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Demonstrator of Atmospheric Reentry System with Hyper Velocity
Sagamihara - Jan 21, 2002 Atmospheric hypersonic flight is one of the key technologies not only for planetary entry probes but also future space transportation systems. DASH (Demonstrator of Atmospheric Reentry System with Hyper Velocity) mission is a collaborative mission between ISAS and NASDA. The main objective of the mission is to demonstrate high-velocity atmospheric earth reentry at the velocity over 10 km/s and to conduct "high-velocity reentry measurements" by onboard instruments during the flight. DASH system developed by ISAS is scheduled to be launched by H-IIA rocket on Jan. 31, 2002. The spin-stabilized satellite DASH has a total weight of 86kg, which can be divided into two portions: a re-entry capsule to conduct re-entry experiment, and its carrier involving a propulsion system, a communication system, attitude and orbit control systems, and others. The attitude of the DASH system at the separation from the rocket is stabilized by the momentum wheel until the ignition of the spin motor (SPM). In order to reduce the reentry point dispersion, the attitude of the orbiter is maneuvered by the cold-gas jets based on the earth-horizon sensor (HOS) and the sun sensor (PSAS). After the deorbit by ignition of the deorbit motor (DOM), the orbiter deploys the yo-yo despinner and the capsule is separated. The DASH orbiter is inserted into the geostationary transfer orbit (GTO). The orbiter in GTO adjust the orbital period by the drift motor (DFM) for the reentry to the planned point. Three days after the launch, the capsule separated from the orbiter will conduct reentry over the Sahara desert in Mauritania. The capsule is exposed to the extremely high aerodynamic heating rate up to 10 MW/m2. The obtained data are transmitted through the telemetry to the ground stations during the slow descending phase after the parachute deployment. The geometry of the reentry capsule is designed so as to have natural aerodynamic stability as well as to perform its ballistic reentry flight. Due to the strict requirment for lightweight and minimum envelope, a blunted cone is selected for the configuration. The capsule subsystems are composed of the mainframe structure, onboard instruments, the thermal protection and control systems, and parachute system including pyro-technique separation devices. The capsule's diameter is 40 cm and its total weight is 19 kg. The capsule is thermally protected by the carbon phenolic ablation heat shield. The cross-type parachute is installed in the capsule. Community Email This Article Comment On This Article Related Links DASH at ISAS SpaceDaily Search SpaceDaily Subscribe To SpaceDaily Express Rocket Science News at Space-Travel.Com
Successful First Test For Vega's Zefiro 9 Engine
Paris, France(ESA) Dec 28, 2005Flames, smoke and a deafening noise accompanied the first firing test of Vega's Zefiro 9 third-stage solid rocket motor. A first examination of the data indicates that everything went well at the test carried out yesterday at Salto de Quirra in southeast Sardinia. |
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