The Falcon 9 first stage almost landing

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I can’t resist. I have to post that video here of the Falcon 9 first stage landing and then falling over from Sunday. You can see it below the fold. It is incredibly impressive, because it shows that the stage actually did succeed in landing, though a failure of some kind afterward caused it to tip over. The company says it was the failure of one landing leg, but if you watch the video you can see that the angle of fall is between two legs, which suggests that the cause was more complicated.

Nonetheless, don’t be surprised if by the end of 2016 SpaceX is successfully landing its first stages on every launch.


  • pzatchok

    If you watch the horizon before, during, and after the landing you will see how much the platform is pitching and rolling.

    They tried to land the thing in very rough seas.

    Even if everything went perfect it stood a very good chance of falling over after landing and before they could get on board to secure it down.

    Even during the telecast they didn’t seem to sure it would land and stay intact. They even mentioned the rough seas a few times.

  • BSJ

    How do you see it falling between two legs?

    It falls and lands directly on top of the leg that failed. The ram just collapses straight into itself and the leg folds back up into the stowed position. A side load would have bent the ram one way or the other.

    Between two leg would have also sent it directly at the camera.

    I still don’t think they’ll ever be able to land on such a small barge. Outside of dead flat ocean conditions…

  • Nick P

    To me this was a successful landing. The subsequent failure of the leg does not deter from the accomplishment.

    Why land at sea in the first place? Are they prohibited from a land landing?

  • pzatchok

    The option of landing at sea gives them the option of launching with more payload and less fuel to return.

    The next step up the payload scale is even more payload and less fuel but no chance at recovery.

  • Gealon

    I second Nick P’s comment, this landing was a success. Just because of a mechanical fault a few moments after the landing tipped the stage over does not detract from the fact that it touched down. Had the leg properly locked, the stage should have remained upright and we would instead be waiting to hear about the fluctuations of engine number 9 rather then discussing whether the landing was a landing or not.

  • Edward

    I always wondered why SpaceX chose a four leg system rather than three or five. With four legs, if one fails, then the rocket tips over, as happened to McDonnel Douglas’s Delta Clipper.

    With five legs, there is redundancy should one of them fail, but if you think you don’t need the redundancy, then three legs would save weight over the four-leg system.

    The rocking and rolling of the deck may be a factor in causing instability and leg-failure. A year or so ago, one commenter on this site said that the single Merlin engine that is lit has a minimum thrust that is greater than the weight of the Falcon 9 at landing, so the rocket has only one shot at landing and cannot hover to wait for a good opportunity to set down. I once suggested that the Falcon may see the barge as a rolling and rocking target and linked to this video. This helicopter, however, has the ability to hover until there is an opportunity for a safe landing.

    Even if the rocket successfully lands, one bad wave could toss it overboard. The good news is that the center of mass is likely low on the body of the rocket, due to the weight of the engines and ulage — leftover propellants — being at the bottom of the tanks.

    In a previous post, pzatchok suggested using an oil-rig platform. This is what Sea Launch does to launch rockets. I suspect that if SpaceX’s barges do not work out then a platform may be necessary. Maybe Sea Launch would be willing to rent out their platform.

    Nick P,
    Returning to land is sometimes an option. They did it in December with a launch from Florida. However, the launch of Jason-3 was from Vandenberg, which may not (or may) have a spare pad (obstruction-free) for SpaceX to use to land a returning rocket.

    On December 23, Robert linked to this article, which gives a profile of a returning Falcon 9. The three burns to return and land are shown in orange:

    Depending upon the payload weight, SpaceX has the fuel to return to land with rockets launching payloads into low Earth orbit, at least up to 200 miles, where the ISS is, but they cannot return to land when launching to the very popular geostationary orbit (many people call it geosynchronous orbit); the rocket needs virtually all of its fuel and oxidizer to get the payload to that orbit and does not have enough left over to return to land. However, Jason-3 is in an orbit 830 miles high, which may (or may not) be too high for Falcon to return, at least when launched from Vandenberg.

    I think that no matter the size or capacity of the rocket, there will always be times when the rocket will push its abilities, such as payloads being too heavy or going too high for some SpaceX rockets to return to land. Thus, landing at sea will be a good skill for SpaceX’s rockets, present and future.


    To use a gymnastic phrase, I do not think that Falcon 9 stuck the landing. The mechanical failure means either that the design needs improvement, that they have manufacturing problems to solve, or that SpaceX is learning the limits of ocean conditions for a successful landing. I hope that a future announcement from SpaceX will tell us which it is.

  • Wodun

    I saw two reasons from SpaceX on Twitter for the barge landing. One, was the performance limitation as other commenters have explained, which may or may not be true. Two, was they didn’t get cleared in time on environmental impact.

    Another unstated reason saw on another blog is that this was the last of their old cores so ey could use it for a riskier landing.

    Pretty amazing they stuck the landing in rough seas. Looks like they are moving onto the next challenge of finding out how robust their design is for reuse and what changes need to be made.

  • Nick P


    “To use a gymnastic phrase, I do not think that Falcon 9 stuck the landing”

    Perhaps but to extend the metaphor, the triple twist and multiple somersaults were only slightly marred by the slight hop at the end. Getting to and successfully setting down on the pad was 99.9% of the vault.

  • mpthompson

    Is there a decommissioned aircraft carrier that could be used for landings? Really big and probably more stable than the barge. Perhaps the Big E could be pulled from mothballs. Of course, a tug towed barge is much cheaper…

  • Dick Eagleson

    Don’t make too much of the “rough” seas. The fact that the ends of the vessel were bobbing up and down quite a bit doesn’t mean the geometric center of the deck – where that big ‘X’ aim point is – were doing likewise. Ship motion on any axis will be at maximum on the ship’s perimeter and at a minimum in the center of the deck. Even in 15-foot seas, the center of that big ‘X’ might not have been moving around much more than LZ-1 was on Dec. 21. The landing looked pretty good until the tip-over started. If no additional miscellaneous gremlins put in an appearance on the SES-9 mission, I think the odds are extremely good that SpaceX will finally have a stuck landing afloat.

  • Very cool that we’re discussing the finer points of recovering a first stage, rather than whether it’s possible at all.

  • Edward

    Dick Eagleson wrote: “The fact that the ends of the vessel were bobbing up and down quite a bit doesn’t mean the geometric center of the deck – where that big ‘X’ aim point is – were doing likewise.”

    I do not think that the Falcon was “tossed” onto its side, but a change in the deck’s angle could possibly over stress one of the legs. Consider the possibility of the bobbing up and down of the barge’s center, which could add to the stresses.

    It looks to me like an overstress event on the leg. It is possible that a manufacturing flaw left one leg weaker than designed, but I think it is more likely that the designers did not anticipate that the landing pad would be moving quite so much, if only in three axes.

    Nick P wrote: “only slightly marred by the slight hop at the end.”

    That was not just a little hop at the end; it fell over. The result is the same as the first two barge attempts: unusable components. Although I acknowledge the improvements over time, and I score the flight and “pinpoint” precision high, I also have to score this landing low despite the good “posture” at touchdown.

    Blair Ivey is correct. We already know that the “pilot” can land safely, he just has to successfully land on the bobbing, heaving, rolling carrier. That is a bit more tricky.

    As for the test of the engines from the successful December landing, we now know that the expensive engines can be reused, whether or not the structure of the Falcon can be reflown. This is a significant advancement in the space age.

  • I need to get a message to Elon Musk. I have seen two of his rockets return flawlessly to earth only to be destroyed by falling over. My message is this: Elon you don’t need a better rocket all you need is something to catch it after it lands. For example some sort of mobile robot able to rove the barge that has the smarts to figure out exactly where the rocket is going to land. During the landing it moves to that spot and grapples the rocket before it can fall. It might even be possible to grab the rocket in flight as it hovers above the deck and eliminate the need for a landing gear altogether. I’m only suggesting this because I hope to place a bid to design such a robot, but something as simple as a softer surface to fall on or some netting might be sufficient.

  • Edward

    I forgot to point out that a stuck landing is one that has no hop. The gymnast lands balanced and hop-free (and topple-over free).

  • Steve

    I thought they had announced very quickly that the cause was a latch on the leg that folded failed to lock in place?

    And that it most likely happened because of icier than expected conditions….

    I liked the idea someone on here mentioned previously of swinging padded arms that quickly rotate into place and are able to catch the rocket before it hits the deck.

  • Yuriy Balabukh

    Provide a Stable landing missiles with such a construction and the landing method impossible.
    Unfortunately, engineers spend a lot of time to stabilize the landing. The desired result will not be achieved.
    There is a solution of this problem but to find it necessary to think unconventionally.
    Not everyone can be a poet even though everyone knows the language and not all engineers are inventors.

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