There are numerous unanswered questions surrounding communication of persons in space. Within the space capsule, the direct verbal communication among crewmembers may be influenced by attenuation related to transmission characteristics of the capsule environment and by high levels of ambient noise. Conditions of space  (particularly weightlessness) can alter nonlinguistic communication cues such as voice tone, facial expression, and distancing. These variations, especially when complicated by the linguistic and cultural differences of multinational crewmembers, could result in miscommunication and interfere with the efficient work operations or social interactions of space travelers. Studies of international crews such as those proposed for exploring the ocean bottom (Glazer, 1974) would offer an opportunity to investigate the implications of linguistic diversity in space. In addition, procedures need to be developed to ensure that verbal messages are received and understood. More generally, greater attention needs to be given to understanding which cues survive and which fail the space environment, as well as the kinds of miscommunication that result from altered cues.
Equally demanding questions involve the establishment and maintenance of working and personal relationships with those on Earth or on other spacecraft. Space planners charged with providing for extended spaceflight face special problems in their attempts to implement communication systems in the face of rapid development in the technology. At the operations level, they must determine how such systems can be designed to avoid overload and to select and prioritize important information. At a more general level, they must determine how these systems can serve the information needs as defined by users and the information needs imposed by mission planners. Questions of protocol and of access must also be addressed.
It is predicted that space travelers, like other users of mediated systems, will find the medium better suited to simple rather than complex tasks and to work related rather than social interactions. Unlike other users, space travelers will not have the option of substituting a direct exchange when they find the medium wanting. Space travel reverses the usual pattern of direct interaction with intimates and mediated interaction with secondary or work related contacts. One of the more important questions for extended spaceflight concerns if, and how, a communication system can be used to deal with the kinds of complex and emotional interactions that are usually reserved for face to face communication. A related area requiring investigation is the effect of mediated/primary interactions with family and friends at home on direct/secondary relationships with crew members. Bedrest studies, such as those conducted at Ames Research Center (Chapman, Winget, Vernikos Danellis, and Evans, 1975; Chapman, Winget, and Vernikos Danellis, 1976; DeRosia and Sandler, 1979) could provide an effective vehicle for examining these  issues, as well as explicating the biomedical and performance issues of weightlessness.
Space managers, like managers everywhere, must deal with problems of keeping needed communication channels open while discouraging those communication activities which tend to inhibit the goals of the organization. Cliques and factions evolve in all large undertakings; however, negative aspects associated with such subgroups could be particularly destructive in the closed environment of space. A possible solution is the involvement of individuals who share memberships in several groups and who can interpret each group to the other. What is not well known is whether the burden placed on these individuals by their intermediating responsibilities is manageable in the space environment.
The effectiveness and efficiency of operations and the satisfaction of participants have been related to the structure of the communication network. We need to determine whether centralized, decentralized, or some combination of these two arrangements are most appropriate to space and how the efficacy of these arrangements might change over very long periods of time.
A phenomenon which has emerged in many confinement experiences is the tendency of separated individuals to direct hostility to outside contacts. In space, this tendency could translate into problems between on board crewmembers and ground control. Several suggestions, including the use of two way video and the training of ground crews in interpersonal relations, have been advanced. The smooth interaction between the crew and the ground is a fundamental issue which needs to be addressed for extended spaceflight. Whatever solution or range of solutions are adopted must take into consideration both the access needs of the ground and the autonomy needs of the crewmembers.
Whether, overall, spacecrews will be aided or hindered by interaction with family members and friends at home is still open to question. However, the prevailing view is that opportunities for private exchanges with loved ones will be reassuring and sustaining to space travelers. Just what level of interaction will provide the most support remains to be determined.