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STABILO Stabilo Mission 1 video - live / Stabilo Mission 1 video / Stabilo Mission 2 video About
Stabilo STABILO 1 ARCA’s
philosophy is that a manned suborbital ship for commercial applications
must be designed taking into account the crew safety. For that purpose,
the ship must have: The
purely space applications design of this ship makes it inappropriate
for powered flights at low altitudes, in dense atmosphere. Because of
that the system is transported to an altitude of 22.000 m with a Solar
Montgolfier. The
Launch Vertical
powered flight Inertial
vertical flight The
reentry
The rocket booster recovery The
cabin recovery
The Monopropellant Rocket Engine The main preoccupation for a spaceship designer is to ensure a high reliability. Since the appearance of rockets, until today, the main element that leads to a rocket vehicle failure is the engine. We consider that the main issue that a designer has to deal with in order to create a reliable ship is the creation of a reliable rocket engine. There are some alternatives, from the fuel point of view, regarding the type of a potential rocket engine that can equip such a vehicle: bipropellant liquid fuel, monopropellant liquid fuel, solid fuel and hybrid fuel. Through 2000-2004, ARCA experimented a series of rocket engines with various types of fuels. After those tests in 2003 the team decided to go forward with a hydrogen peroxide monopropellant engine. This type of engine was tested intensively through 2003-2004. Demonstrator 2B rocket which was launched from Cape Midia Air Force Test Site on September 9, 2004 used this type of technology. A monopropellant system used as a main engine for space propulsion is an unusual proposition mainly because of it’s low specific impulse. A vehicle launched from the ground, using this type of propulsion, in a suborbital mission, with a payload equivalent of about three passengers will be necessary to carry about 7 t of fuel, an unacceptable value. Furthermore, the final acceleration will be around 12G. This
situation is encountered because of: It is clear that a ship equipped with a hydrogen peroxide (85%) monopropellant rocket engine, able to complete the above mentioned mission is not suitable for a ground launch. However a 24% higher impulse can be obtained in the case of an air launch from an altitude of around 22.000m, with an almost fully adapted nozzle. STABILO is the first spaceship that uses a monopropellant tractor engine this solution was choose because it offers a high security of the flight. Despite of the presence of the four nozzles placed at an angle of 20°, that could indicate four engines, STABILO has only one engine. The reaction gases from the reaction chamber are distributed through the four nozzles. The 20° angle lead to a 6% thrust loss. Despite this, our engineers considered that the advantages of a high security of the ship resulting from a tractor engine are more important and the thrust loss could be compensated through a higher fuel quantity and a longer engine run. The reaction is 100% ecological since hydrogen peroxide decomposes in oxygen and hot water vapors. Function of the mission nature, and fuel concentration (65-85%), the engine will be reusable or expandable. While the expandable engines raise no special problems, the reusable engines built from composite materials is a real challenge. Such engines were used before but with ablative cooling (inner layers vaporize in order to keep outer layers at a reasonable temperature). However, this process can be used on "hot" engines at high temperatures. At lower temperatures, the inner layers don't vaporize efficiently anymore. Our engine accumulates the heat inside the inner and intermediate layers so that the outer layers don't change their mechanical characteristics even after a complete engine run. The heat is not released outside. This system is not very economical but is certainly very safe and reliable. The Fuel Tank The fuel tank is also built from composite materials. This technique started to be used by ARCA in 2001 and, until now, we had 100% reliability during the tests and real flight. The STABILO fuel tank is pressurized with helium at a value that allows the complete dislocation of the fuel at a sufficient pressure during the whole engine run. Another important achievement is that the engine is placed directly on the fuel tank structure. The Reaction Control System (RCS) For attitude control at high altitude where the atmosphere is very thin and aerodynamic surfaces are inefficient, STABILO cabin uses RCS. There are 6 small thrusters that use air under pressure. The thrusters do not influence the trajectory, their only purpose is attitude control. RCS is used when the pilot needs to reposition the vehicle, during reentry and to avoid uncontrolled movement of the vehicle after the powered flight phase. The Crew Cabin The most important aspect of the whole project is safety. Therefore, safety and backup systems for the pilot were designed for every stage of the flight. With the cabin placed at the bottom of the ship, the abort sequence has a simple procedure: the crew cabin could be gravitationally separated from the rocket booster and it is recovered with it's parachutes. The cabin offers protection for almost the entire flight sequence, even in unlikely events like complete equipment failure, structural damage, etc. The cabin is pressurized at 0.8 atm and contains navigation, flight control and life support systems. It is designed for one pilot that sits on a chair, specially designed for flight accelerations. The access inside the cabin is assured by a lateral auto-presurized hatch which can be opened both from inside and outside of the cabin. As an added safety, the pilot will use a pressurized suit, offered by another former X Prize competitor, which has a lot of experience with pressurized suits: DeLeon Company. DeLeon and ARCA are partners since 2005 and they are collaboration on a various aspects regarding the manned space flight. The pilot has a panoramic view through three portholes. The position of the portholes was choose in order to offer to the pilot a complete view without being necessary to raise from it's chair. The top engine with it's four nozzles could offer a beautiful image to the pilot, since the exhaust, made of oxygen and water vapors will freeze immediately after ejection, in contact with the outside environment (-60 degrees C). The jet will form small ice particles on which the Sun will reflect. After engine stop and capsule release, the pilot could maneuvering the cabin with the RCS to have a view of the Earth with the four engine traces of ice beneath the ship. The electronic equipment allows piloted flight and ground based commands in semi-automated mode. For the piloted flight, the navigation system acquires GPS and inertial data, without interfering with pilot's actions. For the ground-controlled flight, the electronic equipment offers the possibility to have full control of the spacecraft from the ground base. At the top of the crew cabin is placed a parabolic structure used as a stability system for the reentry. This system stabilize the ship and the tasks of the pilot are reduced to minimum. Stabilo
1 technical data Stabilo 1B This variant is different compared with the initial variant because of the rocket engine position. This allows a lower fuel consumption and the possibility to use a hot high performance rocket engine. The crew cabin and the fuel tank are almost similar with the initial variant.
Stabilo
1B technical data © ARCA 1998-2010 |
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