The European Student Moon Orbiter (ESMO) is planned to be the first European student mission to the Moon. Currently student teams from 19 universities throughout Europe are working on the program. ESMO was conceived by the Student Space Exploration & Technology Initiative under the support of the European Space Agency (ESA); prior to the start of Phase A the full responsibility for the management of the program was transferred to the ESA Education Office. In 2009, Surrey Satellite Technology Ltd (SSTL) was selected as prime contractor. [1] ESMO is scheduled for launch in late 2013 or early 2014. [1]
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The mission objectives for ESMO are: [2]
The educational aim of the project is to provide valuable hands-on experience to university students within a real and demanding space project. This is in order to fully prepare a well qualified workforce for ambitious future ESA missions. [2]
The spacecraft of approximately 190 kg mass and a size of 76 x 74 x 74 cm is designed to be launched as a secondary or auxiliary payload into Geostationary transfer orbit in late 2013 / early 2014. From there, the spacecraft uses its on-board propulsion to travel to lunar orbit via a weak stability boundary transfer. This travel via the Sun-Earth L1 Lagrange point takes three months, but it requires much less propellant than a direct transfer (see Interplanetary Transport Network). [1] [2] ESMO is intended to be operated in lunar orbit for six months.
Payloads being studied are: [2]
The table below provides an overview of the spacecraft platform and the ground segment. [2]
| Subsystem | Description |
|---|---|
| Attitude Determination and Control System (ADCS) | 3-axis stabilized: 2 star trackers, 4 sun sensors, 2 inertial measurement units, 4 reaction wheels, 8 cold gas thrusters |
| On-board Data Handling | 2 ESA LEON2 processors (dual redundant) running data handling software (command timeline and simple FDIR) and ADCS software; 32 MB Serial Flash for payload data storage; CANbus data interfaces |
| Communications | Low Gain Antennas for omni-directional coverage; S-band transponder with PSK-PM modulation and range & range rate capability for radio-navigation; 8 kbit/s downlink / 4 kbit/s uplink between Moon and Earth stations |
| Power | Body-mounted 3J GaAs solar cells for 170 W beginning of life power & 122 W end of life power; 24-29 V unregulated bus; 1800 Wh capacity Li-ion batteries |
| Propulsion | 4 liquid MON/MMH bipropellant thrusters: 22 N thrust each, 285 s specific impulse (modulated by AOCS software during burns for reaction control) |
| Structure | CFRP/Al honeycomb construction box with load bearing central thrust tube |
| Thermal Control | Passive: MLI & surface coatings; active: local heaters for eclipse (e.g. propellant tanks) |
| Ground Segment | Ground stations: 25m S-band dish in Raisting and 15m S-band dish in Villafranca; Perth/Kourou for launch and early orbit phase and manoeuvres |
21 teams from 19 European universities in ESA member states and cooperating states are currently part of the project. Their involvement and responsibilities will be re-assessed in the System Requirements Review.
| University | Country | Responsibilities |
|---|---|---|
| University of Liège | Belgium | Narrow Angle Camera Payload |
| Czech Technical University in Prague | Czech Republic | AOCS Interface Module |
| University of Tartu | Estonia | Assembly, Integration and Verification and Satellite Operation |
| Supaero | France | Star Tracker |
| University of Stuttgart | Germany | Propulsion System - Gas Feed (Cold Gas Thruster) |
| Technische Universität München | Germany | LunaNet Payload & Ground Station |
| University of L'Aquila and University of Rome La Sapienza | Italy | Microwave Radiometer Scientific Payload |
| Politecnico di Milano | Italy | Attitude Determination and Control System |
| Politecnico di Milano | Italy | Propulsion System - Liquid Feed (Bipropellant Thruster) |
| Warsaw University of Technology | Poland | Thermal Control Subsystem |
| Wroclaw University of Technology | Poland | Communications System |
| AGH University of Science and Technology | Poland | Space Environment & Effects Analysis |
| Politehnica University of Bucharest | Romania | Attitude Determination and Control System |
| Politehnica University of Bucharest | Romania | Structure |
| University of Bucharest | Romania | Radiation Monitor Payload |
| University of Ljubljana | Slovenia | Simulator |
| University of Ljubljana | Slovenia | Radar Payload |
| University of Maribor | Slovenia | On-board Data Handling |
| University of Oviedo | Spain | Harness |
| University of Vigo | Spain | GS/OPS-V team. Ground Station VIL-1 team. |
| University of Glasgow | UK | Mission Analysis and Flight Dynamics |
| University of Southampton | UK | System Engineering |
| University of Warwick | UK | Power Subsystem |
Led by ESA's Education Office at ESTEC, the project has successfully completed a Phase A feasibility study and continued with the preliminary design during phase B. [2] So far, more than 200 students have been involved in phases A and B of the ESMO project. [1]
Since November 2009 SSTL coordinate and supervise the work of the students, providing system-level and specialist technical support. [1]
Regular workshops at ESTEC and ESOC as well as internships at SSTL are organized to support the student teams in their ESMO related activities and provide training / knowledge transfer. Additionally, facilities at SSTL will be utilized for spacecraft assembly, integration and testing.
As a major milestone during phase B, the System Requirements Review (SRR) for ESMO was performed in 2010. At SRR the system requirements and system design were finalised. Part of the SRR also selected the university teams to participate in the following phases of the project.
ESMO is the fourth mission within ESA’s Education Satellite Programme following SSETI Express, YES2 and the European Student Earth Orbiter (ESEO).