Location

Cocoa Beach, Florida

Start Date

3-4-1967 12:00 AM

Description

The ability of man to function safely both inside and out of his spacecraft will become even more critical after his pioneering flights such as Gemini and Apollo are completed. As greater numbers of astronauts make flights of long duration, survival may well be a function of a number of extravehicular activities such as routine vehicle inspection, emergency maintenance and repair. erection of structures and platforms, and rescue operations. Current systems remain bulky, heavy, and a possible source of hazard and malfunction. The solid-propellant space power systems examined here are small, light, manually or automatically operated, and have the capability not only to propel and stabilize man in space, but provide a means of power to do an extremely wide variety of critical functions outside or within a spacecraft.

It has often been stated that there is no need to replace a working system. The authors of this paper are in full agreement with this statement. Let us assume for purposes of illustration a simplified spacecraft which requires only two systems for its operation, one in the nose which is hydraulic, and another in the tail which is electrical. Both are well designed and completely workable. As long as they are capable of performing their required function and as long as they are capable of growth to meet additional mission requirements, there should be no valid reason to replace either by a solid-propellant hot gas system. But let us consider further. In the event of a failure of either system during a flight, the parts of one system cannot be used in a repair of the other. It would be very surpris - ing if the motors, switches, etc. of the electrical system could be substituted in any way for any of the valves and cylinders of the various hydraulic devices and vice versa. If, however, both systems were replaced with a compatible gas generator powered system, a failure in either end of the spacecraft could use parts and prime movers frorn the other.

The present philosophy for space-borne systems and components imposes as criteria of design extremely high standards of operational reliability and there is no quarrel with this doctrine. However, high reliability from the standpoint of completion of a manned space mission ·does not necessarily imply complete maintenance- free reliability during the entire operating life of the various systems involved.

We are dealing here with a vehicle containing a crew of thinking, random decision making, non-linear operating, human beings rather than an inanimate object which is capable of performing only the actions for which it has been pre-programmed. At the present time, crew members of space vehicles perform a variety of maintenance functions which enhance the operability of themselves and their vehicles. Such simple non-programmed act ions as tuning a radio or adjusting a thermostat can be considered as part of the maintenance functions.

Bad communications? A pilot will naturally and instinctively tune his command receiver for increased performance or change to another communications channel where reception might be better.

Too hot? A crew member turns down the thermostat on his suit a couple of notches to compensate for the extra heat load caused by unplanned exertion.

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Apr 3rd, 12:00 AM

Solid Propellant Power Systems for Normal and Emergency Space Operations

Cocoa Beach, Florida

The ability of man to function safely both inside and out of his spacecraft will become even more critical after his pioneering flights such as Gemini and Apollo are completed. As greater numbers of astronauts make flights of long duration, survival may well be a function of a number of extravehicular activities such as routine vehicle inspection, emergency maintenance and repair. erection of structures and platforms, and rescue operations. Current systems remain bulky, heavy, and a possible source of hazard and malfunction. The solid-propellant space power systems examined here are small, light, manually or automatically operated, and have the capability not only to propel and stabilize man in space, but provide a means of power to do an extremely wide variety of critical functions outside or within a spacecraft.

It has often been stated that there is no need to replace a working system. The authors of this paper are in full agreement with this statement. Let us assume for purposes of illustration a simplified spacecraft which requires only two systems for its operation, one in the nose which is hydraulic, and another in the tail which is electrical. Both are well designed and completely workable. As long as they are capable of performing their required function and as long as they are capable of growth to meet additional mission requirements, there should be no valid reason to replace either by a solid-propellant hot gas system. But let us consider further. In the event of a failure of either system during a flight, the parts of one system cannot be used in a repair of the other. It would be very surpris - ing if the motors, switches, etc. of the electrical system could be substituted in any way for any of the valves and cylinders of the various hydraulic devices and vice versa. If, however, both systems were replaced with a compatible gas generator powered system, a failure in either end of the spacecraft could use parts and prime movers frorn the other.

The present philosophy for space-borne systems and components imposes as criteria of design extremely high standards of operational reliability and there is no quarrel with this doctrine. However, high reliability from the standpoint of completion of a manned space mission ·does not necessarily imply complete maintenance- free reliability during the entire operating life of the various systems involved.

We are dealing here with a vehicle containing a crew of thinking, random decision making, non-linear operating, human beings rather than an inanimate object which is capable of performing only the actions for which it has been pre-programmed. At the present time, crew members of space vehicles perform a variety of maintenance functions which enhance the operability of themselves and their vehicles. Such simple non-programmed act ions as tuning a radio or adjusting a thermostat can be considered as part of the maintenance functions.

Bad communications? A pilot will naturally and instinctively tune his command receiver for increased performance or change to another communications channel where reception might be better.

Too hot? A crew member turns down the thermostat on his suit a couple of notches to compensate for the extra heat load caused by unplanned exertion.

 

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