Opensource MicroGravity Laboratory

Technology of the OMGL as presented to the IAC 2004 Congress

      You can also read our paper, published in the IAC congress CD, and use a java simulator to simulate the flight of the OMGL on your computer with different parameters.

Slide 6: The OMGL uses rocket propulsion esclusively for automatic air drag compensation, its rocket engine cannot be used to control the flight in any other way, this was decided for security reasons. According to the amount of thrust required, three techniques can by used to propel the OMGL. The first one, the weakest, uses heat from air friction to transform the water in the cooling tubes in hot steam, which is released by the nozzle. The second technique is the water rocket one: 4 compressed air tanks (A in the slide) create a pressurized air bubble above the water level in the large water tank (H20 in the slide), which then release high pressure to the cooling tubes. The water is then heated in the tubes and the result is an emission of high pressure steam from the tube. The third technique use a reaction of the high pressure steam with an alkali metal in the combustion chamber at the bottom of the nozzle. The strongly exothermic reaction generates hydrogen gas which self-ignites thanks to the energy obtained by the alkali-steam reaction. This is the stronger propulsion method and is used only for supersonic wave drag compensation.

Slide 7: The stabilization during freefall is very simple. One large gyro (G in the slide) stabilizes the vertical axis, which is the more susceptible to external forces. 4 smaller gyros (g in the slide), radially oriented, stabilize the other axises. The gyros have fixed axises and cannot be used to change the attitude of the OMGL during freefall, thus directing flight, they can olny be used to passively stabilize the flight. The avionics can only turn them on before the beginning of the freefall and off after the landing. This is another security measure to prevent any kind of directional flight or any kind of control from the avionics.

Slide 8: The experiment container and the large water tank are both protected from vibration by all around passive vibration dampers and by an active vibration and shock waves damping system necessary for supersonic flight.

Slide 9: The open circuit airframe cooling system is integrated in the propulsion system. This liquid cooling systems allows for a thinner airframe to be used, then reducing total mass.

Slide 10: In the upper part of the OMGL, 4 parachute containers and 4 inflatable floater containers are present. The number of parachutes, their dimensions and usage depends on the flight mode. At least one container is for backup parachutes in subsonic flight, and two containers in supersonic flight.