Solar Space Telescope

In June 1998 plans were announced for the launch of a Solar Space Telescope to be jointly developed by Chinese and German scientists. With a target launch date of 2003, the $60 million telescope would have an aperture of one meter and a resolution ten times better than the SOHO spacecraft. China would pay some 80% of the program's cost, and be responsible for the development of the primary instrument on the two-ton spacecraft.

The outer space unequalled superiority and the astronautics high-tech enormous development caused the astronomy to enter the spatial astronomy time. Holds the historical opportunity, fully uses Chinese astronautics technology the advantage, fully displays our country in the solar magnetic field and in the velocity field research and the equipment development creativity and the leading status, develops a host mirror meter, achieves diffraction limit0.1² -0.15² The imagery system, unifies Chinese invention the two-dimensional at the same time spectroscope, and matches by0.5²

The high resolution softXbeam telescope as well as the wide band spectrometer and so on, in the widespread spectrum scope and the continual time evolution, take the upper air between the resolution as the main characteristic, take a magnetism Yuan survey as the breakthrough point, develops the sun transient and the stable state magnetohydrodynamics observation and the research, the realization space conquest with the solar physics research significant breakthrough, enables our country the spatial sun survey aspect to achieve the world leading level; and the date place relations research aspect makes the important progress in the satellite environment, provides the powerful method for the space weather forecast; And for development partial astronautics high-tech(high resolution imagery system, high accuracy posture system, correlation tracking device, star is sensitive, mass memory unit and so on)makes the significant contribution.

The space solar eyepiece is a astronomy satellite, the gross weight 2tons, the solar synchronization circular polar orbit, the axle high 709 kilometers, the three axle is stable, average power1200W, under the data passing on rate 60Mb/s, the size is 5´ 2´ 2 meters 3, this project at present is in the solution essential technology and the system integration demonstration stage. Solves 8 aspects related more than 30 essential technologies in 2001, and will compose the system and the demonstration, in this foundation, comprehensively will carry on the environment experiment. Strives for about for 2 years to complete the type development, expects to 2004-2005 year launch, the movement life 3 years.

The spatial astronomy laboratory ( Space Astronomical Laboratory ) is the Chinese Academy of Science country astronomical observation center ( National Astronomical Observatories ) one key experimental base. Its main duty is develops our country space astronomy technology, the method, the equipment and the instrument.

The Sun, an important research object in astronomy and astrophysics, exerts great influences on the Earth and its environments. It is also a very typical star that can be studied with high spatial resolution. As a natural laboratory, most of its physical phenomena such as huge scale, high temperature and high pressure cannot be duplicated on Earth. The magnetic field in plasma of the Sun plays a very important role in the solar atmosphere structure and solar activities. So, the studying of the magnetic field with high resolution will be the leading topic of the solar astronomical physics at present and in the future. In 20th century, "physical world" in England remarked that the studying of the magnetic field would be the fourth difficulty in physical researching for the 21st century following after the quantum gravitation, fusion control and high temperature super-conduct.

It is not easy to realize high-resolution and very wide spectrum observation of the Sun and its fine structure with ground-based equipments, because the atmosphere on the Earth will absorb the radiation and atmospheric turbulence will blur the solar image. Scientists in National Astronomical Observatory, Chinese Academy of Sciences (NAOC) dedicate to develop a Space Solar Telescope (SST) to do solar observation and research outside the earth atmosphere.

SST will carry five scientific observing instruments working over a wide spectrum with 2-dimension imaging and with continuous time evolution. It is anticipated to achieve a breakthrough advance in solar physics through coordinated, wide spectral coverage, highly temporal and spatial resolution observations of transient and steady states in solar hydrodynamic and magneto-hydrodynamic processes. Some new technologies on SST, such as aerospace large optic mirror, correlation tracker, and high- speed telemetry and telecommand, will be very useful for China country.

This paper will introduce the SST satellite system including the spacecraft service subsystem and the ground support subsystem.

The satellite service system and its ground support equipment are qualified with creativity as well as heritage on the base of reliability. The 1-meter optical telescope will be the most advanced solar observing telescope. Its launcher and service system can use previous satellites such as China-Brazil Earth Resources Satellite(CBERS) for reference. Making full use of the domestic Unified S-Band(USB) network and existent ground station, SST satellite and ground support system is designed according to SST requirement and international standard to guarantee the realization of SST science objects. The scheme has been assessed many times by relating departments.

In June 2000, a group combined by Chinese Academy of Sciences (CAS) and The Fifth Academy of China Aerospace appraised and affirmed the feasibility of SST and its ground support system. In 2001 Chinese Aerospace Department approved the project as a pre-research project of the 10th -five- year plan. So the project is promoted to a new developing phase.

Now SST is advancing successfully and is expected launch in 2008.