Energia - GPI Space
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    SPACE EXPERIMENT "REFLECTOR"
     aboard the "MIR" orbital station
     (final report)

   
 
 

Large-scale reflector is one of basic elements of large space antennas. Therefore works on creation of structures of large-scale transformable reflectors are so actual today. It is evident that the testing of such designs in space is a major stage of these activities.

RSC "Energia" and joint Russian-Georgian company "ENERGIA-GPI SPACE" (EGS) have conducted experiment onboard the "Mir" Orbital Station, whith the purpose of:

  • approbation on space orbit of the structure of new generation large-scale reflector
  • approbation of a new construction system of stabilization and control of process of deployment of the structure;
  • testing of process of deployment and shape formation in the outer space enviroment
  • control of the fixation and preservation of the shape of a mechanical system
  • investigation of the rigidity characteristics of the transformable reflector constuction
  • qualitative estimation of a strething of metal canvas of a screen and formation of a flawless discrete surface of an asymmetrical paraboloid
  • study of reliability of process of deployment taking into account the detection of anomalous processes of transformation and fixation of the shape

 
 

The "REFLECTOR" structure presents the parabolic antenna reflector with the following dimensions in deployed state:

  • Ellipse: D max =6400 mm; D min =5200 mm
  • Height - 1100 mm.

In a transport condition the package(packet) measures:

  • D = 620 Mm,
  • Height - 1060 mm.

The equipment for the "Reflector" experiment, including reflector itself, mounting unit, control panel and complete set of cables, was delivered by the cargo spacecraft "Progress M-42" to the MIR orbital station on July 18 1999.

   
 
 

Crew of the MIR orbital station (commander V.M. Afanasiev, flight engineer S.V. Avdeev, flight engineer J.-P. Haignere) has conducted preparatory activity inside station: transferred the equipment of experiment "Reflector" from the cargo ship to the station, assembled the transport packing for transportation of "Reflector" equipment to the mounting zone on the outside surface of orbital station, assembled the internal electrical circuit, prepared TV and photo equipment. They have also prepared the container with instruments for works on the outside surface of the station.

During the spacewalk on July 23 1999 the cosmonauts - V.M.Afanasiev and S.V.Avdeev have taken out the packing of the "Reflector" unit together with cables and control panel from the airlock of a module "Kvant-2" and have transferred it using cargo robotic arm (Gst II) on a module "Kvant". There the cosmonauts have mounted the "Reflector" unit on an assembly ring of a "SOFORA" mast. While conducting the installation works, the crew made radio reports during communication sessions with the MCC.

 
 
 

Then the cosmonauts have conducted dismantling of a protective cover of transport packing and removal of fixing devices from the "Reflector" unit, conducted the cable of the"Reflector" equipment on "SOFORA" mast and "Kvant" module, installed Control Unit and plugged the electrical connector into the onboard connector on the "Kvant" module.

 
 
 

Commander of crew V.M.Afanasiev switched on the tumbler on the control panel for applying current to an electric circuit of the "Reflector" unit. During a deployment of the unit the unfolding terminated spontaneously, and the diameter of an deployed power ring was ~3200-3500 mm, which was well visible on videomonitors in MCC. The crew tried to help a deployment of a reflector using special bar, but their efforts were unsuccessful. That is explained by that at the absence of a current in a circuit of drives, the reflector should not open even at attempts to shake it manually.

The commission was created in the RSC "Energia", which has presented the early conclusions and recommendations for the further carrying out the experiment. The commission performed the analysis of the probable reasons of the abnormal situation, reviewed all components of instrumentation involved at realization of "Reflector" experiment, designed the methodical recommendations for maintenance of the further course of experiment, designed the cyclogramme of activities of crew during spacewalk of July 28 1999 and sent the radiogrammes on the technique of operations of crew pursuant to designed operations.

 
 
 

During the spacewalk on July 28 1999 flight engineer S.V. Avdeev after visual inspection (pursuant to the recommendations) switched the connector of "Reflector" equipment pursuant to the nominal scheme and switched on the tumbler on the control panel (applied current to electric circuit) of the "Reflector" unit. After that the "Reflector" unit has unfolded completely.

 
 
 

S.V.Avdeev took pictures of the unfolded "Reflector" unit from the surface of the base module of the "Mir" station. The flight engineer J.-P. Haignere conducted a photo and videorecording of process of mounting and deployment of the "Reflector" unit from a window of the docking module of the "Krystall" module. The recordings from the video camera about the works performed on the outside surface of the station, were transmitted to MCC during the communication sessions.

 
 
 

After that, pursuant to the technique of the experiment, the crew performed the rotation of an assembly ring with the "Reflector" unit around the "SOFORA" mast and jettisoned the "Reflector" unit from the "Mir" station.

Thus, on July 28, 1999 the "Reflector" experiment was performed completely: the deployment of the antenna reflector and its repulsion with the photo - and video recording of performed operations. As a result of space experiment "Reflector" the high characteristics of a design of the large-scale transformable reflector, and also reliability of its operation were confirmed.