21 July 2013

Space reentry vehicles, part 3

Part 3: ICBMs and the cold war


Other than vehicles with a detached shock wave, all aircraft heat up more the faster they move.  From the NASA book Facing the Heat Barrier: A History of Hypersonics [1]
At Mach 3 and higher, there was the Lockheed SR-71 that cruised at 85,000 feet. The atmosphere at such altitudes, three times higher than Mount Everest, has a pressure only one-fiftieth of that at sea level. Even so, this airplane experienced aerodynamic heating that brought temperatures above [260C] over most of its surface.
The SR-71 Blackbird gets to 260C over most of its surface.  Aluminium anneals (softens) at 177C (alloys can be higher) making it unsuitable as a material for use on the outside of the Blackbird.  The Blackbird used titanium instead.

18 July 2013

Recent ISS spacewalk water leak

Recently, a spacesuit sprung a water leak and the suit started filling with water, such that the astronaut's life was in danger and the "spacewalk" had to be aborted.

As I mentioned in my space reentry vehicle posts (index), if every reentry vehicle of the capsule type (possible exception of the Space Shuttle) is fake, and the only way astronauts can get back to earth is via such capsules, then the International Space Station is fake too*.

One can look through spacewalk footage to find bubbles coming up.  You can also see scuba gear.  Here's another example:

15 July 2013

Space reentry vehicles, part 1

Part 1: ablation and the detached shock wave

part 2   (index)

(Update 3/9/2013: Please note I've updated my view of the detached shock wave since first writing this post.  I now accept that there is a detached shock wave in the sense of a bow shock, but it is not detached in the thermal sense, as claimed by NASA. More in part 5.)


Most meteoroids burn up almost immediately on entering earth's atmosphere.  The few larger ones that make it to the ground lose 95 - 99% of their mass.  The air around them gets so hot it disassociates to become plasma.  95% of the glowing streak of a meteor is hot air, not hot rock.  According to NASA the temperature of the leading face of ICBMs returning from space is "hotter than the surface of the sun", (5500C+).

Space reentry vehicles, part 2

Part 2: aerodynamics

part 1   (index)

Early on in the design of manned reentry vehicles it was realised that the huge heat and strain of reentry would destroy any protuberances such as wings, rudders etc.  This lead to the minimal design of spheres and cones: