SSE Publications 2002
- Single Stage to Orbit Minimum Requirement through Numerical Simulation
Teixeira Encarnacao, J.G. & Ockels, W.J. (53rd International Astronautical Congres, Houston, October 2002) - Manned In-situ Confirmation of Lunar Ice with Ariane 5
Gerené, S.P.B., Hummeling, R.W.J. & Ockels, W.J. (53rd International Astronautical Congres, Houston, October, 2002) - Finite Element Modelling for Dynamic Analyses of a Closely Packed Configuration of a Small Satellite
Gram, M., Wijker, J.J., & Zandbergen, B.T.C. (European Conference on Spacecraft Structures, Materials & Mechanical Testing, Toulouse, France, 2002) - Risk Management Literature Survey
Bijl, M.G.M. & Hamann, R.J. (Technical Report, Delft, August 2002) - Operation Delfi – A Space Mission Development Project ; Students working on the realisation of the first Dutch university satellite
Annes, R.J., Graaff, J. van der, Meijers, M.A.H.A., Zandbergen, B.T.C. (17th AMSAT-UK Colloquium, Surrey, England, UK, 26 July - 28 July, 2002) - Conceptual Design of a Small, Affordable Launch Vehicle
Artois, K., Breen, N.M., Bulcke, S. van den, Claessens, M.K.R.D.J., Briel, E.M. van, Linden, E. van der, Priems, M.M.H., Schamhart, C.H., Vandenbussche, J.L., Zon, G.M.B.C van & Hamann, R.J. (Technical Report, Delft, June 2002) - Factors in Technical Risk Assessment
Hamann, R.J. & Zandbergen, B.T.C. (3rd European Systems Engineering Conference, Toulouse, May 2002) - DOORS RTM VCD Template
Hamann, R.J. (Technical Report, Delft, May 2002)
Abstracts
Single Stage to Orbit Minimum Requirements through Numerical Simulation
It is widely known that producing a single stage to orbit (SSTO) spacecraft is no easy task. It is also understood that it will be the first step towards spacecraft that operate in much the same way as today's airliners. This is believed to decrease the cost of reaching space through more efficient use of a single vehicle and higher lzunch rates, opening up space for tourism or as a transportation medium. This paper is a study on the physical requirements of a SSTO spacecraft. The simulation takes into account curvature of the Earth, its gravitational field, the exhaust pressure loss and atmospheric drag. No attention is given to the type of propulsion, winged or lifting body, active or passive cooling and stability and control. Any mass required for these subsystems is included in the construction mass. Both vertical and horizontal (from altitude) take-off are simulated. Main result of the paper is to show the relation between construction mass and specific impulse a given spacecraft needs to reach its low Earth orbit.
Manned In-situ Confirmation of Lunar Ice with Ariane 5
A study is performed to investigate the feasibility od a manned expedition to the Moon Using the European Ariane 5 launcher. The primary objective of the mission is to confirm the presence of water at the lunar South-Pole craters. Secondary objective is to perform lunar surface science and making a first step towards a lunar outpost. Results show that a minimum of two Ariane 5 launches are required. The first launch will bring a Lunar Landing Vehicle (LLV) into low lunar orbit, the second will launch two astronauts in a Crew Transfer Vehicle into a rendez-vous trajectory with the LLV. Arrived in the low lunar orbit, the CTV will dock to the LLV, the LLV will undock together with a habitation module and land at the designated landing site near the rim of the South-Pole Shackleton crater. Total mission duration will be 36 days.
Finite Element Modelling for Dynamic Analyses of a Closely Packed (Small) Satellite
Shortened abstract:
The optimal use of space in small satellites is important. Therefore in these satellites the equipments are usually packed closely together. The finite element modelling of closely packed satellites is difficult because the interactions between the structure and the various equipments are many. This paper describes the finite element modelling of a small satellite for dynamic analyses such as sine frequency response. The result of the analyses is verified with help of available qualification test data.
Operation Delfi – A Space Mission Development Project
In 1997/1998 the faculty of Aerospace Engineering (AE) at Delft University of Technology (DUT), the Netherlands, initiated ‘operation Delfi’ with the purpose of enhancing space research and education at DUT. To this end a program was initiated encompassing a broadening and deepening of the space engineering curriculum and the development of a low-cost microsatellite. Currently, students are working on the detailed design of a small, low-cost, technology test satellite named Delfi-1. It aims to demonstrate several advanced space technologies, including an inflatable gravity gradient boom and an adaptive communication system. The phase A/B studies, presently being performed, will form the basis for future full-scale development of the satellite. Click here for the full paper.
Factors in Technical Risk Assessment
It is a common opinion, that technical risk assessment is an important activity in small and large design and development projects in the space industry. Not only managers profess that belief, but also the engineers within a project agree with that view. It is, however, astonishing to see how rarely a thorough and continuous effort in this field is undertaken in day-to-day project life, especially in small to medium size companies and in small projects.
The paper attempts to identify possible reasons for this phenomenon, based on methods and tools used for technical risk assessment in a medium sized company and on the practice of applying these on a range of projects.
Basic requirements for any method or tool used were that it did not require specialist knowledge, was directly related to the technical content of the work (and hence made sense to the people performing that work) and that it would not become a significant effort to use method or tool within the project. In addition, a necessary condition for acceptance of method or tool was a good introduction into the organization and sufficient support for the users. In addition, it should be possible that method and tool are used directly by the full team. Also company processes have to take the risk assessment into account.
The technical risk assessment methods used are discussed and their main characteristics summarized. The introduction of the methods and tools, and the adaptations initiated on request of the users are described. The results of an evaluation of actual use of the methods and tools within the company are given, as well as the results of a limited check on the positive and negative aspects of method and tool by an out-of-company “control group”. Conclusions are drawn relative to possible barriers to the routine application of technical risk assessment in the design and development process.
Based on these findings an tentative approach is defined to arrive at a better acceptance and use of the method and tool by the target group: the engineers performing the design and development work on a small to medium sized project.
