateurs and Students Thin Satellites • Development of Very Thin Satellites • Worldwide Activities in Thin Satellites • Interference effects Concerning Thin Satellites Forecasting and Conclusions • Selected References

22. Main Applications of Small Satellites • Radio communication systems with limited power and bandwidth including Radio Amateur Services • M2M and Automatic Identification Systems (AIS) • Weather predictions • Remote sensing • Earth and atmosphere exploration • Scientific Research • Cluster operation using tether or radio links • Intelligence, Surveillance and Reconnaissance (ISR) military and defense missions • Test of new space systems and technologies • Training man power in space technology and science

24. Swiss Cubesat. to reduce junk A previous EPFL Swiss cube sat. was launched on 9.09 from India for scientific missions and radio amateurs services at 375 MHz. and is still operating.

25. Far East ActivitySpecial Student Pico-sat. from Vietnam. This LEO Pico-sat was launched in 10.2012 from the ISS with 7 other small sat. using a Japanese robotic arm.

26. NASA and DARPA MainActivities • NASA, DARPA and the DOD have collaborated in the FASTSAT project investing $80M (for2010 only) to develop high quality special small satellites and launchers. • Comtech-Aeroaustro & Utah state U. have developed for NASA a Coral bus, a P pad launcher, a 3U cube-sat. kit, and STP novel and high reliability small satellites. • Development of small satellites with education institutions for attracting, motivating and training engineers and scientists, especially in space science. • In 2011/12 the NASA participated in the design and launched free of charge 8 US students sat. For 2013/14 will be launched 32 sat. up to a total weight of 45kg.

27. Future Femto Sat (2) • Sprites use a multi-chip module architecture to achieve a form factor of 2cm x 2cm x 2mm. Using matched filtering techniques, the sprite can close a communications link from a 500km orbit altitude. • In the design packages the traditional spacecraft systems (power, propulsion, communications, etc) will be included into a single silicon microchip smaller than a dime and unconstrained by onboard fuel. The target is a Sat. On a Chip (SOC)