[meteorite-list] Demonstrator of Atmospheric Reentry System with Hyper Velocity

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 09:55:49 2004
Message-ID: <200201220310.TAA17389_at_zagami.jpl.nasa.gov>

For those of you in the Sahara Desert, expect to see a
fireball in early February.

Ron Baalke

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http://www.spacedaily.com/news/rlv-02a.html

Demonstrator of Atmospheric Reentry System with Hyper Velocity
SpaceDaily

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.
Received on Mon 21 Jan 2002 10:10:29 PM PST