Apr 17 1981
From The Space Library
The New York Times said that launch pad 39A at KSC, earlier reported to have been seriously damaged by Columbia's blastoff, suffered "very minimal" damage, according to a KSC damage-assessment team. Wayne C. Ranow, an assistant to pad-site manager Tip Tallone, supplied a preliminary list of items damaged and added that just a few more seconds of "hang time" before the Shuttle cleared the pad would have caused much more damage. NASA spokesman Hugh Harris said KSC had expected "a lot more damage than that;" although it would take two weeks to restore the pad this time, "we will learn from the experience and change some things" to avoid delays in the program. The impact of the 6.6 million pounds of thrust was "similar to what we saw with Apollo," Harris said. (NY Times, Apr 17/81, A-26)
ARC reported the effects of weightlessness on physiological processes shown in 14 U.S. experiments carried on unmanned Soviet satellite Cosmos 1129 in 1979. This was the only U.S. opportunity for biological research in space since 1975. The Vostok spacecraft sent into elliptical orbit and recovered within the Soviet Union 18½ days later was like those; of two previous Cosmos missions in which the United States had participated in 1975 and 1977. Use of Cosmos vehicles was inexpensive for the United States because the Soviet Union paid for spacecraft, launch, and support activities; 40 scientists from 18 U.S. universities and research organizations shared in the mission.
The U.S. experimenters found changes in enzymes and in animal bone strength, growth rate, and mineral content, like the changes experienced by astronauts and cosmonauts; the results would help explain some of the problems of weightlessness. The Soviet Union provided 37 white rats and 60 fertile quail eggs, shared by the experimenters; U.S. scientists provided carrot tissue cultures and plantlets and carrot slices inoculated with tumor-forming bacteria. One of two control groups of white rats kept in Moscow lived in ordinary cages and ate the flight diet; the other, called "synchronous control," was housed in an identical spacecraft on the ground and subjected to vibration and gravity forces like those of launch and reentry, experiencing whatever changes in environment the orbiting Cosmos transmitted to earth. The only difference between the synchronous control group and the mammals in flight was the weightlessness.
After the Cosmos flight, the animals were recovered immediately, before they could readapt to Earth gravity, and a recovery team set up a mobile lab at the landing site to autopsy about a fifth of the rats. The rest were flown to Moscow, where some were autopsied after 6 days of readaptation to gravity, and the rest after 29 days. The Cosmos rats showed a 20% deficiency in bone mineral content compared to the synchronous-control subjects. In the rats readapting to normal gravity, some changes reversed within a few days; others took longer to return to normal.
Under normal conditions, the total amount of bone in an adult human or animal remains constant, with bone continually resorbed and replaced by newly formed bone. In spaceflight, production of new bone seems to slow down, but resorption continues, resulting in net loss of bone and a decrease in strength. The greatest change is in weight-bearing bones, but even those not bearing weight (as jaw bones) show changes in mineral content and the cells forming new bone.
The experiments included the first attempt to breed animals in spacemating the rats and examining how embryos developed in a weightless state. This experiment did not succeed, however, and no litters were produced; the control group, to the surprise of Soviet and U.S. scientists, showed the same results. The scientists were still seeking a reason for the failure. The quail eggs provided no information on embryo development because the incubator failed on the 13th day of flight. The plants showed no ill effects; carrot embryos and plant tumors grew in space just as on the ground, suggesting that spaceflight had no effect on carrot tissue. (ARC Release 81-21)
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