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IAC–02-P.1.04 UNOSAT: THE FIRST BRASILIAN UNIVERSITY NANOSATTELITE Stancato, F.; Manhas ,E. M. Jr;Oliveira, M; Mendes, L. H.;Oliveira, G. O.;Paiva, M. C.;Cunha, D. K.;Negrão, C Universidade do Norte do Paraná Lone, L. P.; Lone T Universidade Estadual de Londrina Londrina, PR. Brasil Louro, A. C.; Instituto Nacional de Pesquisas Espaciais Mônaco, D. Instituto de Aeronáutica e Espaço [email protected] Contacts were made in the beginning of 2001 to see a launch possibility as secondary payload at the third qualification flight test of the VLS, the Brazilian launcher. Soon came the positive answer and the project began. A very simple nanosatellite project was chosen. The mission was going to download 5-parameter telemetry and one voice message. The different project parts were divided among the thirteen undergraduate students: structure, radio link, solar panels, energy controller module, telemetry and instrumentation. They were also responsible for the systems tests, integration and follow final tests. An outreach activity was also made. It is shown the program management strategy, what had worked and what not, funding strategy and the educational benefits. ABSTRACT In 2000 it was created in the Universidade Norte do Paraná, UNOPAR University, an educational undergraduate aerospace group called SPACE. During the 51st International Astronautical Congress in Brazil, the participant students got in contact with different small satellite programs from different universities. Motivated by these contacts they began a nanosatellite project feasibility study. Copyright 2002 by Fernando Stancato. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission. Released to IAF/IAA/AIAA to publish in all forms. 1 The launch is scheduled in the end of 2002 this kind of activities is taken in all the continents. It is a consensus that university small satellites programs give invaluable educational benefits, providing the students an excellent opportunity to put in practice their knowledge (STANCATO, 2001) With these objectives the SPACE began a nanosatellite project: UNOSAT – Undergraduate University Orbital Student Satellite. It is the first Brazilian university satellite and represented an extremely challenging project as the teacher’s team had small experience in space projects, very small budget and two-year time frame from the concept to launch. The results of the program proved that using some managing project skills the team managed to complete all the project phases and the benefits in education were accomplished. INTRODUCTION In the beginning of 2000 it was created a group called SPACE – Sistema de Pesquisa Aerospacial Científica Educativa – with the objective to make the undergraduate students put in practice their knowledge in the project, construction, tests and operation of aerospace projects, providing an hands-on experience. The group was formed within the Universidade Norte do Paraná – UNOPAR University with students and teachers from the Telecommunications and Computing engineering. Although the university began its activities in 1996 and the engineering courses in 1998, the group had a tremendous growth after its formation. HISTORY The idea to begin a small university satellite came when a team of one teacher and three students went to the 51st International Astronautical Congress in 2000 at Rio de Janeiro. The students got in contact with small satellites projects been carried in some universities. One of them was the program UNISAT developed at the “La Sapiensa” Rome University. They managed to bring two researches from that university to give a lecture at UNOPAR University in Londrina. It was known that it was been prepared the third qualification flight of the Brazilian launcher VLS – Satellite Launch Vehicle. Contacts were done with the officials of the program to see the possibilities of having a piggyback launch Figure 1- The SPACE team in the end of 2001. Educational small satellites programs are not new. The first ones can be traced back in 1980s. The Utah State University did its 15th Annual Small Satellite Conference last year. A review of Micro/Nanosatellite programs was presented (FARROW, 2001) in the last IAF conference stating that at least 10 nanosatellites projects was under development for launch by late 2001. It presents a 35-paper list that shows how 2 oportunity. Figure - 3- UNOSAT inside the SATEC. undergraduate students, no one cursing more than the third engineering year, a straight project had to be elaborated. For the engineering team, the most important information was how some internal parameters was changing, so it was decided that the nanosatellite would send in packet transmission some hardware telemetry. Many amateur satellites also send some vocal messages. The students decided that something similar would be amazing. The SATEC orbital information became important when the team got the new that the UNOSAT would have a joint flight. The SATEC and UNOSAT will have a circular orbit with the altitude of 700 Km and 15o of inclination. It will roll at 170 rpm on the z-axis and will have no attitude control. In the first days the UNOSAT solar panels will be perpendicular to the solar radiation but three months later will receive no radiation. As the team decided for a oneyear orbit life, an energy manager module had to be developed. The satellite would have three transmitting operational modes: high, medium and low rate. It would turn off Figure 2- The VLS-1 payload area. In the beginning of 2001 came the positive answer. As one INPE satellite – SATEC- was already assigned to this flight; there was no space for a separate satelization of both satellites. Studies began how to make possible the flight. As there was some internal space available inside the SATEC then came the solution to put the UNOSAT inside the SATEC. The SATEC team reserved an area in the sides of SATEC to put the UNOSAT solar panels. After some discussions and different antenna locations, it was found that the best possible option was to use a monopole antenna in the top of the SATEC. In this way the UNOSAT would be completely independent from the INPE’s satellite. MISSION As the team had small time and experience to prepare the satellite, the simplest design was chosen. As the main objective of the project was educational and the working team was to be 3 also the equipments and enter in the “hibernation” mode when it passes in the winter and summer solstice. SOLAR PANNELS In the preliminary design the solar panel was fixed in the front cover of UNOSAT. This was done in order to make easier for integration in whatever configuration it would have. At the first configuration the UNOSAT was going to be installed in an aperture done in one side panel of SATEC. Later as it was put inside the SATEC, an area for the solar panels was reserved in the lower lateral sides. It will be 4 solar panels with the following characteristics: Figure 4 - The SATEC in the Earth orbit during the year. Table 1. Solar Panels Characteristics Power at BOL 8W Solar Cells Si, 20 mm X 40 mm Dimensions 620 mm x 100 mm STRUCTURE It is basically a rectangular box with external dimensions: 400 mm wide, 250 mm high and 85 mm deep. It weights 4.370 Kg. Since the preliminary design it was thought to have lateral tabs just to help attaching, as it would not be possible to have independent satelization. The box was done in cast aluminum and later machined. The structure has only one opening in the front. It is closed by a 3 mm aluminum sheet and fixed by sixteen 3 mm bolts. COMUNICATIONS It will be used a 5W output ham-radio as the transmitter at 148.135 MHz FM frequency. It will use a 460 mm monopole antenna with 1,5 dB gain. TELEMETRY MODULE A commercial microcontroled telemetry module was used to inform 5 parameters: tension on the battery pack 1, pack 2, pack 3, and the battery and the transmitter transistor temperature. It outputs this information on audible FSK Ax25 protocol. ENERGY CONTROL A microcontrolled module will control the batteries charging and discharging, transmission rate and beginning. Three redundant methods were used to begin the transmission: 10 minutes after liftoff (umbilical disconnection), 1 minute Figure 5- The UNOSAT structure and internal components. 4 after satelisation (open a circuit) or 12 hours after turning on the satellite. It was decided to use three redundant batteries banks: two non-space qualified Ni-Cads (B2, B3) and one not rechargeable Li-MnO2 (B1). Each Ni-Cads banks are 1200 A.h and the Li-MnO2 is 11 A.hs. The level of the charge of the batteries will set the transmission rate: 100 % of the best 40 % of the worst 20 % of the worst 10 % of the wors t High rate Medium Low rate rate Figure 8- The battery levels that set the transmission rates. The microprocessor will always measure the charge level of both batteries. To avoid overcharging when one of the batteries level achieves full charge it will disconnect the solar panels from the batteries. It will connect again when one of them reaches 80 % of the charge. When one of the batteries reaches 10% of the charge the microprocessor enters in the hibernation mode: it turns off all the equipment, links itself to the dry batteries bank and at each 3 hours it wakes up and measures the batteries level. When one of them reaches the full charge it enters in the transmission mode again. The high rate was calculated to mach the solar panels energy input with the onboard electronics and the transmitter output in each of the first day’s orbits. Figure. 6 – Nicad and Li-MnO2 batteries Figure 7 – Onboard computer and its case. Each transmission is formed by a telemetry packet (0,3 s) plus a voice message (10s). It was established three transmission rates: High rate: 1 transmission at each 37 seconds; Medium rate: 1 transmission at each 94 seconds; Low rate: 1 transmission at each 1,5 minute. DIGITAL VOICE PLAY/RECORDER It was used a commercial digital voice play/recorder that was used in mobile phones that can record and play a 20 seconds message. THE PROJECT MANAGEMENT Human resources As said before the main objective was to give the students and teacher a hands-on 5 approach on different engineering course topics. The project was an opportunity also to put in practice the Project Management procedure (PIGNOLET, 1997) The project was divided in 8 phases: review of the project. In that meeting the next launch date was expected to be in July 2002. With this date, a reschedule was done and the project of the main energy controller board was started. It was put a date of the end of January 2002 to do the integration of the system and final tests. Fortunately that was rescheduled to October 2002 and the launch is foreseen to the end of the year. Phase A – Definition. In this phase it was decided what to do. It was decided the project mission and its parts. For each part a teacher was invited to be the manager of it. As we had no funds it was decided the each teacher would try to find funds for the project and select the students to work with. Phase B – Planning. It was studied a time frame of about 6 months. That was the first time frame we had. Phase C - Project. All the parts should be dimensioned and the main parameters are calculated. Phase D – Construction. Phase E – Tests of the parts. Phase F – Integration. Phase E – Final Tests. Phase G – Operation. Difficulties Found Many was the challenges in the UNOSAT project: Lack of experience: Nor the teachers or the students had experience in the space area project. From the beginning the team noticed that it has a completely different approach from other common projects. Lack of bibliography: As the students were not from the aerospace engineering course, it was not found any book regarding satellite construction at the universities in the state. Timetable Lack of docent staff: The course began in 1999 and the docent team was in formation. In the beginning of the project there was no teacher for the antenna project. The phase A and B was done simultaneously on February 6, 2001. All the teachers (five) met and decided the basic concept of the nanosatellite and a 6month timetable was done. It was decided that September 5 would be the final date to give the satellite to INPE for integration. In fact the 6 first months were spent in studding the shape of the antenna and discussions with INPE team to see the position and shape of our antenna and the electrical interfaces between our satellite and the solar panels, antenna and the umbilical. On August 1 was done the second meeting with the INPE team in order to decide the electrical interfaces and a Interfaces with other institutions: As the UNOSAT was not going to have the antenna and the solar panels fixed in it but in other satellite, some decisions were difficult to take. An agreement on the antenna position came only 11 months after the project start. Lack of resources: That was one of the more difficult item found. Just after receiving the news that it would be possible a ride in the next VLS launch a 6 cost estimation was done. Taking the experience of other students project (LEON, 2000), (GRAZIANI, 2000), (HEIDT, 2000) it was decided not to use space qualified items. Some quotation showed that as we had no money we were right. From January 2002 until September was the construction time and integration. During this phase it was found that spare parts is a must as components may break or even equipments (we lost two radio transmitters: one simply broke and the other had a bad heat dissipation). Another advise is to have more than one student in each part as if they leave it will leave a hard slot to be replaced. In March 2002 the student working in the more difficult and main important component (on board computer) simply gave up, as he could not solve some problems is the prototype. And he did this, three months before the first subsystem ambient tests! Fortunately another skilled student had joined the group on another project and could project built and test a new OBC in these three months! These intercurrences left just one month to make the control software just before the UNOSAT- SATEC integration and the Thermo- Vacuum tests. Table 1 - Costs for space qualified and not qualified items Solar Panel Batteries Space Not Space Qualified Qualified (US$) (US$) 18.000 430 8.000 92 The problem began when we presented the UNOSAT proposed costs of US$ 8.000 at the university. The answer came in a very polite way that the university could not afford that expenses (specially that the investment would be only on no recoverable items!) From March 2001 until May 2002 all the tentative to seek sponsors were in vain. All the telecom companies that operate in the state and two satellite operators were asked and a negative answer was gotten. It was even tried to have a broadcast radio sponsorship making a competition on their listeners to put their “voice in the space”. The students went is trade show to sell “put your name in Space” as who would give a donation would have his name written inside the UNOSAT. In June 2002 the university finally recognized the immeasurable value of the opportunity and that made it possible to buy all the needed components. BENEFITS Many benefits came to the students: Academic They had an opportunity to put in practice many subjects they had in the university. There was also the motivation factor, as there was an immediate purpose for their studies. Lack of time: During the first year, while some members were looking for sponsorship others were beginning the project of different parts. Some hardware tests were done as the use of a telemetry module, transmitter and receiver. Figure 9 – Part of the UNOSAT team. 7 Responsibility Although made by students it had the quality enough to pass in the tests. Research activities in the university usually is linked to a very comfortable time schedule. As usually there is not a deadline to finish the work and there is also the possibility to postpone the date, there is not much need on time administration. That was not the case with this project. Since the beginning, the top management priority was not to delay the delivery of the satellite as we were taken a free ride. That caused the ambient to be very stressed as the team had to have always an emergence plan in case the launch would be eminent. That led to an easily possible scaled down project. Another good point was to always have a shorter schedule than needed. It was always put for the team a deadline some weeks before the real date. As students do not have much planning experience, that strategy permitted them to better finish some points that were under planned. It was noticed that by the end of the project most of the students had learned that in engineering “ the best is the good in time”. Teamwork As always happen in high-stressed teams some divergence occurred, especially at the end of the phases. But the students overcame that with personal agreements and mutual clear friendly corrections. International Experience All the students had some international contact experience both indirect and direct experience as in two consecutive years two student participated in a UN Congress giving lectures about the UNOSAT project. Reliability The students also learned to think that it is better a simple design that you have confidence that will work than a very complex and beautiful project that may fail. As a satellite is something that must work for the first time, this led the students to make a good review of what worked and what not and be conservative in the design using redundancy in critical parts. Figure 10 – One student gave a lecture in one UN space congress about the UNOSAT in 2001. High Quality The evaluative reviews with both teams of the launcher and the SATEC satellite team were an excellent class of the high quality needed for the space projects. 8 Workshop Brasileiro em Educação para o Espaço. São José dos Campos, 1997. Farrow et Al. Micro/Nanosat Development Programs for Partnership Among Universities, Govenment and Industry: Benefits and Difficulties Encountered. IAF-01-P.2.08. Toulouse, 2001. Stancato et Al. SPACE a multidisciplinary Hands- On Activity. IAF-01-P.1.08. Toulose, 2001. Figure 11 - ...and another in 2002. CONCLUSION It could be seen that despite a mountain of difficulties, a motivated team can overcome them with some management criteria and a lot of a work. The students participating in a handson project incorporate inherent space project virtues: reliability, high quality, teamwork, time and resources management and international experience. REFERENCES P. DeLeon et al. Development of Educational Microsatellites in Argentina. IAF-00- P.1.03. Rio de Janeiro, 2000. H. Hiedt et al. Cubesat: a new generation of Picosatellite for Education and Industry Low-Cost Space Experimentation. Paper SSC00-V-5B presented at 13th Annual Small Satellite Conference, USU, 2000. F. Graziani et Al. UNISAT Program: a University Tool for Space Education. IAF00-P.2.07. Rio de Janeiro, 2000. G. Pignolet et Al. Conceitos em Projetos para Educação Espacial. 1o 9