Space demostration of bare electrodynamic tape-tether technology on the sounding rocket S520-25

A spaceflight validation of bare electro dynamic tape tether technology was conducted. A S520-25 sounding rocket was launched successfully at 05:00am on 31 August 2010 and successfully deployed 132.6m of tape tether over 120 seconds in a ballistic flight. The electrodynamic performance of the bare tape tether employed as an atmospheric probe was measured. Flight results are introduced through the present progressive report of the demonstration and the results of flight experiment are examined as the premier report of the international cooperation between Japan, Europe, USA and Australia. Future plans for maturing space tether technology, which will play an important role for future space activities, are also discussed

T-REX: Bare electro-dynamic tape-tether technology experimetn on sounding rocket S520

The project to verify the performance of space tether technology was successfully demonstrated by the launch of the sounding rocket S520 the 25tu. The project is the space demonstration of science and engineering technologies of a bare tape electrodynamic tether (EDT) in the international campaign between Japan, USA, Europe and Australia. Method of "Inverse ORIGAMI (Tape tether folding)" was employed in order to deploy the bare tape EDT in a short period time of the suborbital flight. The deployment of tape tether was tested in a various experimental schemes on ground to show high reliability of tape tether deployment. The rocket was launched on the summer of 2010 and deployed a bare electro-dynamic tape tether with length 132.6 m, which is the world record of the length deployment of tape tether. The verification of tether technology has found a variety kind of science and technology results as the first in the humankind and will lead a large number of applications of space tether technologie

Opposed-Cavity Solar Thermal Thruster Made of Single Crystal Tungsten

This paper shows promising preliminary experimental results of heating test in relation to a solar thermal propulsion (STP) thruster with a pair of cavities aligned in back-toback position, so-called the opposed-cavity STP thruster. It was made of stainless steel, or made of single crystal tungsten that is an ideal material in respect of its high material strength and an absolute impossibility of recrystallization embrittlement under high temperature conditions. Besides, the opposed-concentrator, which consists of a pair of face-to-face concentrators, was prepared for the opposed-cavity STP thruster. Combining with them led the thruster temperature to 1,400K even in not-so-good vacuum and solar concentration condition under solar power density of 800W/m 2 . In addition, a TERC-type secondary concentrator was designed and examined in order to more highly concentrate solar power at the focus. Furthermore , new-designed main concentrators are unde r manufacture now in order to obtain more effective heating in the thruster cavity chamber

Atomic States and Collisional Relaxation in Plasma Polarization Spectroscopy: Axially Symmetric Case

An ensemble of atoms (or ions) is described in terms of the density matrix, and two quantities, population and alignment, are assigned to each atomic level for axially symmetric plasma environment. Collisional relaxation is treated semiclassically as transitions between vectors in the Liouville space and interpreted as elastic or inelastic transitions among the population and the alignment of the levels. A spatially anisotropic velocity distribution of perturbers is expanded in terms of Legendre polynomials, and rate coefficients are defined for the transitions. A set of rate equations are constructed for the system of populations and another set for that of alignments. In the case of an isotropic Maxwellian distribution of perturbers the former reduces to the conventional collisional-radiative model describing the ionizing plasma component of populations. As an example, berylliumlike oxygen in an anisotropic plasma environment is treated by this mehod

Panel Extension Satellite (PETSAT) -A Novel Satellite Concept Consisting of Modular, Functional and Plug-in Panels

Abstract A novel concept of satellite design, named PETSAT, is proposed in this paper. In this concept, a satellite is made of several Functional Panels such as the CPU panel, Battery panel, Communication panel, Attitude control panel, or Thruster panel, each of which has a special dedicated function. By connecting these panels with a reliable connection mechanism in a plug-in fashion, the total integrated system has a full satellite's function. Various combinations of functional panels, (for example, two CPU panels + one communication panels + three attitude control panels + two battery panels, etc.) provide flexibility to deal with various mission requirements, even though the basic panels are the same for various missions. The concept, technical issues and conceptual study results of PETSAT will be discussed