February 18, 2010
EADS Astrium GmbH CryoSat Project Manager: Interview With Klaus KÃ¶ble
As Satellite Prime Contractor for CryoSat, EADS Astrium has led a consortium of 30 firms from Europe, the U.S. and Russia to design and build the satellite. In his role as Astrium Prime Project Manager, Klaus Köble has been leading these efforts for the past three years.
Klaus Köble, a German national, joined Astrium Friedrichshafen (DORNIER Satellite Systems at that time) in 1988. He gained several years of experience in design and assembly of Earth observation satellites and instruments.Before moving to the CryoSat team, he worked for 10 years at Astrium as a System Engineer, Assembly, Integration and Testing Manager and Launch Manager in national and international space projects. Klaus joined the Astrium CryoSat team three years ago to take up the position of Astrium Prime Project Manager.
He received a Master degree in Engineering from FH Aalen (Germany) in 1988.
ESA: What role does the prime contractor play?
Klaus Köble: As prime contractor for the CryoSat mission, Astrium is responsible for the design and build of the satellite, leading a consortium of 30 firms from Europe, the U.S. and Russia, on behalf of ESA.
Astrium integrated the satellite platform and was also responsible for the integration of all the instruments. In addition, we built the Mass Memory and Formatting Unit, as well as the Power Control and Distribution Unit. After system integration, Astrium performed the functional and performance tests, proving that the mission requirements could be achieved and that the system is robust enough for the lifetime of the mission. During the environmental test campaign, the prime team checked to ensure that the satellite was capable of surviving the severe conditions of launch and the space environment.
ESA: What have you been responsible for throughout the process of designing, building and launching of CryoSat?
Klaus Köble: As the prime project manager, I am accountable for accomplishing the agreed project objectives. My main duty is to assure that the contract is executed in an efficient way, allowing the delivery of the spacecraft in compliance with the system requirements to ESA. In addition, I am responsible for managing the three project constraints, which are cost, time and quality. This may appear very academic at first glance, but managing a project effectively depends highly on the spirit among the ESA and industry teams and on a trustful cooperation with ESA management. It was very helpful throughout the different phases of the CryoSat project that we were able to establish and maintain an exceptionally good and trustful relationship between the ESA and Astrium project teams, including our subcontractors.
ESA: CryoSat has to fly in an unusually high-inclination orbit to measure the thickness of ice at the polar regions. What challenges did this represent in terms of design?
Klaus Köble: CryoSat has a high inclination orbit of 92Ãº in order to get the best visibility of higher latitudes (>72°) and sufficient cross-overs up to the polar regions. The orbit is not sun-synchronous, so the direction from which sunlight falls on the satellite is constantly changing. The operation of the SIRAL instrument demands that its antennas point towards Earth's surface within a few tenths of a degree. This means that rotating the satellite to face the sun is out of question. Mechanisms are very costly and so the satellite geometry was arranged such that the solar panels, rigidly fixed to the satellite body, formed a 'roof' with a carefully optimized angle, which will provide adequate power under all orbital conditions.
ESA: The mounting of CryoSat's two main instrument antennas represented a challenge. Can you tell us about that?
Klaus Köble: Any distortion in the support of the antennas will cause errors with direct effects on the quality and accuracy of the received scientific data. In addition, the stability of the alignment between star trackers and antennas is of equal importance.
To stay within the permitted error limits for the mission, such distortions have to be less than 30 arcseconds: approximately the same as the size of a football seen from 2 km away. This represented a significant challenge, given CryoSat's unusual orbit.
Since the orientation of the spacecraft body towards the sun is permanently changing, the temperature distribution among the spacecraft is not static, but variable over every orbit. To avoid any distortions from the changing thermal environment, the antenna support structure had to be intrinsically stable and had to provide direct mounting possibilities of the star trackers. Hence, the structure was designed using low expansion materials, like carbon fiber-reinforced plastics, and a special support on the main spacecraft body, isolating disturbing deflections from the antenna support structure.
ESA: Unlike most satellites, CryoSat does not have any deployable solar panels. How were you able to provide adequate power under all orbital conditions and still fit within the launch vehicle?
Klaus Köble: The main features of the satellite design can be traced back to the driving factors, that the CryoSat mission, although with demanding mission objectives, is still a low budget mission. Hence, expensive spacecraft elements and an expensive launcher were out of the question. In order to guarantee an adequate solar power provision with CryoSat's non-sun synchronous orbit, we had to select new, highly efficient solar cells. Although these cells are expensive, in the end the complete package turned out to be most efficient.
ESA: Once CryoSat is operational, will EADS Astrium GmbH still have a role to play in the mission?
Klaus Köble: The launch of CryoSat marks an important milestone for us but is not the end of our contribution to the mission. We will support ESA's European Space Operations Centre (ESOC) team during the Launch & Early Orbit phase in the frame of initial acquisition and platform checkout. After the spacecraft is put in nominal mode, the instruments will be switched on, validated and calibrated. Together with our subcontractors, we will provide engineering expertise during this phase as well. Our direct contribution will last at least until the commissioning phase is successfully concluded.
ESA: Where will you be for launch?
Klaus Köble: During the launch campaigns of my previous projects, I was always at the launch site for launch. For CryoSat, we have an excellent ESA/Astrium team in Baikonur that can handle all aspects of the launch by themselves. Therefore, this time I will be together with Richard Francis, ESA's CryoSat Project Manager, at ESOC in Darmstadt, Germany. Together with our joint project team, we will be there during the launch and initial acquisition phase, providing project support to the operations staff. So, there will be no champagne for us for the first 10 hours after launch, but we are convinced there will be an opportunity to celebrate once the spacecraft is safe.
On the Net: