Taiki, Hokkaido, Japan.- A few days ago in their Japanese page, the Institute of Space and Astronautical Science (ISAS) -part of the Japan Aerospace Exploration Agency (JAXA) since 2003- announced the realization of the first series of stratospheric balloon launches for 2017.
The campaign will be performed at the Taiki Aerospace Research Field (TARF), the dedicated launch facility that the agency have in Hokkaido Island in northern Japan, near the town of Taiki-Cho.
According to the brief press release, four missions will be carried out -as long as the weather cooperates- starting on June 5th.
In no particular order, these will be the experiments to be performed:
The Japanese balloon program which was established in early 50's, has grown during more than six decades to become a very sophisticated and innovative program.
Founded on the premises of a ground-landing scheme in the 50's and 60's, the fast growth of the population and aerial traffic forced to evolve to the actual scheme of performing the balloon flights and payload recoveries from the sea.
Also they would became experts in maximize the use of physical space for balloon launches. In 1975 a dedicated balloon launch facility was built in a mountanious region near Sanriku. First using a vertical balloon launch method, soon the needs for bigger balloons and payloads forced to built a special platform which would allow a semi-dynamic launch system to be introduced. And that was another characteristic of the program: the development of new techniques and devices to perform this activity.
In 2008, the program moved to the Island of Hokkaido, to establish a new balloon facility in the Taiki Aerospace Research Field (TARF). Instead of changing their balloon operations philosophy to take advantage of the greater space available turning to a conventional dynamic launch technique, they decided to improve more the semi-dynamic launch system. Thus was born the "Sliding launch system" whose main advantage is that it allows to inflate a balloon inside the hangar to avoid sudden gusts of wind during that critical part of the launch process and when the right conditions are met, the inflated balloon can be pulled out and launched. By combining the ability to inflate the balloon inside the huge hangar and the vast launch pad around, this updated semi-dynamic launching method allows to launch balloons with a volume up to 2.000.000 m3. More details can be obtained in our detailed account on the subject.
A key detail for stratospheric ballooning in marine ambients is to minimize the environmental impact of such activities. Japanese law is extremely restrictive on this regard and so, JAXA adapted their operations to safety regulations.
An example of this can be found in a recent modification made to the materials used to manufacture a super-pressure balloon model known as "Tawara". Due to an additional requirement from the Japan Coast Guard to eliminate the possibility of balloons sinking at sea in order to minimize the risk of marine pollution it was necessary to use lighter materials so the envelope balloon originally made of multilayer "BH25" was replaced by a 20 microns thick polyethylene while the load ropes made of a special Kevlar composite were replaced by one made of ultra-high-molecular-weight polyethylene (UHMWP).
A detailed account of the procedures and systems developed to support balloon operations at sea was recently published in the Journal of Astronomical Instrumentation.
The article entitled "Marine Search-and-Recovery Operation of Scientific Balloons in Japan" is available for free and is detailed enough to appreciate the effort put by the agency on this issue.