SpaceX Will Attempt To Recover Super Heavy Rocket by Catching it With Launch Tower (techcrunch.com) 130
SpaceX will try a significantly different approach to landing its future reusable rocket boosters, according to CEO and founder Elon Musk. It will attempt to 'catch' the heavy booster, which is currently in development, using the launch tower arm used to stabilize the vehicle during its pre-takeoff preparations. From a report: Current Falcon 9 boosters return to Earth and land propulsively on their own built-in legs -- but the goal with Super Heavy is for the larger rocket not to have legs at all, says Musk. The Super Heavy launch process will still involve use of its engines to control the velocity of its descent, but it will involve using the grid fins that are included on its main body to help control its orientation during flight to 'catch' the booster -- essentially hooking it using the launch tower arm before it touches the ground at all. The main benefits of this method, which will obviously involve a lot of precision maneuvering, is that it means SpaceX can save both cost and weight by omitting landing legs from the Super Heavy design altogether. Another potential benefit raised by Musk is that it could allow SpaceX to essentially recycle the Super Heavy booster immediately back on the launch mount it returns to -- possibly enabling it to be ready to fly again with a new payload and upper stage (consisting of Starship, the other spacecraft SpaceX is currently developing and testing) in "under an hour." The goal for Starship and Super Heavy is to create a launch vehicle that's even more reusable than SpaceX's current Falcon 9 (and Falcon Heavy) system.
Why not? (Score:5, Interesting)
Re:Why not? (Score:5, Insightful)
Re: (Score:2)
If they can get the landings down so good (which they appear to be), I think that might be a reasonable risk in a cost/benefit-type scenario.
Re: (Score:2)
Re:Why not? (Score:5, Informative)
I suspect the SpaceX version would be several orders of magnitude cheaper.
As to optics, it's a test program at the moment.
Re:Why not? (Score:4, Funny)
> I would bet NASA would be really irked if a tower was destroyed at KSC
Towers are destroyed at the Kerbal Space Center all the time.
Re: (Score:2)
That's true, and I'm not a rocket engineer -- (and maybe a bad example) but I don't worry about destroying my living room when I pull my car into the garage.
True, but your car generally doesn't explode in a ball of flame if you bump something too hard while parking.
If they can get the landings down so good (which they appear to be), I think that might be a reasonable risk in a cost/benefit-type scenario.
It's an interesting approach. Post landing inspection would be critical to ensure no undetected damage could result in a failure and loss of the vehicle in the next or subsequent flights.
Re: (Score:2)
> but I don't worry about destroying my living room when I pull my car into the garage.
He drives a Pinto, you insensitive clod!
Re: (Score:3)
> but I don't worry about destroying my living room when I pull my car into the garage.
He drives a Pinto, you insensitive clod!
That problem is solved by not backing into the garage or letting the door hit the rear end....
Re: (Score:2)
> but I don't worry about destroying my living room when I pull my car into the garage.
clearly, you don't have teenage drivers about . . .
A friend of mine actually failed to stop in the driveway and went through the wall into her bedroom . . .
oddly, her father thought it was funny . . .
Re: (Score:2)
Re: (Score:2)
Now that you mention it . . . growing up, the house on the corner seemed to have someone plowing through a wall every few years . . . and on multiple occasions, birds crashed through the windows after eating the fermented berries on that same house's bushes . . .
Re: (Score:2)
There's a house in my neighborhood that's situated on the outside of a rather sharp turn in the road, with poor visibility. Their front yard is lined with large boulders in an approximation of WW2-era tank trap. They must've had an incident or two.
Re: (Score:2)
They could create a landing hook structure away from the one used for the launch. This would save the tower complex from possible destruction. True, it would have to be moved to a launch tower - one that has been saved from being ruined, I feel this later movement could easily be done by established moving equipment for this far lighter weight, it could deal with the saved segment and even lay it flat for refurbishment in a shed.
Re:Why not? (Score:4, Insightful)
"since any failure is likely to destroy the launch tower."
Why? My guess that is why they're moving from using the launch mount to the tower for retrieval, to minimize the risks to destroying the ground equipment. If past animations are to be believed the launch tower can rotate, so you rotate it to the side of the tower where you just have a concrete pad/flame diverter. If you miss the catch it plows into a concrete pad and maybe damages the catching hardware which could be designed for quick/easy replacement. Of course you would have to have fire suppression systems and the towers base would have to be reinforced but you have to do that anyways just for the launch. At landing super heavy will basically be empty of fuel, so even if it did explode it is not likely to be very energetic.
Re: (Score:2)
I think it'd be more the force of the explosion if it came down too fast, like SN8, that might be a problem. Can't really move the ground out of the way. Though water does have a lot more give, and he has been talking about mostly using ocean-based launch platforms.
But yeah, if you figure the launch arm is essentially a boom crane with some sort of "catching fork" on one side that reaches out into the plane of the landing maneuvers, it could even dissipate modest sideways impacts by spinning around the t
Re: (Score:2)
A good point - but I'm not sure how much else there really is in the tower to begin with. I mean, what's really there:
Passenger loading ramp, probably built into the launch arm
communication and charging cables
Plumbing for fueling.
Am I missing anything?
Plumbing and cables are likely to be far cheaper than the tower itself, and the loading ramp is relatively simple, and likely built into the same arm he seems to be talking about catching the booster with.
Trade landing leg weight for fuel? (Score:5, Interesting)
Present SpaceX landings rely on reaching zero velocity at the touchdown point: The minimum engine throttle on a single Merlin can cause the first stage to go back up as it gets lighter. That's why most landings are rather hard on the landing legs: They have to absorb all the residual velocity needed to 'stick' the landing.
A Superheavy catch will require something much closer to a true hover to permit a catch without over-stressing the tower. Keeping multiple Raptors lit should make this possible without needing to make them throttle any deeper. Much as we saw during SN9's ascent.
Re: (Score:2)
I think the Raptor engines are able to throttle much lower, as well.
Re: Trade landing leg weight for fuel? (Score:5, Informative)
They canâ(TM)t - 55% for raptor vs 57% for Merlin. The difference is that super heavy has 28 raptors compared to falcon 9â(TM)s 9. As a result falcon 9â(TM)s minimum total the throttle is 6.3%, while super heavyâ(TM)s is 2%.
Re:Trade landing leg weight for fuel? (Score:5, Interesting)
He already replied in agreement to a tweet saying that since mass is much less of an issue for ground equipment they can do a lot more shock absorption, with longer travel distance than legs would provide.
The way I see it is they could essentially build a high speed fork-lift into the tower that first matches speed with the rocket and then starts applying force to catch it, if needed.
Anyway, I don't think it would require anything that would look like a hover on human timescales.
Re: (Score:3)
mass is much less of an issue for ground equipment they can do a lot more shock absorption, with longer travel distance than legs would provide.
So they're basically building...a high tech trampoline? (Yep, I dared to use the T-word!)
Re: (Score:2)
I would think it's more along the lines of a shock absorber, like we have in our cars but much bigger and with a cut-off valve at the bottom to prevent it from spring back up.
Re: (Score:2)
Re: (Score:2)
Oops, I just wrote that; you beat me.
Re: (Score:2)
trampoline
Fun fact, those used to be called a "jumpoline" until your mom used it.
Sorry, couldn't resist. Apologies to you and everyone else's mother
Re: (Score:2)
I thought about a high tech swimming pool to cushion the landing, but that would probably result in engine corrosion over time. Maybe big springs under the pads that the fins land on? or some other mechanism to make the pads cushion the landing: they could be pistons pushing water out from under themselves through relatively small channels. Shock absorbers.
Hover used as a final landing fuel optimization? (Score:2)
Say final remaining fuel is a relatively low cost component of total mission cost. And vertical hovering and even some horizontal mobility (thermal issues aside) can be used above final landing to burn down remaining fuel leading to a light, empty and reliably well positioned vehicle at capture. Pretty sure SpaceX has good simulations and optimizations of the landing process that convince them this approach is better than the vehicle lifetime cost of robust legs.
Re: (Score:2)
Re: (Score:2)
Also, for many payloads, 'mission performance' is a poor metric, as it's either going to need retanking anyway (>GTO) or is so enormously overspecced that having a payload margin of 80 tons versus 70 tons doesn't matter at all.
Re: (Score:2)
Re: (Score:2)
For launches to orbit you're probably right, they'll usually have way more payload capacity than actually needed... at least for the immediate future, until we start building real orbital infrastructure.
But it makes a big difference for the missions that call for orbital refueling. If you want to fully refuel a Starship in orbit - say, if you want to get to Mars as quickly as possible to reduce radiation exposure to passengers, then you're going to need 1,200 tons of propellant. Which at 100 tons of payl
Re: (Score:3)
The boosters do also have maneuvering thrusters up at the top near the grid fins. Not sure how much crosswind they can counteract against, but it would be more than zero.
Re: (Score:2)
I think it's only lower atmosphere winds that are likely to be a problem - it'll have plenty of time to correct for anything happening in the upper atmosphere.
Meanwhile, launch/landings can already only occur when the wind is very low - the same gust of wind that might knock it into the tower, could also twist it out of vertical as it touched down, or knock it over after landing.
Figure too that as big as it is, it's also heavy. A last-second gust of wind won't actually move it that much.
Re: (Score:2)
[...] Much as we saw during SN9's ascent.
Do you mean SN8? SN9 has not flown yet. It just went through its cryogenic tank testing yesterday though, and will fly some time in January. And did you mean ascent or descent?
Re: (Score:2)
They meant SN8, but they also meant ascent. SN8 went up on a slow controlled hover-plus trajectory rather than a standard accelerating ballistic trajectory that everyone was expecting.
Holy moly! (Score:2)
That man thinks big. If he can pull this off (and based on his track record, that's more likely than not), I'll be glued to my screen watching that landing!
Re:Holy moly! (Score:5, Interesting)
Agreed. This is ballsy engineering.
A few years back I was talking with some aerospace contractor employees. They had nothing but contempt for Elon and his SpaceX. They had a lot of nasty quips like "North Korea has a better launch record!"
Then he went and did what they all said couldn't be done. Can he do it again? We will see. I get the impression that he doesn't make these kinds of predictions without talking to his engineers and working through the numbers first.
Re:Holy moly! (Score:5, Interesting)
Agreed. This is ballsy engineering.
This one will be really interesting. They must have some basis for thinking they can actually do it, but there will be quite a few unexpected hurdles. If they can do it, the payoff (both in reputation and product quality improvement) will be huge. If not, if will probably not damage them much.
Re: (Score:3)
Knowing how SpaceX operates, they'll probably have a number of spare tower arms already under construction during their first launch attempt in case things go awry. Their testing strategy is always that it's okay to destroy things so long as they don't cost too much and you've got more waiting in the wings.
Re: (Score:2)
Knowing how SpaceX operates, they'll probably have a number of spare tower arms already under construction during their first launch attempt in case things go awry. Their testing strategy is always that it's okay to destroy things so long as they don't cost too much and you've got more waiting in the wings.
That is a pretty sound approach to experimental engineering. You need, you know, experiment to find out things. And it is always good to know how much margin for error you actually have because you went over it. Also has the PR advantage that if it fails on the first few tries, not only can you claim that was sort-of expected, it will be the literal truth!
Re: (Score:2)
Heck, the explosions themselves are a huge PR advantage. Everybody loves fireworks. How many people do you suppose watched the SN8 landing that could really have cared less about a successful landing? That's free mind-space for SpaceX.
Re: (Score:2)
Very true.
Re: (Score:2)
I imagine one benefit to this would be if they can make it lands over the exhaust tunnel, there will be less blowback hitting the rocket like you see on falcon 9's at touchdown. Seems like a big win for minimizing maintenance between launches.
I'm not sure "can't" is in his vocabulary (Score:2)
> I get the impression that he doesn't make these kinds of predictions without talking to his engineers and working through the numbers first.
I get the exact opposite impression. This is the same guy who said he'd have fully-autonomous cross-country driving within two years and he didn't even have very good lane-following at the time.
I get the distinct impression that Elon Musk dreams up wild stuff, then his engineers have a choice:
1. Figure out how to build the ship in a bottle that Elon dreamed up.
2. G
Re: I'm not sure "can't" is in his vocabulary (Score:2)
No I bet tesla engineers on self driving just massively under estimated the amount of work to go.
Even waymo which is way ahead of tesla is years behind schedule.
Everyone keeps using the words AI when our smartest sinus dumber than ants who can problem solve. Everytime out say alexa, hey siri or etc. Te audio snippet is recorded transmitted to a cloud server processed and a command instruction is sent back. This seems fast as you are only talking about a couple of kilobytes with broad band and 50 ms ping
Re: (Score:2)
They had a lot of nasty quips like "North Korea has a better launch record!"
And they're still gainfully employed in the field of engineering where hard facts are easy to check? [wikipedia.org] I wouldn't trust such incompetent people.
Re: (Score:2)
That was some years ago when SpaceX was still low on its learning curve. So the actual numbers were supportable, but their statements were political in that they ignored that SpaceX was trying for a reusable vehicle and NK of course didn't care about that for some reason.
I suppose the real story is that they were seeing themselves as threatened but this upstart who hadn't put the years into the industry as they had. The government and institutional structures they worked in would never allow for the k
Re: (Score:2)
Re: (Score:2)
And then a few years later it will be as boring as watching an airplane taxiing to the terminal.
I've been watching SpaceX launch streams since around the beginning, I still watch most of them but it's getting pretty boring at this point.
Starship is exciting because it's new, but with what Elon is planning, something like a thousand active vehicles, launches could get excitingly boring pretty quick.
Re:Holy moly! (Score:4, Interesting)
And that's the goal. :)
Re: (Score:2)
No, it's not the goal, but it is a good indicator that "you're there". I remember years ago watching the dwindling hype that each successive Space Shuttle launch caused. And thinking that when I hear about a launch that happened *last* week that I didn't know about, then we'll be "there".
We're not "there" yet, but I have hopes.
Canâ(TM)t wait! (Score:5, Funny)
The first couple of tries will be spectacular.
Re:Canâ(TM)t wait! (Score:5, Interesting)
I was born after the great "Right Stuff" generation so my perspective might be skewed. However, every time I see an expended SpaceX rocket land on the droneship I get chills. It's amazing that they are able to do this, in my opinion. I can't wait to watch what happens when, not if, they pull this off.
Will
Re: (Score:3)
There's a special spot in technology development where somebody goes from "lol, look at the idiots" through "holy shit, they actually did it" to "yawn" in a fairly short period of time.
Pilots smashing into the sound barrier to Chuck Yeager breaking it to reading spreadsheets on Concorde. SpaceX making pretty explosions to landing a rocket to doing it every other day.
Re:Canâ(TM)t wait! (Score:5, Insightful)
I was born just before Sputnik, read every word written about the space program through my youth.
I watch every Falcon launch and every booster landing. I remember the comments and articles stating confidently that there's no way in hell an anti-aerodynamic first stage can return safely. And 20+ times per year, I watch a first stage return from near orbital altitude through atmosphere transitioning from hypersonic through supersonic to zero to settle on its ass within a few meters of bullseye to a target in a suicide slam. On land within a kilometer of its launch tower, or on a barge in the middle of the ocean.
Much is made of reusability, which is a huge win. From my point of view, the consistent accuracy of their landings is the real magic.
Re: Canâ(TM)t wait! (Score:2)
The first stage is basically a guided bomb on return. Gives you an idea on how accurate they are....
Re: (Score:2)
The first couple of tries will be spectacular.
I don't root for them to fail, but when they do, I confess I am entertained.
If you had asked me 20 years ago if I thought a modern company could behave the way SpaceX does, I would have said no, impossible. There were all kinds of Earth-shattering kabooms during the original rocket development programs of both the US and Russia in the '50s and '60s, but those were government programs on the next best thing to a wartime footing. They were literally developing weapons of mass destruction. The public percep
Elon's a mad man (Score:2)
The difficulty on this will probably be an order of magnitude harder than landing on a drone barge ship. I know he's talked about this kind of landing in the past, but I always assumed they'd land with feet back on the pad with some sort of mobile launch tower. Rocket launches, mobile tower backs off 100ft or so to give the 1st stage room for a landing, once the rocket lands, the tower grabs or hoists the mostly empty 1st stage and re-centers for the next launch. Even drone ship landings are sometimes off c
Re:Elon's a mad man (Score:5, Informative)
The difficulty on this will probably be an order of magnitude harder than landing on a drone barge ship.
Not necessarily. They need get the booster into position, but probably not that accurately. And then it just needs to hover for a few seconds. All the equipment will be ground-side, so it can be as heavy, energy-hungry and computation-hungry as needed. That said, it will still be very interesting to see whether they can pull this off and then manage to make it reliable.
Re: (Score:2)
Electromagnets on the ground?
Some kinds of stainless steel are more or less non-magnetic, others are (the kind your refrigerator is clad in, for example). I don't know what kind of stainless steel the rocket is built of, but if it was magnetic, and if you had several large electromagnets arrayed around the booster's landing site, you could adjust the flux to pull the booster one way or another. (No need for flux capacitors, either.) The landing would still need to be pretty accurate up to that point--you
Re: (Score:2)
The at the point of impact, landings on the drone ships usually touch down pretty spot on (though they sometimes face challenges with heavy seas), but the booster sometimes slides a bit as it powers down its engines while it's on the deck.
No question, though, this is a step up in difficulty.
Re: (Score:2)
> he's talked about this kind of landing in the past, but I always assumed they'd land with feet back on the pad
He's usually talked about landing back on the "launch mount". One of the videos had an outboard landing platform and a crane to move it back to the launch mount too.
They simulate the heck out of all of this, so if it's being built it already works in software.
Musk's engineers (Score:3)
See Musk hires engineers who think things can be done. Attitude wise it makes a huge difference. Contrast that with the "can't do" engineers Toyota is stuck with .. coming up with imagined BS problems as to why something can't be done: https://spectrum.ieee.org/tran... [ieee.org]
Re:Musk's engineers (Score:5, Insightful)
See Musk hires engineers who think things can be done.
Engineers don't say can or can't be done. They say how long it will take, and how much it will cost. And they are notoriously optimistic.
Managers know to add a generous padding factor, say 100%, to engineers estimates. More for software.
"Yes men" are a dime a dozen. The real challenge is knowing when to quit, as SpaceX did with the composite hulls, and NASA did with the SLS ... oh, sorry, that is *still* going?!
Scotty is the Chief Engineer (Score:3)
Scotty is the Chief Engineer. But calling him a manager, well them are fighting words!
Re: (Score:2)
I know a lot of engineers who say "it can't be done." I also know a lot of managers who hear something like "a prototype will be ready for testing by the end of March" and translate it into "the finished product will be delivered to the customer by the beginning of March."
Re: (Score:3)
That may be all the difference there is: everywhere I've worked we get handed a schedule after us engineers give a reasonable estimate - that with luck - can be accomplished if nothing major bites us in the ass.
The schedule is obtained by management who chops 30-40% off to be "competitive", so we can "sell" the idea. And then the schedule the engineers had ending in Jan. gets cut to ending in Sept. the year before.
I've also been on the receiving end of creating a prototype, proof of concept, and had it st
Re: (Score:2)
See Musk hires engineers who think things can be done. Attitude wise it makes a huge difference.
It helps that one of Mr. Musk's degrees is in physics. In the fields of endeavor he has chosen, the first question he has to ask is, "Can it be done?" and he's actually equipped to answer that question. It may be a spherical cow in a vacuum as far as models go, but he can come up with a model to try to answer the question with some degree of confidence. The spherical cow models are probably where some of his more, shall we say, "optimistic" estimates come from, but it means that he already has at least a
Shock-Absorbing Pad (Score:4, Interesting)
I’m also conscious of the amount of effort that will be required to nail a landing accurate to within a few tens of centimetres in order to be able to engineer something that can be ground-based to effect vehicle capture.
As a slightly adventurous alternative, how about this... Build your entire landing pad (i.e. an area of proportionately equivalent dimensions to those used today by F9), but instead of just pouring concrete, dig and line a hole, put in a set of pneumatic suspension so that the entire pad is build on a series of air-ram shock absorbers. With decent sensors and modern computers it will be possible to adjust the pressure in the rams around the perimeter of the pad such that even if the SH booster lands slightly ‘off’, this could be caught and managed.
It’s obvious to see why they are looking at the grid fins to assist capture - that part of the rocket already has to be incredibly strong to survive the deployment of the fins without distorting the fuselage - but look at the size of the fins against the dimensions of the rocket and you realise how quick-acting and accurate such a capture system would have to be.
Re: (Score:2)
Now that is the most interesting, whacky, far-out, and possibly reasonably outside-the-box approach I've heard so far.
You need to get a job at SpaceX.
Re: (Score:2)
Sadly, I have to tell you that in my exceptionally limited experience, SpaceX don't really appear interested in outside-the-box armchair-quarterback thinking. I have actually contacted them [only the once] with a suggestion for massively increasing the stability of the autonomous drone ships (OCISLY and JRTI).
I thought my suggestion was not only childishly simpl
Re: (Score:2)
>so that the entire pad is build on a series of air-ram shock absorbers.
Or use the concrete landing pad as the plunger in liquid (possibly water) as the shock absorber . . .
Re: (Score:2)
The issue you will find is that water is not compressible [while air is], so in addition to the very considerable increase in inertia of the fluid, you also have the problem of allowing it to "flow away" from the point where pressure is being applied [the pad].
Compressability is what you want - the separation between the gas molecules under the pad form the "shock absorber" that smooths out the force of the landing.
Re: (Score:2)
Hydraulic shock absorbers have been in use for a long time, and they do allow the relatively incompressible liquid to flow away--that's not a "problem", it's part of the solution. That's basically what hawk (and others) are proposing.
Re: (Score:2)
Re: (Score:2)
> nail a landing accurate to within a few tens of centimetres
>but look at the size of the fins against the dimensions of the rocket
Those grid fins are probably at least 3m long - if they could support the weight of an empty booster from out near the ends, that's a lot of room to work with. Falcon 9 is already routinely nailing landings within a meter or two (not including sliding after landing), and there's no reason a larger rocket should find similar accuracy any more difficult. In fact it should
Re: (Score:2)
I can't help think that the additional complexit
Re: (Score:2)
So SuperHeavy's grid-fins might be as long as 15ft=5m if they scale linearly. Even assuming stationary "catching arms", they could be off-center by almost half that distance and still catch the (end) of the fins. But I really think moving arms that will swing in to touch the side of the rocket will be where it's at - then the weight can be carried by the grid-fin mounts, rather than the fins themselves Or at least greatly reduce the torque on the fins by catching close to the mount.
Moving the grabbers ev
Re: (Score:2)
dig and line a hole
Perhaps you haven't noticed that the Boca Chica site is right next to an ocean coast, where the water table happens to be very close to the ground. There's a reason why 39A/39B at KSC were built as concrete mounds.
The driver is quick reuse here (Score:2)
It's pretty obvious that some big folding landing legs like with the F9 would be much easier (and with a first stage the mass penalties are not that bad). But the problem then is that you have to land it elsewhere on a landing pad and transport it back to the launchpad to fly it again.
For beyond-LEO missions though Starship needs refueling in orbit. This means up to five additional launches of tankers to refuel a ship in orbit. To achieve this they need not only to reuse the first stage, but really, really
Re: (Score:3)
To achieve this they need not only to reuse the first stage, but really, really quick reuse.
I don't see how a 24-hour turn-around would be a problem. Just build more boosters to fly more often. They will have a limited number of flights anyway.
But it may only take an hour to move an empty booster by crane-on-rails a short distance (100m?) from landing pad to launch pad.
To me, landing on the launch pad falls in the "nice if you can manage it" category. If it works, it saves time, cost and weight, but is not essential.
As you say, the weight penalty for a booster is not that bad. It
Re: (Score:2)
They need to figure out a way to get the upper stage into LEO so it can be used as a space station or long-haul ship segment, even if its just kept as unpressurized bulk storage.
Re: (Score:3)
They need to figure out a way to get the upper stage into LEO so it can be used as a space station or long-haul ship segment, even if its just kept as unpressurized bulk storage.
That's called Single Stage To Orbit, and if all you want to do is put empty cans in orbit, it can be done. If you want any sort of significant payload, it's mostly not possible. In any case, no one has any particular interest in using spent rocket stages as parts of a space station now that Bigelow Aerospace has conclusively proven that purpose-built inflatables work exceedingly well for the purpose. There's a Bigelow module still attached to the ISS right now. It's been there for four years.
Using a spe
James Bond Film "You Only Live Twice" (Score:2)
It'll be interesting to see what they come up with (Score:2)
I didn't expect them to utilize the tower. I always thought they'd modify the launch mount so that part of it could detach on hydraulics and maneuver to better catch the booster (think the below link, only larger and a ring with launch/landing clamps). It'll be interesting to see what they come up with and how well it does/doesn't work.
https://www.youtube.com/watch?... [youtube.com]
great idea... (Score:2)
Spare Launch Pads aren't cheap (Score:2)
Currently, a failed vertical landing destroys the spacecraft and little else. This idea may end up costing the entire launch complex.
Re: (Score:2)
Re: (Score:3)
has society already forgotten the lessons of 1986 and 2003?
Of course not, that is why any humans are placed in front of the booster and an emergency eject system will separate them if required. For this to work you need some warning that things are going to blow but it looks like such warnings do exist in most cases. It will be interesting to see what sort of safety record SpaceX holds in another 20 years.
Re: (Score:2)
No LES on Starship. The goal is to get to airliner-levels of reliability.
I personally do believe that space vehicles can get to airliner-levels of reliability. But, it will take 40+ years from the time that people start trying, just like it did with airliners. I have high hopes, but low expectations, that Starship will be able to get that type of safety record. The next vehicle, though, just might.
Re: (Score:2)
as reliable as boeing which just killed 2 loads of (Score:2)
passengers because they didnt want to pay for proper engineering and quality control?
Re: (Score:3)
aircraft have to go through complete overhauls of various systems after a certain number of running hours, including things like scanning analysis of metal parts to ensure there are no cracks developing internally.
what makes anyone think they are going to be able to do an hour turnaround without serious safety problems?
does space-x have some kind of hyper-improved version of maintenance and quality control that enables it to defy basic laws of maintenance schedules?
Choose a target and aim for it. You cannot change a decision that was never made. If it turns out to be impossible, they've proven it rather than theorized it.
do they have magic materials that dont need to be analyzed? some kind of fairy tale fasteners that never need to be retorqued ...
or are they just cutting corners and building things in tents like with a certain other associated company that has notorious quality issues?
"move fast and break things" does not work in space. you cannot afford to break things in space. you have to be extremely boring and careful.
has society already forgotten the lessons of 1986 and 2003?
it is very easy for people with nothing personally at risk to say that killing people is an acceptable risk. the surviving families tend to disagree as does the general public.
Those were tragic, and I remember them.
But, rather than presume it's going to end the same way let's see how they do. SpaceX has delivered impressively so far.
Re: its time to for some healthy skepticism (Score:3)
Huh⦠you realise that aircraft regularly take off with an hour turnaround, or less⦠he didnâ(TM)t say that there would never be a turnaround greater than an hour, or never be a time to move a booster to a bay to do maintenance. He said that they would be able to do an hour turnaround in the best case.
Re:its time to for some healthy skepticism (Score:4, Insightful)
And that would be the same here.
You mean just what aircraft do? Airplanes don't have their engines torn down between every flight.
It's also worth noting that instead of operating for hours at a time on each flight - potentially a dozen or more on a long-distance flight - rocket engines only burn for a few minutes per flight. They involve extreme conditions, to be sure, but not for very long. Additionally, they've eliminated one of the big sources of "wear" in rocket engines with Raptor - that is, coking. Methalox isn't prone to coking up your turbopumps in the way that kerolox is.
You mean the car that ranked #1 in reliability from WhatCar in both the electric and luxury segments, received high marks across the board on quality and reliability in the Bloomberg survey, just yesterday was ranked the second-highest quality brand for sale in China by JD Power*** [scmp.com], and a car which I own personally and has been top notch in quality and reliability?
If airplanes had taken your "everything has to be flawless before you start testing" notion, the Wright Brothers would have been long dead before humans took to the air. You need high reliability by the time you put humans passengers onboard, but by all means, destroy things during testing if it helps you iterate faster.
*** - For whatever JD Power is worth. But I know people like to bring up their previous claims, so their reversal is worth mentioning.
Re: (Score:3, Informative)
aircraft have to ... what makes anyone think they are going to be able to do an hour turnaround without serious safety problems?
Aircraft can turn around in the time it takes to refuel, so you have not thought that through.
They have a six thousand hour service interval.
If a rocket engine can do just one hour of operation between servicing, that is over twenty flights.
The long service interval of a commercial jet engine is possible because they have far fewer moving parts than a car engine.
A rocket engine is even simpler than a jet engine, so achieving a just few hours of operation between overhauls is far from absurd.
There is no "ba
the main lesson they have not learned (Score:2)
unrealistic schedule pressure and an authoritarian management structure that quashes dissent, all combines to lead to normalization of deviance
Re: (Score:2)
Odd, last time I flew on a plane (I admit, it was a while ago), it did not undergo any structural inspection at all between landing, taxiing up to the gate, and taking off again.
Re: (Score:2)
has society already forgotten the lessons of 1986 and 2003?
Have we built anything that puts the crew module on the side of a rocket stack since then? No? Then apparently the core lesson has not been forgotten. But some apparently still haven't learned the other lesson yet, which is don't use SRBs on crewed missions.