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JASE, SUN MONITORING WITH A RADIOTELESCOPE IN A MARS-LIKE ENVIRONMENT j DE CROMBRUGGHE Guerric 1 , JUMP student group 2 , FOING Bernard 3 1 E-mail : [email protected] 2 Van Vynckt Delphine, Jago Alban, de Crombrugghe Guerric, Denies Jonathan, de Lobkowicz Ysaline, Le Maire Victor, 3 ILEWG / ESA Mertens Alexandre, Reydams Marc Keplerlaan 1, 2200 Noordwijk, The Netherlands Université Catholique de Louvain E-mail : [email protected] E-mail : [email protected] GOAL : ASTRONAUT SAFETY EXPERIMENT The Sun : a threat for astronauts Radiotelescope monitoring DESIGN Specifications Solution On Earth: The Sun’s energy production has a beneficial interest for all but can be also destructive. On Earth through the protection of the magnetosphere and the atmosphere, we can easily use this energy. On Mars: Without protection, human are exposed to the high energy of radiation from Sun. Basic idea: Speed of the electromagnetic waves : 3.10 8 m/s Average speed of the solar flare : 4 … 8.10 5 m/s The difference of speed allow us to predict the solar flares by monitoring the Sun. Main bursts caused by solar coronal mass ejection or solar storm: type II (100 to 200 MHz), type III (100 kHz to 600 MHz). In situ testing Radiotelescope of ~25 cm typical size: • corresponds to a quarter-wave radiotelescope for 150 MHz, • allows to observe both type II and type III, • small-size, advantage for space-applications. JUMP – Junior Ucl Marseken Pis A group of six students from different degrees (bachelor, master, PhD) and backgrounds from the Université Catholique de Louvain (UCL), Belgium. They simulated for two weeks the life of astronauts at the Mars Desert Research Station (MDRS), a station installed in a Mars-like environment, in the Utah desert. More information : http://www.crew94.be JASE – Jump Astronaut Safety Experiment Using a radiotelescope, the astronauts can easily detect a solar storm before the radiations reach Mars’ surface. They have then a few minutes to reach a safe place (cave, habitat, etc.). Phases of the project : • design and building of the radiotelescope, • tests and calibration, • In-situ testing at the MDRS. Requirements: • must be cheap and easy to build (including acquisitation), • must be as light and small as possible (including acquisitation), • can be operated with a space suit. Performance: • must allow an astronaut to make the difference between a solar storm and other events. ANTENNA: 6-arms Yagi antenna • one reflector, one feeder, four directors, • optimized for stability and gain, • no motorisation : must be manually handeled. ACQUISITION: common digital oscilloscope • low-precision, • ready-made solution, • easy to handle. Antenna Coaxial cable Oscilloscope Screen reading Speaker USB key Computer Direct reaction: visual and hearing Later analysis Directivity The solution was computed with to the software NEC2. Simulation shown that the solution was stable enough regarding to the target application. Figure : theoretical current distribution in the antenna according to NEC2. RESULTS Later analysis example : 13 April Tests shown that the antenna was satisfactorily matched for 149.5 MHz (reflection coefficient below -10 dB), which is very close to the target frequency. The gain and directivity was good enough for basic radioastronomy (Jupiter, etc.). Figure : theoretical pattern of the antenna according to NEC2. 13 April, 09:52 am: 1. A typical solar storm noise is heard in the speaker while three astronauts are out of the habitat, 2. The astronauts are warned: they have ten minutes to protect themself, 3. The astronauts are told when the storm is finished: in ten minuts they will be able to leave their shelter, 4. During post-analysis, the signal is correlated with data from Earth : it corresponds to a Type III solar burst. Conclusion Even if it needs to be optimized, the developped system is an efficient, light and easy way to prevent solar storms. It can also be used for radioastronomy when solar monitoring is not necessary, taking advantage of the lack of atmosphere and magnetosphere. Partners Further prospects • Quantification of the risk to which the astronauts are exposed., • Automated system, • Use of several antennas, electronic beam steering, either analog or digital beamforming (after baseband conversion), Acknowlegements Pr. Christophe CRAEYE, TELE / Université Catholique de Louvain, for his precious advices, and Christian KINON, TELE / Université Catholique de Louvain, for his technical expertise. Soho’s record of the burst Credit : Nasa/Esa/Soho
