The thread for space cadets!

[Berzerker]

It should be noted, that the center of gravity is still located inside the Earth 100% of the time. Interestingly, the Solar System barycenter moves out of the Sun pretty frequently due to the mass and distance of Jupiter.

If our solar system did have a large 9th planet with a distant orbit wouldn't it show up as missing mass while measuring our barycenter?

I did google search in Russian, it looks like aside of previous article in Kommersant, even tabloids don't consider this version seriously. If report you read contains references to specific Russian media I can read it, but all I found for today is government officials labeling sabotage version as a crazy conspiracy.

Cant they figure out if the hole is where a rivet or bolt was located?

They'd be binary planets. Earth and the Moon are very nearly binary planets because the center of gravity between them is removed from the Earth's geographical center due to how large the moon is. Really the Earth/Moon system is kind of a freakish thing because most moons are not nearly as large relative to their primary as our Earth is. Pluto and Charon both orbit a spot outside of Pluto for the same reason and if Pluto was considered a planet we'd likely have to consider Charon to be one as well and they'd be a binary planet system.

Is it possible Pluto and Charon were one body that split (or broke up)? Not only is the Moon too large for the Earth, it doesn't orbit Earth's equatorial plane so something might have dragged it off line. Now if the Earth was once larger the Moon wouldn't be so unusual.

 

[red_elk]

Cant they figure out if the hole is where a rivet or bolt was located?

I hope they can.
It was drilled. And it's not supposed to be there.

 

[uppi]

If our solar system did have a large 9th planet with a distant orbit wouldn't it show up as missing mass while measuring our barycenter?

In theory, yes. In practice, I would wager that the effect is much to small to be measurable.

 

[hobbsyoyo]

Is it possible Pluto and Charon were one body that split (or broke up)? Not only is the Moon too large for the Earth, it doesn't orbit Earth's equatorial plane so something might have dragged it off line. Now if the Earth was once larger the Moon wouldn't be so unusual.

Sure it is possible Pluto and Charon were one body. I don't think we have enough data to make that determination yet.

The current theory behind the Earth/Moon system is that the Earth was originally a bit smaller than it is now and its orbit was shared by a Mars-sized body we call Theia. This arrangement was unstable and Earth and Theia collided. Most of the core of Theia sank into our core which raised the mass and gravity of Earth above what it would have been. Meanwhile a chunk of mostly crustal material from both bodies sheered off and went into orbit around the Earth as the moon. Its orbit is largely a function of the collision angle and speed between Earth and Theia at impact I believe.

 

[Timsup2nothin]

There's actually a good reason for their to be an independent Space Force, I just don't trust the Trump administration to screw it up.

Right now, the USAF is responsible for just about everything the military does in space. The problem is that the command structure of the military favors combat experience. The Air Force personnel who work on the space side tend not to be put in combat posts as their skills don't often directly translate into those roles. So you wind up with a situation where the people put in charge of the various space commands do not have a space background and have no vested interests in the field. This is about as effective as having ground-pounding generals head up the Army Air Force post-WWII and was why they split the Air Force off shortly thereafter. It's even worse on the procurement side where there isn't nearly as much institutional expertise in buying rockets and spacecraft as there is for buying air craft. Given how badly major aircraft acquisition projects tend to go, they really do need a smarter bureaucracy to handle the space side of the military.

Unfortunately, I fear the new Space Force will be a boondoggle that will just turn into another trillion-dollar cash grab by contractors with little benefit to the taxpayer or the military. I mean, this would mean more jobs for people like me but I'd rather not have the government waste more money on the military than it already does. Any notions that the Space Force will be 'budget neutral' (i.e. just shift money from the USAF to the SF) are fantasies.

Historically, the shift from the Army Air Corps to the independent USAF accomplished absolutely none of what anyone hoped that it would, while the navy maintaining control of naval aviation has done none of the harm that proponents of the independent air force claimed would be inevitable if they didn't get their way so it seems unlikely the Army would really have fared any worse.

That said, the Air Force is inappropriate for dealing with space (and incompetent at pretty much everything), and space forces should certainly be put under command of the Navy. The Navy is familiar with operations of the sort required, because maintaining and operating naval vessels is also not something you want to hand over to people just because they have a muscle where their brain should be and/or can hit a target with a bullet. While "at sea" may not be as hostile an environment as "in space" it is at least somewhat similar logistically, while nothing the air force does is even in the neighborhood.

 

[r16]

and naturally a shapeship would be a submarine .

 

[Timsup2nothin]

and naturally a shapeship would be a submarine .

Well, it's a lot more like a submarine than an airplane.

 

[r16]

while totally unrelated to thread but for a piece of stuff am writing , how likely it's for some USS Agusta or something to ram a Russian boomer so that the guy who discovered Titanic could steal the codebooks and the like ?

 

[Thorgalaeg]

Well, it's a lot more like a submarine than an airplane.

Umm... no.

 

[Broken_Erika]

Well, it's a lot more like a submarine than an airplane.

 

[Lexicus]

Umm... no.

Umm...yes?

 

[BenitoChavez]

The part where the ship goes from land to space is closer to the Air Force side of things. The part where the ship stays in space is closer to the Navy side of things.

 

[Lexicus]

Proper spaceships wouldn't really be going from land to space.

 

[red_elk]

It's called spaceship and not spaceplane for reason!

 

[BenitoChavez]

Proper spaceships wouldn't really be going from land to space.

Well to get to space, something needs to go from land to space. I assume you are referring to building the ships in space and if so, you still need to send up the resources and people/robots to build them.

 

[Lexicus]

Well to get to space, something needs to go from land to space. I assume you are referring to building the ships in space and if so, you still need to send up the resources and people/robots to build them.

Still, getting stuff into orbit doesn't bear much resemblance to taking off in an airplane. Even if we consider that it does, if you're talking about a bunch of takeoffs of raw materials being assembled into a spacecraft in orbit, the connection with airplanes taking off is tenuous at best.

 

[BenitoChavez]

Still, getting stuff into orbit doesn't bear much resemblance to taking off in an airplane. Even if we consider that it does, if you're talking about a bunch of takeoffs of raw materials being assembled into a spacecraft in orbit, the connection with airplanes taking off is tenuous at best.

Well sure, it is tenuous. But so is the connection between a submarine and a spaceship. There are a whole host of challenges that space has that water doesn't and vice-versa.

But if you are forming a military space force for the first time nobody really knows how to do it so you have to consult with the people who are in the closest field to what you are trying to do. If you are trying to send stuff from land to space, that would be people at NASA. But NASA isn't a military organization, so if you are trying to keep it in the military that would be the Air Force.

 

[Thorgalaeg]

Structurally a spaceship is similar to an airplane and the opposite to a submarine. It is pretty much a wingless pressurised aircraft fuselage, a light structure designed to keep air inside against much lower external pressure. High altitude planes share many problems and solutions with spaceships, and in some cases like the space shuttle spaceships are nothing but very special airplanes. Thats the reason you have aerospatial agencies conglomerates and manufacturers spesialised in both aeronautic and spatial technology. Never heard of any submarinespatial agency though.

 

[hobbsyoyo]

Historically, the shift from the Army Air Corps to the independent USAF accomplished absolutely none of what anyone hoped that it would, while the navy maintaining control of naval aviation has done none of the harm that proponents of the independent air force claimed would be inevitable if they didn't get their way so it seems unlikely the Army would really have fared any worse.

That said, the Air Force is inappropriate for dealing with space (and incompetent at pretty much everything), and space forces should certainly be put under command of the Navy. The Navy is familiar with operations of the sort required, because maintaining and operating naval vessels is also not something you want to hand over to people just because they have a muscle where their brain should be and/or can hit a target with a bullet. While "at sea" may not be as hostile an environment as "in space" it is at least somewhat similar logistically, while nothing the air force does is even in the neighborhood.

So you're saying the best branch to run a non-independent space organization is the Navy and not the branch that is already performing this job function?

Submarines do have similarities to spacecraft - but only the ones in science fiction. Our current ships aren't anywhere near sophisticated enough to be comparable to a ship at sea when it comes to longevity and independence.

Also, we launch maybe 3 or 4 manned missions (space ships) a year as a species. We launch dozens of spacecraft (satellites) every year. And those have even less in common with naval ships than space ships do.

spacecraft = satellite
spaceship = manned space vehicle

Proper spaceships wouldn't really be going from land to space.

They'd be assembled out of self-contained ships that rendevouz and dock autonomously in orbit. We won't be launching raw materials into orbit for assembly for a looooong time. For now most of the modules will be more or less complete, fully functional spaceships themselves that happen to link up.

BFS would be an exception to this if it comes to pass.

Still, getting stuff into orbit doesn't bear much resemblance to taking off in an airplane. Even if we consider that it does, if you're talking about a bunch of takeoffs of raw materials being assembled into a spacecraft in orbit, the connection with airplanes taking off is tenuous at best.

Flight (especially takeoff) is actually the closest analog to a rocket launch. In fact, some rockets and spacecraft are themselves miniature planes.

Spoiler :

Edited to remove the reference to an idea being silly because it wasn't actually silly.

 

[Timsup2nothin]

Structurally a spaceship is similar to an airplane and the opposite to a submarine. It is pretty much a wingless pressurised aircraft fuselage, a light structure designed to keep air inside against much lower external pressure. High altitude planes share many problems and solutions with spaceships, and in some cases like the space shuttle spaceships are nothing but very special airplanes. Thats the reason you have aerospatial agencies conglomerates and manufacturers spesialised in both aeronautic and spatial technology. Never heard of any submarinespatial agency though.

Well, at least this made a little bit of sense. Yes, if the only consideration being applied is the direction of the pressure differential across the hull they are exactly opposite, and your denial of the similarity is completely accurate. Of course if you don't consider direction as the only criteria, both of them are self contained environments operating in a hostile environment for extended periods of time.

One could note that I never said that we should be contracting with Electric Boat or General Dynamics to build space craft because they are built like a submarine. I said that the navy should be operating them because they operate like them. The space shuttle may be a "very special airplane," but part of what makes it special is that very few airplanes have to deal with the logistics of having a crew live in them for several days at a time. Come to think of it, I think that makes them totally unique...among airplanes. Of course, that is just a routine aspect of every boat ever made, other than my little Sunfish sailboat, but hey...leave it to the Air Force.

@hobbsyoyo ...when's the last time the Air Force launched an unmanned drone and expected it to just stay launched? If you want to talk satellites, navies have been sticking things permanently out in the ocean for centuries.