The thread for space cadets!

well , we don't have to pur armed guards in the room when Waterfleet and wingy guys debate the Budget so that they won't gouge out each other's eyes , ours being more , actually far more , civilized . ı will readily agree when spaceships become ships travelling places they will be more relevant to be run navy style , and like if you are going to fight tomorrow you would be operating like a sub , because they will naturally be firing all kinds of lazer stuff at you . ( Lasers are for losers like America .) The distinction , in the future , maybe then if you have room to take of your socks before going to bed , it's a ship . If remain canned in your spacesuit (-273 , + 1500 centigrades ) it's a plane .
 
BBC said:
Hayabusa 2 rovers send new images from Ryugu surface

Japan's space agency (Jaxa) has released new images from the robot rovers it has deployed to the surface of an asteroid.

The photos reveal new details of the surface of the space rock, which is known as Ryugu.

On 21 September, the rovers were released on to the surface by the "mothership", Hayabusa 2.

Hayabusa 2 reached Ryugu in June after a three-and-a-half-year journey.

The pictures show in clear relief the rugged, boulder-strewn landscape of this unusual Solar System body.

The robots, known as Rover 1A and Rover 1B, are now both confirmed to be working on the surface of the space rock.

The 1kg autonomous rovers move about by hopping, using the asteroid's low gravity. Each one contains a motor-powered internal mass that rotates to generate force, propelling the robot across the surface.
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https://www.bbc.com/news/science-environment-45667350
 
Uf. Too bumpy. They should send a Toyota Land Cruiser instead.
 
it's going to be one of those weird ones .


am on my way home and almost 10 police cars are tearing up the street , sirens screaming . You know the instant rumour mill , can hear people that some guy has machine gunned some place , 10 dead . Will become 5 dead by the time ı make it to the light rail . But as the usual suspect , ı can even see the wide eyes as this guy "tests" whether ı knew it beforehand , with excited speaking some about "They from ..." Yeah , one can surmise Martian Infantry has arrived in town ...


naturally it will turn out to be a natural gas explosion in an house where contractors had worked on the pipes the day before , no doubt they forgot to twist the pipes to the full , lack of sealing , what ever the phrase is in English . Only 7 wounded , though one in critical condition .

it's of course America's fault . Simply as an hypothetical where FBI hears of any deployment (and not that it's a Space Army regional HQ and all dat) a week before and fails to believe and acts only two days before and throws everybody out as if it's the only observatory on Earth that was trying to photograph Dejah Thoris sunbathing topless at the time and desants need a week to acclamatize to the gravity of Earth , what would be the average speed of that craft , depending on the current distances ?

this is a bona fide question depending the really existing and silly and sad and true reality . Poster is a veteran of MOO where conventional engines travel one tile per turn , nuclears two and fusions three . Hopefully sheer stupidity of the belief will be proven by the calculations to be done ...
 
not increasing post count , but it happenz because it's so dumb . Would cheapen the question above .

Spoiler :


back in the mists of time when Neocons were just about dreaming about Dabya or something similar , their Zionist equivalents were dreaming of something else . Like inventing a computer code that conclusively proves some guy named Bibi at the head of Likud will fight a nuclear war with Turkey and win and Neocons will not have to bring God to Earth , that kind of thing . Left Wing Zionists are not the only ones who are like "What!!?" This is like the Refahyol era here with old school Islamists in charge with Antisemitism out in the open , it's supposed to be a PR point , as well . Tel Aviv has spent so much effort to make here a client country , a veritable storm is the result . So , after a decade of effort they come up with an all together less catastrophic version . Remember the nuclear war ? First it was against Yeltsin's Russia , then downgraded to us getting a couple from Pakistan . Who foolishly fell to Indian games to get them to declare themselves Nuclear , which then led them to be kicked around in some place on the border , like Kargil or something like that , too . Still too much , hence , some Islamist takes power , according to this Rand study and fights West by all means necessary and gloriously leads the country and transforms it . Into an enemy of West . Which finally fights a space battle in 2030s with this new , never seen before Turkey and defeats it and civilization comes back to these lands . Bloodlessly , because there were a couple of camp survivors down there still alive . And in positions of influence too , totally aghast at what kind of punishment would have been meted out to survivors after we were taken out conventionally . Hence , people , the space battle where it's satellites that die , and not cities in Anatolia , each with more than a million people . Not true , they will still kill us all with Americans as the vanguard , but somebody has to do that PR business within corridors of power in D.C.

they are giggling like girls , the old guard as they recount the old days and ı imagine that's why am a Starfleet admiral , an idiot that will still beat down that West in space with hands tied down . Like back in 2014 , there were still no takers , as America put up beardies all over the map instead . And well , the glorious achievements of New Turkey are so stupendous that London has silenced its company account . We were not drowned in some deluge of how New Turkey now invented helicopters , to say the least ! On the days it turns out like 80% of the shoes are not made in the country , too ...

oh , they are even building a Zeppelin , which is naturally a building that obviously won't fly . A theme park of sorts , it might even inspire kids to become scientists of space , even astronauts , which will obviously happen one of these days , am pretty sure some business people had bought tickets of this Virgin Galactic . Obviously chosen by the American Colonial Governor to be nearby to my house , where ı can possibly walk to . This is what happens when you are famous ...

so , America wants a Space Force . Using Turkish experience , you can readily assume it will be a platform to advance the careers of Trump's people , doing nothing worthwhile about its stated charter and everything else for political power . There was a telecommunications authority that was created , like 85% of its personnel was sacked from State service afterwards , many arrested for being Congregation . But then it can only be like farcical , when both sides are so stupendous . They agree to release the pastor and Ankara decides it has an advantage and demands extras even . So called Kemalist generals claimed Unity Engine , Little Imperialist had the so called State Channel full with documentaries on how the Americans were in fear of UFOs hence would allow Sunni Brothers to take over everywhere down to South Africa , too . No , it doesn't exist and how could it ?

yet , some cool advice and free . The symbol of the American Space Force should be a glass vase , so that when it's smashed into a thousand pieces , there will be no hard feelings . Or one could even shut up , couldn't he /she ? And yeah , Elon Musk fired the first shot , in the interplanetary war , with the rock music Tesla . Ever saw the Mars Attacks , where brains just explode with proper music ? Yeah , the space minefield ! Though , for the life of me , ı can't remember who was in that movie ...
 
Had space militarization been handed over to the Navy in the first place, instead of the Air Force, it wouldn't have been so badly botched as to lead to calls for an independent command.


I'm going to get to the rest but I had to stop at this.

The Navy was given space militarization first. They botched it so bad the Army (with Von Braun) were brought in to clean up the mess and rectify the situation with a rocket of their own. The actual (not replica) payload from this failed launch is currently at the Air and Space Smithsonian museum. It's awesome how well it survived the explosion tucked away in the nose cone that broke off early in the explosion.

Fun starts at 00:20

They broadcast this on live, prime-time TV IIRC.
Spoiler :


A19761857000CP02.jpg
 
Adapting the processes of those existing functions to different technology in a different remote location is not an out of this world scale task.
It literally is though out of this world though.

I'm sorry, while I find your argument has merits, I just don't buy that the Navy is better suited to this role. They'd wind up in the same problems in my book and a whole bunch of new ones that come with the learning curve.

And that's just routine. I used to tell people that part of why the Navy put up with me was because when a submarine breaks down in the middle of the Pacific it isn't like you can just pull up to Radio Shack and get parts, sometimes you have to improvise, and sometimes you have to cannibalize. Naval Officers are experienced with listening to and evaluating repair plans that are not in the book, presented by technicians who they may or may not completely understand, and make decisions on their own that the people 'back at the base' might find questionable with their hindsight. When a plane breaks down an Air Force officer's involvement ends when he either walks away from the landing or gets carted away from the crash.

Operationally, the similarities are distinctly parallel across the board.
This is nice but irrelevant to the actual business of flying spacecraft. Once you've sent it up, there is no cannibalization or repairs and you want as many people 'back at the base' on the line to talk through the problem and suggest fixes. You would never just fly something in the blind on your own without doing your due diligence in trying to get everyone in the supply chain that is relevant and all of the key players in operations on the line. That is not just the commercial or civil take on space operations - that's how the Air Force does it as well.

It's not a comparable situation to either aircraft or ships.

I think space commands should stay under the USAF because the current government and our military industrial complex would turn any changes into an orgy of wasteful spending for less capability in the short to medium term. But if the space commands do need to move, they need to move to their own independent command. Just because the USAF sucks doesn't mean a space command would suck as well - or at least if it sucked it's not necessarily going to suck in the same way for the same reason.
 
First off, once again the "learning curve" argument applies to switching now rather than the question of whether it should have been done differently in the first place.

Second off, ships don't go to sea planning on cannibalizing any more than spacecraft would. But it does happen if you go to sea enough. So the Navy has experience with that. They have experience with "all hands on deck" back at the base, contacting every supplier and expert that might be relevant, and putting all the big brains together to figure out what can be done about their busted ship out in BFE. You think the air force had any kind of experience like that going in? A plane is busted, it goes down, that's that. The Air Force had a lot of experience with post mortems, not with crisis management.

So, once again, I'm arguing not for change, but for why it was a mistake to go that way at the time. Your arguments against change now are sound, but they are just as sound if they are applied to why we shouldn't create a separate space command either.

By the way...nuclear power, as opposed to "hey, fission, we can blow stuff up" was developed for and by the navy. Civilian experimentation got as far as "if we make bricks out of these materials and stack them properly they will get hot...hey, really hot...maybe this isn't a good plan." The army got as far as "hey, if we bury this installation under a twenty foot thick cap of concrete maybe we can pretend we were never really interested in nuclear power...bury some empty coffins too, at closed casket funerals no one will know the difference." For a very long time naval nuclear power was nuclear power. Even when I was getting out of the navy, forty years after Nautilus, every civilian nuclear power plant I considered getting a job at was staffed well over half with navy trained operators, and everyone who wasn't trained in the navy had been trained by people who were. I think the fledgling space program would have been much better off if they'd looked at that explosion and said "that's one, keep at it" rather than changing teams.
 
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A bunch of stuff has been happening in the US -

Aerojet Rocketdyne announced that they are tax-sucking failures once again. They had a deal with the USAF to develop a new staged combustion engine to replace the Russian RD-180 in the new Vulcan rocket from ULA. The deal was that the USAF would pay for 2/3 of the development and AJ would pay 1/3. Then AJ renegotiated to shrink their share to 1/6. Then this week they announced they were done spending any more of their own money on the engine and that while they will build a prototype, they won't even test it - which was the terms of the original deal. So basically that engine development is dead.

This forced ULA to (finally) pick Blue Origin's BE-4 methalox engine as the engine of Vulcan. Oddly enough, BO has announced their intentions to go after national security launches which are pretty much 100% of ULA's business right now. SpaceX is already eating ULA's lunch and now they are going to be paying a new competitor (who will use the exact same engine for their own rocket) for their engines. I do not think this bodes well for ULA but I wish them luck.

Stratolaunch released designs for a new range of rockets and spaceplanes they will pair with their giant mothership airplane. This is good because we've all known for a long time that their plan to launch tiny little Pegasus rockets from their plane was stupid. This makes more sense. Also, they released details of a new Hydrolox staged combustion engine to power these rockets and space planes which is awesome. Less awesome: they named the rocket engine PGA after their billionaire funder Paul Allen. I guess that makes sense though given they currently make $0 and have depended on his bottomless pockets to fund their efforts for over a decade now.


stratolaunch-family-879x485.jpg

stratolaunch-pga.jpg


https://spacenews.com/stratolaunch-confirms-launch-vehicle-development-plans/
https://spacenews.com/stratolaunch-releases-new-details-about-rocket-engine-work/
 
Jim Bridenstine (NASA admin) says he's open to cooperation with the Chinese in space. Unfortunately, without Congress granted authorization to work with the Chinese there is nothing Mr Bridenstine can do on that front.
https://spacenews.com/nasa-opens-door-to-additional-cooperation-with-china/

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A start-up in China called Landspace is gearing up for their first launch basically any day now. They claim to be the first private space company in China and are building a small, 3-stage solid rocket to deliver 200 kg of payload into polar orbit.

They are also working on Methane powered engines (like Blue Origin and SpaceX) for larger liquid fueled boosters. I am not sure if they are planning on developing re-usable boosters. I know another Chinese start-up is pursuing that goal but I've been able to find information either way on LandSpace. One of the major appeals for Methalox engines is that they are very re-use friendly. Methane is a much simpler molecule than RP-1 (refined kerosene) so it burns much cleaner. RP-1 engines tend to 'coke' or fill their internal plumbing with carbon soot deposits during firing which hurts their performance and even cause them to blow up as they create lots of hotspots inside the engine which weaken the metal.

There are other advantages of Methane as well but the big one is re-usability which makes me think they are going in that direction.

zhuque-1-rocket-assemble-test-august2018-landspace-copy-879x485.jpg
 
A crazy thing about Methane engines is that while they are a relatively novel technology, there is no technical reason why they should be. What I mean is that there is nothing uniquely challenging about Methane-fired engines and in fact it has a lot of advantages that make it easy to work with. The main reason no one built and used Methane engines in the past is simply because there was no heritage for the engines.

The space business is ultra-conservative technologically and the fact that no one has done a thing before means everyone else is more likely to pass it up themselves. Methane does pose a bit of a problem in that launch-pad infrastructure doesn't currently support it but in the scheme of things that's a smaller consideration. This is especially so since Methane isn't a exotic, rare gas with crazy handling requirements. Quite the opposite - for decades it's been primarily flared (burned off) at oil fields around the world. It's so plentiful relative to its demand that it is cheaper to waste it than process it. What this means is that even if a launch pad doesn't support this fuel it won't be expensive to source it and reconfigure your storage and plumbing network at the launch site to handle it.

At some point the basic rocket fuel combinations were settled on and the industry sort of stopped tinkering with new ones. Methane didn't make that initial cut for whatever reason and got left out until now.
 
<rooting in vague dim memories>

Methane.

<root root>

Very small molecule. Containment difficulties.

<speculate>

Problem overcome by advancements in material sciences?

As I recall it back in the dim and distant day methane demanded a level of tightness in plumbing that was beyond our capability. A shutoff valve that would contain butane until you wanted to light your cigarette would give you a pocket full of methane constantly until your lighter ran out, because the disk/seat interface wouldn't be tight enough to contain it. Packing a valve stem on a throttle valve that could be used to regulate the flow of octane would give you methane seepage past the stem that would give you an explosive atmosphere in your control room. Burning it off was an acknowledgement that it was getting off of its own volition anyway and there were places we didn't mind having it burn.

Has that really changed?

Keeping in mind that you not only need your launch pad and your rocket to have tight enough plumbing, but the places that have been flaring it off will have to be upgraded to handle it as well.
 
For rocket plumbing, the small molecule problem is a solved problem*. They regularly deal with molecular hydrogen and helium since the 60's which are worse when it comes to leaking. The one detail about all this I am very unsure of is the purity of the gas being used. I've seen it both referred to as Methane by some sources and Liquefied Natural Gas (LNG - a mix of methane and other stuff) by other sources.

I assume in the end they will develop some specification of fuel that has an allowable percentage of non-methane gases. They can use this to their advantage to tweak things like the gas's partial pressure and boil off rates while overall still having a much more clean fuel than RP-1.


*It's solved in the sense that there are straightforward, if very expensive and rare, solutions.
 
Considering that I have driven a car powered by methane and lived in a home heated by methane for years without either blowing up or having to burn it off, I am pretty sure that the plumbing has been solved.

Maybe. That seems like a good indication. I know that there were furnaces that routed leak by from the cutoff valves to feed the pilot light. Sort of a constant "flare off" approach. Cars leak everything, all the time, which is why garages have ventilation requirements so if they leaked a little methane that wouldn't be anything out of the ordinary. As Hobbs referenced there is just so much of it coming up out of a well that even a small percentage of leakage can accumulate into a lot of free methane running loose, so production facilities would consider it a more substantial issue than a house or a car.

It has been a very long time since containment of methane was of concern to me, though, other than holding in a fart until an appropriate moment. These issues may all be just holdovers from a bygone age.
 
Coincidentally, Scott Manley put up a great video explaining why next generation rockets are moving toward Methane.


It's ten minutes long and highly worthy of a watch.
 
One interesting thing I just learned from the video is that Methane is actually less energetic than RP-1 (refined kerosene). Normally, this would mean the specific impulse (fuel efficiency) of the fuel would be lower for Methane compared to RP-1. However, due to the specifics of the combustion chemistry, the exhaust products of Methane tend to be lighter than those from RP-1. What this means is that the lighter exhaust more than makes up for the lower combustion energy and the specific impulse actually is improved over RP-1.

Moreover, because there is less energy from combustion, the engines will run cooler for the same amount of thrust. :cool:
 
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