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Blue Origin Thread (merged)


Aethon

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Looks like not an SSTO, but as Space Shuttle: 1st stage booster + 2nd stage+ship two-in-one.

 

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42 engines, 42 turbopumps, 42x2 fuel lines. What can go wrong?

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Why bother with a smaller one? It's already flying.

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... as reusable samples also do up to 10-20 times.

Edited by kerbiloid
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There is no LES. The idea is that it works or it doesn't, like an airliner.

The difference is that airliners have millions of flight hours of experience. This is a whole new vehicle, designed with some very risky assumptions and (in my opinion) many new failure modes that don't seem to have been properly thought through. 

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I would assume that the Spaceship is capable of blasting free of the booster if necessary. If there's a problem with the Spaceship itself there's probably nothing that can be done. 

You can't just ejector-seat 100 people, and the Spaceship doesn't contain parachutes because it lands propulsively. Any cabin detatchment would have jettisoned its means of landing safely.

But at least its launch abort scenarios are likely to be more benign than the shuttle's.

Edited by RCgothic
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And where do you think current airliners got their millions of hours of experience? There were crashes - and planes still crash occasionally, there are hundreds of casualties. Every road has to begin somewhere, with someone taking first step, stumbling, maybe falling - but continuing to go forward :)

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6 minutes ago, Scotius said:

And where do you think current airliners got their millions of hours of experience? There were crashes - and planes still crash occasionally, there are hundreds of casualties. Every road has to begin somewhere, with someone taking first step, stumbling, maybe falling - but continuing to go forward :)

The volumes are uncomparable. Planes started off with 1 person, then 2, then 10, then 100, then 1000. Progress was incremental. No single aircraft has ever introduced more than one or two major technical innovations. There is also a lot of experimentation and testing involved, with prototypes, certification, regulations. Aviation didn't go from the Wright Flyer to the 747 in one step, which is what SpaceX wants to do.

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I don't think the video is necessarily meant accurate in all the details; it's cool and inspiring without being wrong in any stupid way. But I suspect in the real thing the tanker would rendezvous from ahead rather than from behind, for example.

10 hours ago, CatastrophicFailure said:

By the looks of it, they're aiming for turnaround in hours, not weeks.

I wonder what the option is if the first stage doesn't return in immediately usable state - scrub the flight and return the spacecraft and crew to Earth? Or have another first stage available within a short timeframe? And if it's the latter then I'd be inclined to have both craft and tanker ready on their own lifters before launching either, and use the returning stage as plan B or for the next flight. Turnaround in days rather than weeks, maybe.

5 hours ago, magnemoe said:

Also a bit sceptical to landing on launchpad, is that even possible as in is it an flat surface to land on?

For much the same reason, I wouldn't want to land on a pad I needed to reuse shortly even if I had the accuracy to do it, just in case. Not until I had many pads in service. I do see merits in reconditioning rocket and pad together, though. Barge + submersible crawler + rolling VAB to recondition rocket and pad?

Off to watch the video again.

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5 hours ago, magnemoe said:

Yes they have to refuel an rocket larger than saturn 5. 
Also a bit sceptical to landing on launchpad, is that even possible as in is it an flat surface to land on?

The whole point is that it isn't flat. The booster has no landing legs, but fins that guide the rocket into slots in a launch mount stand. You don't carry the landing legs, they stay on the ground and you "dock" with them.

IMO, this concept won't survive the first couple of review cycles, for two reasons:

  • There are too many faliure modes and a single mishap puts your entire program at risk. Miss the landing structure by a few feet, get a gust of wind during the last seconds, come in too hard, and you lose everything.
  • Musk claims that LC-39A will be a single launch pad for F9, FH, and BFR. Having common trench design for F9 and FH is one thing, but including the launch/landing mount structure and a flame trench for the BFR (as well as acoustic suppression systems) at the same time is going to be complex.

The benefits are simply not worth the risk. 

 

Edited by Nibb31
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41 minutes ago, CSE said:

I don't think the video is necessarily meant accurate in all the details; it's cool and inspiring without being wrong in any stupid way. But I suspect in the real thing the tanker would rendezvous from ahead rather than from behind, for example.

I wonder what the option is if the first stage doesn't return in immediately usable state - scrub the flight and return the spacecraft and crew to Earth? Or have another first stage available within a short timeframe? And if it's the latter then I'd be inclined to have both craft and tanker ready on their own lifters before launching either, and use the returning stage as plan B or for the next flight. Turnaround in days rather than weeks, maybe.

For much the same reason, I wouldn't want to land on a pad I needed to reuse shortly even if I had the accuracy to do it, just in case. Not until I had many pads in service. I do see merits in reconditioning rocket and pad together, though. Barge + submersible crawler + rolling VAB to recondition rocket and pad?

Off to watch the video again.

Yes, it could easy pop up some issue with the first rocket who can not be fixed on the pad. 
On the other hand the mars stage is designed to go to mars. It can easy wait some days in orbit. 
Still using two rockets would be far more reliable, it would also leave the returning stage as an backup.

Animation was made by an artist and made to be fast, not required to be accurate.

28 minutes ago, Nibb31 said:

The whole point is that it isn't flat. The booster has no landing legs, but fins that guide the rocket into slots in a launch mount stand. You don't carry the landing legs, they stay on the ground and you "dock" with them.

IMO, this concept won't survive the first couple of review cycles, for two reasons:

  • There are too many faliure modes and a single mishap puts your entire program at risk. Miss the landing structure by a few feet, get a gust of wind during the last seconds, come in too hard, and you lose everything.
  • Musk claims that LC-39A will be a single launch pad for F9, FH, and BFR. Having common trench design for F9 and FH is one thing, but including the launch/landing mount structure and a flame trench for the BFR (as well as acoustic suppression systems) at the same time is going to be complex.

The benefits are simply not worth the risk. 

 

Understand and yes it sounds risky, note that this rocket should be able to hover but still. 
As you say wind would be an issue and if you fail you lose the pad who is far worse than losing the stage unless you have many pads. 

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If a plane crashes during landing you lose the plane and the runway.  

When there where only one plane and one runway this was a problem, not so much anymore.

Only the scale is different this time.

 

They are not going to try to land on the only pad and take of again within a few hours on the first launch. The vidio only describes the vision on how this will work when launching/landing rockets are as easy as planes are today.

We have more than one plane and one runway today.   Tomorrow we will have more than one rocket and one launchpad.

I think that a feasible time plan for this should be as long as it took from wright brothers to commercial flight (~50 years).  Slightly longer if we don't get any new world wars to direct funds towards developing technology.

 

 

Edited by Nefrums
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2 hours ago, CSE said:

I don't think the video is necessarily meant accurate in all the details; it's cool and inspiring without being wrong in any stupid way. But I suspect in the real thing the tanker would rendezvous from ahead rather than from behind, for example.

I wonder what the option is if the first stage doesn't return in immediately usable state - scrub the flight and return the spacecraft and crew to Earth? Or have another first stage available within a short timeframe? And if it's the latter then I'd be inclined to have both craft and tanker ready on their own lifters before launching either, and use the returning stage as plan B or for the next flight. Turnaround in days rather than weeks, maybe.

For much the same reason, I wouldn't want to land on a pad I needed to reuse shortly even if I had the accuracy to do it, just in case. Not until I had many pads in service. I do see merits in reconditioning rocket and pad together, though. Barge + submersible crawler + rolling VAB to recondition rocket and pad?

Off to watch the video again.

@Nefrums covered some if it. I got about halfway thru the explanation video-the man is truly a visionary but he's a horrible presenter-it would take several tankers to refuel the spaceship, but he's thinking (long term) of thousands of spaceships departing for Mars at once. Meaning many pads being constantly used. So if there is a failure, it's more of an inconvenience than a functional setback. Given the sheer size of the rocket, there may be some real practicality to landing right back on the launch pad vs nearby and moving it. And they've already demonstrated the needed accuracy for this multiple times. But like Nibb said, the built in supports will have to go. 

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1 hour ago, Nefrums said:

Only the scale is different this time.

I don't quite agree. Yes, the initial single pad is clearly only the R&D setup, and the full scale operation will have more pads at more locations - in fact, a tanker-based setup might be more flexible in terms of locations, because an out-of-plane launch site just translates into more refuelling, not into the rocket lacking the capability. But it's about how much unused pad time is available during the Mars transfer window: that's a key difference between aircraft and interplanetary. You can mitigate it by launching earlier and waiting in orbit, just advance one pad's-worth of launches by the estimated time to repair a damaged pad. Maybe these tickets would be cheaper. But how early, how much waiting, and could you make it quicker and cheaper by landing off-pad?

 

1 hour ago, Nefrums said:

The vidio only describes the vision on how this will work when launching/landing rockets are as easy as planes are today.

Even before then, perhaps - it might not be that far off, counted by the cumulative number of rocket flights, as compared to how many cumulative aircraft flights had taken place before designers routinely made aircraft that were incapable of safe landing on an unpaved runway. But I think it's a large number of years, even if spaceflight really steps up a gear, before landing on the pad is so low risk that it's a better policy than landing nearby and using a crane. I'd love to be wrong.

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53 minutes ago, CatastrophicFailure said:

@Nefrums covered some if it. I got about halfway thru the explanation video-the man is truly a visionary but he's a horrible presenter-it would take several tankers to refuel the spaceship, but he's thinking (long term) of thousands of spaceships departing for Mars at once.

Thousands of spaceships departing isn't going to happen anytime soon. That would be once a self-sustaining colony is well established. The first synods are going to be 1 or 2 ships.

Also, he mentioned getting the total refueling process down to a couple of weeks, which means maybe 2 flights per week. I don't think anyone is envisioning a turnaround of a couple of hours.

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1 hour ago, Nefrums said:

They are not going to try to land on the only pad and take of again within a few hours on the first launch. The vidio only describes the vision on how this will work when launching/landing rockets are as easy as planes are today.


I agree that the video isn't meant to be a scientifically precise engineering simulation, but rather an attempt to illustrate the concept of "rapid reusability" to a broader public. (It didn't help that Musk called it a "simulation".) I would be surprised, for example, if they have a tanker standing right next to the pad while launching the booster.

But I'm sure that the pad and booster will use the "launch mount" shown in the video. Maybe not for the first test flights, but the system will be designed for exactly this way of landing.

I think this is evident from
1. Musk's explanation about the cost structure of the system, and how they hope to achieve the radical cost-per-payload improvements that are needed to succeed, and
2. Physics.

The interplanetary vessel has one "flight" every 26 months and is thus very expensive per flight. The booster can fly any time, which is why it's meant to be flown "a lot".

Musk's style of "reasoning upwards from basic physics principles" must have raised the question about the sense of carrying ridiculously massive landing legs on every booster flight. The basic question is: "What is the purpose of landing legs?" Answer: they are the interface between the booster and the planet it is standing on. Followed by the question "do landing legs perform any function for which they must necessarily be attached to the booster instead of the planet?"

Musk pointing out how they managed to improve F9 landing accuracy over time seems to indicate that the answer to that question is "no". I would guess that getting rid of the legs is one of the conceptual ingredients that they count on to achieve their performance targets.

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3 hours ago, Scotius said:

I hope question asked during press conference were more intelligent than those dropped during presentation? :-/


Musk mentioning the "improbability drive" from the Hitchhiker's Guide, and some of those questions in the Q&A, made me think:

"If only we could build a stupidity drive. That is a resource that we will never manage to run out of."

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