China first the space hands in course of study of test of meeting butt joint to already was finished, after with “ heavenly palace aircraft of target of a ” undertook successfully twice handing in meeting butt joint, “ god boat 8 ” airship will carry out an instruction to return the earth late on November 17. Of spacecraft return with blasting off is the process that goes against actually. Emissive process is spacecraft cross aerosphere quickly from ground classics and enter its to run orbital course; And returning a process is the process that spacecraft reachs the floor from decelerate of moving orbit classics. Whole returning a process is the system is mixed complex, medium, beautiful, Russia spacecraft returns 3 spaceflight big country land means, adiabatic means and land the choice each has his strong point of field. Apollo, alliance and spacecraft of divine boat department are adopted same kind return land means manned spaceflight implement the structure with different basis, main component lands to return 3 kinds means: Type of ballistic type, ballistic — lift and level land. Use the spacecraft that ballistic type returns, like artillery shell, return along a very abrupt method, passing through lift does not arise when aerosphere, cannot undertake placement is controlled consequently, placement error is so bigger, and overload is compared big (can amount to 8g ～ 9g) , be close to human body can susceptive limit. Placement is dispersed bigger also. Russia and United States return type spacecraft inchoately to use this kind of form, if the “ of Russia is Oriental the “ of airship of date of ascendant ” of ” date, “ and United States is mercurial ” date airship. Ballistic – the spacecraft that lift type returns uses bell shape structure commonly, passing through the lift with the certain generation when aerosphere, can have proper control to its flight contrail consequently, placement accuracy is taller, overload is lesser also (do not be more than 4g) . Airship of ” date series mixes the “ alliance of airship of series of date of “ Apollo ” , Russia what date series airship uses ” of “ god boat is this kind is returned land means. The level lands returned spacecraft has an ala to return spacecraft namely, the most typical is American space shuttle. Its appearance and plane are similar, can realize a level to land. This kind lands means overload is the smallest (make an appointment with 1.5g) , it is the touchdown that the spacefarer feels the most comfortable means, and capability of space shuttle control is very strong, placement precision is very tall, can land on designation airport runway, also can repeat use. Russian spacecraft combustion drops in temperature in American spacecraft chooses manned spaceflight of adiabatic eaves tile implement return cabin the speed that in distance ground the height of kilometer of 70 kilometers —40 counts kilometre with every second passes through when dense aerosphere, return cabin surface temperature to be able to achieve 1000-2000 Celsius, if be not adopted,prevent heat effectively to drop in temperature measure, whole like returning cabin to will resemble an aerolite, be burned to be cindery. Accordingly, how dropping in temperature is the biggest technology difficult point. Because be a choice,airship serves as manned spaceflight implement, of China the airship of ” allied ” of airship of ” of “ god boat and Russia is to use what use no longer, what use accordingly is the method that ablation defends heat, use a kind of instant outside airship namely high temperature resistant material, it is high polymer material commonly, when high temperature heats, exterior share data will be fused, evaporate, sublimate or decompose vaporization. Certain quantity of heat is absorbed in these process lieutenant generals, this kind of phenomenon calls ablation. Ablation prevents heat is to let burn-up of exterior share data conciously, take away quantity of heat, achieve the goal that saves main structure thereby. These heat-insulating material end in combustion later, those who remain is carbonization layer, airship bottom pitch-dark can prove covering layer him sacrifice, traded the security of airship. And American manned spaceflight implement give priority to with space shuttle, those who use is the method that covers many 20 thousand adiabatic tile in space shuttle surface undertakes protective to space shuttle and astronaut. Adiabatic tile basically divides composition by two, lining is low-down of coefficient of thermal conductivity high temperature resistant fiber of pottery and porcelain, outer it is thin thin an insulation thermal insulation. The material of adiabatic tile has a lot of kinds character, even if in same wear space shuttle to go up, the sort of adiabatic tile also is differ in thousands ways. For instance, in plane coping, the conduction that can use white drops in temperature material, in order to make space shuttle keeps cool in the flight; In be heated degree taller bottom, use 2 oxidation silicon normally, and besmear a black is isolated from outside layer; And in the plane forehead taper with be heated top rate body place and both wings brim, need to use high temperature resistant carbon to make material. In Russian spacecraft all spacecraft of be born United States drops more the sea returns the ground smoothly to ensure spacefarer and spacecraft are safe, according to manned spaceflight implement the orbit characteristic that move, each country chooses to land field is main abide by below 4 conditions: It is airship general from this area in the sky much circle second through; 2 it is field should be widened; 3 it is relief wants gently, the earth\’s surface wants enough and hard; 4 it is weather situation be close friends. Chinese Inner Mongolia is mid 4 child Wang Qi altitude rice of 1000 meters of ——1200, visibility is high, relief evenness is open, without the great river, climate of mainland of the temperate zone in belonging to, dry little rain signs of human habitation is exiguous, suit manned spaceflight very much implement land. Consider these factors integratedly, of airship of series of ” of “ god boat advocate land field choosing was in on Inner Mongolia mid prairie. In addition, wait for an element considering soup, built to reserve around wine spring again land. American thing two sides all is close to ocean, own a well-trained coastal lifesaving team and advanced maritime lifesaving technology and equipment, and sea stretch to the horizon, facilitating search and reclaim, so American manned airship chooses mostly maritime land. Accordingly, american space shuttle serves as Kennedy spaceflight center advocate land, edward thises air base serves as reserve land. Russia is had extensive in inferior fine inferior prairie and Siberia big Campagna, the thing is continuous on 10 thousand lis, so manned airship uses a country mostly means reclaims on inland. Advocate land set in district on the does obeisance to Kenuer to launch a northeast prairie with open, exiguous signs of human habitation, the area is kilometer of 40 much square about. (Zhangyu cropland)

Filed under: News