Blue Origin Thread (merged)

[StrandedonEarth]

Ran out of hydraulic fluid? What was there a leak maybe? Hydraulic fluid isn't consumed.

From the Twitter feed linked above:

Chris (Robotbeat) â€Â@Robotbeat 31m31 minutes ago

@dtarsgeorge @rocketrepreneur In aerospace, hydraulics are pressurized with gas (no pump) and no return lines. Pretty standard, actually.

Sort of surprising, I thought they would have used some sort of electro-mechanical actuators. Hydraulics is probably lighter/faster/stronger. Maybe they'll switch in the long run: No consumables and less/no pollution from the grid-fin system..

Edit: Also wondering if that had anything to do with the hard landing, TVC trying to compensate after the fins stopped working?

Edited January 10, 2015 by StrandedonEarth

[Motokid600]

So the fins ran out of hydraulic pressure not so much fluid. Well I guess the idea is the fins only need to work a short amount of time. So having a more complex ( heavier ) recycled hydraulic like you see on anything else is pointless.

Edited January 10, 2015 by Motokid600

[Streetwind]

Hydraulics are exceptionally reliable, which is always a good reason to use them in a rocket. And there's probably a limited amount of electricity available to the first stage - we don't know if the Merlin engines (also a deliberately simple design) can even generate any. The first stage already needs to run a double-redundant copy of the entire rocket avionics and flight control that's usually housed in the second stage, and it probably has to do so from battery power alone.

As for the grid fins being the culprit of the bad landing, I don't think that's the case. Elon simply wanted to share a little extra info, and as you know, Twitter only lets you put down a few words each post.

The fins do not have the job to slow down he rocket, but rather to steer it. As the rocket hit the barge as intended, the steering presumably went largely right. Even with more fluid, the fins wouldn't have prevented the hard landing.

What most likely killed it was wave motion. Since the stage cannot hover (it cannot throttle down far enough to reach a TWR of 1 even with only a single engine), it needs to do a suicide burn and then kill its engine, and for that, you need to know exactly where the landing surface is. Unfortunately, even though the drone barge is able to hold its horizontal position fixed pretty precisely, it will still constantly rise and fall with the waves. So where do they aim the suicide burn? At the top of a wave, which would cause the rocket to drop down if the barge is lower than that? At the bottom of a wave, which will cause the rocket to hit the deck hard if the barge is higher than that? At the middle, where it is correct twice as often but also wrong twice as often? And not to forget, each wave is different, and overall wave intensity can change by the minute!

So depending on how the landing burn was set, and the sea conditions at the time, the most likely course of events probably involved the barge simply being higher up than the rocket expected. And possibly even meeting the rocket while still in an upwards motion, causing the two to slam together with more force than the landing system is designed to cushion. And maybe it wasn't 100% vertical yet either, which gives the "landing on a slope" effect - whichever leg hits the surface first, causes the entire craft to fall over in the opposite direction.

[Firov]

So depending on how the landing burn was set, and the sea conditions at the time, the most likely course of events probably involved the barge simply being higher up than the rocket expected. And possibly even meeting the rocket while still in an upwards motion, causing the two to slam together with more force than the landing system is designed to cushion. And maybe it wasn't 100% vertical yet either, which gives the "landing on a slope" effect - whichever leg hits the surface first, causes the entire craft to fall over in the opposite direction.

This seems like a reasonable explanation, and is one of the problems with attempting to land at sea.

Though it seems they could get around this issue by installing a hydraulic lift system on the barge which, when combined with gyros and wave action sensors, could effectively prevent the barge's vertical movement, both rotation and translation, from affecting the landing pad. There would be limitations to the maximum sea state they system could compensate for, of course, but I doubt they would attempt a landing in extremely heavy seas anyway.

[Guest]

It's don't matter. Barge is temporary solution, it's only purpose is to be hit by the rocket in the X spot.

I think, if SpaceX can repeat that again, next landing will be on land, and land is not moving anywhere, unless there is an earthquake or you are exceptionally drunk.

[Motokid600]

Honestly it sounds like it would've just been easier to fly it back to land as its intended in the future.

[Firov]

It's don't matter. Barge is temporary solution, it's only purpose is to be hit by the rocket in the X spot.

I think, if SpaceX can repeat that again, next landing will be on land, and land is not moving anywhere, unless there is an earthquake or you are exceptionally drunk.

True, the barge is only a temporary solution for the Falcon 9R, but with the Falcon9R Heavy, they're going to have to retrieve the first stage core on a barge, as they're doing here, because it's going to be too far down range to effectively fly back to land. Also, while the plan was never to recover/reuse the earlier first stages that landed in the sea, they are absolutely trying to retrieve the ones that set down on the barge, and possibly even reuse them as a proof of concept.

[Motokid600]

... There HAD to be atleast one camera on that barge, right?

[PakledHostage]

Though it seems they could get around this issue by installing a hydraulic lift system on the barge which, when combined with gyros and wave action sensors, could effectively prevent the barge's vertical movement, both rotation and translation, from affecting the landing pad.

This is a good idea but you'd have to consider the stability of the barge. The hydraulically actuated platform would be very heavy. Heavy structure mounted high above the centre of buoyancy is desabalizing. Especially if it is moving around. That doesn't mean you can't do it, but it may be cost prohibitive to design around it.

[Streetwind]

... There HAD to be atleast one camera on that barge, right?

The barge is studded with cameras all over.

However, SpaceX does not generally release footage of failures. It was even announced beforehand that in case of success, they'd attempt to show a replay in the stream, but in case of failure, there would be no release.

SpaceX has also never released footage of the F9R-Dev1 destruction. We only have footage of that because fans were camping McGregor and recorded it happening. There has also been one additional flight of F9R-Dev1 about which there is absolutely nothing known. It happened a couple months before the loss of the vehicle. No footage (official or inofficial) exists, nor any word as to what happened.

No footage exists from the first of the first stage return attempts, during which they discovered that the RCS system was undersized for the task and the stage spun up, centrifuging the fuel up the tank walls and starving the engine. However, there is video footage for all following attempts, since they were all successful.

Furthermore, almost all recordings (including the official SpaceX one) of Falcon 9 Flight 5, which had the engine loss event, are edited to remove that particular part of the recording, jumping ahead several dozen seconds instead. You can still see it in unofficial recordings of the launch, though.

The only official footage of failures that can be found directly from SpaceX are the second and third Falcon 1 flights, which happened ages ago. (The first also failed, but SpaceX has no video on it.)

So yeah, expect no video of this. SpaceX stopped publicizing failures years ago. Apparently Elon does not subscribe to "any publicity is good publicity". He wants to advertise with successes only.

Edited January 10, 2015 by Streetwind

[Pixel of Life]

This is a good idea but you'd have to consider the stability of the barge. The hydraulically actuated platform would be very heavy. Heavy structure mounted high above the centre of buoyancy is desabalizing. Especially if it is moving around. That doesn't mean you can't do it, but it may be cost prohibitive to design around it.

Another option would be buying or renting a semi-submersible offshore platform. They're very stable but can also be moved if need be, which would make them an ideal place for landing a rocket. I have no idea how much these things cost, but after some googling, I'd estimate they could probably find a used one for less than $100M if they're lucky.

[Motokid600]

-

I see. Thats an interesting way to go about it I suppose. And it is a private company, so..

[merendel]

I can see why they wouldnt post video of the crash on the deck of the barge. While the folks at this community would see even that crash as a very successful attempt we are also much more knowledgeable on this subject than the general population. While we are thinking "OMG they just flew that rocket through the eye of a needle from hundreds of KM away and just bairly missed sticking the landing. so close, they'll nail it next time" the rest of the uneducated masses will see "OMG that rocket just crashed into that boat and they want to try that on land? Not anywhere near me they dont." Sadly the panicked masses calling their representitives could cause much more problems for the company than the additional publicity would be worth unless the crash was particularly tame (aka landing almost stuck but the rocket toppled over after touchdown but no boom)

Personally after proving they can hit such a tiny mark as that I have no reservations about them attempting that over land. Keep it to unpopulated areas just for safety of course but that was an extremely precise landing and I have no doubt they can repeat it.

[Nuke]

Another option would be buying or renting a semi-submersible offshore platform. They're very stable but can also be moved if need be, which would make them an ideal place for landing a rocket. I have no idea how much these things cost, but after some googling, I'd estimate they could probably find a used one for less than $100M if they're lucky.

yea there are other ways to have a stable landing platform at sea. oil platforms are capable of this. there is also that flip research boat that is supposedly extremely stable (though not large enough to land a rocket on its tail end). even a catamaran vessel would work well here, we have a few catamaran ferries here that are rock solid even in rough seas. a barge is probibly the worst thing you can use for this. but finding an old decommissioned oil platform and retrofitting it with a landing pad, might be both cheap and effective.

[FITorion]

So far as I've seen thus far... my video seems to be the only one that has the re-ignition of the first stage.

There has got to be other people with video of... Sure the launch was in the middle of the night... but there has got to be people who were at the launch that got video... I can't believe that I'm the only one. They have to have just not shared it yet... But why don't any of the professional news people have any video?

[Dkmdlb]

Have we seen anything official on the habitat? Is it a centrifuge? Inflatable?

Yet another victim of NASA/the media's misleading/dishonest marketing of Orion as the spaceship that will take people to Mars.

[Bill Phil]

Orion, at most, will be the craft that people take to GET to the craft that goes to Mars. Although an improved Dragon capsule might be preferable.

[B787_300]

From a Source I have... They have video from the barge. They will probably only release parts of it (most certainly not the entire thing)

Also I wonder why they went with a open hydraulic system instead of using electric actuators

[merendel]

From a Source I have... They have video from the barge. They will probably only release parts of it (most certainly not the entire thing)

Also I wonder why they went with a open hydraulic system instead of using electric actuators

Simplicity and weight most likely. Electric actuators require power and they have a finite energy budget to run everything. To add more power they'd need more batteries which are heavy. Closed loop hydrolics are reliable but also heavy as you need pumps (more energy budget as well) to move the stuff and are often sensitive to extreme temperature shifts. A once through hydraulic system, most likely a pressurized gas is comparatively lightweight and scaling it up for more capacity probably requires less than the other options.

So in the end they had the choice of a finite electrical control, a liquid hydraulic control also finite due to electrical needs, or a finite once through hydraulic control. they probably chose the one that was the lightest and least likely to break down for the application.

[Guest]

Orion is craft that can get people off the craft that carry them from Mars. Dragon II do not have adequate heat shield for this.

P.S.

Also, Orion can serve as command post of bigger interplanetary ship.

Just a few pessimistic thoughts:

In reality, I think it will be no manned interplanetary ships at all. Moon landing was just a political show. Humans were put to risk for no valid reason. With advances in AI and remote control, manned interplanetary missions becoming more and more meaningless, before they ever happen. It is a curiosity of the few and political show of the many, but nowadays no one is willing to pay for such a show, especially if someone dies in process.

Yes, I understand, it's very unpopular opinion on this forum, but today I feel especially pessimistic and depressive, so I decided to spill it.

Edited January 11, 2015 by Guest

[RocketPilot573]

I can see why they wouldnt post video of the crash on the deck of the barge. While the folks at this community would see even that crash as a very successful attempt we are also much more knowledgeable on this subject than the general population. While we are thinking "OMG they just flew that rocket through the eye of a needle from hundreds of KM away and just bairly missed sticking the landing. so close, they'll nail it next time" the rest of the uneducated masses will see "OMG that rocket just crashed into that boat and they want to try that on land? Not anywhere near me they dont." Sadly the panicked masses calling their representitives could cause much more problems for the company than the additional publicity would be worth unless the crash was particularly tame (aka landing almost stuck but the rocket toppled over after touchdown but no boom)

Personally after proving they can hit such a tiny mark as that I have no reservations about them attempting that over land. Keep it to unpopulated areas just for safety of course but that was an extremely precise landing and I have no doubt they can repeat it.

This is what I was thinking, this isn't a failure, this is a partial success.

[GigaG]

I wonder if we'll get any still pics of the aftermath even without any video.

But nice job, SpaceX, for getting another spacecraft into orbit successfully and getting the landing target right! And if the hydraulic fluid is truly the problem, they said that they put more in the next one.

By the way, they said that grid fin hydraulic fluid ran out. Aren't grid fins just stationary? What would running out of fluid do? Did they retract early upon losing pressure?

Also, will the DSCOVR mission try a barge landing?

[Leszek]

I wonder if we'll get any still pics of the aftermath even without any video.

But nice job, SpaceX, for getting another spacecraft into orbit successfully and getting the landing target right! And if the hydraulic fluid is truly the problem, they said that they put more in the next one.

By the way, they said that grid fin hydraulic fluid ran out. Aren't grid fins just stationary? What would running out of fluid do? Did they retract early upon losing pressure?

Also, will the DSCOVR mission try a barge landing?

According to the youtube video the fins rotate to help steer the craft.

Incidentally while I was looking for this video I found another. There has been some discussion here about how they keep the barge stable with mostly guesses on how they do it. I found this video stating they use thrusters.

https://www.youtube.com/watch?v=ekJcUBKv50Y

Edited January 11, 2015 by Leszek

[MaverickSawyer]

No, the grid fins are steerable, and help with attitude control in the lower atmosphere. As for running out of fluid, that means that they would no longer be steerable, causing the booster to lose control and miss the targeted point.

[Leszek]

No, the grid fins are steerable, and help with attitude control in the lower atmosphere. As for running out of fluid, that means that they would no longer be steerable, causing the booster to lose control and miss the targeted point.

I wonder if they are fail safe such that they return to neutral position if something goes wrong with the hydraulics. Say if they are spring loaded. They would then be able to help keep the stage stable and perhaps give the engines a chance to save the ship yet.