fig2 enables to better locate , with respect to each other , fig3 a and 3b relating to the first described embodiment of the invention ; it will be discussed later . in both fig3 a and 3b , the element 1 and the element 2 , which are to be assembled and then separated , are each represented by a plate , which makes up their respective outer structure . the main connecting elements of both elements 1 and 2 to each other comprises a mixture 30 containing a connecting agent , placed between two connecting plates 10 and 20 , more accurately between the respective connecting surfaces 12 or 22 of these two connecting plates 10 and 20 , and bolts 40 enabling each of these elements 1 and 2 to be secured with their respective connecting plates 10 and 20 . lines a - a and b - b of fig2 explain the cross - sections , represented by fig3 a and 3b . indeed , the line a - a intersects the structure by passing through bolting attachment elements , that is , a screw 40 . thus , along the entire structure to be maintained , assembled , and then separated , are a plurality of attachment elements , such as two screws 40 , each screwed through one of both structures 1 or 2 , against which the screw head presses . securing these screws 40 is carried out in nuts 41 incorporated and enclosed in the connecting plates 10 and 20 , by virtue of a recess . it is noted that the connecting plate 10 has a land 14 laterally extending with respect to the direction of the structures of the elements 1 and 2 , thus pressing against one end 24 of the other connecting plate 20 . indeed , in the case of an aeronautic , or even spatial , launcher , the tangential forces between the elements 1 and 2 can be very significant . consequently , to complete the connection function of the connecting element of the mixture 30 , the land 14 of the first connecting plate 10 enables most of the longitudinal strains transmitted between both elements 1 and 2 to be uptaken . the line b - b does not intersect these attachment elements . thus , fig3 b only represents the head of two screws 40 which project from the entire structure . fig4 shows the assembly in a perspective view , in particular both elements 1 and 2 , both connecting plates 10 and 20 which are relating thereto and heads of the screws 40 . fig5 shows that the mixture 30 is actually sandwiched between the connecting surface 12 of the connecting plate 10 and the connecting surface 22 of the connecting plate 20 . fig6 a and 6b relate to a second embodiment of the invention and correspond to fig3 a and 3b . thus , it is found the first element 1 , the second element 2 , their respective connecting plates 10 and 20 and the means for assembling these elements , as screws 40 . however , the connection between both connecting plates 10 and 20 is made by a stack 50 . the stack 50 is detailed in fig7 . it comprises , in this example , two outer layers 52 made of resin or glue , enclosing or sandwiching a thermite layer 57 , mixed with resin or glue . the elements 1 and 2 are , in the preferential application of the invention , for the first element 1 , an aerospace or aeronautic launcher stage with a rank n , on the end of which is attached the second element 2 , which is either a second launcher stage with the rank n + 1 , of the launcher , or an operational load , for example containing equipment or a facility to be put into orbit . to immobilize both elements 1 and 2 , the latter are brought to the melting temperature of the solder or glue used for this assembly . for example , if these structures to be assembled are made of titanium and if the solder chosen is a silver alloy , the entire zone to be assembled is brought to the melting temperature of the silver alloy , which is about 960 ° c . for this , several conventional methods are chosen , for example induction soldering , oven heating soldering , under a neutral atmosphere , or resistance soldering . for the assembly relative to the present invention , it is noted that induction soldering or resistance soldering are more suitable for high volumes . once the soldering is carried out , the heating means are removed and the connection is thus operational . the mixture 30 thus contains heating means , which comprises thermite , preferably sheathed thermite ( definition of thermite : mixture of a metal fuel that can often be aluminum , but not only , and of an oxidant , often a metal oxidant ). this type of material , by an exothermal oxidoreduction reaction , produces temperatures in the order of 1800 ° c . it is set out that the connecting means are placed surrounding the entire connection , which is on the periphery of the entire first element 1 and second element 2 , preferably an aeronautic launcher . to carry out the separation of the elements 1 and 2 , the mixture 30 placed between both connecting plates 10 and 20 should be triggered . remote pyrotechnical triggering by an electrical control connection 60 , is used . in the case of two elements of an aerospace launcher , the first element 1 and second element 2 are intentionally placed under pressure . hence , during the pyrotechnic triggering , they will move away from each other , under the so - called champagne cork effect , along the linear axis of the assembly . in the case where there is no pressure inside both these elements , or between the structures , the distancing can be made by any other known means such as springs , distancing rockets , pneumatic means or the like . after the first element and the second element are disengaged , the internal structure of the second element has again a surface with neither protuberance , nor pull - out . moreover , the invention meets a provision of article 5 of the space operations act ( soa ), relating to the satellite lunching operators , in order to ensure the environment protection of the outer space , in particular for restricting risks related to space debris . while at least one exemplary embodiment of the present invention ( s ) is disclosed herein , it should be understood that modifications , substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure . this disclosure is intended to cover any adaptations or variations of the exemplary embodiment ( s ). in addition , in this disclosure , the terms “ comprise ” or “ comprising ” do not exclude other elements or steps , the terms “ a ” or “ one ” do not exclude a plural number , and the term “ or ” means either or both . furthermore , characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise . this disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority .