Goddard, Robert H.: Report Concerning Further Developments. The Smithsonian Institution Archives, 1920. Mar. [2009. június 26-i dátummal az eredetiből archiválva]. (Hozzáférés: 2009. június 29.) „In the case of meteors, which enter the atmosphere with speeds as high as 30 miles per second, the interior of the meteors remains cold, and the erosion is due, to a large extent, to chipping or cracking of the suddenly heated surface. For this reason, if the outer surface of the apparatus were to consist of layers of a very infusible hard substance with layers of a poor heat conductor between, the surface would not be eroded to any considerable extent, especially as the velocity of the apparatus would not be nearly so great as that of the average meteor.”
Goddard, Robert H.: Report Concerning Further Developments. The Smithsonian Institution Archives, 1920. Mar. [2009. június 26-i dátummal az eredetiből archiválva]. (Hozzáférés: 2009. június 29.) „In the case of meteors, which enter the atmosphere with speeds as high as 30 miles per second, the interior of the meteors remains cold, and the erosion is due, to a large extent, to chipping or cracking of the suddenly heated surface. For this reason, if the outer surface of the apparatus were to consist of layers of a very infusible hard substance with layers of a poor heat conductor between, the surface would not be eroded to any considerable extent, especially as the velocity of the apparatus would not be nearly so great as that of the average meteor.”
