Machining knowledge brings balloon to edge of space

source: Link Magazine February 2016

STT Products is a company that focuses on, among other things, the development of innovative technologies in the field of precision mechanics and mechatronics. SRON, part of the Netherlands Organization for Scientific Research (NWO), develops ground-breaking technology and advanced space instruments.

A current example is the STO2, a balloon that is intended to bring infrared detectors to the stratosphere to investigate the formation of stars and planets there, 40 kilometres from the earth’s surface. For this, the balloon had to meet a number of conditions, such as being able to be launched from any location; that it must be able to perform measurements for at least six months; and that it should above all be a stable platform for extended periods at the desired height of 42 km above the earth’s surface.

Dr. Jian-Rong Gao, project leader at SRON: “Actually, there were two major problems to overcome regarding the oscillator technology for the applied 4.7THz channel based on the heterodyne detection.” He mentions the need for proper coordination of the frequency of the local oscillator with that of the special detectors, for which a quantum cascade laser has been used. A new technique that was only published in 2003 and for which SRON developed a local oscillator in collaboration with MIT (Massachusetts Institute of Technology, USA). The second essential problem is frequency stabilization, which must also function at an altitude of more than 40 km above Antarctica. The electrical solution called the superlattice harmonic mixer has been developed in collaboration with a Russian research group.

During the entire phase, SRON collaborated intensively with TUDelft, which manufactured all applied detectors in the clean room of the Kavli Institute of NanoScience, part of the Applied Science at TUDelft. “The mechanical parts for all of the components mentioned had to be manufactured at STT with the utmost precision and reliability,” says design engineer Tiddens. “We have advised on the machining techniques to be used and the components produced on the basis of the mechanical design specifications and the design drawings. The constructions have been adapted and refined on the basis of our knowledge and experience!”

Dr. Jian-Rong Gao indicates that without the help of STT Products, the project would not have been completed on time. “The fact that they managed to realize everything correctly and on time was crucial for the deployability of the detectors and the local oscillator!”