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gildings in this subreddit have paid for 8.31 months of server time

Powerful new European solid-fueled rocket motor aces first test-firing – Spaceflight Now by calapine in space

[–]Decronym 155 points156 points  (0 children)

Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I've seen in this thread:

Fewer Letters More Letters
ATV Automated Transfer Vehicle, ESA cargo craft
BFR Big Falcon Rocket (2018 rebiggened edition)
Yes, the F stands for something else; no, you're not the first to notice
BO Blue Origin (Bezos Rocketry)
C3 Characteristic Energy above that required for escape
DoD US Department of Defense
ESA European Space Agency
GOX Gaseous Oxygen (contrast LOX)
GTO Geosynchronous Transfer Orbit
ICBM Intercontinental Ballistic Missile
Isp Specific impulse (as explained by Scott Manley on YouTube)
JWST James Webb infra-red Space Telescope
LEO Low Earth Orbit (180-2000km)
Law Enforcement Officer (most often mentioned during transport operations)
LNG Liquefied Natural Gas
LOX Liquid Oxygen
MMH Mono-Methyl Hydrazine, (CH3)HN-NH2; part of NTO/MMH hypergolic mix
MaxQ Maximum aerodynamic pressure
NG New Glenn, two/three-stage orbital vehicle by Blue Origin
Natural Gas (as opposed to pure methane)
Northrop Grumman, aerospace manufacturer
NTO diNitrogen TetrOxide, N2O4; part of NTO/MMH hypergolic mix
PSLV Polar Satellite Launch Vehicle
RD-180 RD-series Russian-built rocket engine, used in the Atlas V first stage
SLS Space Launch System heavy-lift
Selective Laser Sintering, see DMLS
SRB Solid Rocket Booster
SSO Sun-Synchronous Orbit
ULA United Launch Alliance (Lockheed/Boeing joint venture)
Jargon Definition
cryogenic Very low temperature fluid; materials that would be gaseous at room temperature/pressure
(In re: rocket fuel) Often synonymous with hydrolox
hydrolox Portmanteau: liquid hydrogen/liquid oxygen mixture
hypergolic A set of two substances that ignite when in contact
methalox Portmanteau: methane/liquid oxygen mixture

[Thread #2832 for this sub, first seen 17th Jul 2018, 15:03] [FAQ] [Full list] [Contact] [Source code]

First shot at photographing the milky way! Happy with how it came out by iNyano in space

[–]jawanda 1 point2 points  (0 children)

Cool, you're on the right track then!

My post processing routine ... varies a bit by shot. But since I'm using a tracker, it starts with bringing each of the exposures into Adobe Camera Raw (usually there will be two exposures with identical settings, but one with tracker activated, one with it deactivated, like this: https://i.imgur.com/J6j1yLg.jpg also notice how my white balance was not as realistic in this photo ... this is a couple years old ;) ).

I'll do color correction on the first exposure in Camera Raw, then copy the exact same settings to the second exposure. Then I bring them into Photoshop and start with the combining process, which can take anywhere from 30 minutes to (literally) 8 hours. Once the photos are combined, I'll make my final adjustments, usually do a little more noise reductions (even though I'm shooting around 320 iso most of the time, there's long-exposure noise), and... that's about it. There are a dozen mini-steps in-between but they're too nuanced to get into in this kind of post, and they vary from shot to shot.

Edit: Wow, Reddit Gold? Thanks kind stranger!!

Astronauts explain why nobody has visited the moon in more than 45 years — and the reasons are depressing. Astronauts often say the biggest reasons why humans haven't returned to the lunar surface are budgetary and political hurdles — not scientific or technical challenges. by mvea in space

[–]ursois 6857 points6858 points  (0 children)

No reason to go back? No reason to go back!?!? I'll give you a reason to go back. Did you know that in an earth-atmosphere density environment on the moon, you could fly by strapping wings to your arms? If we built a lunar colony with a big enough ceiling, we could fly around in it. There's your reason.

Edit: Oh WOW! My first gilding! Thank you, kind stranger!

NASA has done almost no research into the effects of sex and reproduction in microgravity, despite it being key to living on Mars and beyond. It’s time to start shifting from a short-term view of space, to a long term one. by rleech77 in space

[–]revilOliver 3 points4 points  (0 children)

This is very clearly a false dichotomy. You appear to be stating we can only do one or the other. Why not both? Why do you assume that every dollar spent on space would have been spent helping the environment? Also I’m not sure you are aware or the thousands of projects that NASA has done and is currently doing to investigate climate change and help the Earths biosphere. In addition there are threats to humans from space. Things like asteroid impacts and Coronal Mass Ejections from the Sun. These are other things that NASA studies. Some of these we may never be able to do anything about, but perhaps with more investment we can understand them better and save ourselves. So while I understand your desire to save this planet, there are already millions of people and billions of dollars being spent on that. So if you don’t mind, I think NASA can continue to explore new areas of science and the world won’t end as a result.

Donald Trump nominated a man with no space experience to be NASA’s second-in-command by EdwardHeisler in space

[–]easye2889 12.6k points12.6k points x2 (0 children)

This dude spent time on NASA's budget committee, has a law degree and extensive background in budgeting and administration- hes perfect for the job.

Let the engineers and scientists do there thing. Let this dude do his thing. Not sure what the outrage is about. This dude will likely spend the bulk of his time fighting for budgets with politicians - hes literally perfect for this role.

Edit: Whoa. Morning reddit! Thanks for the gold!

Donald Trump nominated a man with no space experience to be NASA’s second-in-command by EdwardHeisler in space

[–]TheCrabRabbit 417 points418 points  (0 children)

List of previous Deputy Administrators:

Summation: Seems pretty important to have space experience if you're managing the people and money for a space program.

Edit: Getting a few reaponses that take issue with the number of examples I provided. I felt the previous 5 would be enough to indicate my point, but if you'd like to, you can look at the list of admins yourself. You'll find that 15/17 admins had previous experience, and those that didn't had doctorates in related fields.

Karen Nyberg Shows How You Wash Hair in Space by IvyGold in space

[–]TexasThrowDown 221 points222 points  (0 children)

You've never done the ole' bend and spread?

Tiny moon Phobos seen from Mars surface. by gvirus911 in space

[–]mankispanki 14 points15 points  (0 children)

I love photos of Phobos but whether we wanted it or not, we've stepped into a war with the Cabal on Mars. So let's get to taking out their command, one by one. Valus Ta'aurc. From what I can gather he commands the Siege Dancers from an Imperial Land Tank outside of Rubicon. He's well protected, but with the right team, we can punch through those defenses, take this beast out, and break their grip on Freehold. Edit: Holy wow! I got gilded thank you so much stranger!!

Dust, Stars and cosmic rays swirling around Comet 67P/Churyimov-Gerasimenko, captured by the Rosetta probe by modaladverb in space

[–]modaladverb[S] 8098 points8099 points x2 (0 children)

This animation is a series of images from the Rosetta spacecraft and features the towering cliffs of the comet 67P/Churyumov–Gerasimenko surrounded in what appears to be a snowstorm. Of course, it isn’t a snowstorm. It is largely a combination of star motion in the background and dust and cosmic rays in the foreground. Most of the streaks in the foreground are most likely dust particles which are likely part of the comet's coma, a hazy envelope of dust and gas that commonly forms around the comet’s central icy body, also known as nucleus. These particles are floating rather far away from Comet 67P and not, as it looks like in the GIF, on the icy world. Rosetta captured the images at a distance of 12 km from the comet. At this distance, Rosetta’s OSIRIS camera doesn’t have the sensitivity and resolution to observe dust particles flying around directly above the comet. The apparent motion of these particles is largely thanks to the movement of the spacecraft through 67P’s coma and, since the images are compressed into a short GIF, the action appears much faster than how it occurred in real time. The dust was of high scientific interest. Three of Rosetta’s instruments studied these dust grains by analysing their composition, mass, momentum and velocity, and profiling their 3D structure. Studying the smallest and the most pristine grains is helping scientists to understand the building blocks of comets. The motion of the stars is the result of a combination of Rosetta’s changing position as it takes images and the comet’s rotating motion. The stars from the constellation Canis Major are on the right side of the GIF and the stars of the cluster NGC 2362 are in the upper-left hand corner of the images. ESA‘s Rosetta Mission is the first mission in history to rendezvous with a comet and escorts it as it orbits the sun. These missions help us to learn more about the „time capsules“ of our solar system, the evolution of our solar system and the role comets may have played in the formation of planets. The mission also showed us how a comet changes as it is subjected to the increasing intensity of the sun's radiation when it enters the inner solar system and it sent valuable scientific data of the comet. The effects of solar radiation and solar winds, trigger an effect called outgassing. Here, frozen or absorbed gas is released. The released gas carries dust away with it. This dust forms an extremely tenuous atmosphere around the comet called "coma". The Sun's radiation pressure and solar winds cause a tail to form, which points away from the Sun. The comets gas and dust form a separate tail. The tail made of dust is visible because it reflects sunlight, the tail made of gases glow from ionisation. Comets are made of material left over from the epoch when our solar system formed, about 4.6 billion years ago due to the gravitational collapse of a molecular cloud. A comet's nucleus is made of rock, dust, ice and frozen gases such as carbon monoxide, carbon dioxide, methane, ammonia and a variety of organic compounds. Rosetta is the first spacecraft to witness at close proximity how a comet changes as it is subjected to the increasing intensity of the sun's radiation. The observations will help scientists learn more about the origin and evolution of our solar system and the role comets may have played in the formation of planets. To create this GIF, the images have been rotated by 90 degrees. Without this rotation, the „snow stars“ would move sideways.

A mirror from the James Webb Space Telescope by arrenlex in space

[–]SupaSimonOFCL 380 points381 points  (0 children)

This looks like the engineers in the photo are about to drop the hottest rap album of 2018.

Astronomers witness a rare, mid-sized black hole eviscerate a star in a distant galaxy. The new research not only verifies that Einstein's theory of general relativity holds true on cosmic scales, but also confirms that intermediate-mass black holes (100-100,000 solar masses) really exist. by clayt6 in space

[–]CrudelyAnimated 9 points10 points  (0 children)

Picture your mother in law sitting on a plaid sofa; we'll refer to her as "Object MIL". The lines of plaid illustrate normal North-South gridlines across the map of spacetime. The indentation MIL makes in the sofa illustrates gravity's effect on local spacetime, stretching and distorting those plaid lines in its vicinity. The effect is that all snacks dropped on that fabric eventually roll into the gravity well and are held nearby but still visible. If MIL's mass is large enough, the walls of the indentation are theoretically "infinitely steep" and the well "infinitely deep". In this example's hyperbole, the lines no longer trace a path "out" of the hole, and anything that falls into the hole is crushed infinitely small by MIL's mass. This is what we call a "black hole".

When object MIL rotates to reach for more snacks on the end table, the plaid lines stretch and distort in a circular fashion, like a spiral. They are still the map lines that connect the North end of the sofa to the South end of the sofa, but the sofa's own spacetime has been changed so much by MIL's enormous rotating mass that straight lines across the universe must curve to get through MIL's locale. That's what we call "frame dragging".

Thank you for subscribing to Mother In Law Physics Phacts.

Astronomers witness a rare, mid-sized black hole eviscerate a star in a distant galaxy. The new research not only verifies that Einstein's theory of general relativity holds true on cosmic scales, but also confirms that intermediate-mass black holes (100-100,000 solar masses) really exist. by clayt6 in space

[–]clayt6[S] 175 points176 points  (0 children)

Good question! There is a handy calculator for determining the size of a black hole's event horizon here.

On the low end, for a 100 solar mass black hole, the diameter of the event horizon would be about 370 miles (590 kilometers). Since the radius scales linearly with the mass of the black hole, a 100,000 solar mass black hole would have an event horizon diameter of about 370,000 miles (590,000 kilometers).

Also, here is some extra info on accretion disks (1) and event horizons (2) that I typed up in a different post reply last month:

(1) - Accretion Disks When material gets close to a black hole, that stuff doesn't just get sucked into the black hole like water down a drain. Instead, the material orbits the black hole (like a planet would a star). However, black holes have insanely strong gravitational fields (especially when they are 20 billion times more massive than the Sun), which means that objects near black holes tend to get shredded apart and added to a disk of material around the black hole called an accretion disk.

When a lot of material collects within an accretion disk (like hairs do near a drain), all that material smashes and grinds together. These collisions are incredibly energetic and create a lot of friction-induced heat. Since the universe can't truly create or destroy mass/energy, when the material loses some of its energy to friction, it falls closer and closer to the black hole. This causes the disk of material to get more and more dense, and it spins faster and faster. The friction continues to build, and eventually the material begins to glow like the filament of a light bulb. The more material and the larger the black hole, the brighter the surrounding disk around a black hole will glow.

(2) - Event Horizons Also, there have been many great questions (and thanks to everyone for helping answer), but I saw u/coendoz237 asked:

[ ... I]f the matter in the accretion disk is drawn inexorably toward the black hole due to its immense gravitational pull and the black hole also stops any light from escaping, how then can we see the light emitted from the accretion disk? Is it far enough from the black hole to allow it to escape? And if so, what kind of distances are we talking about here? Do we have an estimated size of the disk?

This is a great question and very interesting too! You're describing the event horizon, which is basically the outer edge of the actual black hole. If anything (including light) makes it past the event horizon, it's gone for good and is now part of the black hole. Outside that is the accretion disk, where things are blazing hot, but are still things.

The larger the black hole, the farther out the event horizon stretches. The exact distance of the event horizon, which is also called the Schwarzschild radius, depends solely on the overall mass of the black hole. For a three solar mass black hole, the event horizon is only about 5.5 miles. (If I did this right) For a 20 billion solar mass black hole, the event horizon spans about 250,000 miles (diameter). This is roughly the distance between the Earth and the Moon.[The diameter is wrong here, a 20 billion solar mass black hole would have an event horizon that is nearly 800 AU wide (an AU is the average Earth-Sun distance). This is about 20 times wider than the orbit of Pluto (which averages about 40 AU).

As far as the accretion disk goes, that depends on how much material is around the black hole itself. Some black holes already ate everything they could, and are now just drifting with no accretion disks at all.

Edits: Formatting stuff. Also, thanks for the gold kind stranger!

Trump to launch sixth military branch, the Space Force. by Bubbahard in space

[–]-HiReddit- 18.6k points18.6k points x6 (0 children)

Once again as much as I dislike Trump, this comment from u/bogey-spades from a r/space thread a month ago explains the reasoning well

Yikes, this thread has certainly turned into a bit of a mess. Let's read the article:

Trump previously floated the idea of a space corps in March in a speech to military members in California. The proposal, which has received congressional support in the past, is facing criticism from the Pentagon. The creation of such a force would mark the first new military branch since the Air Force was established in 1947.

"I was saying it the other day – 'cause we're doing a tremendous amount of work in space – I said, maybe we need a new force. We'll call it the space force," Trump said in March. "And I was not really serious. And then I said, what a great idea. Maybe we'll have to do that."

In fact, the military has conducted operations in space for a long time, says Terry Virts, former commander of the International Space Station and a 30-year veteran of the U.S. Air Force.

For Virts, the debate is "not advocating for somehow militarizing space. That happened 50 years ago," he tells Here & Now's Peter O'Dowd. "Every nation on Earth that has a significant military has some space component to it. What I'm advocating for is really making it more efficient and a more effective way to organize the military."

So this is largely focused on organizational change.

Currently, the Department of Defense is actually the umbrella organization for the Department of the Army, Department of the Navy, and Department of the Air Force.

The Army falls under the Dept. of the Army, the Air Force under the Dept. of the Air Force.

The Navy and Marine Corps are separate branches that both fall under the Dept. of the Navy.

Most of the country's military operations in space are handled by the U.S. Air Force Space Command, a division of the Air Force that employs about 36,000 people at more than 130 sites around the world.

Just so you understand: that's larger than NASA which has ~18,000 employees.

One of the Space Command's main priorities is to operate GPS, weather and communication satellites, Virts says.

So Air Force Space Command actually does quite a bit - they are responsible for launching, maintaining, upgrading, and operating GPS, for instance. They also track space debris for NASA and other organizations, as part of their bigger job:

"A big part of what Space Command does is called space situational awareness," he says. "They track objects in space and keep track of what other countries are doing in space. There's a lot of what happens in space that directly affects combat operations in the Army or Air Force or Navy."

The military has opposed the idea on the grounds that more bureaucracy isn't what the military wants in an era where people want them to spend less, not more:

For years, the Pentagon has opposed the idea of creating a space force because leaders argue it would make the Defense Department bureaucracy more complicated.

"The Pentagon is complicated enough," Air Force Secretary Heather Wilson told reporters last June. "This will make it more complex, add more boxes to the organization chart and cost more money. If I had more money, I would put it into lethality, not bureaucracy."

As far as some questions/points people have raised:

Isn't this Weaponizing Space?

So actually, the Outer Space Treaty only prohibits WMDs (weapons of mass destruction) in Earth orbit, on the Moon, or on any other celestial body or stationing them in orbit. It also exclusively limits the Moon and other bodies for peaceful purposes which prohibits military maneuvers, facilities, etc.

There is no prohibition on conventional weapons or for the use of space for military purposes though: you can certainly use spy satellites, communications satellites, weather satellites to support military operations, etc. in space.

GPS, after all, was invented by the military for military use in the 70s before it became available to the general populace.

What would this Space Force Do?

Per the article, and other articles on the subject, it seems to largely be focused on keeping the Space Command operations of Air Force separate and independent from the Air Force.

Keep in mind that the Air Force has an extremely broad mission - from maintaining air superiority to its strategic bomber force to maintaining the land-based ICBM and bomber-based nuclear deterrence/stockpiles to maintaining the country's airlift/aerial refueling command.

Space, as you can imagine, falls to the wayside when the different areas compete for funding or focus.

What Congressional members are proposing is that by creating a separate branch, it will be focused entirely on space and space-operations so that they don't have to compete with other parts of the Air Force for funding anymore.

Will this lead to an arms race? Another Space Race?

Hard to say - every modern military has space operations and increasingly relies on space for communications, intelligence, reconnaissance, etc. Even seemingly mundane things - like predicting the weather - is incredibly important, if history is any indication.

It's hard to capture the Space Race of the 60s which pitted not only the US against the Soviet Union, but pitted Western styles of government and economy vs. Eastern/Soviet styles of government and economy, etc. and thus transcended a lot more than just geopolitical boundaries (hence why so much was focused on PR to generate innovation and interest to show dominance in our way of living, etc.)

Today, you don't see that so much - there isn't nearly the clash of ideals/culture between the US and China or Russia.

Will this spur advancements in the area?

Maybe.

After all, the military has had classified reusable space planes for nearly a decade now, and the history of the DOD and DARPA teaming up with NASA on a ton of experimental planes and rockets is long.

To say nothing about sending some personnel that you may have heard of that simultaneously worked in the DOD and NASA, or the numerous DOD facilities they share with space industry and NASA in general is huge.

People often forget that the government agencies are in it together.