[masraum]

Originally Posted by GH85Carrera

Long-radius centrifuge experiments by the Naval Medical Research Laboratory starting in 1958 kept subjects in a 30-foot (9.1 m) diameter centrifuge complete with living quarters for up to three weeks. The experiments found that the subjects took three to four days to overcome motion sickness and balance issues.

That's fascinating. Thinking about the statement above, I was thinking "that had to be have on earth, and therefore in earth's gravity. If it was just a rotating room, then it wasn't really a simulated artificial gravity situation. To make it effective as an artificial gravity situation in earth's gravity (not in orbit) the thing would have had to be humming, and I can't imagine most folks being functional or healthy.

I did a little poking around and found the following.
HISTORY OF ARTIFICIAL GRAVITY

The earliest of the extensive tests of sustained rotation were conducted in the Naval Medical
Research Laboratory in Pensacola, beginning in 1958. The Slow Rotating Room (SRR) had a 5-m-radius
with complete living facilities, in which subjects could live for periods ranging from 1 day to 3 weeks.
Rotation rates ranged from 1 to 10 rpm, with the floor of the SRR staying horizontal. Initially, most
subjects developed motion sickness symptoms when they made head movements at room rotation rates in
excess of 3 rpm and, through that experience, learned to restrict them. Incremental increase in the speed
of the room was employed. After several days, most subjects were able to make head movements without
nausea at rotation rate up to 6 rpm. Only some of the subjects could go further to move comfortably at 10
rpm.
Research was also performed to examine the problem of adapting the postural system to a 3-rpm
run. Like for motion sickness, their balance control was initially disrupted on entering the SRR, but it
recovered within 3-4 days. Then, most subjects were able to walk on thin rails about as well as Earth-
normal, throw darts, and pour coffee without having to think about motor control. They also performed
watch-keeping tasks within normal limits (Guedry et al. 1964).
When the SRR was stopped after 12 days, subjects felt an after-effect and an erroneous motion
sensation during head movements. Their balance control was again disrupted for 3-4 days. These effects
were stronger after runs at 10 rpm than after runs at 3 rpm (Graybiel et al. 1965).
The investigators concluded from these studies that humans can adapt to rotation rate of 3 rpm,
and that a 14-day period of rotation at this velocity causes no significant changes in general condition or
performance. In contrast, no adaptation took place when subjects were rotated at 10 rpm for 12 days,
implying that a 10-rpm rotation rate is close to the upper threshold of endurance.
As a next step, ways of adapting humans to rotation at 10 rpm were investigated through
incremental increases in rotation speed over time. Symptoms of motion sickness at 10 rpm, as well as
impaired balance, were prevented by increasing rotation rate in nine approximately 2-day stages over the
course of 16 days (Graybiel et al. 1969). Results also indicated that the time needed to adapt can be
shortened greatly by making many specific head movements. The higher rotation rate, the more difficult
the adaptation, but adaptation to 10 rpm was possible as long as rate-increase increments were held to 1-2
rpm with a period of 12-24 hour at each increment (Faget and Olling 1968). The time needed for this
adaptation might therefore prove to be too long for practical use during spaceflight. However, anti-motion
sickness drugs could then be used to attenue motion sickness while the terminal velocity is more rapidly
achieved (Lackner and DiZio 2000b).
Interestingly enough, during the long-duration SRR runs periodic 10-15 minutes stops were
required for re-provisioning. Over time, the on-board experimenters who helped in this activity made
transitions between the stationary and SRR rotation without experiencing motion sickness or disruptions
of movement control. They showed perfect dual-adaptation (Cohn et al. 2000, Lackner and Graybiel
1982), thus indicating that is is possible to be simultaneously adapted to rotating and non-rotating
environments. Also, in all the subjects, there was retention of the adaptation to the SRR for several days,
which implies that transitions from weightlessness to rotation should be acceptable under certain
conditions (Graybiel and Knepton 1972).
Beginning in the 1960s a major ground research program on artificial gravity was conducted at
the Institute for Biomedical Problems in Moscow. Their earliest tests in the MVK-1 small rotating
chamber at speeds up to 6.6 rpm allowed rotating one or two subjects for up to a week. It was followed by
the roomier 10-m radius Orbita centrifuge, capable of rotating two to three people for several weeks at
speeds up to 12 rpm. The longest tests were for 25 days at 6 rpm.
The initial exposures produced the expected disturbance of dizziness, equilibrium, and
coordination. Within an hour, the usual pattern of motion sickness symptoms occurred, including
vomiting in some cases. In 4-5 hours, subjects also complained of drowsiness and headache. Three
periods of vestibular adaptation were distinguished for these long-duration exposures. The first 1-2 days
were characterized by severe motion sickness. This was followed by a week during which the nausea and
related acute symptoms disappeared, but drowsiness and headache remained. Finally, after the first 7-10
days, subjects showed immunity to motion sickness, even when additional vestibular stimulation was
provided.
As found in Graybiel’s SSR studies in Pensacola, the severity of motion sickness symptoms and
the time to adapt to prolonged rotation on the Russian small rotating room MVK-1 were related mostly to
rotation rate. There was an absence of any motion sickness symptoms at 1 rpm, moderate symptoms at 1.8
rpm, and marked symptoms at 3.5 rpm. On the larger Orbita centrifuge, however, symptoms appeared
only above 1.8 rpm. Head movements brought on discomfort in all cases (Kotovskaya et al. 1981).

Yes, please
Gunther Werks Tornado.


Not really my thing, but also very cool as a speedster