underlying Morphology of a repeat indicator
High-temperature reusable surface insulation (HRSI)
HRSI tiles (black in color) provide protection against temperatures up to 1260 °C. There are 20,548 HRSI tiles which cover the landing gear doors, external tank umbilical connection doors, and the rest of the orbiter’s under surfaces. They are used in areas on the upper forward fuselage, parts of the orbital maneuvering system pods, vertical stabilizer leading edge, elevon trailing edges, and upper body flap surface as well. They vary in thickness from 2.54 cm (one inch) to 12.7 cm (five inches), depending upon the heat load encountered during reentry. Except for closeout areas, these tiles are normally 15.2 by 15.2 cm (6 by 6 inch) squares. The HRSI tile is composed of high purity silica fibers. Ninety percent of the volume of the tile is empty space giving it a very low density (144 kg/m³, 9 lb/ft³) making it light enough for spaceflight.  The uncoated tiles are bright white in appearance and look more like a solid ceramic than the foam-like material that they are.
The black coating on the tiles is Reaction Cured Glass (RCG) of which tetrasilicide and borosilicate glass are some of several ingredients. RCG is applied to all but one side of the tile to protect the porous silica and to increase the heat sink properties. The coating actually is also absent from a small margin of the sides adjacent to the uncoated (bottom) side. To waterproof the tile dimethylethoxysilane is injected into the tiles by syringe. Densifying the tile with tetraethyl orthosilicate (TEOS) also helps to protect the silica and waterproof.
An uncoated HRSI tile held in the hand feels like a very light foam, less dense than styrofoam, and the delicate, friable material must be handled with extreme care to prevent damage. The coating feels like a thin, hard shell and encapsulates the white insulating ceramic to resolve its friability, except on the uncoated side. Even a coated tile feels very light, lighter than a same-sized block of styrofoam. As expected for silica, they are odorless and inert.
HRSI is used in conjunction with stronger, waterproof materials in the Space Shuttle heatshielding to give a balance of strength and resistance to the high re-entry temperatures experienced in Earth’s upper atmosphere.
HRSI is primarily designed to withstand transition from areas of extremely low temperature (the void of space, about -270 °C) to the high temperatures of re-entry (caused by interaction, mostly compression at the hypersonic shock, between the gases of the upper atmosphere & the hull of the Space Shuttle, typically around 1600 °C).
because the speed of sound barrier is broken for reentry of the spaceshuttle and the barrier of the atmosphere with the sound vacume; the basis of a direct sound value waveforrm is inaccessible by any format except for the reentry burn that defines the force field barrier about the EARTH as the tiles are related to the enterance into O2 ritch environments and waveforms of O2
In some models of phonology as well as morphophonology, the underlying representation (UR) or underlying form (UF) of a word or morpheme is the abstract form the word or morpheme is postulated to have before any phonological rules have applied to it. If more rules apply to the same form, they can apply wholly independently of each other or in a feeding or counterbleeding order. The underlying representation of a morpheme is considered to be invariable across related forms (except in cases of suppletion), despite alternations among various allophones on the surface.
In many cases, the underlying form is simply the phonemic form. For example, in many varieties of American English the phoneme /t/ in a word like wet can surface either as a glottalized [tˀ] or as a flap [ɾ], depending on environment: [ˈwɛtˀ] wet vs. [ˈwɛɾɚ] wetter. In both cases, however, the underlying representation of the morpheme wet is the same: its phonemic form /wɛt/.
In other cases, phonological rules may change the phonemes involved. In such cases, pipes (“|”) or double slashes may be used in transcription to distinguish the underlying form from its phonemic realization. An example is the word cats, which has the phonemic representation /ˈkæts/. If we take the underlying form of the English plural suffix to a ‘z’ sound, as many phonologists do, then the underlying form would be
This discrepancy cannot be avoided by choosing a different underlying form of the plural: If we assume it is an ‘s’ sound, as it’s spelled, then the word dogs, phonemically /ˈdɒɡz/, would have the underlying form //ˈdɒɡs// (in both cases, there has been progressive assimilation of the final segment). As this example illustrates, the underlying form of a morpheme is a theoretical construct, and depends on the analysis that is used.
Sandhi, such as the tone sandhi of the Chinese languages, is another phonological process that changes the phonemes of a morpheme from its underlying form.
A.G.Gurwitsch analysed the embryonic development of the sea-urchin as a vector-field, as if the proliferation of cells into organs were brought about by putative external forces.
basically a morph O2 waveform could be made for every planetary reentry value based on the Underlying functions of Morphology by PHONOLOGY
In developmental biology, a morphogenetic field is a group of cells able to respond to discrete, localized biochemical signals leading to the development of specific morphological structures or organs. The spatial and temporal extent of the embryonic fields are dynamic, and within the field is a collection of interacting cells out of which a particular organ is formed. As a group, the cells within a given morphogenetic field are constrained — i.e. cells in a limb field will become a limb tissue, those in a cardiac field will become heart tissue. Importantly, however, the specific cellular programming of individual cells in a field is flexible: an individual cell in a cardiac field can be redirected via cell-to-cell signaling to replace specific damaged or missing cells. Imaginal discs in insect larvae are examples of morphogenetic fields.
data courtesy of Wikipedia
Space Shuttle Discovery as it approaches the International Space Station during the STS-114 on 28 July 2005.
A closer view of the tiles under the forward fuselage and the front end of the left wing. The corner of the nose-gear door can be seen at the lower left. The dark solid black tiles are new ones which have never been through a reentry yet. (At top, the white object is the open left cargo bay door.)