From Aviation to Astronautics

Abstract

Now that major space flight operations are under way in Russia and America there is a natural interest in such topics in this country among those working on aeronautics and guided missiles. At present one can only speculate on how this country will eventually contribute to space flight. As the Duke of Edinburgh has remarked, the difficulty is not due to lack of scientific talent but to the absence of surplus funds. Even so, we can make effective contributions in many ways and we should not lack boldness in seeking out possible ways of doing this. In the meantime, however, there seems to be a place for a review of the present technical situation and prospects for the near future, as seen from the standpoint of one in the British Aircraft Industry. As the majority of interplanetary flights will begin through the Earth’s atmosphere and many will finish by way of the same medium, the Royal Aeronautical Society can claim a special and legitimate interest in these matters. Ever since its inception the Society has encouraged the discussion of new technical advances, although its ability to do this has sometimes been hampered by the requirements of security. The same restrictions apply to this paper with the result that I have chosen to draw upon published material throughout, and to review the subject on a broad basis. I hope the work will not be less acceptable on these grounds.

Galactic Winds

“…Some emission may also come from electrons accelerated locally in internal wind shocks. Steepening of the spectral index of the radio continuum emission in M82 (Seaquist & Odegard 1991), NGC 253 (Carilli et al 1992), NGC 4631 (Ekers & Sancisi 1977Hummel 1991) and NGC 891 (Allen, Sancisi, & Baldwin 1978;Hummel 1991) indicates energy losses of the electrons on their way from the starburst, either from synchrotron losses or inverse Compton scattering of the relativistic electrons against the IR photons produced in the nuclear region. In some objects, the relativistic component of the wind appears to decouple from the thermal component beyond the Hα-emitting structures (e.g., NGC 3079, Duric & Seaquist 1988), perhaps participating in a "cosmic ray wind" rather than a thermal wind (Breitschwerdt & Schmutzler 1999).…”

A High Spatial Resolution X‐Ray and Hα Study of Hot Gas in the Halos of Star‐forming Disk Galaxies. I. Spatial and Spectral Properties of the Diffuse X‐Ray Emission

“…NGC 891 is a spiral galaxy very similar in size, total luminosity, spiral-type and molecular gas spatial distribution to the Milky Way, seen almost exactly edge-on (van der Kruit 1984;Scoville et al 1993). Despite these similarities, NGC 891 is forming stars more intensely than the Milky Way, as it is twice as rich in molecular gas (Scoville et al 1993), twice as IR-luminous as the Milky Way (Wainscoat, de Jong & Wesselius 1987), and several times more radio-luminous at 1.4 GHz (Allen, Baldwin & Sancisi 1978). The IRAS f 60 / f 100 ratio for NGC 891 is higher than that of the Milky Way (0.31 for NGC 891 vs. ∼ 0.2 for the Milky Way, see Rice et al 1988 andPérault 1988).…”

“…12b), and forms the basis of the X-ray shadowing experiment performed by Bregman & Irwin (2002). NGC 891 has a radio (Allen et al 1978), Hα (Rand et al 1990;Dettmar 1990;Hoopes et al 1999), HI (Swaters, Sancisi & van der Hulst 1997) and Xray halo, all of which extend to heights ∼ 5 kpc above the plane of the galaxy. Dense dust clouds and filaments have been traced to heights of |z| ∼ 2 kpc (Howk & Savage 1999.…”

Ablative Materials

“…Ablative heatshield materials not only protect a vehicle from excessive heating, they also act as an aerodynamic body and sometimes as a structural component (2,3). Intensity and duration of heating, thermostructural requirements and shape stability (4,5), potential for particle erosion (6), weight limitations (7)(8)(9)(10), and reusability (11) are some of the factors which must be considered in selection of an ablative material.…”