Progress of Apollo 14

Press, Volume CXI, Issue 32525, 8 February 1971, Page 13

Progress of Apollo 14

(Contributed)

During a television broadcast scheduled for early this afternoon (New Zealand time), the Apollo 14 crew will demonstrate part of several experiments they will make during the 67}-hour Earthward leg of their flight. Three laboratory dishes, holding a jelly containing amounts of different organic chemicals, will be heated gently inside an electric field. One, for the benefit of colourtelevision viewers, contains a combination of dyes which is expected to separate into its red and blue components. These two components will move at different speeds in the electric field when the jelly becomes liquid on heating. Because all parts of the spacecraft including the particles of dye—are falling Earthward at the same rate, the components will remain separated when the jelly cools. On the Earth, differences in density would create a circulation (convection) in the dishes and remix the components quickly. In this experiment, although a little mixing will recur, there will be a greater degree of separation than is possible in Earth-bome laboratories. Another dish contains human haemoglobin, and the third genetic molecules of salmon. These will enable decisions to be made about several experiments planned for the Skylab series, and might lead to the production of vaccines and related substances in orbiting factories. The Skylab missions, the first of which is scheduled for late next vear, might also investigate the casting of; metals, and a seemingly-j trivial set of tests with this in mind will be made during the TV programme.

Small quantities of water with different surface tensions will be pushed slowly from a syringe. The way droplets are formed and be-

have when ejected will be studied, and the results might influence the choice of equipment in the initial Skylab experiments. Similarly, the feasibility of growing crystals (for electronic components) may be indicated by another simple test. By placing an immersion heater in a flask of water containing temperature-sensitive dves. the movement and heat flow in a liquid will be shown. A more important variation of this experiment is being made throughout the mission. Among the changes in the Apollo 14 and Apollo 15 spacecraft made after the Apollo 13 explosion were several inside the servicemodule oxygen tanks. In the original tanks, two 75-watt coils were used periodically to heat the liquid oxygen, providing an internal gas pressure. Stirrers prevented the gas generated forming envelopes around the heaters. In both altered service modules, the two oxygen tanks, and a third added for emergencies, each contain three 50-watt coils but no stirrers. The oxygen tanks for Apollo 16 and Apollo 17 are of a different type and have a greater capacity for the extended work they will do while in orbit round the moon. Because the last two missions of Project Apollo will need almost all available oxygen, one of the three modified tanks of Apollo 14 will be used until nearly empty.

The low level in that tank might accentuate the situation created by the removal of the stirrers. Pockets of gas, which would not conduct much heat, could form [regularly around the coils [and permit them to overheat [Splashing by the remaining i low-temperature liquid might fracture the coils and indicate that some changes would be required in the tanks of later spacecraft, including some being built for the Skylab missions. y