beams, one transmitting intelligence, illuminate the MIROS, which reflects each to its own separate transmitter. The material from which the MIROS is constructed causes a transfer of the intelligence between the two beams. Progress has been made in basic research to permit cross-coupling the laser beams. Theoretical studies, verified by laboratory experiments, clearly demonstrate the operational potential of the technique. It is intended to continue this research and to initiate an experimental flight program.

In data encoding, work has progressed on TV systems for squeezing the greatest possible amount of image information through an information communication channel. A particularly notable recent accomplishment was a system which adjusts itself to the amount of detail in a portion of a TV image. The principle of operation is known as "adaptive delta modulation." Basically, only significant changes in the brightness from point to point in a scene are transmitted. Internally, the system follows these brightness changes with greater precision and less equipment than other schemes. Experimental circuits exist and improvements and reduction to engineering practice are contemplated under continuing investigations. Computer programs have been devised to simulate operation of a device that can train itself to recognize particular patternsfor example, cloud patterns associated with hurricanes. This automatic pattern recognition system is portrayed schematically by figure 219. At present, an enormous amount of human effort is required to scan the TIROS photographs received on the ground. Automatic devices which can do such work tirelessly would clearly be very

valuable. Moreover, they might be placed aboard the spacecraft themselves to monitor cloud conditions directly-transmitting only selected pictures and warnings to Earth. It has now been proven feasible to design a system of this kind and extensions and improvements are planned during follow-on work.

A substantial effort has been initiated and will be continued toward the development of TV systems which transmit and receive entire images more or less continuously. Such "area-scan" systems are contrasted with current ones in which an electron beam sweeps across a screen, either extracting information to be transmitted or building up the scene at the receiving end. The "area-scan" systems have certain advantages-for example, more detail for a given amount of hardware.

Other examples of information development in progress are instruments to detect space phenomena such as the speed of protons, and a grating spectrometer to measure radiation in the spectrum between the infrared and the highest frequency radio waves. Research is in progress on digital computers for on-board data processing in order to minimize the sensitivity of solid-state devices to particle radiation encountered in space. In one approach, computer circuits are being studied that use variations in the degree or direction of magnetization of pieces of material with uniform properties throughout each piece. Localized damage from radiation, which affects a very small area, will not impair the entire piece and hence the operation of the circuit. It has been found possible to design an entire computer using magnetic devices. Though somewhat slower than solid-state computers, their sensitivity to radiation will be hundreds of times less. One such computer is being assembled currently.

HUMAN FACTORS

The success of future manned missions will depend upon the effective utilization of man, the ability to maintain him for extended periods of time, and the protective systems to assure his well-being. Research in this field is aimed at the following related objectives:

1. Obtain a better understanding of man's capabilities and limitations in aerospace environments through research on body systems and psychophysiology, as well as biological and medical selection factors.

2. Obtain design requirements for equipment and subsystems which will guarantee an adequate crew environment when applied to development of life-support systems, protective systems, and man-machine control systems and displays.

3. Integrate human requirements into the design of advanced systems.

The technology required for life support systems and components for mission durations of 20 days to 3 years is being developed. This includes stored and partially regenerative systems as well as the more advanced regenerative and closed systems. The application of the various systems is illustrated by figure 220. To increase the feasibility of missions of long duration with increased numbers of astronauts, the weight penalty per man-day-represented by the ordinate of the figure must be decreased. The curve compares the relative weight of MERCURY, GEMINI, and APOLLO systems with the

weight of new systems which are projected from our current program of research.

An integrated multiman equipment test was conducted during the past year. The atmosphere of a simulated space vehicle was regenerated by means of a sodium superoxide system which removed the carbon dioxide and supplied the required oxygen. A closed waste disposal system was used in which the urine and feces were treated in a biological reactor employing the activated sludges process. This process results in potable water which is reused by the crew.

In addition to tests of the atmosphere and waste disposal systems, toxicological, microbiological, behavioral, and food problems were included in the study. The test was intended to run for 30 days but operation was terminated after 5 days due to equipment failure and nausea of the participants. Based on the symptoms, it is believed that nausea was caused by vapors, the source of which is presently being investigated. This contaminant was not detected on the gas chromatograph during the tests. The five-man tests will resume again after the source of the difficulties is identified and corrected.

Studies have shown that long duration manned missions require that breathing oxygen be provided by the closed cycle regeneration of expired carbon dioxide. An electrocatalytic unit, being developed under an Ames Research Center contract, has reached the breadboard stage as shown by figure 221. Carbon and water are products in this unit. Product water is electrolyzed in a unit generating breathing oxygen, with hydrogen as a byproduct. The electrolysis unit design was based on results of fuel cell research. Based on laboratory tests, 210 watts power are required to provide a man's oxygen requirements continuously. The electrolytic cell weight, with controls, is less than 4 pounds per man.

An advanced breadboard of an electrolytic oxygen generation unit is also operating at Ames Research Center. This unit is capable of generating breathing oxygen from water vapor in the atmosphere of the closed space cabin.

A flight test mass spectrometer has been developed and is being fabricated for sensing the composition of inhaled and exhaled gases, gases in the compartment and astronaut's suit. The unit, which weighs less than 35 pounds including a flight vacuum system, is less than 10 by 10 by 20 inches overall size and is capable of operating continuously in flight. It will be tested by flights in F-104D and X-15 aircraft.

In the area of physiological monitoring during space flight, two achievements of significance lie in the areas of brainwave analysis and motion sickness. For the first time in 30 years of electroencephalograph analysis (EEG), brain wave patterns have been identified which reveal the state of sleepfulness or wakefulness of the subject. This identification was established by means of a computer analysis. A continuation of the analysis will enable remote monitoring of physiological and psychological states of man during space flights. A fully automated recording and monitoring EEG machine which will accurately relate EEG responses to tasks was completed and is now in use at the Manned Spacecraft Center. This machine, which is the first of its kind, is capable of comparing the responses of any number of subjects on the same task, or any number of recordings of the same subject repeating a given task. The machine relates the EEG signal to the task with an accuracy of 0.001 second.