SpaceX Looking For Help With "Landing" Video 110
Maddog Batty (112434) writes "SpaceX recently made the news by managing to soft land at sea the first stage of rocket used to launch its third supply mission to the International Space Station. Telemetry reported that it was able to hover for eight seconds above the sea before running out of fuel and falling horizontal. Unfortunately, due to stormy weather at the time, their support ship wasn't able to get to the "landing" spot at the time and the first stage wasn't recovered and is likely now on the sea bed. Video of the landing was produced and transmitted to an aeroplane but unfortunately it is rather corrupted. SpaceX have attempted to improve it but it isn't much better. They are now looking for help to improve it further."
Something Awful (Score:2)
I smell a Photoshop Friday theme...
Watching that video on YouTube, it'd be tough to clean up or reconstruct - there's a lot of information missing.
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There's a lot of information missing to be sure, but it's still worth pointing out that SpaceX posted the raw transport stream data [spacex.com] that they got from the rocket, so reconstruction can be done on the raw data rather than YouTube.
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Neat (Score:5, Insightful)
I appreciate them looking for public help. It's a gesture of trust and openness usually not seen from either goverment or private corporations.
Though I suspect most the the video is beyond salvage.
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you mean vertically? (Score:1)
how does something fall horizontally? some strange gravity out there.
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In this case "fall horizontal" means "fall into a horizontal position". Not "fall horizontally".
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a satellite in orbit is constantly falling. horizontally.
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Absolutely not. There is still significant gravity in space - it falls by inverse-square law, after all. In LEO the force of gravity is practically undiminished. For a "long" structure you'll soon find out that vertical does exist, because that's the way the long axis of that structure will be oriented. Look up "gravity gradient stabilization".
Of course that discribes the axis toward/away from the Earth. I don't know if there is any preferred direction beyond that, but it would surprise me if extended
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The ends of an extended object stretching perpendicular to it's orbital direction (port/starboard) will feel a force towards the centre of the object.
NSEW have the same meaning in LEO as they do on the surface.
reconstruction via telemetry (Score:1)
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Did you already inspect the MPEG bitstream they provided to see what data it does and doesn't look like it might contain?
I did. By watching the video. It's busted beyond repair. There isn't a single worthwhile I-frame. No amount of data outside the I-frames can be used to reconstruct anything.
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But did you reverse the polarity of the tachyon beam?
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use a 3d rendering program to reconstruct the iframe as it would be near enough, using imagination too, and guesses.
Replay the BPs and again guess whats missing.
Re:reconstruction via telemetry (Score:4, Informative)
partially fixed clip has at least one iframe showing that camera was mounted on top of the fuselage looking down, camera was stationary = all iframes had to see same fuselage
this one iframe could be copied over all the broken ones to see if there is any useful data in the rest of the file
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More than that, you've got good quality imagery from that same camera from the launch, and a significant portion of the frame there is going to be the same. Notably, of the two iframes that SpaceX was able to partiall recover, the big chunk missing from one of them is of the fuselage (which would be the very similar on launch).
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Notably, since the fuselage is expected to look more-or-less the same throughout, superimposing a static image of it is rather useless.
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not really, it will validate if the pframe data is there, it will also show what parts of original iframes were damaged, and what type of damage you are dealing with (random garbage, bit flips, shift)
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More than that, you've got good quality imagery from that same camera from the launch,
Do they? I thought I read in the reddit thread that the launch video was actually from a second stage camera.
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I haven't seen that, so I can't comment on that, but SpaceX would presumably have the raw feed from every camera during launch. If they don't, then their video director would have to be switching blindly between cameras during launch.
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That's not repairing the video, that's creating a separate animation.
They don't want an animation of what it probably would have looked like - they did all that shit before the launch.
They want an actual video of what it actually looked like. They can't get that with the data they have.
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Much Wrong Here. (Score:1)
Well, it was Raw until YouTube re-compressed the hell out of it. Seriously, I don't think you have any shot if you start off with this YouTube footage. If they really want help we need the actual raw bitstream. I/Q output from the receiver would be even better. Even better than that would be diversity receivers. Aren't those guys the rocket scientists?
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Yes, but not video experts.
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There's raw data in one of the links above. Some .ts format.
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There is no such thing as MPEG4 transport stream.
Transport stream is MPEG2. Its contents can be MPEG4, MPEG4 AVC, H265 or anything else.
Re:Much Wrong Here. (Score:5, Informative)
It still is raw. If you follow the link in the summary "looking for help" http://www.spacex.com/news/201... [spacex.com] it takes you to their page where they show you the before and after videos via youtube and give you access to the raw footage. Here's the link they provide to the raw footage: http://www.spacex.com/sites/sp... [spacex.com]
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It really doesn't in this case. It's clearly busted beyond repair. The raw stream does not have any damned I-frames that are salvageable, and the Youtube version accurately represents this fact.
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True, but we have out of band information. We know the video is shot continuously (no cuts between different camera angles or cuts in time), so the image data should be linear (as in not suddenly turning into another color or luminance value). We also know that it depicts one scene, so there is a strong covariance between the macroblocks.
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Re:Much Wrong Here. (Score:4, Informative)
Well, it was Raw until YouTube re-compressed the hell out of it. Seriously, I don't think you have any shot if you start off with this YouTube footage. If they really want help we need the actual raw bitstream. I/Q output from the receiver would be even better. Even better than that would be diversity receivers. Aren't those guys the rocket scientists?
Available for download: This is the location for the original raw ".ts" file [spacex.com]. A second link is also given to a repaired raw ".ts" file [spacex.com] showing the results of their efforts. If preferred, you can also get the original ".ts" files at the spacex [spacex.com] website near the bottom of that webpage.
A 2nd backup camera? (Score:2)
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The other cameras were on the recovery ship, which couldn't reach the recovery area without, you know, sinking. They'd have ended up roughly where the master recording currently is, resting on the ocean floor.
The problem isn't the camera, it's that the data was garbled during transmission. In part because both the source and destination locations were in constant (and, given the storm, quite random) motion. It's hard to hit the side of the barn when you're aiming from mid-air in the center of a tornado.
That
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Stronger signals take bigger transmitters with higher power consumption. They don't normally require such a signal: for launch (and eventual solid-ground landings) they have line of sight with big receivers, and when they actually recover a stage, they'll be able to get recordings. The splashdown was below the horizon from the launch site, and the video signal was picked up from a chase plane. To top it all off, weather was lousy and deteriorating fast.
They'll have a lot more launches and landings, another
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Stronger signals take bigger transmitters with higher power consumption.
Its a fucking rocket dude, the cost of a high power transmitter that doesn't use fucking mpeg or any compression is an unnoticeable drop in the bucket. Hell, 20 of them wouldn't be a noticeable dent in the budget compared to the fuel it burned holding for 8 seconds.
Its fucking retarded that this is what they have to work with.
Re:A 2nd backup camera? (Score:4, Informative)
There's not a lot of equipment that's flight rated for the kinds of vibration, temperature and pressure swings required by an external rocket, not to mention power source transmitter and antenna(s). Oh, and it can't interfere with the landing telemetry in any way.
Re:A 2nd backup camera? (Score:4, Informative)
You *do* realize the power output of a rocket engine isn't electrical, right?
In reality, spacecraft have strictly limited power budgets. The booster's electronics are running off battery power from the moment the umbilicals disconnect. It also flew above the bulk of the atmosphere, so you can't exactly rely on air cooling to keep the transmitter from frying itself...and there's plenty of other power-consuming, heat-producing electronics that have rather more important functions. And a more powerful transmitter would be completely unnecessary for the solid-ground landings, which SpaceX hopes to start by the end of the year.
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Redundant systems are only for taxpayer funded projects. Commercial systems save pennies without them, adding dollars to executive bonuses.
It's down there somewhere. (Score:2)
Lemme take another look.
They're not going to get better results... (Score:5, Interesting)
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Terrestrial broadcast HDTV in the US uses 8VSB [wikipedia.org] encoding:
Re:They're not going to get better results... (Score:5, Insightful)
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You're thinking like a scientist or a researcher, not like a businessman. Which system is cheaper? That's going to be the main criteria for something like SpaceX. How likely is it that we will ever need better data, and if we have better data will it actually make us more money? Privatization of space operations is all well and good, as long as everyone keeps in mind their rather strict limitation: the need to make money all the time no matter what.
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I think you are living in the past.
And thats why you (and if SpaceX didn't record it, them to) will fail. Kids who think like you are the reason SpaceX is asking for outside help.
I'm fairly certain you don't understand how these things actually work.
And NASA most certainly would disagree with you as well. As do I, none of my video transmitters on my aircraft are digital. Even my telemetry radios can record the analog stream, though I don't do it.
You most certainly CAN filter the analog stream to create a cleaner signal to the digital stag
Re:They're not going to get better results... (Score:5, Funny)
I was a "rocket scientist". In fact, I worked for NASA at JPL. It's a modest little place in Pasadena, California. I doubt that you heard of it.
I also worked on MEG-4 decoding software, so I know something about digital video streams.
As for being a "kid", thanks for the complement. I know I look young for my age. I wrote my first program in 1968 on punch cards for an IBM 360. In PL/1.
Now I'm going to say it again more slowly:
The. Video. Stream. Was. Not. From. The. Rocket.
It. Was. From. An. Aircraft. Sent. Out. To. View. The. Splashdown.
It. Was. Not. A. Telemetry. Data. Stream.
Since. It. Was. Not. Telemetry. It. Was. Not. Recorded. In. Analog. Form.
The. Camera. System. Was. Not. Spacecraft. Grade.
It. Was. An. Off. The. Shelf. Piece. Of. Equipment.
I hope that this makes sense to you. I know it's Slashdot, so a lack of real applicable technical expertise is the way to get modded up. Unfortunately for me, I have this problem with facts: I try to stay factual, so I often get modded down. For some reason I still keep trying. I think it's a personality flaw.
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I'm no rocket scientist, but i can read... The SpaceX page clearly says "[this is video] recovered from the Falcon 9 onboard camera", so what's all this nonsense about the stream being from some airplane? Also in some of the final frames of the improved video you can clearly see that it's a camera mounted on the top of the rocket looking down at the fins, seeing smoke and flame from the engines.
I really believe that you know what you're talking about, but I think in your haste you might have missed some r
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Of the shelf piece of equipment....
GoPro?
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So if the camera was on the aircraft how did it get corrupted?
I thought that the camera was on the booster and the aircraft was there to receive data from the landing attempt. I can see that since it was probably not in LOS to any piece of land and sending the data to an aircraft would be simpler and probably cheaper than sending it to a satellite.
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Has no Slashdotter actually compared the two files? Clearly the bytes that have changed in the repaired file have been right-shifted 1 or 2 bits and the "new" top bits (bits 7 and sometimes 6) being set (by hand?) to 0 or 1 probably as needed. I don't think I see anything shifted by three bits or more, mostly just one and sometimes two. It looks like they had trouble syncing each byte as it was received via some serial feed (without FEC I assume) -- if I had the time I'd setup a build of VLC in a debugge
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Agreed. I've done this in the past and starting as close to the original analog telemetry stream as possible is essential. Even if the noise is so bad that analog filtering doesn't recover any new data in the preD, simply knowing where there is missing data and exactly how much can help tremendously in reconstructing the data. Their raw mpeg files don't provide any of that information.
Stop landing over the sea. (Score:1)
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computer, enhance ... (Score:2)
try "computer, enhance ..."
CSIs (Score:1)
They should just send frame by frame to the CSI guys and they will than click ----enhance----, DUH.
Forward Error correction? (Score:1)
So they try to transmit raw MPEG without any FEC coding?
I guess they could have been more successfull by beaming analog CVBS instead.
Telecommunications has improved since the 80s, you know.
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Re:Missing video (Score:5, Insightful)
Errm, they did have a well planned means to evaluate success: telemetry data. Which they have good copies of. The video is just candy.
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And this is the best PR stunt they could make instead of just tossing it, recovering that video has next to no practical value for SpaceX. A little geek challenge while they wait for the next test closer to land that'll probably be filmed from many angles.
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Well, yeah, the video is primarily of PR and posterity value... But is there a problem with that?
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They claim the stage was successfully able to soft-recover. Except it wasn't actually recovered. Thats a failure by every definition, they just don't care that the overall mission was a failure, they're happy to have the onboard systems do their job.
Of course, there were systems to do this in the 60s, but hey, don't let that ruin your day. And don't let the fact that you can buy hardware and software to manage the flight itself over the counter for peanuts ... including OSS versions.
Managing a decent and
Re: SpaceX always have an excuse for failure (Score:5, Informative)
You seem a little harsh on them.
Recovery of the booster would have been nice for investigation, but it was never intended to be flown again and was never the stated goal. The goal for that mission was a controlled descent and touch down on the ocean, which they accomplished. A 'soft-recover' wasn't the term that they were using.
This goal needed to be reached so that Range Safety at the launch pad can determine that SpaceX can reliably put a rocket down within a mile or so of a target. The next launch - in the next week or so - will attempt to land in the ocean much closer to the launch facility.
The technical difficulties of a soft landing are considerable given the hardware that they've got. With the weight of the empty booster, they can't throttle the engines back far enough to hover. So they fall towards the surface and at the right moment fire the engines to reach a computed zero velocity at touchdown. Doing this with gusty 30-40 knot winds on the surface is tough. 'Landing' on a continuously-undulating surface where there is no consistent level is tougher.
And yes, parts of this have been done before. Sure, there's open-source avionics stacks that can do this thing no problemo. But a controlled return of the first stage of a liquid fuel rocket has never been done before, and this kind of work has most certainly never been done for the relatively tiny amount of money that SpaceX has been spending. *That* is the thing that's getting tongues wagging.
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=Their experimental task, get the 1st stage to 0 velocity at 0 m so it would softly settle on the ocean was a success.
Most falling objects tend to get to about 0 velocity at 0m :)
Anyway, I can't help but think that it would've been smart to eject a floating lump of flash memory before the rocket sank rather than relying on a live radio link.
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It's entirely possible it actually was recorded in some buoyant piece of hardware, just in case...but it'd probably have been intended to be picked up out of the debris field of a descent failure in fair weather. Where would it have ended up after the storm tore the rocket apart?
They could engineer a ruggedized black box with a tracking beacon and deployment system...but that's a bit much when they've only got a few water landings left, and those are unlikely to happen in storms. I think they were more conc
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They claim it was successfully able to return to the surface and perform a soft "landing". Which it did...and it did so in thoroughly bad weather, in high winds and on heavy waves instead of solid ground. Their mission objectives were met completely the moment the rocket cut its engine and started tipping over. Actually fishing the thing out of the ocean intact would have been a nice bonus, but it has nothing to do with their actual plans for recovery and reuse...and the only reason it didn't happen is that
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Meh, I'd say they've been pretty successful by their definition.
The problem is, most people define success differently then they do and this is a particular example.
The system failed, but one part worked. They call success, but from a practical perspective it was an utter failure. The system as a whole failed and the stage was lost. To me, thats a failure.
They are just happy the thing was capable of hovering for a few seconds. Considering its a freaking guided rocket, I would expect that to be a relat
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The point of this test was never to recover the first stage.
That was a tertiary goal, absolutely, but it wasn't the primary objective of this test. Even if they had recovered it, they had absolutely no intentions of reusing this stage, since refurbishing a stage that's been exposed to salt water is more trouble than it's worth. It would take an estimated two months to get a water recovered stage ready for flight again.
SpaceX wanted to see if they could null out the rotation rate during descent to prevent an
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Maybe they should have transmitted to an airplane instead?
English... learn it some time.