space

Ex-SpaceX employees at Virgin Galactic are given this shirt

Ex-SpaceX employees at Virgin Galactic are given this shirt

Sounds like a lot of other space companies are gathering up the employees burnt out by SpaceX. Heres hoping theres a better quality of life for them now.

Long hours. If you are committed and fine with working a lot, SpaceX is great for you. If you are not, you get burned out really fast.

What's the problem with SpaceX?

I have this vision of a 15-year-old Richard Branson deciding "I'm going to start a company called Virgin and become a billionaire, and then I'll be able to make all the virgin double entendres I want!"

If this picture doesn't blow your mind...

If this picture doesn't blow your mind...

For anyone that doesn't know it, Chris Hadfield has co-hosted one of those "competition shows" where contestants who want to be astronauts go through a rigorous testing process, and some are dropped each episode. This one aired in September/October and has six parts, and the winner doesn't get to automatically be an astronaut, but they get a strong recommendation from the assessment team to help them move through the real process of making it.

I'm normally not a fan of such shows due to their artificiality, but this one's an interesting watch because it uses genuine testing and qualification processes from actual astronaut training sites across the world.

It's over now but might be aired again and it's likely there will be a season 2.

http://www.bbc.co.uk/programmes/profiles/2Lr802gqK9zQNtGWdMfSZT8/commander-chris-hadfield - his profile

http://www.bbc.co.uk/programmes/p05bf1jt - the show's homepage.

(I'd have lasted about 3 minutes)

I was genuinely amazed when I had the opportunity to be within a metre or so of the space shuttle at KSC (Kennedy Space Centre) on a trip to Florida. The tiles (which I thought were not tiles as a kid) are amazing and have an exact location and number on the shuttle. As a kid born in the seventies and one who watched the shuttle programme unfold it was an honour to get so close to such an immense Machine. Kudos to the engineers, crew etc that made this thing possible. Just waiting for the next step in the space travel transport to be in awe again.

Thank you very much!

STS-74

STS-74 was the fourth mission of the US/Russian Shuttle-Mir Program, and the second docking of the Space Shuttle with Mir. Space Shuttle Atlantis lifted off from Kennedy Space Center launch pad 39A on 12 November 1995. The mission ended 8 days later with the landing of Atlantis back at Kennedy. It was the second in a series of seven straight missions to the station flown by Atlantis.

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Mars Reconnaissance Orbiter catches Curiosity Rover parachute landing... August 2012

Mars Reconnaissance Orbiter catches Curiosity Rover parachute landing... August 2012

That’s pretty sweet. I’m all impressed when my model rocket parachute deploys...this damn thing was traveling for months and the chute perfectly deployed

https://youtu.be/gwinFP8_qIM

The Parachute was hardly the impressive part. Really impressive is the skycrane they used to set down the rover afterwards: 1:50s

https://youtu.be/gZX5GRPnd4U

Your wish is granted.

https://youtu.be/fJgeoHBQpFQ

Here it is in real-time, with the frames interpolated to make it smooth:

NASA's Mars 2020 Rover Artist's Concept - NASA Jet Propulsion Laboratory

NASA's Mars 2020 Rover Artist's Concept - NASA Jet Propulsion Laboratory

Wow, that looks a lot like Curiosity. I assume this one will have more rugged wheels. Anyone know if they're planning the same EDL approach?

Yup, skycrane, the whole shebang. It's basically an updated version with lessons learned incorporated.

The JPL lecture on this thing Thursday was terrific. They probably have the archived recording of the talk somewhere on their site by now.

Third time's the charm. After 2 scrubbed launches earlier this week, watched my first rocket launch at Vandenberg AFB of a Delta II rocket carrying the JPSS-1 satellite

Third time's the charm. After 2 scrubbed launches earlier this week, watched my first rocket launch at Vandenberg AFB of a Delta II rocket carrying the JPSS-1 satellite

Very nice shot! You've picked a pretty cool launch to watch, too; the second to last Delta II to launch, and the last one to use nine solid rocket boosters.

Lucky describes how I felt afterwards! I was hoping to capture the trail of the stages that fall off but they don't glow brightly enough at the settings I used to be seen. I didn't know it was going to be the last to use 9 SRMs, thanks for letting me know!

Hi I shot this on a Canon 6D with a 24-70 mm ii f2.8 at 24 mm as a 2 photo composite. Trail details: f20 ISO 160 Background details: f4 ISO 1600 (which is close to unity ISO for the 6D). Cheers!

johnkphotos is correct. This is a 2 photo composite. One for the stars and one for the rocket trail. You can see it in a few of the brighter stars that have a small tail behind them which comes from the long exposure for the rocket trail.

Dinosaur killing asteroid hit Earth in exactly the wrong spot

Dinosaur killing asteroid hit Earth in exactly the wrong spot
Dinosaur killing asteroid hit Earth in exactly the wrong spot

Or, in exactly the right spot if you prefer humans to dinosaurs.

Or maybe we would've evolved to be badass dinosaur hunters riding around on stegasauruses

Didn't know the past had so much lag and desync

Since I'm of mammalian descent, I would argue that it hit in exactly the right spot.

I woke up at 3am this morning to take a picture of 4 butts and a rocket.

I woke up at 3am this morning to take a picture of 4 butts and a rocket.

I just saw this on your Instagram as I was scrolling through my feed! Weirded me out seeing it here. Awesome picture though!

Unfortunately I woke up too late this morning and missed the livestream, but it looks like it went off without any major hitches. I feel bad for Cygnus (the spacecraft being launched), as it always seems to play second fiddle to SpaceX's Dragon resupply craft. You'd figure with those neat looking solar arrays it would garner a little more attention.

thanks very much! and thanks for the follow!

Agreed with Sailorcuff.

I like the butts. Not the butts specifically, but that you put people in the picture. Not just that you put people in the picture - a lot of photos do - but because these people aren't (visibly) part of a huge crowd. Not just that, but usually when they're isolated, they're some sort of officials at a designated viewing locations, while these appear to be your everyday common Joes just standing around in a field. The choice of lens also makes them appear to be much closer to the action.

All around, awesome picture!

Astronomers discovered a star that went supernova in 1954...then again in 2014. Lead author: "This supernova breaks everything we thought we knew about how they work."

Astronomers discovered a star that went supernova in 1954...then again in 2014. Lead author: "Thi...

Sufficiently energetic processes will naturally create anti-matter through pair creation. For example, if you have high energy gamma rays interacting with matter then they can easily create electron/positron pairs. Which is what is happening here. All atomic matter glows, it's an inherent property of matter essentially, since it's impossible for it to be at absolute zero and all atomic matter above absolute zero will have thermal energy that will then be radiated according to a "black body spectrum". Room temperature stuff glows in the infrared. Stuff at a few hundred degrees starts to glow in the visible spectrum. Stuff in the thousands of degrees, like the surface of our Sun or welding arcs, will glow primarily in the visible spectrum and some in ultraviolet (which is why you can get "sunburned" by welding arcs). If you keep going up and up and up in temperature then the upper limit of the energy of "light" (photons) of the glow of the matter will go up as well, from visible light through UV through x-rays into gamma rays.

At high enough gamma ray energies it's possible for a single gamma ray to have more total energy than the rest-energy (mass) of an electron-positron pair (2x 511 KeV or 1022 KeV). The gamma rays can then create electron-positron pairs inside the ultra-hot core of the supermassive star. Remember that this is inside the interior of a star, which is a high density plasma crammed tight with atomic nuclei and electrons. So the positron doesn't spend a long time before it smacks into an electron and annihilates with it, releasing gamma rays in the process. However, this slight delay in time between pair creation and annihilation screws with the subtle balancing act between pressure, temperature, and fusion rate in the star's core. In a "properly functioning" star the energy released from fusion increases the temperature in the core through radiative heat transfer which increases the pressure which keeps the star "propped up" against collapse and against a runaway fusion chain-reaction. If the fusion energy -> temperature -> pressure feedback loop gets broken though, by pair creation sucking up energy from one of the steps and making it less effective then the star can become unstable. Fusion reactions increase, temperature increases, pair creation rate increases, but the star's core doesn't expand and keep things in check.

Eventually this process trips into a runaway cascade and the result is basically a thermonuclear bomb that burns on the order of entire solar masses worth of fusion fuel in a matter of seconds. Potentially releasing enough energy to gravitationally unbind (blow up) the star. This is called a pair-instability supernova, and it was generally considered to leave no remnant behind. But it might be possible that the process could leave behind a star big enough to go supernova on its own (through core collapse, perhaps) or repeat the pair-instability explosion process multiple times.

High energy gamma rays can create particle/anti-particle pairs (this is basically the reverse process of annihilation), but the energy required is a lot.

Hot matter gives off photons (light), we call this "glowing". Hotter stuff glows with more energetic light. Room temp = infrared (not visible but you can feel the heat on your skin), hundreds to thousands of deg. C = glowing red/white/blue in the visible spectrum (depending on temp), many many millions of degrees C = glowing in gamma rays as well. At high enough temps the photons that are part of the "glow" can create matter/anti-matter pairs, the lightest of which (and the first to be reached) is electron/positron pairs.

Stars are actually prevented from collapsing by the glowing of the matter in the core. The glow transfers thermal energy created from fusion, which keeps the temperature and pressure in the star's core in balance. Imagine a star inside a room with a light and a switch. Flip the lights off and the star begins collapsing (which, weirdly, also increases the rate of fusion). Flip the lights on and the star begins puffing back up again, and reaches a natural point of balance between forces (gravity, energy released from fusion). When some of the glow spends some of its time in the form of particle/anti-particle pairs (which will return their energy into photons by annihilating, but not immediately) that's like someone flicking the light switch off for just a little moment of time every now and again. And because the collapse of the star increases fusion rates and increases pair-creation rates that means the light switch ends up spending more time in the "off" state and it becomes a runaway process. Leading to more collapsing and more fusion energy and more pair-creation.

Eventually this reaches a state where enough fusion energy is released in a very short time (seconds) to explode all or part of the star into space, this is a "pair-instability supernova" (flicker, flicker, flicker, boom). Because it's basically a star blowing itself apart it was thought that this sort of thing happened only once during a star's life, but if the star somehow avoids blowing itself completely apart it might be possible for a less massive remnant to settle into a stage of life where it eventually returns to those pair-instability conditions decades later.

Does that help?

For those of us who aren't theoretical astrophysicists, how would a massive star create anti-matter as they're proposing?

For those of that also aren’t theoretical astrophysicists or even scientists, huh?

My favourite photo ever taken: Pluto at twilight

My favourite photo ever taken: Pluto at twilight

I'm old enough to remember textbooks that had 'artist depictions' of what the surface of Pluto might look like. I'm so happy that I lived in a time where our knowledge went from theoretical paintings to fuzzy images to these incredible images.

I'm glad these photos exist. The old textbooks never drew Pluto with a nice blue atmosphere.

My pet hate is searching up space wallpapers and being presented with artistic renderings and fictional imagery. Why would you want that when you can have the real thing instead?

That is my new background. Awesome picture man

Falcon 9: Launch and Landing

Falcon 9: Launch and Landing
This is what you're looking at.  And a similar shot from another angle.

Animation of the flight path.  You get a good to-scale overview 4 minutes in.

is what you're looking at. And a similar shot from another angle.

Animation of the flight path. You get a good to-scale overview 4 minutes in.

Shortly after midnight on July 18 a SpaceX Falcon 9 rocket launched from Space Launch Complex 40 at Cape Canaveral Air Force Station, Florida, planet Earth. About 9 minutes later, the rocket's first stage returned to the spaceport. This single time exposure captures the rocket's launch arc and landing streak from Jetty Park only a few miles away. Along a climbing, curving trajectory the launch is traced by the initial burn of the first stage, ending near the top of the bright arc before stage separation. Due to perspective the next bright burn appears above the top of the launch arc in the photo, the returning first stage descending closer to the Cape. The final landing burn creates a long streak as the first stage slows and comes to rest at Landing Zone 1. Yesterday the Dragon cargo spacecraft delivered to orbit by the rocket's second stage was attached to the International Space Station.

Source

Edit:

Apologies to the photographer, I had linked to the APOD page, but should have linked to the following as well:

Website mseeley.net. IG feed (@mseeley20) Twitter feed (@Mike_Seeley) /u/Mseeley1

ELI5 anyone? On why the landing is almost perfectly straight? Shouldn't it have some what of an arc too?

god damn. what a fucking feat. doing something like this in KSP would be crazy. doing something like this in KSP RO would be absolutely nuts.

real life?

i'm just done.

Try one of these subthreads