Non-engineers see this as a failure. Engineers and scientists see this as an awe-inspiring success from which to learn, iterate and try again. I don't fault reporters for exagerated headlined focusing on failure. They don't know any better. That is not what their lives are about and most might be challenged to understand that nothing in that video constitutes failure in the context of evolving a design. In fact, failure is absolutely necessary in order to better understand the problem you are trying to solve.
I can't help but feel bad for that one poor little RCS thruster doing its level best to keep the first stage upright, but ultimately running out of fuel.
As if this weren't impressive enough already, according to a comment made by Scott Manley[1] it sounds like the final maneuver (where it appears the rocket is making a fairly strong lateral correction) is entirely intentional. Not sure if anyone here can confirm or deny the claim, but apparently the trajectory prior to landing is not supposed to be exactly above the barge as one would expect - I understand it may be an attempt to limit exposure/damage to the barge in case of failure.<p>[1] <a href="https://www.youtube.com/watch?v=C9I55o8hQgs" rel="nofollow">https://www.youtube.com/watch?v=C9I55o8hQgs</a>
It was jaw dropping as-is, but when they finally do stick a landing I imagine the engineers will be running around like little kids screaming with the pure joy and exhilaration of it all. I hope they share the video at mission control as well when the day does come!<p>The sheer drama of how fast it comes down, the awesome power of the Merlin engine just blasting away delta-v... I wonder how many g's it takes on that final burn?<p>Would a drougue have simply added too much weight or too much complexity to deploy? I guess slowing down the freefall velocity before the burn just doesn't really help all that much?<p>Amazing that Falcon Heavy will have <i>27</i> Merlins on board.
The best part of their reusable rocket project is how incremental the progress has been. I'm not sure I would have appreciated the difficulty of what they're doing <i>as much</i> without these failures.
Come on people, have a go at it yourselves:<p><a href="http://moonlander.seb.ly/" rel="nofollow">http://moonlander.seb.ly/</a>
I wonder what happened there. Looks at 4 seconds the guidance system figured it needed to pull an ultra manoeuvre to slow the the horizontal speed(was drifting left) but ended up with a solution putting the rocket upright again at nearly 0m. If it would have left some altitude for stabilizing I think they would have had it.<p>Arm chair rocket science is fun.
It must be amazing working in a field where failure is almost as exciting as success.<p>What's the main obstacle to slowing down and stabilizing the rocket on its descent to the platform? Is it just a matter of speed or also the shape of the rocket and its center of gravity? Would a set of 3 parachutes might slow it down a little bit or at the very least straighten it before the rockets need to kick in saving some fuel?
Anybody know anything about the tech they're using to guide the stage to the barge? Since the flight is so short, I suppose they could get a GPS position on the barge at liftoff and pre-program that as the initial target, but I'd think they need some kind of terminal guidance actually tracking the barge to hit it reliably. Maybe visual or radar, or a radio beacon or something?
We know it does three separate burns while coming back down (Boostback, entry burn, landing burn).<p>I wonder if each burn starts with the RCS thrusters to turn the stage "nose up".<p>i.e. when it's free falling, does it always roll around and fall nose down, requiring RCS to get it back to nose up?<p>It would be awesome to see footage from the entire return trip. Do they have cameras mounted on stage 1?
Is there a reason you couldn't have things on the side of the landing pad that "grab" onto it and secure it?<p>It could be as simple as a huge ring of cable that just closes around the top of the rocket, then pulls it tight on all sides- like the guidelines on a tower to keep it stable.<p>Maybe they don't want to do that because they think they can do it without it?
What happens once it lands successfully?<p>Won't one stray wave tip it right over into the ocean?<p>Those landing struts are only 1/10 the length of the rocket.<p>If this wasn't so tall, it wouldn't be nearly the problem that it is.<p>Are they perhaps really trying to develop a Dragon landing system?<p>And using this extra tall rocket as a worst-case scenario?
Anyone know how fast the engine's gimbal is? The video makes it look like the gimbal lags significantly behind the angle of the rocket, so even when you're rotating one way, you end up burning more toward that angle as the engine slowly gimbals to the other side.<p>Granted, this is in slow motion. I just would've expected the engine to be gimballing to the other side even before there was a noticeable rotation.
It's interesting to think that if you are building rockets, up til now you've never really gotten to take the rocket apart _after_ flying it - it's burnt up in the atmosphere or at the bottom of the ocean somewhere. I imagine there will be lots of interesting insights that come out of recovering, undamaged, a flown first stage and taking it apart to see what's experienced wear etc.
Question: Why don't they land into the water instead of a hard surface? (Wouldn't this give them more leeway in terms of impulse?)<p>Edit: i.e. landing on a net stretched (under the lake/ocean-surface) by 3 or 4 ships - reel the net it in to raise stage out of the water, I'm pretty sure seawater is <i>not</i> significantly corrosive from 2-3 hours of exposure.
Seems that the control system only tries to guide it on the X & Y axis, but if I was controlling it and saw it coming in at that steep angle, I'd fire hard on the Z axis to try to raise it up, fix the angle, and then lower it down again.<p>Is it correct to say that this landing control system never tries raising the craft vertically?
If any of the engines has a TWR above one when landing, even at it's lowest setting, i can't help but wonder why don't they use a smaller engine which can be more effectively used to land.<p>I'm sure theres a perfectly good reason for this, there's a reason SpaceX has its reputation, but i'm curious as to why.
I almost think it would be easier to let it do what this video shows, and build a giant metal net to just prevent it from sinking. Or is that harder than landing on a small platform?
Pretty inspiring after all this time that the problem is not so much getting stuff up, but landing it successfully. I kind of feel like this is where we should have been in the 70s.
this might be a silly question but why can't they use parachutes? wouldn't a mostly empty rocket float? or is there an issue with the salt water and whatnot
Makes me wonder if they just leave them on the ground of the ocean or recover them?<p>...I bet otherwise the Russians or Chinese would love to get their hands one of them :)