Technical Research on ISS Russian Segment

WMHP Experiment

Experiment WMHP forms part of the scientific research program performed by Brazilian Astronaut Marcos C. Pontes (BSA) on the Russian Segment of the ISS in the frame of CENTENARIO Brazilian Soyuz Mission Project. The Brazilian Space Agency is a customer of the preparation and implementation of the research program.


To study the processes of fluid dynamics in microgravity conditions.


  • Tests of functioning of small-size heat pipes filled with distilled water.
  • Assessment of the coolant efficiency.

Science Hardware Used:

Kit with MHP equipment consisting of:

  • Block MHP;
  • MHP memory map (in cover).

The equipment consists of a single unit, which accommodates two heat pipes and a data acquisition system. Distilled water in amount of 50 and 60 ml is used as a coolant. Each miniature heat pipe is divided in length to three different parts: an evaporator (20 mm), an adiabatic section (50 mm) and a capacitor (30 mm).

The heat is transferred to the evaporator by an electric heater attached with the use of thermal grease. The heat is removed from the capacitor through a copper radiator and two cooling fans. The heat is supplied to the system gradually with the use of an electric heater through a miniature heat pipe. The system functioning will be verified under seven different modes at power levels from 5 W to 35 W. To control the temperature variation along the heat pipe, three thermocouples are attached к its surface (Omega T-type), one of which has a direct contact with the data acquisition board. The rest thermocouples are accommodated on the heat distributor and insulation. All data is stored on the memory map, which is returned to the ground upon the experiment completion.

Experiment Results:

Information on miniature heat pipe operation recorded on the memory map.