Falcon 9 Puts Payload in Orbit and Almost Lands First Stage
Falcon 9 Launches Supplies to the Space Station
“The mission is the company’s sixth cargo delivery flight to the station through NASA’s Commercial Resupply Services contract.”
SpaceX Successfully Launches Cargo Resupply Mission to the ISS but Fails to Recover Falcon 1st Stage, SpaceRef
“SpaceX successfully launched a Falcon 9 rocket with the Dragon spacecraft to the International Space Station today to deliver over 1950kg of supplies. The attempt to land the Falcon 9 first stage on the drone ship in the Atlantic failed as the rocket toppled over after landing according to CEO Elon Musk.”
Crap. I was really hope they’d stick the ocean landing this time.
I’ll bet that the deck of that barge is a lot more slippery than the Texas dirt they’ve been practicing on. I wonder how much difference it makes when the feet slide? Maybe time for some non-slip friction paint. Or electromagnets; I’ll give them the patent for free :_>
Not sure what material the pads on those legs are made of (rubber? steel? composite?), but that stage is still double-digit tons heavy. Even if the decks are a washed, so long as it’s on a relatively even keel, that stage won’t slide.
I am more interested on how that stage will handle the trip home against wave motion and wind (it’s now a cylindrical sail). Will it remain unsecured, or will SpaceX send in some crew to zip on board and tie it down (or maybe they can figure out a way to do that remotely).
I’m pretty sure they have to go strap it down. I wonder how long they have to let it sit before it’s safe for humans to get near the thing.
The plan is to weld shoes over the landing legs’ feet to secure the stage to the deck.
Hopefully after the residual LOX has been vented, “just in case”.
How much ya wanna bet that there’ll be a light-weight “strong back” that will end up on the barge once this has been proven?
(I can imagine the funky multi-petal system we’ve seen for the Soyuz/Progress launchers…)
(laughs maniacally)
I’m sure Wile E. Coyote would have some fun working out a way to secure the bird.
It will be interesting to find out what the cause was. So far they have been able to determine the cause of each failure so I expect that will be the case on this one also. If I am counting correctly they have had four successful pinpoint zero velocity water landings, which in theory would have been landing successes if a barge had been sitting there. So it’s somewhat unfortunate that the first two barge attempts had problems, the hydraulic issue on the last attempt and whatever caused the problem today.
possibly very heavy wind – check out the flag in the twitter picture.
*edit* it occurs to me that the flag could be blowing from the blast of the rocket exhaust.
https://vine.co/v/euEpIVegiIx
Amazing video posted by Elon showing the rocket almost nailing it. Control authority is there, but apparently late to correct for…?
Well, your guess is as good as mine – check this out:
https://vine.co/v/euEpIVegiIx
Due to high off-vertical angle it kicks up quite a plume of steam off the ocean just before it returns to vertical.. Wonder if that could have confused the radar system. For water landings of course there would have been steam, which presumably they would have accounted for, but it would not have been expected for a barge landing
It looks to me like that entire swing to the side is simply erroneous. Good thought that the steam may have confused it, but it started swinging to the side before then.
To me it looked like the swing to the left was necessary. It was heading for the left side of the barge, without a last second maneuver I think the landing leg on that side would have been perilously close to the edge. The swing to the left brought it to the center of the barge. You can also see a quick left and right thruster firing from the top of the stage, presumable to keep the “nose” in place above the center of the barge while the bottom of the rocket straightened itself out.
As it came back to the center of the barge it now had some horizontal momentum to the right which needed to be killed off with a quick swing to the right, which is the last maneuver that we see. But then it would have needed to come back to vertical before touching down, presumably that is what it failed to do although we don’t know for sure because the video cuts out at that point.
Also all we have is a 2D perspective we can’t see what it also may have been dealing with in the perpendicular axis.
Even though everyone including Elon say it can’t hover, it sure looks to me like it hovers in the final moments as it does the swing to the right. Optical illusion I guess?
Musk says bi-prop valve, the big question is when did it fail, and was any of the maneuvering that we can see in the video the result of the failure. I.e. was the “big swing” required because the failed valve put it into a situation that required a massive correction maneuver? Or was that considered a nominal maneuver, and the valve failure occurred at the very last moment just as it was about to touch down.
Without knowing more about the cause of the initial swing to the left, it’s really hard to say. Fun to speculate about though. If it was a sticky valve, the fix should be fairly simple.
It certainly did need to swing to vertical and kill its lateral inertia, but just couldn’t quite do that. I think it was closer to a good landing than it appears, which is basically why I think that first swing to the left was not nominal or intentional.
Well, the “final moment” is about the only time it can be said to hover. As it arrests its momentum, the velocity approaches zero, and the ~half-second before and after zero velocity the speed should be very low indeed. At the scale of the video we’re seeing, such small movements are obscured by the blast of the rocket exhaust. Optical illusion is as good a way to characterize that as any.
Musk tweeted it was stiction in the bi-prop throttle valve, and that it was fixable. Next try should be CRS-7 which is NET June 22.
I think that SpaceX are learning that this is a lot harder than they expected. Still, it looks like that they are 90% of the way. They just need to iron out a few more details. Maybe next time!
Given Musk comments at MIT , I think he expected it to be this hard.
As I recall at MIT Musk said, his guess on first barge attempt was 50/50 then he went on to say that they would have many chances next year and by the end of the year guessed 90 percent they would have landed one.
I’m not sure that it’s 90% anymore… Check out this vine that SpaceX just released:
https://vine.co/v/euEpIVegiIx
Maybe at 85%. It’s admittedly coming down way too fast.
Still, consider their progress: They managed to turn a supersonic stage about, fly it back a ways, turn it about again for landing… and bulls-eyed that barge.
Their targeting is phenomenal. They just need to slow that sucker down. Perhaps program it to slow to zero-velocity & hover 20 ft above the pad – like they did with Grasshopper – let the stability issues dampen out (also avoids inadvertent effects from the surface), and then continue down.
The engine can’t throttle down far enough. What you see in the short video is exactly the right landing speed. “Hover-slam”. Vertical decent speed isn’t what killed it, horizontal skew (and the need to yaw so far over to correct) is.
I was also surprised how fast it came down. But I guess they must feel that since the computers and thrusters can react seemingly instantaneously there is no need to waste fuel hovering. When you watch the last second of the landing it is really amazing how quickly and precisely it is maneuvering in the final milliseconds.
They also probably figure that problems that occur will likely not be mitigated by hovering.
For crewed landings I’m sure it would be slowed down, but for recovering boosters they are probably going for pure efficiency and minimal fuel so as to not impact payload capacity.
I don’t think it’s just wasting fuel. The current generation of engines simply don’t throttle down far enough to hover. Their minimum thrust is greater than the mass of the rocket+fuel at that point. So they are either going down under braking, or going up under acceleration.
Yeah, I was stunned at how precisely it reaches zero-vertical velocity at precisely deck level.
(The horizontal…)
Nope. Same “hoverslam” manoeuvre, IIRC.
So they may eventually find they need some additional way to translate horizontally… maybe some horizontal firing jets that take over the horizontal movement at very low altitude. And a bunch more software complexity.
That is unless they can get more on target higher up, which I’m sure would be the goal before that.
It can’t hover – the thrust of the single rocket engine exceeds that of the weight of the nearly empty first stage.
So touchdown has to be at exactly when it reaches zero velocity, or else it will start to ascend again.
Early flights of the Grasshopper rockets were ballasted to prevent this from happening, and later flights tested this “Touchdown at zero velocity” technique, which SpaceX calls the “Hover-Slam”
This reminded me of the CGI video SpaceX put out showing the landing of Dragon (coming in hot, not a straight vertical drop, etc..).. but not the same results.
Its a rocket, not an african rhino. 😉
I had a family member, not into rockets at all say why don’t they put memory foam on the barge or something.
The actual landing part can be tested without an upperstate, near to the sea shore. With all those waves do not assume the barge is horizontal.
3 on target in a row. SpaceX land landings still on schedule
http://spacenews.com/spacex…
Takes more than being on target to be successful.
You seem to have major hostility and wish them to fail.
Why, I don’t know. Creating a low-cost elevator into space seems to be a commendable goal, and they are iterating into success. That is something to be excited about.
I just try to keep some realism to all of the SpaceX fan club here. I’ve never wished them to fail. I hope they do succeed. It’s just that many here think SpaceX can do nothing wrong and think there’s no way SpaceX will fail.
I am a member of the fan club, but I have always been aware that they are in a tough unforgiving business. I admire them for 1) having a vision beyond doing contract work, 2) a willingness to break stuff, 3) a real desire to make spaceflight cheap, and 4) a willingness to go clean sheet, and never accepting conventional wisdom just because, and a desire to constantly innovate.
(and make mistakes, miss deadlines, find things out the hard way, etc.)
John
SpaceX has demitrated that they can safely drive this thing. They have passed every part of there driving test but for the parallel parking part. It is time to move on to solid ground, landing attempts!!!!!
They just put two tons of cargo into orbit, so, success.
First stages invariably are thrown away. SpaceX is learning how to save it and reuse it. Success on a whole new level.
Almost only works when your playing hand grenades or atom bombs. Still I wish them luck
Works when you are trying to convince 45th to let you start flying to land.
Apparently it hasn’t worked yet since SpaceX does not yet have permission to make an attempted landing at the Cape. Dang facts.
At least SpaceX is trying. The other players have failed so far because they have not even tried. They have been content to let millions of dollars of hardware pancake on impact after every flight.
Silly idea, but could they try and land it in the Bahamas?? or anchor an oil rig to the sea bed off the Cape???
Their ultimate goal is to bring it back to a landing pad on the coast. Barge landings will then become the exception, used only when they are launching large payloads and don’t have enough remaining fuel to return to the coast. I don’t think they would want to incur the expense of building a permanent platform that would not be used that often. Also a barge gives them more flexibility in terms of landing location.
Does anyone know what changes/improvements have they made to the first stage after last failed landing?
More and/or bigger tanks of hydraulic fluid that run through pumps to supply the grid fins with power. The last failed attempt ran out of this fluid (it is an open system) before landing, reducing control authority.
If I remember correctly they just said they would add more hydraulic fluid, which I took to mean that the tank(s) had additional capacity. Adding additional or larger tanks would be a design change that I don’t think would have been done in this short of a time frame. I’m just guessing though.
My interpretation of Musk’s comments was that the next cores coming off the line were already upgraded before the loss of the first barge landing attempt.
Which suggests that some of the ocean “landing” attempts had gone close to running out of fluid and they’d already revamped the design. The first barge-landing core was the last of the previous design iteration.
Yet I believe that is exactly what SpaceX did. Overall, this is a relatively minor change to a minor subsystem which is only needed during the first stage recovery phase of the flight.
It looks like it arrived with too much energy in the terminal phase. The controller is still making large inputs even when the rocket is within one vehicle length of the surface. To me that says that they are probably using a control algorithm that is not taking the terminal conditions into account. That would surprise me, actually, since I assume they have access to the best control system engineers.
In any case, I suspect that tweaking the controller gains will solve the problem.
The amount of energy was just fine. The thrust of a single Merlin 1D exceeds the weight of the rocket at that point, so the terminal firing is timed very carefully to produce zero velocity at the surface of the ship.
The problem, as Musk stated, was with a stuck valve. It seems likely to me that this was caused by the exposure to space minutes before. Like they experienced with the upper stage on Falcon, cold does funny things to equipment. It would have frozen in space and may have become sluggish such that the rocket response was impaired when the engine gimbaled to make it vertical at touchdown. Thus, the over correction and touchdown at an angle off of vertical that was not stable.
Musk has deleted that tweet about the valve being the cause???? Not sure why???
Looks like you are getting a sticky key on your keyboad. Must be the same vendor as the F9 throttle valve. ;-P
It looks like it was right on target at approx 500ft, then for some reason veered off in the last seconds and couldn’t recover in time. Did it lose the target?
I have come to suspect that a faulty sensor reading is a likely culprit – say that the guidance got a faulty reading that it was a dozen meters away from where it needed to be, so the stage swings wide to correct, then gets a true reading and swings back to come back on target? That sounds very much like what appears to happen in the video. There just wasn’t enough time to kill the lateral velocity from that final correction. It may have been very close to a good landing.
The giant empty thin-walled fuel tanks would crumple like tissue-paper.
If it’s so sensitive to lateral velocity, how stable will it be with cross winds. Seems even on land it may be difficult to land or the weather conditions might have to be nearly calm.
Winds are somewhat lower onshore, and unlike the runway, a landing pad could be shielded by tree lines or artificial barriers to reduce crosswinds.
It may not have been winds, by a hardware issue causing the control system to work out of phase. Should be a simple fix with an oil can.
allright, couple more tries and they might have it, good for SpaceX. Maybe they could devise a catch mechanism that would grab the rocket and keep it upright?
The landing legs were designed for solid ground and have worked well in that environment. The barge landings were required only because the Range lacked confidence in landing guidance. SpaceX has landed on target three times. It is time (and safe) to shift to landing on land. This will eliminate the problems with sea motion.
To the extent that there are any, yes. Certainly with the last attempt that was called off, it was about not being able to keep the platform stable. In this instance, it was about a loss of precise control of the vehicle. I expect that the Eastern Range will want to see one or two landings stuck before they clear an attempt on land.
That may well be the case, but the high winds and currents offshore may have contributed to the horizontal drift that required extreme corrections and then caused the stage to tip over. Winds onshore are typically considerably lower and the landing pad is actually stationary.
I’d be interested in some backup on that. Usually coastal areas have considerable winds that come in from the sea towards the land.
I wondered about the winds as well. As a long time Florida resident I have observed that coastal winds tend to shift twice per day as the land heats and then cools.
This flow dominates our summer weather and is responsible for the tropical rains we experience. Winter is not as dramatic.
In the video you can see a steady wind from right to left with the smoke moving that way. I suspect it’s only a few mph breeze.
Respectfully disagree. Notice the white caps on the water surface. That tells me the wind is no less than 15 mph, maybe more.
Thanks!
I’ve heard reliably that the first solid ground landing of an F-9R will not occur at Canaveral, but at the West Coast launch site, Vandenberg AFB instead , later this year . Just don’t ask me where to put the X on that map of southern California …
That is a disappointment.
Right here:
34°37’59.2″N
120°36’57.2″W
https://www.google.com/maps…
For anyone who needs some geographical assistance, Yale’s map shows VAFB launch complex 4, the former Titan IV launch complex which is now leased by SpaceX as the Falcon west coast launch site.
Yale has placed a red marker on SLC-4W which is an inactive pad where SpaceX plans to land the Falcon stage. To the right of the marker is SLC-4E where Falcon 9 is launched from and eventually Falcon Heavy.
If you zoom out a couple of clicks, above and to the right of the SpaceX complex is SLC-3E where Atlas V is launched from.
I suspect that what is happening is that CCAFS probably won’t approve until a successful landing has occurred at VAFB. Meanwhile VAFB probably won’t approve until a successful landing has occurred on a barge. July is coming up pretty quick, probably too quick, so later in the year at VAFB sounds plausible.
They will still do barge landings when they have a large payload and don’t have enough fuel to return to the cape.
If they do landings at the Cape after many successful landings, there should be adequate measures to ensure residents of Cocoa Beach and Titusville the first stage won’t land in their neighborhood.
Each one of the landing attempts reached the surface within a few meters of the aim point. Getting a structure that tall balanced on a rolling deck is considerably more difficult, and except in very calm seas it may be impossible. Even recovering the SRBs was a challenge when dealing with the Atlantic.
I wonder what kind of racket those rockets make? (sorry!). People here in Naples bitch constantly about the noise from our small airport. A rocket roaring down could be noisy?
The Florida landings will take place at CCAFS so local communities will be no more impacted by the noise than they already are by the launch. In fact from an aural perspective it will create the odd impression that the landing is being played back in reverse!
SpaceX should land one of its stages from a TX launch at Naples airport. That would be freaking awesome.
Think of the huge crowds of space buffs in Titusville, Cocoa Beach, plus everyone on I95 and Hwy 1 stopping to watch the rocket land. For those folks the more noise the better!
That reminds of a tale I heard. After taking 45 minutes for the chaos of cars to clear the beach after a launch, a frustrated driver asked a cop standing there why they didn’t organize and direct the traffic out. The cop replied that they had tried to do just that, but then it took 3 hours to clear the cars!
I do not foresee returning stages or capsules landing anywhere near populated areas for several years, if ever. Of course airliners land very close to populated areas every day, but less than one in a million of them crashes so it is accepted that the risk is low. Until rocket powered stages and capsules build a long track record I don’t expect public officials or the public in general will accept it.
The landing is technically a part of the launch, so I’m sure the RSO will have the authority and the ability to terminate the landing if the stage goes outside of prescribed boundaries
My thoughts exactly! Why make it more difficult by landing on a floating barge? Space X has clearly demonstrated they can land very precisely. If it explodes, that is manageable as long as it is in a precisely contolled location. It is less likely to explode on flat level land that is not moving.
Perhaps the thinking is that if we can make it work on a barge solid ground is dead simple?
The ocean was not the reason it didnt work.
I have been saying for a while that the 1st stage could use an arresting hook at the top and catch a gantry.
Seems that the weight of the hook would be less than the landing legs.
And a barge OR ground mounted gantry could be articulated to help move into place for the “terminal hookup”.
In fact for landing on the “ground” you could have a pit filled with water.
If the booster missed the hook, it would drop into the water and make less of a mess.
The stage is a hollow balloon of metal, designed to be strong along its vertical axis. There is no way it would survive this sort of treatment.
Seriously!?!
You are suggesting that What I propose is outside the realm of probability for a launch vehicle??? (kind of like LANDING???)
We ARE talking about a structure that can lift 750,000 lbs of weight under 850,000 lbs of thrust and you dont think it is strong enough to support 12,000 lbs of engines hanging vertically? OK. Then I would propose it is in NO WAY strong enough to LAND either.
If the cables ran to the octoweb the it might work. essentially it would be supported from the bottom,
Structural engineers are a very odd bunch 🙂 Fortunately they are 100% correct.
Think of the rocket this way: you can load a vertical 4×4 with a stunning amount of mass. Suspend the same piece of wood at the ends and place the same mass at the center and wham! Same with rockets.
You analogy is missing the point. Lets try it again: If a 4X4 can handle 1000 lbs COMPRESSION while standing vertical, how much weight can it handle vertically in TENSION?
To compare to this example it would only need to hold 50 lbs. Can a 4X4 do that? YES
Another example. Anyone can stand on an unopened aluminum pop can without crushing it. The pressure inside, caused by the carbonation of the contents, keeps the very thin aluminum walls stable. But, when the same can is empty and at atmospheric pressure, it’s awfully hard for an average adult male to stand on one can without crushing it flat. A structural engineer would say that the walls on the can experienced a structural failure caused by buckling.
Also, when a stage launches, it’s pressurized, which gives it a lot of strength. I’m not sure when for the Falcon 9 first stage, but at some point, the tanks either do, or might, lose their pressurization (possible deliberate venting of the LOX tank after landing).
When it’s on the pad each part of the stage is always supporting whatever is above it. That continues during launch, descent and landing since all of the force continues to be downward through the structure. Your idea has the top of the stage having to support everything beneath it, 1 g at rest and a bit more at the moment when it is snagged, depending on the vertical velocity. Not saying it would be impossible but it would take a structural redesign.
It’s like the difference between standing on your legs and being lifted by your arms.
Is an empty soda can stronger in compression or in tension? I would argue that it is stronger in tension
That is a good point about tension vs. compression. But I think the compression/tension aspect only affects a structural part which is exactly parallel to the force. But there is a lot more going on including parts which are at an angle,such as braces. Also the examples so far don’t take into consideration attachment points.
Let’s say you have an upper and a lower deck in the back of your house. The upper deck is held up by 4×4 posts which are sitting on the lower deck. There are also some angled 4×4 braces between the two decks. It is all plenty sturdy and you can have a party full of people on both decks with no problem. But now remove all of the people, and your grill and any other weight. Now bring in a crane and attach it to a hook that has been placed in the middle of the upper deck and start lifting. Of course the first thing that happens is that the deck board which the hook is attached to immediately starts to pull up from the rest of the deck, because it is held down with just a few dozen screws. So you have to massively secure it, along with several other boards so that the upper deck can be lifted from the central point.
Now you have the upper deck structurally adjusted and you signal the crane operator to start lifting again, but now you have a problem with the lower deck, which is hanging underneath the upper deck by the 4×4 posts and the braces, which are quickly becoming unattached at the top and bottom because the handful of screws that they are attached with are pulling out. So you have to massively attach the 4×4’s to the upper and lower decks with various hardware, like maybe some rods and bolts. Also the 4×4 braces are not working so well either because they were configured at an angle to help support the upper deck, not help left lift the lower deck.
Now comparing a backyard deck to a rocket stage is like comparing a skateboard to a Formula One car, so I don’t consider my example as proving anything, but just an illustration of some of the structural issues that I think would occur.
An opened, empty, soda can in tension may be stronger in theory, depending on how the load is applied. Apply the force evenly distributed around the rolled top of the can and somehow evenly distributed around the bottom of the an and what you say is correct. However, apply the load at the top at a point in the center (keep the bottom load the same for the sake of argument) and the can will not be able to tolerate nearly as high of a tension load without permanently deforming the top (it will bend).
You are proposing a landing system where there will be a single load point in tension (arresting hook) as opposed to the existing design which is optimized to evenly spread the compression load of launch evenly to the upper stage via the outer cylindrical structure. Essentially what you’re proposing would require a new, possibly heavy, structure for the top of the sage to support the tension loads of an arresting hook without deforming the top of the stage.
Sorry BUT these launch vehicles are designed to take the DYNAMIC loads of launch as well as the static loads. The dynamic loads during liftoff (vibration and acoustics) are FAR GREATER than the static loads of placing the booster section in tension under it’s own weight. So I can assure you that the upper structure could take being hung by the top when empty. Would it have enough design margin to survive THE ANALYSIS to show it is worthy of flying again? Maybe not, but I will bet any amount of money that it COULD hang without failing.
And again: The booster section can handle almost 1 MILLION pounds of thrust in compression, but you want to argue it cannot handle less than .5% of that in tension? What do you think the structure is made from a stack of poker chips?
The pressure stabilized ATLAS first stage could not support ITS OWN WEIGHT on the pad without pressurization, but it could survive being suspended under tension
Unrelated and in fact opposite in direction, but I remember hearing more than once many years ago that the LM was always suspended because on Earth it could not support its own weight. I was later told by someone that this was an urban myth. I haven’t heard it repeated in many years so I suppose that was the case. I guess the fact that all of the photos of the LM that we used to see it was always suspended, which probably led to someone jumping to that conclusion.
I would guess that their thinking would be that if their rocket can’t land on a concrete pad then they need to go back to the drawing board.
Edit – I realize you are referring to barge landings which are more tricky, but I still think they would concentrate on solely using the onboard systems to make a controlled landing in a variety of conditions.
Unrelated, but my cousin gave me a tour of the Seahawk helicopter that he flies for the Navy. In the cargo/passenger section in the middle there was an electric winch with a cable going through the floor. I asked him what they used that for, he said if they are landing on a ship in rough weather they can hover about 100 feet up and lower the cable down, someone on deck then hooks the cable onto an attachment on the deck. The pilot maintains hovering thrust and a crewmember in back operates the winch to basically pull the helicopter down onto the deck.
Okay I will be more specific. They are probably going for pure efficiency and minimal fuel so as to not impact payload capacity without crashing all the time.
More millions$ lost. I think they will get it though. The Falcon needs wings. Elon would say: Falcons have wings don’t they? They have their reasons and I wish they would say. I will change flat spin to their retro burn method. A wet delta wing attached to a fuselage. Ship it to the Cape and bolt the wings on. The Shuttle landed this way for years. It is well known how to land with a computer. The Shuttle landed this way and never had a failure of control. If they can’t come up with computer control, put a human pilot in it. Elon has got it all wrong. The falcon it is named for is not a stick. It has wings or lifting body and landing gear. It does not land on its tail. It glides in and does use thrusters at the last minute. He needs to change the name. The next time he is up in his jet, to check this out, go as high as possible, flight idle, and glide back to a landing. Of course if he is coming up short he would give it a burst of power. Same with the Delta Falcon. Hook up the Delta Falcon flight computer to the jet to check it out. Use low fuel and one engine to take off for flight tests. Paul Allen should love this, but he only likes big. Bruno should like it, since the owners of the company he works for, do a lot of aviation. NASA needs an aviation project. They ought to have money in that fund to run a test. I suggest building the airframe, then barter it to SpaceX for engines. NASA has done a lot for SpaceX, maybe they would do that for NASA. SpaceX would own it and do what ever it wanted to do with it.
Just like H2, Musk is adamantly opposed to wings on his rockets. (not saying that is the best decision, just that he is a diva, and made those choices)
You must have more info than I do. I heard him say one time that you don’t have to have wings to land a stage. He did not sound adamant.
When ask about building a SABRE like launcher he replied:
“If you want to get to orbit or beyond, go with pure rockets. It is not like Von Braun and Korolev didn’t know about airplanes and they were really smart dudes.”
Von Braun included a shuttle in his Mars plan. It was written as Apollo matured, 1968 or so.
The Mars plan by a “really smart dude” had a launch date of 1985 or so.
When ISS is splashed and the new launch bubble bursts, Space X is going to crash along with the rest of these rent seeking clowns.
The management nightmare killed Von Braun. Poor guy.
in 1969, Von B, having his launchers sidelined, adopted into his plan the shuttles that NASA was proposing. He was more interested in a Sat V or Nova with an Orion (not the capsule) nuclear explosion propulsion stage, but that was denied.
http://www.astronautix.com/…
http://www.astronautix.com/…
http://www.astronautix.com/…
Of greater interest, and closer to this discussion, is his 1952 plan where he had a fleet of gliders land on Mars.
http://www.astronautix.com/…
Also, the third stage of his launchers were gliders.
http://blogs.houstonpress.c…
BTW, I have no pity for Von B. He bears complicity with the horrors of Dora and Nordhausen.
“Space X is going to crash along with the rest of these rent seeking clowns.”
I assume those clowns are ULA who exist purely parasitically on the taxpayer.
SpaceX will be doing very well without an ISS.
You’re confused. Von Braun’s Mars plan can be had here, though it’s just the kindle version:
http://www.amazon.com/Wernh…
The shuttle was a trans-atmospheric vehcile that would have spurred even more R&D for the country. The launch window that he wanted to make was in 1985.
That is important: with all the lifting power that we had with the VAB and Saturn V, it still was going to take 15 years to get ready to go to Mars. All that time in those days with the resources that they were accustomed to operating with and still 15 years!
The plan is unlike the earlier stuff in that it was integrated into the VAB, mobile launchers and what not. You should get it. Von Braun was supernatural.
I’ve noticed a lot of Von Braun/concentration camp stuff, especially over the last couple years. Too bad. Without him and his guys the U.S. would have been hammered by the Russians.
Maybe @torybruno should use wings instead of his always second place engine recovery idea
The Russian had a scissor with wing idea too??
This has to be one of the most stupid posts in the history of NASA watch.
More millions$ wasted… really?
No money was wasted in this launch – in fact, profit was made. The real problem here is how people view how SpaceX spends their profit. While companies like ULA, Boeing, and Lockmart worry about profit, SpaceX re-invests an obscene amount of their profit back into the company and R&D.
This is why SpaceX has come so far so fast. And this is why the dinosaurs of old space are rapidly becoming extinct.
No doubt. ULA published a paper *years* ago on the ACES upper stage. The engineers *might* finally get the funding to develop this for the second version of Vulcan (NGLS).
I chose my word lost carefully. I did not say wasted.
While the shuttle had an autopilot capable of landing, the pilot-commander always took the controls for the actual landing. IIRC, they took manual control about 20 miles out from the runway.
Correction noted.
The commander would take control as they approached the Heading Alignment Circle. About a quarter of the way around the HAC the pilot took over and flew it for about one quarter, then the commander took over again for the remainder of the HAC turn and for the entire final approach and landing.
In many cases the pilot was on their first spaceflight, and getting a brief chance to fly the ship even if only for a few seconds was helpful since many of them would command their next mission. Those few seconds allowed them to get a feel for the handling compared to the sims and STA. As high-fidelity as those were I’m sure they appreciated getting a few seconds with the real thing.
The Merlin 1D can throttle, down to 40% according to Elon Musk – However, even throttled down its thrust exceeds the weight of the nearly empty stage.
“Almost Lands First Stage”
It Crashed Keith. It’s dead Keith. “Almost” landing by SpaceX should be equivalent to “Almost” XXX by NASA. Both are “failed” XXX. 🙂
“It Crashed Keith. It’s dead Keith.”
That is not how the process works.
This was a partial sucess, right on the edge of nailing it.
They are iterating into a full landing.
First restarting the engines in a supersonic environment, then soft landing in the ocean, then a bullseye on a microsopic platform, but with insufficient control fluid, and now, a near zero vertical speed bullseye landing. That last series of corrections to align left horizontal motion.
Fix that and its nailed.
Certainly impressive, looks like it was coming in quite fast but then rather like a stunt driver parallel parking at high speed it’s all about the accuracy and control, I guess they come in at what they consider the optimum speed giving the greatest stability and control. Pity the video is only of the last few seconds, it would be interesting to see if there were any control issues a few seconds earlier, looks as if it was well aligned initially then seemed to get caught off guard by something and while it was valiantly trying to correct itself it was just a bit too late to get back to exactly vertical and avoid a lateral bounce.
I would not ever want to be standing on that barge.
Just like Elon has said twice now…the chance of a successful landing is 50/50.
Actually , it will always be 50/50…
Just like airplanes, huh.
And yet, at a prelaunch press conference on Sunday, SpaceX Vice President Hans Koenigsmann put the odds of a successful landing at 75 or 80 percent. Guess he should have coordinated with Musk first.
There’s a youtube vid out there now that includes the end game (it’s posted to the SpaceX portion of Facebook, but trying to copy the link gives you a “hey, this is private” error)… poor rocket — it fought tipping over to the end (look at the Reaction Control jet at the head)! My guess is a leg broke.. it was agonizingly slow to tip, fall, and explode.
https://www.youtube.com/wat…
Watching that vid and trying to see though the plume, it does look like the leg makes contact – there’s even a hint of a bounce/slide (hard to tell really, at this scale).
(Edit) It also appears, at a critical moment, the barge rolls a bit. The motion of the rocket seems coupled to the motion of the barge. Visualize a line perpendicular to the barge surface and it looks like the rocket is trying to align itself to that as it comes in. Could it be that whoever wrote the code used a lazy cheat for finding vertical?
Hmm. I wonder if there are any active transponders on the deck sending location data to the rocket, or if the rocket finds the deck like my Enclave finds the garage door (with more accuracy, one supposes).
I have seen mention (uncorroberated) that there was a sticky valve that slowed reaction time. The control system always lagged the position.
This “stiction” apparently is a simple fix. We will know in June.
Not sure if it’s been pointed out before but just noticed in the video a small puff on the RHS of the otherwise quite smooth engine plume just before the stage veers off vertical, anyone know what this is? If it’s some sort of control thruster there seems no need for it to be operating at that point. (Just had another look, it seems to be correcting a slight off vertical situation, did it over compensate?)
Dang, it looks like it came in pretty hot, with the legs not completely extended. Umm… the software does know that the barge deck is a couple of meters above the average sea surface, right? (Just checking. Sillier mistakes have been made before. Ah, now I see the note/rumor about a sluggish valve.)
The worst was when metric and english units were mixed up on a mars probe and it had an unplanned reentry. oops.
I’ll wager that the legs are designed to deploy late, just as they did in the video. It looked as if they were fully extended prior to touchdown.
Well the video wasn’t live, but it seems SpaceX has learned that blowing up rockets while doing REAL rocket Science is good PR!!!! 🙂
Send the next one to land!!!
Jason 3 in July. There is talk that a dry landing may take place at VAFB.
A dry landing would be easier in many ways, not the least of which because the target location is bigger. On land, if you get one leg off the concrete pad, you’re hopefully on gravel or in the grass and won’t topple over. On the barge, if you get one leg off the deck, your stage goes up in a Hollywood style “explosion”.
This is one of the reasons the Space Shuttle landed at Edwards Air Force Base many times before attempting a landing at Kennedy Space Center. Go off the runway at Edwards, and the shuttle is still on dry lake bed, so nothing bad should happen. Go off the runway at KSC, and you might just have “a bad day”.
There should be a barge landing in June.
I agree but where I was going with it is that what seems intuitive to us as safer, which is a slower approach, hover (or close to it if not possible), and lining up vertically above the target at a much higher altitude, may not provide as much additional safety as we think when you are dealing with the incredibly fast reaction times that are possible now with modern software and hardware. Our thinking, understandably, is probably influenced by over a hundred years of human controlled landings of aircraft and helicopters.
Of course there are automated airplane landing systems, however they tend to mimic what a human pilot would do during landing, not necessarily because it is more efficient but because they have to stay within existing ATC conventions, and they also have to consider the comfort of the passengers (and also their seat upholstery cleaning costs). A long time ago I heard of a study by FAA (I think) where they found it was more efficient for an airliner to delay descent until it was close to the airport, then idle the engines and make a very steep descent. And counter to common belief they found that it was quite safe and they felt that any qualified airline pilot would be able to do it. But they realized that the idea was not practical because passengers would not like the feeling of dropping out of the sky, and also the fast pressure change would be uncomfortable. And again the upholstery cleaning costs.
So while a lot of people (including me) are initially shocked seeing the Falcon stage come down that fast and maneuver that abruptly, likely the SpaceX engineers are looking at it only from the software/hardware point of view and are proving that things can move much quicker than was previously possible.
New video out. The nose does not move. The engine must not shut down and it is still trying to hit the X. It was hovering or on the deck, but the engine pushed the bottom out of plumb. The computer really messed up. Over control. They have a lot of fixing to do. The gear was out. This is good video. I could not get that vine thing to work very well.
They may not have a “lot of fixing to do”. The thought is that a throttle valve was sticky, causing the engines to be slightly out of sync with the control system. This made the control system keep overshooting while trying to correct for the lag.
It is quite likely a simple direct single point hardware fix.
Not hardly. A software problem. It was more than slightly. It tilted and the engine shut down. That has nothing to do with lag. Why the engine was shut down at that point, SpaceX will have to tell us that. It should have moved over and then moved the nozzle to get back to vertical, then shut down the engine. If it had shut down the engine while it was vertical, even though GPS was saying it was not on the X, it would have landed. Not out of fuel, since there were flames. Also the the person said the stricture valve was a tweet. I did not see it there. It may be very easy. Just rewrite the software. Still a lot of work. Timing is critical. Hopefully SpaceX will confirm, if not then I am wrong. Balance a broomstick and you can see how it works.
The software was responding (properly) to the location, speed and attitude of the rocket. The proble was (maybe) that a hardware component did not do what the software asked, so the software tried to correct, yet in the meantime the slow valve answered the last control request, not the new one.
As Aviation Week described it:
SpaceX founder and chief technology officer Elon Musk tweeted that “excess lateral velocity caused it [the booster] to tip over post landing.” In a later tweet that was subsequently withdrawn, Musk then indicated that “the issue was stiction in the biprop throttle valve, resulting in control system phase lag.” In this statement, Musk was referring to “stiction” — or static friction — in the valve controlling the throttling of the engine. The friction appears to have momentarily slowed the response of the engine, causing the control system to command more of an extreme reaction from the propulsion system than was required. As a result, the control system entered a form of hysteresis, a condition in which the control response lags behind changes in the effect causing it.
In a manned aircraft this situation is called “pilot induced oscillation”. It is most definitely not good.
In Arthur C. Clarke’s novelette, “A Meeting With Medusa”, something similar occurs.
During the maiden voyage of a gigantic dirigible, a remotely guided news channel video drone swings close to the airship. Getting caught in a wind gust, the remote pilot corrects for the wind. Unfortunately, the signal going up and down from geosync comm satellite and then back the other way to the drone has an inevitable lag. What the driver sees and what the drone receives is always out-of-date. He keeps correcting but it just causes the drone to go further and further out of control. It crashes into the airship and brings it down. (not really a spoiler – that is just the prolog)
Just curious: why isn’t SpaceX considering using the landing legs in concert with the grid fins to create residual drag prior to the terminal burn? I seems to me that they could use those big paddle-like structures as rudders for directional control and to lessen the fuel required for landing. That might require another control and feedback loop, but could they not slave that to the grid fins? They would probably have to offset the fins and the legs for better aerodynamic response, but wouldn’t that give them slightly better control on the vertical axis, and make the RCS thrusters slightly more effective in heavy air as well?
The Barge landing site should have an electric Magnetic deck that has enough power to hold the rocket down instead of having men weld shoes over the landing feet. How much power would they need to generate to do this? And how heavy/much steel would the feet need to weigh???
Space should have 5 legs not 4!!!
They need to have LEG OUT capitablity!! 🙂
How much is a reusable booster worth?? Thirty plus million to make new. Both worth more if making many flights.
I think weight of added leg well worth the price.
This very discussion has been had many times over (e.g. on the sci.space Usenet Newsgroup when DC-XA toppled over, cracked open, and burned. This is an engineering trade-off. Three is obviously the minimum, but there is no redundancy. Four may or may not offer redundancy, depending on the details of the design. Five does offer some redundancy, but depends on the details. If you have five, but come down at an angle and break one leg, it might still topple over, depending on where the CG is located, the geometry of the legs, how far over the vehicle is leaning, and etc.