Extracting Race, Extracting Space

Through charts such as “Variations in Rectal Temperature at Sea Level as a Function of Activity,” the compendium established the thermal parameters within which a man can work before his physiological response is altered by environmental conditions. This chart worked to establish a “neutral boundary” by mapping data points published across four articles written by physiologists in the United States and South Africa.7 While the chart’s caption states that the aforementioned “superficial differences between ethnic groups appear to be due to habit patterns and experience relative to working under hot conditions,” the South African racial category of “Bantu” marks the outer edges of NASA’s “neutral boundary zone.”8

South African historians concerned with histories of race-making and scientific racism have long maintained that the state’s use of the word “Bantu” (as opposed to “African” or “Black”) “constituted an essential element of the abusive racist vocabulary of apartheid.”9 Its re-appearance in the formulation of extra-planetary design standards prompts questions about how ideas about the future of life and labor in space have been racialized. In fact, “Bantu” men were tested first and foremost to establish the limits of work in high heat by the South African researchers in work that was included in the NASA compendium.

In one of the South African papers cited by NASA contractors, “Responses of Unacclimatized Men Under Stress of Heat and Work,” researchers at the Chamber of Mines Applied Physiology Laboratory describe how they selected a group of unacclimatized black African laborers to test forty-three different combinations of heat stress conditions, on the basis that they were “a representative selection” of the men recruited to work on the South African gold mines.10 Each group of men spent two days in these experiments.

On the first day, men carried out four hours of continuous work at a rigidly standardized rate in cool conditions. On the following day, they repeated the same routine in one of the forty-three heat stress conditions. At the beginning of each session, and again at the end of each hour, researchers measured the men’s heart rates (in the standing position, in beats per minute) as well as body temperatures (in the rectum, in °F.) The men stood naked to be weighed at the beginning and end of each experiment. While their fluid intake and output were measured in calibrated cylinders, their sweat-rates were calculated using the algebraic sums of the weight loss and fluid quantities.

In this study, heat stress conditions were defined by air temperatures (with 100% humidity) of 84, 87, 90, 93 and 96°F. They planned to test wind velocities of 50, 150, and 500 ft/min, in conditions of light work (100 cal/m²/hr), moderate work (150 cal/m²/hr) and hard work (240 cal/m²/hr). At 96°F, however, they reported that it was “impossible to expose raw men to hard work and wind velocities of 50 and 150 ft/min for more than 45 minutes.” At 93°F, during hard work, many men developed fevers of 104°F in less than 4 hours. These men were withdrawn from the study, as “this body temperature was accepted as an arbitrary limit above which it would not be safe to continue.”11 In subsequent attempts to compare heat tolerance between racial and ethnic groups, the Applied Physiology Laboratory set experimental parameters based on these miners’ performance.

South African anxieties about white fitness come to the fore in a second paper cited by NASA consultants. The paper, “Natural State of Heat Acclimatization of Different Ethnic Groups,” describes their attempts to compare heat tolerance among (1) white and Aboriginal Australians in the hot, humid tropics at Weipa on the Cape York Peninsula of Australia; (2) French soldiers and Chaamba Arabs at Hassi-Messoaud in the Sahara Desert; (3) Kalahari Bushmen in the desert region of the Bechuanaland Protectorate; (4) “River” Bushmen in the Okovango swamp region of Bechuanaland; and (5) Bantu and white South Africans living in the temperate climate of Johannesburg. As they worked to account for multiple physiological reactions to heat exposure, they drew contradictory conclusions about the anthropological differences they observed.

On one hand, they wrote that white Australians showed “above-average adaptation to heat.”12 To account for their advantage, they emphasized that all the experimental subjects from this group were actively engaged in sport. Researchers therefore argued that commitment to activity of fairly moderate intensity could be enough to overshadow the effects of anthropological differences. They write:

It can truthfully be said that of all the groups tested [the white Australians] were the worst equipped for tolerating heat exposure. Of the three Caucasian groups they certainly were the heaviest, had the highest body fat/weight ratio, and were the most advanced in years. Yet they put up a better performance than even the local inhabitants (i.e., Aborigines) of the area. This is certainly ample proof to our previous assumption that the climate in which the population resides and works may overshadow any possible effects of anthropological differences. Activity of fairly moderate intensity has been shown to be a pre-requisite to proper acclimatization … and the information presented here again shows that when Caucasians remain active in tropical areas they are physiologically as well, if not better, adapted to heat than the locals.13

Just one page later, however, the researchers draw the opposite conclusion in their discussion of “Bantu” and “Caucasian” performance in a stepping-exercise experiment. Here, when they observe that the oxygen/work ratio for “Bantu subjects” doing stepping exercises is “significantly lower than that for Caucasians,” they suggest that the difference could be explained by the fact that the African miners sweat significantly more than their counterparts. They speculate that “the slightly lower value for pulse rate and rectal temperature could be attributed to this higher efficiency and consequent lower heat production,” but that, “on the other hand, it may well be that the colored races will always have a slight but insignificant advantage in heat tolerance.”14

It appears that NASA contractors cherry-picked from the conclusion of this article in order to write, in the compendium, that observed differences between ethnic groups are superficial. Indeed, the summary of “Natural State of Heat Acclimatization” suggests that “in spite of large differences in nutritional background, anthropological make-up, age and motivation, there is but little difference between ethnic groups in heat tolerance provided that they have been similarly active in the same environment.”15 Its authors go on to argue that differences in how various groups respond to heat in physiological terms will secure or threaten their health in changing environmental conditions. They write:

Some sweat more and others show quicker rises in pulse rate but the ultimate result in body temperature response, the decisive factor in heat tolerance, is the same. It is possible that if heat exposure of long duration is involved and the water intake is restricted then the heavy sweaters will be worse off. Such severe conditions would not be entirely uncommon in some parts of the globe.16

In the end, the South African physiologists make several contradictory, even competing claims about racial similarities and differences in physiology under hot, wet conditions. They contend that “the climate in which the population resides and works may overshadow any possible effects of anthropological differences,” despite the fact they insist that “when Caucasians remain active in tropical areas they are physiologically as well, if not better, adapted to heat than the locals.”17 In the same study, they suggest that “the colored races” may “always have a slight but insignificant advantage in heat tolerance.”18 And they argue that the physiological difference that explains why African miners perform better in high heat (e.g. sweat rate) could become their greatest weakness if water intake is restricted during prolonged exposure to a high heat environment.

“Natural State of Heat Acclimatization of Different Ethnic Groups” was published as part of a symposium on temperature acclimation. The discussion published as part of the symposium proceedings underscores the fact that there was no consensus on how to define or study racial difference among physiologists. One attendee, Dr. Baker, argues that the researchers at the Applied Physiology Laboratory were not attentive enough to the problems of racial differences in anatomy. He argues that there are observable differences between races when it comes to characteristics like body size, fat, and the relation between surface area and muscle mass:

Since these are such important factors in sweat loss and in rectal temperature rise under hot conditions, it is very easy to select, whether accidentally or intentionally, racial groups which show one to be higher or lower than the other in such responses. Therefore until the studies are either based on representative samples of races defined by body composition or until a matched-pair design, matched for body composition, is undertaken, I feel still in the dark as to what are the exact meanings of these results.19

The authors of the study, in turn, respond that matched samples would be unrepresentative of the ethnic groups compared:

[Dr. Baker’s] point ignores the fact that there are very significant differences in these characteristics between ethnic groups. The average weight of Bushmen is 48 kg and height 160 cm; the comparable figures of Caucasians in South Africa is 70 kg and 174 cm. I defy Dr. Baker to collect two matched samples. Assume that he could, then they would be so completely unrepresentative of the ethnic groups that the comparison of heat responses would be quite valueless.20

A second attendee raises concerns about the sample size of the South African studies. Observing that, beyond the miners’ studies, the majority of their experiments were conducted with a relatively small number of subjects, he argues that “it is especially important under these circumstances to remember that ‘nonsignificant differences’ may merely mean that the evidence is inadequate for forming judgments.”21 Attending to the way group data was plotted, this attendee points out that the South African team should study how the curves of changing pulse rate, rectal temperature, sweat rate, etc., change over time. He observes that, within the South African data, it seemed that the curves for one group were consistently above or below that for another group. He concludes that these differences could become significant if questions of reproduction were considered at times of environmental crises:

It sometimes seems that small differences in the physiological state (or genetic constitution) of individuals are inconsequential for survival. However, although this may often be true during most of the life span, it seems likely that apparently quite trivial differences will assume crucial significance at times of environmental crises. Under natural conditions, such crises are likely to occur at least once during the prereproductive and reproductive years, and will exert very strong selection pressures.22

This history should shape questions about the racialization of the laboring body, as well as contemporary debates about its reproduction beyond the geochemical limits of the earth. We may not be able to separate NASA’s design standards from apartheid’s infrastructure any more than we can separate the construction of the neutral boundary from the extractive industry on Earth.