Purpose of the flight and payload description
The MACFT (Membrane Aeroshell Capsule Flight Test) was an experimental demonstrator vehicle developed in the framework of MAAC (Membrane aeroshell for Atmospheric-entry Capsule) a project carried out by researchers at JAXA/ISAS and collaborating Japanese universities. The concept centered on deploying a large, lightweight flexible aeroshell before atmospheric reentry, allowing the vehicle to decelerate at high altitude where atmospheric density is low, reducing aerodynamic heating. Rather than withstanding the thermal environment of reentry as traditional capsules do with ablative materials rated to over 2000 degrees Celsius, the MAAC approach avoided it by deploying a large aeroshell in orbit before reentry begins.
In the image at left we can see a scheme of the model used in the balloon tests. The flare-shaped membrane aeroshell, supported by an inflatable torus, could be packed compactly during launch and deployed in near-vacuum conditions. Because the vehicle decelerates at high altitude using a low ballistic coefficient, it could achieve soft landing or splashdown without a parachute, and the inflatable structure provided buoyancy for ocean recovery. The system didnt depended on the shape of the payload being recovered, making it potentially applicable to a range of missions.
Details of the balloon flight
Balloon launched on: 8/28/2004 at 6:31 jst
Launch site: Sanriku Balloon Center, Iwate, Japan
Balloon launched by: Institute of Space and Astronautical Science (ISAS) / Japan Aerospace Exploration Agency (JAXA)
Balloon manufacturer/size/composition: Zero Pressure Balloon model B100 100.000 m3
Flight identification number: B100-10
End of flight (L for landing time, W for last contact, otherwise termination time): 8/28/2004
Balloon flight duration (F: time at float only, otherwise total flight time in d:days / h:hours or m:minutes - ): ~ 4 h
Landing site: On the Pacific Ocean, near japanese shore.
Normal vertical launch, ascent to 20 km with drift towards the Southeast. At approximately 200 km from the coast, the balloon is deballasted, allowing it to ascend to float altitude with drift towards the West (returning to the coast). At approximately 120 km from the coast, the payload is jettisoned and falls vertically to the ocean. The balloon continues its westward drift until the end of the flight.
The drag coefficient extracted from flight data showed that the vehicle covered the subsonic through transonic range up to approximately Mach 1.4. These measurements were compared against data from transonic and subsonic wind tunnel tests showing that these values were within the range of the wind tunnel results. The test vehicle achieved stable flight through the subsonic and transonic regimes. The mission served as the foundation for subsequent development steps leading toward the sounding rocket experiment.
External references
- Ballooning activities in Japan Advances in Space Research 42 (2008) 1619
- ISAS press release JAXA website
- MACFT web site Institute of Space and Astronautical Science
Images of the mission
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