Expanding frontiers! After missions to the Moon and Libration Points the participants of the SSDW 2010 faced the challenge of designing human missions to asteroids. Assisted by enhanced software tools each of the two teams created an independent concept.

The 13th SSDW was held at the Institute of Space Systems (IRS) in Stuttgart, Germany. 32 students and young professionals from 12 nationalities and with diverse backgrounds in engineering, physics and economics were selected from a large applicant pool and invited to the University of Stuttgart from 25th to 30th July 2010 for a truly international, multidisciplinary challenge. The participants formed two competing design teams, tagged "RED" and "BLUE" and faced an intense one-week program.

The participants had to comply with the following mission statement:

"The objective is to outline a comprehensive study of a sustainable international exploration concept to address all interest humankind currently takes in NEAs. The missions shall allow for extensive manned and robotic exploration, enabling new insights into NEAs, the solar system, and its development. In addition, they shall serve the purpose of technology demonstration and maturation for future human activities on the way to Mars and deflection missions for potentially hazardous NEAs. The architecture as well as the concept spacecraft shall exhibit growth potential and extendibility towards further manned space exploration."

Team RED "NEORED"

After the welcome and introduction, the first three days included half-day lectures addressing critical aspects of human space mission design, while the participants already engaged in workshop sessions during the afternoons. This hands-on design team work started early in the timeline and grew in importance throughout the workshop, where full days were dedicated to systems and subsystems engineering, modeling, simulation and concept refinement. Even though densely packed with project work, the SSDW also encouraged socializing between the participants during cultural activities on most evenings.

The two design teams considered various options within the specified frame of the mission statement, both at systems and subsystems level. Two distinct approaches were chosen for detailed assessment (Team RED and Team BLUE). Although many subsystem concepts were similar, the mass to be launched into Low-Earth-Orbit is twice as much for Team RED compared to the design by Team BLUE. An evaluation showed however that the propulsion systems in the concept of Team RED was more elaborate.

Team BLUE "LEMAX"

Design NEORED

Design LEMAX

Concept Team NEORED

Team NEORED layed out a mission agenda to visit four asteroids in individual missions. Most of these missions have durations of half a year each with the first starting in the year 2024 and stays at the asteroids of about 2 weeks. The transportation of the modular spacecraft is accomplished by 12 launches by Falcon 9 Heavy and Atlas V HLV. The crew transportation system relies on the Soyuz launcher. Overall, the project involves contributions from NASA, ROSKOSMOS, ESA and JAXA.

The spacecraft is equipped with a variety of measurement systems which are utilized in the proximity of the asteroid before three EVAs are executed. A detailed schedule for the three crew members was created, where some the tasks performed during EVA depend on the findings of the preceding phase. The following data were presented with respect to the spacecraft:

• Command Module, Habitation Module, Transfer Vehicle, Soyuz TMA with a total mass of around 40 tons and a length of 36 m
• Power consumption of 14 kW
• First and second propulsion stage with a total mass of around 170 tons and a length of 36 m
• Physico-chemical ECLSS (Environmental Control and Life Support System) includes air, water and waste managements systems
• Critical systems were identified, for instance the EDC (5-6 hours before CO2 values become critical)
• Radiation shielding by aluminum and polyethylene

• Inspires young generations to seek knowledge in the fields of mathematics, physics, engineering and others
• Expands human presence beyond Low Earth Orbit
• Increases human knowledge particularly in the fields of: NEO geology, human psychology and physiology
• Increases the experience of humanity in space travel with the final aim of traveling to Mars and beyond

Staff SSDW2010

Concept Team LEMAX

Team LEMAX also planned for a series of missions where the first mission in 2025 has a total duration of about 5 months and an allocated time of 11 days at the asteroid. Similar to the concept of Team NEORED, the cooperating partners are the USA, Russia, Europe and Japan. The spacecraft design exhibits the following features:

• Exploration Vehicle (including external storage), Mother Vehicle (Node, Airlock, Re-entry capsule, Truss structures) and Propulsion Stages
• Crew of 3 with 3 scheduled EVAs at the asteroid
• A total mass in LEO of about 150 tons, of which 116 tons are allocated to the Propulsion Stages
• Power consumption of about 11 kW when the Exploration Vehicle is docked to the Mother Vehicle
• Solar cells and NiH2 batteries for power generation and storage
• A required dV of about 6.6 km/s for the first mission
• Failure analysis of ECLSS identified carbon dioxide unit and de-humidifying unit as most critical
• The scientific payload mass is estimated to be around 350 kg

• Increased mission performance through cooperation
• Distribution of responsibilities guarantees a certain level of independence
• Return of invested budget in the form of purchase orders
• Advances in industrial skills and creation of new jobs