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Mercury spacecraft cooling question
I was looking at some cutaways of spacecraft, and am trying to figure
something out. Both Gemini and Apollo incorporated significant cooling radiators in the designs (external on the Apollo SM, mounted inside the skinning of the Gemini equipment module), but how was cooling handled on Mercury? There aren't any radiators on its exterior, and although you could use water boil-off for cooling on fairly short flights, the 34 hour long Faith 7 flight would seem to need a lot of water to make this concept work for that period of time. Pat |
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Mercury spacecraft cooling question
"Pat Flannery" wrote in message
... I was looking at some cutaways of spacecraft, and am trying to figure something out. Both Gemini and Apollo incorporated significant cooling radiators in the designs (external on the Apollo SM, mounted inside the skinning of the Gemini equipment module), but how was cooling handled on Mercury? There aren't any radiators on its exterior, and although you could use water boil-off for cooling on fairly short flights, the 34 hour long Faith 7 flight would seem to need a lot of water to make this concept work for that period of time. Pat Several things to consider: 1 Mercury was battery-powered, while Gemini and Apollo used fuel cells - much more heat generated. 2 Mercury was only one-man; less people = less heat generated. 3 Mercury was a _very_ basic vehicle; while Gemini was somewhat more complicated and Apollo was a whole different story where complexity is concerned. 4 In Mercury, the crew member only had to sit fairly still; in Gemini, there was a lot more activity (EVA included). On Gemini, were the radiators also for the crew and electrical systems? |
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Mercury spacecraft cooling question
Pat Flannery wrote:
I was looking at some cutaways of spacecraft, and am trying to figure something out. Both Gemini and Apollo incorporated significant cooling radiators in the designs (external on the Apollo SM, mounted inside the skinning of the Gemini equipment module), but how was cooling handled on Mercury? There aren't any radiators on its exterior, and although you could use water boil-off for cooling on fairly short flights, the 34 hour long Faith 7 flight would seem to need a lot of water to make this concept work for that period of time. The first hit I got on a web search for "Mercury Capsule Cooling" was: http://ntrs.nasa.gov/search.jsp?R=14153&id=8&qs=Ns%3DHarvestDate%257C0% 26N%3D4294967096%26Ne%3D25 For which the abstract reads: The approach to orbital thermal control of the Project Mercury capsule environment is relatively unsophisticated compared with that for many unmanned satellites. This is made possible by the relatively short orbital flight of about 4 1 2 hours and by the presence of the astronaut who is able to monitor the capsule systems and compensate for undesirable thermal conditions. The general external features of the Mercury configuration as it appears in the orbital phase of flight are shown. The conical afterbody is a double-wall structure. The inner wall serves as a pressure vessel for the manned compartment, and the outer wall, of shingle type construction, acts as a radiating shield during reentry. Surface treatment of the shingles calls for a stably oxidized surface to minimize reentry temperatures. The shingles are supported by insulated stringers attached to the inner skin. Areas between stringers are insulated by blankets of Thermoflex insulation. This insulation is especially effective at high altitude due to the reduction of its thermal conductivity with decreasing pressure. As a result of the design of the afterbody for the severe reentry conditions, the heat balance on the manned compartment indicates the necessity for moderate internal cooling to compensate for the heat generation due to human and electrical sources. This cooling is achieved by the controlled vaporization of water in the cabin and astronaut-suit heat exchangers. Not sure if there is an online copy, you may have to order paper. I notice they mention 4 1/2 hours vs the 34 of that other flight. Might have to get the paper to resolve that one. Maybe they just left the rest of the capsule (un)insulated "just enough?" rick jones -- Wisdom Teeth are impacted, people are affected by the effects of events. these opinions are mine, all mine; HP might not want them anyway... feel free to post, OR email to rick.jones2 in hp.com but NOT BOTH... |
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Mercury spacecraft cooling question
"Rick Jones" wrote in message
... The first hit I got on a web search for "Mercury Capsule Cooling" was: http://ntrs.nasa.gov/search.jsp?R=14153&id=8&qs=Ns%3DHarvestDate%257C0% 26N%3D4294967096%26Ne%3D25 Still looking; try this for starters: http://www.hq.nasa.gov/office/pao/History/SP-6/ch1.htm |
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Mercury spacecraft cooling question
It is drifting, but while perusing some of the hits I got, I came
across this one: http://www.time.com/time/magazine/ar...romoid=googlep which I thought was somewhat interesting. rick jones -- web2.0 n, the dot.com reunion tour... these opinions are mine, all mine; HP might not want them anyway... feel free to post, OR email to rick.jones2 in hp.com but NOT BOTH... |
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Mercury spacecraft cooling question
From he http://history.nasa.gov/alsj/apollo.precurs.html
"The Gemini program provided opportunities to prepare for Apollo in other ways as well. The crews of Gemini 5 and 7 spent eight and fourteen days in space, respectively and, although they had far less elbow room than the Apollo crews, they proved beyond any doubt that there were no physiological or operational barriers to the conduct of a ten-day lunar mission. Five of the Gemini astronauts ventured outside their spacecraft and, when they tried to do strenuous work, discovered that the air-cooling system used in the Gemini suits wasn't going to be adequate for Apollo. An astronaut sitting inside a cramped capsule simply couldn't work hard enough to generate much body heat and, consequently, could be kept cool by oxygen flowing through the suit. But when he got outside and flexed his arms and legs against the internal pressure of the suit, the extra heat load quickly overwhelmed the airflow cooling system. What was needed was a system which could carry away the excess heat; and, as a result of the Gemini experience, NASA and its contractors developed a system for circulating cooled water through tubes woven into an undergarment worn next to the astronaut's skin" http://www.hq.nasa.gov/office/pao/History/SP-45/ch3.htm under "[52] Table 3-II. Summary of Modifications to MA-9 spacecraft." adds "5. Added 9 lb of cooling water.... Increase cooling capability because of mission [duration]" |
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Mercury spacecraft cooling question
Alan Erskine wrote:
http://www.hq.nasa.gov/office/pao/History/SP-45/ch3.htm under Nice link, nearly got in trouble with my wife for staying at work longer to read it For some reason, perhaps all the talk about weight gain in contemporary vehicles, I found this one fun: http://www.hq.nasa.gov/office/pao/Hi...-45/fig3.5.htm rick jones -- Process shall set you free from the need for rational thought. these opinions are mine, all mine; HP might not want them anyway... feel free to post, OR email to rick.jones2 in hp.com but NOT BOTH... |
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Mercury spacecraft cooling question
"Rick Jones" wrote in message
... It is drifting, but while perusing some of the hits I got, I came across this one: http://www.time.com/time/magazine/ar...romoid=googlep which I thought was somewhat interesting. Pity NASA doesn't read its own reports; it might learn something. |
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Mercury spacecraft cooling question
Rick Jones wrote: It is drifting, but while perusing some of the hits I got, I came across this one: http://www.time.com/time/magazine/ar...romoid=googlep which I thought was somewhat interesting. This one: "On the Cooper flight, the control cords holding the retrorocket package to the capsule failed to fall free as intended because the explosive separating devices 'were not loaded with the appropriate charge.' " .....is very similar to the equipment module separation problems the Vostok spacecraft had that would leave the two spacecraft modules attached by a umbilical till aerodynamic forces during reentry pulled them apart. Pat |
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Mercury spacecraft cooling question
"Pat Flannery" wrote in message
... This one: "On the Cooper flight, the control cords holding the retrorocket package to the capsule failed to fall free as intended because the explosive separating devices 'were not loaded with the appropriate charge.' " ....is very similar to the equipment module separation problems the Vostok spacecraft had that would leave the two spacecraft modules attached by a umbilical till aerodynamic forces during reentry pulled them apart. Pat With the exception being that with Mercury, the spacecraft didn't go into the atmosphere nose-first. |
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