Elsevier

Displays

Volume 23, Issues 1–2, April 2002, Pages 75-85
Displays

Displays in space

https://doi.org/10.1016/S0141-9382(02)00012-4Get rights and content

Abstract

The chapter describes the human and environmental factors that dictate the way that displays must be designed for, and used in space. A brief history of the evolution of such display systems covers developments from the Mercury rockets to the International Space Station.

Introduction

The ergonomics of working with display units in space has been a topic of research since the start of the space race in the 1950s. It is characterised by a strongly conservative approach in using new technology—everything has to be as near 100% reliable as possible. From the very beginning, the emphasis has been on making sure that it was humanly possible to perform the necessary tasks during a flight. Gradually the focus is switching to adopting technology and designing systems that improve performance. This article outlines the factors that affect human beings working in space and presents an overview on the evolution of the controls and displays of spacecraft.

Section snippets

Environmental considerations

The major environmental issues affecting display and workstation design in space are weightlessness and illumination. They are described in more detail below. Other environmental factors are mostly of concern for the overall well being of the astronauts and affect the overall spacecraft design rather than the design of workplaces. The spacecraft must shield the astronauts from the high levels of radiation in space. It must insulate them from wide variations of temperature and it must contain an

Weightlessness

It can be argued that the use of the word ‘weightlessness’ is misleading, in purely physical terms, to describe conditions inside a spacecraft orbiting around the earth. It is the weight of the spacecraft (i.e. the attraction between it and the earth) that keeps it from flying away in a straight line. The spacecraft and everything in it including astronauts are free falling together giving, locally at least, the sensation of zero-gravity. You do not feel pulled down onto the floor because the

The visual environment

The intensity of sunlight in space, unfiltered by the atmosphere is much greater than that which we experience everyday on earth: around 25% more intense than a bright sunlit day on the ground. When orbiting the earth a spacecraft usually spends a little less than half of its time in the shadow of the planet. In the so-called low-earth-orbit that most manned spacecraft occupy the orbit lasts around an hour and a half. (Only the Apollo moon missions have so far taken astronauts beyond such an

Human capabilities

The human beings perform remarkably well in space. The changes that do take place in capability are usually of two types. In general the ability to control one's body-reaction times, co-ordination, awareness of posture and feeling for forces needed to move is impaired when one first arrives in space. As one learns and adapts to the new environment one's performance returns to almost normal levels. Physical capabilities, on the other hand, tend to degrade gradually. Bones become weaker as does

Workstations

Displays in manned spacecraft have reflected advances in display technology and the increasing complexity of the vehicles themselves. As the vehicles became more complex more displays were needed; as the display technology improved the increasing amounts of information could be more efficiently managed. Another aspect of workstation design has been posture. Postures in space vehicles are designed for the high g-forces of launch and re-entry; in space stations they are designed for

American space vehicle displays—Mercury to Shuttle

The cramped one-man capsule of the Mercury spacecraft had a relatively limited number of displays. There was not a lot that the astronaut could do to control the capsule, the rocket was relatively simple and the life support system was primitive. There was not a lot of information to display. The Gemini rocket was a more sophisticated and complicated system. More individual rocket motors and more complex systems meant more information to display to the crew. But the display technology was the

Russian space vehicles—Soyuz

The Russian Space Agency has been using the reliable Soyuz spaceship since the 1960s after a rapid evolution from Votsok and Voshkod craft. In 1979 the original Soyuz model was replaced with the Soyuz T, which itself gave way to the Soyuz TM in 1986. In all these years the controls and displays have remained largely unchanged—illuminated buttons in regular rectangular arrays. A TV screen was for manual docking and a little globe that spins underneath a set of cross-hairs was for showing the

Space stations—restraints and workplaces

Away from the rigours of launch and re-entry astronauts like to float around and dislike the restriction of complicated restraint systems. In the claustrophobic cabins of the first spacecraft it was quickly realised that any surface could be and would be pushed against to hold one's position. All controls—buttons, switches, dials and levers—need to have raised guards or to be recessed into the panel to prevent their accidental activation. In the larger spaces of the Shuttle and on-board Skylab,

Displays on the International Space Station

The International Space Station (ISS) is by far the largest and most complex spacecraft built so far. It would simply be impossible to use single function hardwired displays to monitor and control it. The majority of the displays that can be called up on the station's computer screens are concerned with the efficient and safe operation of ventilation, air purification, temperature regulation, power and data distribution, water distribution and fire detection systems. Most of the computer screen

Space suits

A modern space suit is really a very small spacecraft. It has most of the same systems that a spacecraft has albeit reduced in size and with a shorter operational autonomy. The controls and displays for these little spacecraft are greatly simplified with respect to their larger cousins. They can afford to be simple because the basic operational response to a malfunction in a space suit is to get back to the airlock, get into the spacecraft and get out of the suit.

Basically the suit systems work

Work-arounds

Famously there were seven Mercury astronauts; perhaps a dozen or so astronauts ever used the Gemini spacecraft and only a few tens of astronauts ever trained for and flew in Apollo rockets. The user-base for the Soviet Vostock and Voshkod rockets will be similar to Mercury and Gemini. The then-Soviet (now-Russian) Soyuz spacecraft has been in service for over 30 years in four different versions and has been used by less than three hundred people. Even the Space Shuttle which carries up to seven

The future

New display technology tends to get in space only after it has been widely accepted on ground (or in aviation) despite the fact that space agencies often commission research into the use of new displays. NASA was working on the projection of computer displays on the inside of EVA suit helmets around 1990 [9]. Nevertheless astronauts are still carrying printed checklists with them when they don their spacesuits. Both NASA and the European Space Agency have worked on wearable computers with

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The views expressed in this article are those of the author and do not necessarily reflect those of his employer, Human Engineering Limited.

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