x-ref

welcome to frank smith's online dealie (wow there's a bunch of junk here yes there's a bunch of junk here)
Things I Like
Who I Follow

koriblr:

nevver:

Your moment of Zen

What a damn beautiful planet this is, sometimes…

fouriestseries:

Lagrangian Points

The Lagrangian points are the five locations in an orbital system where the combined gravitational force of two large masses is exactly canceled out by the centrifugal force arising from the rotating reference frame.

At these five points, the net force on a third body (of negligible mass) is 0, allowing the third object to be completely stationary relative to the two other masses. That is, when placed at any of these points, the third body stays perfectly still in the rotating frame.

The first image shows the fields due to the first mass, the second mass, and the rotating reference frame. When added together, these fields generate the effective field shown in the second image. The five Lagrangian points are indicated with gray spheres.

The first three Lagrangian points (labeled L1, L2, and L3) lie in line with the two larger bodies and are considered metastable equilibria. L4 and L5 lie 60° ahead of and behind the second body in its orbit and are considered stable equilibria.

Lagrangian points offer unique advantages for space research, and the Lagrangian points of the Sun-Earth system are currently home to four different satellites.

Mathematica code posted here.

Additional sources not linked above: [1] [2] [3] [4] [5]

projecthabu:

     The Historical Redstone Test Stand was built by Wernher von Braun in 1953, to perform static testing on the Redstone family of rockets. The stand was used until 1961, and performed 362 static test firings. A control room is situated inside bunker constructed of three railroad tanker cars. Testing was viewed through cannibalized tank periscopes. The second test stand, shown in the final photo, is the cold calibration unit, used to configure the rocket cooling systems.

     The site is peaceful now, sitting among the beautiful foliage of Huntsville. Though, as I walked around the quiet grounds of the test site, I was almost expecting the Redstone IRBM, perched atop the stand, to roar to life, piercing the tranquil silence, just as so many historic rockets had before. In previous firings, this stand was used to test the Jupiter C rocket used to carry Explorer 1, America’s first satellite, into orbit. As well as the Mercury-Redstone rocket (MR7), which boosted Alan Shepherd into the history books as the first American in space. Countless advancements in the field of rocketry can be traced directly to this very location, nestled in the heart of the south.

(via spaceexp)

spaceexp:

A quartet of Saturn’s moons surround and are embedded within the planet’s rings in this Cassini composition

Moebius illustration of the French M*A*S*H movie poster. Dig that Mort Drucker style!

Yes, still reading Heavy Metal. Here’s a film column from May 1984 with a hot tip on David Lynch’s plans before he shoots Dune II and Dune III (filmed simultaneously). Hint: It’s a sci-if film called Ronnie Rocket, kind of a Ziggy Stardust thing. Somewhere along the multiverse…

Pretty cool.

natgeofound:

In an anechoic chamber, a teacher in Illinois studies how people detect sound, June 1967.Photograph by James L. Stanfield, National Geographic Creative

image

Your Friday longread: NASA’s new eBook about communicating with aliens by Douglas Vakoch (via i09).