DerekL1963

The distinction is made in different places in different ways, there is not (as Kerbart and others will try and tell you) any fixed and universally accepted division. The Submarine Force (not the USN) calls submarines "boats" because back in the day they were very small compared to the major combatants of the day. During roughly the same era we also had "torpedo boats" and "torpedo boat destroyers" - the former went away, and the latter became the destroyer of today. Unless its a vessel that moves under it's own power and is assigned into Naval Service (a paperwork dodge that lets Navy ships be run by civilians) rather than to the Navy, then it gets the USNS prefix.

The overall architecture was being laid out at a time when they considered themselves to be doing well if one launch fired off on schedule - and on orbit assembly would require as many as (IIRC) four launches (depending on the architecture) in very short order (within a week). Another issue is programmatic risk - you accept a helping of risk every time you push the "go to space today" button. More launches equates for more chances for something to go wrong during launch which means more total risk.

IIRC, the lack of efficacy associated with the V1 had less to do with inherent limitations of rockets and more to do with Britain's excellent counterespionage efforts that effectively kept the Germans blind to where their rockets were falling. V1 wasn't even a rocket... it was a cruise missile. And even without those efforts by the British, it's CEP was still on the order of "somewhere in the county, or maybe the adjacent county" (between 7 and 19 miles). That's simply insufficient for military purposes.

Are we just ignoring the V1? No, we're not ignoring the V1. It pretty much proves what fredinno says - before nukes, missiles weren't that useful for military purposes.

Because pretty much nobody other than Reaction Engines Ltd. and a few remaining heavilty blinkered fanboys believe it shows any promise at all. It's an extraordinarily complex and expensive system with many, many potential bugs. That and, as p1t1o points out, the bulk of the fanboys tend to chase the latest shiny.

You run into the same problem you run into in the "beat Sputnick [sic]" discussion - the technologies needed don't even begin to arise before the 1920's/30's, and then from aviation. You simply aren't going to cold start a Space Race in 1900 without serious alterations to the technological time line. No, the tech isn't "fine for the most part". You have no advanced welding until after WWI. You have no serious aluminum industry until after WWI. You don't have miniature vacuum tubes until practically WWII. You don't have vacuum tubes designed for high stress environments until WWII. You don't have high performance gyroscopes until right before WWI. (These come out of aviation and submarine torpedo requirements.) Etc... etc...

Whether it's a "real" service module or not is irrelevant. What they "could" have done is irrelevant. It does exist, and it does carry equipment which is required to extend the capsule's life beyond a few hours.

Yes, you're missing what I plainly said in my previous message: As I said above, you didn't describe the mission - that the capsule is the payload. Your statement that "After reaching orbit and ejecting payload, re-entry would take place using the base heat shield, landing on a hover at the launch pad with the throttleable main engines. In no case would re-entry be manned, as the capsule would re-enter separately" which leads to the impression that the payload is separate from the capsule. When the capsule is the payload rather than the command element, the separation event is inevitable. It'll have to be accepted as one of the routine risks.

We must be talking past each other, or something. Would you have the crew cabin be built into the nose of the rocket, so that the rocket goes and docks with the ISS like the Shuttle did? The point is to have a RLV which can launch different payloads based on its configuration. I don't see what would be gained by building the crew cabin into the rocket body. No, we're not talking past each other. Did I say anything about building the crew cabin into the nose of the rocket? No, I did not. Did I say anything about different configurations or not? No, I did not. Did I say anything about building the crew cabin into the body? No, I did not. I asked a simple question, and when asked by you I provided amplifying information as to why I was asking. Then instead of answering the question about apples, you went off on a discussion about oranges, pomegranates, and bicycles. You do know the Dragon V2 has a service module? There is no service module mentioned or in your illustrations, only the capsule. And as to your last question, once again my mind boggles - we're discussing the capsule in independent flight, always have been in this sub discussion. (And docking to ISS has never previously been mentioned.) The safety issue occurs because you have a separation event, which can happen early or happen late, or nearly not happen at all. (And all these things have happened to Soyuz.) So separation events are something to be minimized if possible. The confusion has arisen because you made the didactic statement about "capsule separation will be the normal mode" and the completely failed to provide the reason for this when asked - it took two tries to pry that information out of you. Had you stated that vehicles mission was to deliver a capsule on orbit in the first place, this confusion would never have arisen. Well, at the very minimum, it's easier to get a 7-tonne capsule back to Earth than it is to get a 50-tonne nearly-empty rocket back to Earth. It's something we're good at. o.0 Wait, we're going to be flying a 50 ton booster routinely, and we won't get good at it? What's the point of flying it then? Seriously, an actual rocket is more than a collection of Really Cool parts and concepts thrown together like Lego because they're Really Cool. You need to think through the entire operation, step by step, looking at what the mission requires and whether or not the vehicle will supply that requirement. You also need to remember we're not inside your head - you need to explain your operational concept and not be surprised when you fail to give information and we ask for it.

o.0 You honestly don't grasp the difference between separating in order to get rid of a part that can't re-enter, and separating for vague hand waving reasons? And no, it wouldn't be far safer - it would be far less safe because the on orbit lifetime of the capsule will be measured in hours, if something goes wrong and re-entry has to be delayed, the capsule crew is in considerable danger. We're not discussing aborts, we're discussing normal operations. And what's different between the best way for the booster and the best way for the capsule? I've searched the world over, and there isn't an emoticon that expresses how boggled I am. You do know that re-entry plasma is an order of magnitude hotter than rocket exhaust? That no known material can withstand that direct assault?

In case of abort? And I quote from the original post, just as I did in my post. It's not an abort mode - it's a normal mode.

The military increased the requirement for crossrange, but they didn't establish the requirement. - That originated within NASA itself, as when they finally actually looked at operations, they discovered that cross range was very useful. Cross range increases abort opportunities and widens the windows, and the same for landing. Not really. With a complex and heavy system to control the shocks in the inlets, the duct isn't going to be all that effective - more a source of drag than propulsion augmentation. (Fixed ducts like to perform in a fairly narrow range of altitudes and speeds - which is precisely what rockets don't fly anything like.) And good luck trying to keep those sharp edges at the base of your ducts from burning away during re-entry... and in keeping re-entry plasma away from the walls of the ducts. Why would you do something so supremely silly as to increase the risks to the crew by adding a separation event, and reduce the performance of the vehicle by adding in the weight of all the stuff needed for the crew capsule to re-enter and land?

I'm not so sure about that. I work in the transportation sector (albeit not spaceflight) and despite how much customers have their mouth full about “supply chain management” and “on time delivery,” they seem to be very eager to drop all that if it means shaving off $0.02 of transport cost per product for something that sells for $50 in a retail store (and no, this is not an exaggeration, sadly). In a business environment where “proven” bottom line savings are given much more significance than “vague” statements as long term viability or network impact (as much as you’d have highly accurate calculations of those) that price tag will remain a huge selling point. Do you work in a sector where the thing being delivered costs a fair fraction of a billion dollars and represents tens to hundreds of millions of dollars in revenue per annum? If not, then (no offense) your experience is less than irrelevant because it's nothing like the situation we're discussing. This isn't a package of action figures for Toys 'r Us where it doesn't matter if it gets there on the 2nd or the 5th so long as it's there before the movie opens on the 9th. It's a piece of infrastructure that cost a great deal of money upfront, and it costing more money every minute it's sitting on the ground racking up interest charges and leasing payments and not selling any bandwidth. SES may accept the delay, but I suspect not for an indefinite period of time - and they're not SpaceX's only current or potential customer.

Keep in mind that this launch is scraping the absolute bottom of the barrel of the F9's capability in reusable mode. When the SES-9 contract was initially penned, it was expected to fly expendable. Then it should fly expendable. Seriously, delaying a customers payload (which has already been delayed because of an earlier LOV accident) because your experimental system has repeatedly failed does not strike me as good business. SpaceX already has a poor track record for meeting their schedule commitments, and no matter how cheap that's only going to be tolerated for so long. Losing LOX to boiloff isn't the problem. The problem is the temperature rise of the subcooled LOX.

That requires that OneWeb has the money to build the constellation and pay the launch bills when they come do and makes enough money to still be in business when it comes time to maintain the constellation. That's a lot of chickens yet to hatch.

Countdowns routinely get held for all kinds of reasons. If your rocket can't withstand a hold anytime after fueling but before ignition, your design is flawed. Time to go back to the drawing board.

A mechanical nightmare...

Yep. If you're comfortable building big rockets, it's also possible to send up a large station pre-assembled. The station in question didn't even go up pre-assembled. The core (along the thrust axis) went up in three parts, plus three more for the remaining 'arms'. I think the problem most people have with big stations and mechanical stability is that they rely on regular clamp-o-trons and stock joints, or both.

Back in the day there was a firm (practically religious) belief in the alt.space community that there was a large (and unmet) demand for small launchers. Nowadays, despite abundant proof of lack of demand, that belief persists. The smallsat/cubesat "boom" exists because they can hitch a cheap ride on someone else's booster. (That is, that portion of it that isn't PR hype or overactive imagination.) Launches where the small/cubesat owner pays the full ticket are rare practically to the point of non existence. There's pretty much no evidence and little likelihood of this changing.

Sounds like something from the British Interplanetary Society - they have never been afraid to dream big and dream crazy.

Not really, no.

It doesn't have to be a long cylinder, it just has to be balanced. I've moved an 80-odd ton station that was shaped like a child's jack from Kerbin to Duna before. (But I had KJR installed, and it was all fastened together with Sr. ports.)

You can't make the kind of ceramics that will withstand rocket exhaust with ancient world technology - the kilns used aren't predictable enough, don't burn hot enough anyhow (they're wood and charcoal fired), and the ancients didn't use the input materials needed (let alone have any method of purifying them). Banded metal could mean anything, so you're just handwaving. If you're riveting, your tank is far too heavy anyhow (and probably won't hold together if you put cryogenics in it). It probably won't withstand the pressure either... not without highly trained and experienced riveters. Either way, welding or riveting, there's a lot of skills and precursors you'll have to bootstrap. And without relatively modern steels or preferably aluminum, it'll be too heavy because it'll be too thick, welded or riveted. Guidance won't be 'tricky' - it will be impossible without at least gyros for reference. Fuel chemistry is far, very far, from being the main challenge.

Then frankly "you are not going to space today", not in anything that can actually lift off and has a better than .01% chance to not blow up before it gets to orbit. Basically you need high quality steel for the case and nozzle (or tankage and engines) and at least 1930's tech in a wide variety of areas (though especially in gyro's and hydraulics/pneumatics), and all of those require considerable precursors. Not that ancient civilizations had much in the way of excess manpower, between armies and farmers they were actually usually lacking in those departments.