gutterboy44
Member
Holy shit that vine is awesome. That thing was coming in hot. Reminds me of my first Mun landings in Kerbal.
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SpaceX Attempting 1st Stage Landing After Rocket Launch (AKA Crazy Space Stuff)
- Thread starter DrForester
- Start date
- Status
https://twitter.com/elonmusk/status/588166157510828033
The flight control system has two major outputs - engine orientation and throttle. It sounds like the throttle didn't respond fast enough to commands, resulting in a delay between the command and the change in throttle. That sort of delay would result in exactly the sort of over-compensation we're seeing in the landing video.
Thankfully, it sounds like there's an easy fix.
The flight control system has two major outputs - engine orientation and throttle. It sounds like the throttle didn't respond fast enough to commands, resulting in a delay between the command and the change in throttle. That sort of delay would result in exactly the sort of over-compensation we're seeing in the landing video.
Thankfully, it sounds like there's an easy fix.
Chittagong
Gold Member
Holy fuck that's impressive to watch. Looks like trying to land a matchstick on its tip. Surely some sort of robot mega hand would help in grabbing it once its close.
How are they planning to sort out all that lateral movement when landing? That base is so damn small, it's crazy.
Ah, that makes sense.
Ah, that makes sense.
John Carmack offering control interface advice to Elon Musk for his spaceship has made my boner have a boner.
The Chosen One
Member
The landing could be solved by using magnets. Big ass magnets.
The rocket would need to come in a lot slower but then you would use magnets to stabilize its final decent and landing.
The rocket would need to come in a lot slower but then you would use magnets to stabilize its final decent and landing.
https://twitter.com/elonmusk/status/588166157510828033
The flight control system has two major outputs - engine orientation and throttle. It sounds like the throttle didn't respond fast enough to commands, resulting in a delay between the command and the change in throttle. That sort of delay would result in exactly the sort of over-compensation we're seeing in the landing video.
Thankfully, it sounds like there's an easy fix.
Cool to see Carmack and Musk talking about this. As much as I think Carmack can do great things at Oculus, I wonder if he would be better at Space X.
A-Dark-Injection
Member
Doesn't Carmack have his own space company, Armadillo Aerospace?
Yeah, but it's dormant for now.
I think it's always been a side project for him. He's got such a brilliant mind, which is why I'd really like to see it used to help get humans to space. But clearly if he wanted to make the career change, he could.
Carmack's famously smart, but his mind is not uniquely brilliant. SpaceX is the hot place to work, which means they can attract lots of brilliant minds (and work them into the ground - the parallels with game development are striking), so I'm sure they have a high Carmack quotient already 
greatestjediever
Member
Carmack's famously smart, but his mind is not uniquely brilliant. SpaceX is the hot place to work, which means they can attract lots of brilliant minds (and work them into the ground - the parallels with game development are striking), so I'm sure they have a high Carmack quotient already
Pssh, I have a lot of former coworkers and classmates that work at SpaceX. I'm smarter than all of them.
...I kid. Some really intelligent, hard working and good people over there. Some of them were fortunate to head out to Cape Canaveral to watch it live. Pretty close! They'll get it soon.
ScepticMatt
Member
blu
Wants the largest console games publisher to avoid Nintendo's platforms.
I'm sure somebody already suggested this, but why not make the landing pods just a tad longer, to provide for a greater base? Of all possible things they could improve, I presume this must be among the lowest-hanging fruit.
SneakyStephan
Banned
https://twitter.com/elonmusk/status/588166157510828033
The flight control system has two major outputs - engine orientation and throttle. It sounds like the throttle didn't respond fast enough to commands, resulting in a delay between the command and the change in throttle. That sort of delay would result in exactly the sort of over-compensation we're seeing in the landing video.
Thankfully, it sounds like there's an easy fix.
Input lag ruins everything
video games AND rocket landingsZoltanXerxes
Member
This is incredible! I know that many failures and hardships will come of this, but nothing gets learned without failure. I'm really excited them!
blu
Wants the largest console games publisher to avoid Nintendo's platforms.
That's clear. Nevertheless, they're still aiming to demonstrate a landing 1st stage by the end of the year, right?
Carmack's famously smart, but his mind is not uniquely brilliant. SpaceX is the hot place to work, which means they can attract lots of brilliant minds (and work them into the ground - the parallels with game development are striking), so I'm sure they have a high Carmack quotient already
Very true, I'm sure they have tons of brilliant minds there already. Haven't they been pulling a lot of the top NASA people to build their program?
Canadian Broadcast Company (CBC) has the best simulation footage of the launch:
https://www.youtube.com/watch?v=NCpI0KpKUpg#t=159
https://www.youtube.com/watch?v=NCpI0KpKUpg#t=159
You have to stop at some point. I don't think someone just pull the magic number from his hat, it has hundreds of factors being optimized/compromised.
Their engineers seem to have a lot of confidence at their engine's capability to stabilize the first stage, but my feeling is the landing seems a lot trickier than launch.
Melon Husk
Member
A hobby project that got too big to be just a hobby.
Youtube comments are salty as fuck about KSP not getting credited, lol.
perfectchaos007
Member
Kuwait space program?
ScepticMatt
Member
DrForester
Kills Photobucket
That little rocket on the top was trying his hardest.
SneakyStephan
Banned
Seems like once they sort out the control lag thing it should be a breeze.
They were so close despite the wild overcompensation.
They were so close despite the wild overcompensation.
DrForester
Kills Photobucket
So, something I don't get about this.
Lets assume a good landing. What then? Wouldn't it likely tip over on the journey back to land? If landing goes safely, does a crew then board the barge to tie it down for transport?
Lets assume a good landing. What then? Wouldn't it likely tip over on the journey back to land? If landing goes safely, does a crew then board the barge to tie it down for transport?
Well, even if they do get the thing back safely ... I wonder what kind of challenges they'll run into when they try to relaunch. In many ways, it's probably safer to have it built from scratch. They'll likely need entirely new methods and procedures to clear it for flight.
I mean, I'm absolutely certain they've thought of this, but there's certainly quite a bit more to be done even after they get it back in one piece.
I mean, I'm absolutely certain they've thought of this, but there's certainly quite a bit more to be done even after they get it back in one piece.
I would imagine so. Once the rocket has landed and been made safe there isn't much risk of explosion even it if tipped over because of waves or wind.
The_Inquisitor
Member
Barge is only being used while process is proven out. Final plan is to land back on land.
Not at all. The rocket weighs fractions of its liftoff weight because almost all of the fuel to launch the second stage and dragon out of earth's atmosphere has been burned. Parachutes have been used and failed because they didn't slow the first stage down enough to keep it intact. When landing on other planets only propulsive landing will work since there is usually little to no atmosphere on the places we want to visit, as well.
The first stage's mass is all at the bottom of the rocket when landing, so that will keep it in place when it lands. I would imagine it would be secured for the ride back to shore, also.
PS: That video is fantastic.
One engine firing instead of 9, for just a few seconds. It's no big deal. Fuel is cheap.
Yep. Current plan is to drag some brackets over the landing feet and weld them to the deck. Of course, once they're returning to land, they can just pick it up with the same erector that they use to launch it.
That video is KSP as fuck.
blu
Wants the largest console games publisher to avoid Nintendo's platforms.
ULA think they can pull off catching a parachuted engine block in mid air.
Let's see who gets a vulcan lair first.
I was watching the video, aww the little rocket on top didn't make it...then GIANT EXPLOSION. I lost it, was not expecting that.
ScepticMatt
Member
They hope to land on sold ground next:
http://www.defensenews.com/story/de...ground-attempt-reusable-landing-sea/25827625/
http://www.defensenews.com/story/de...ground-attempt-reusable-landing-sea/25827625/
Melon Husk
Member
Two new videos have come to my attention, both are entertaining in their own way:
1. GoPro footage of the barge landing is out. https://vid.me/i6o5
Damn it got close.
2. Landing x Scott Manley
1. GoPro footage of the barge landing is out. https://vid.me/i6o5
Damn it got close.
2. Landing x Scott Manley
Landing like this uses very little fuel compared to the launch itself, since the upper stage, payload, and most of the fuel are gone by that point. Also instead of fighting against gravity and drag while going up, gravity and drag actually do a lot of the work in coming back down and then slowing down.
There are numerous problems with parachutes:
- They are not light. The Space Shuttle solid rocket boosters weighed about the same as the empty F9 first stage, and they used the biggest parachutes ever - over 3.5 tons of parachutes, not even including the mechanisms and support structure for them.
- F9 would need even larger parachutes. Even using those enormous parachutes, the shuttle SRBs hit the water at around 50mph. The SRBs could survive because they were thick steel tubes designed to withstand very large forces, since the whole things were basically large combustion chambers. The F9 structure is much weaker, and would most likely not survive an impact at that speed. The engines at the bottom would almost certainly be damaged, if not completely destroyed. In the water landing tests they've done before, even a soft landing just results in a bunch of scrap metal because it can't even survive tipping over after touchdown.
- Landing in the water is no good, even if they could somehow do it softly. Getting corrosive seawater in everything is bad for reusability, and would drastically increase the cost and time required to get the stage ready to use again. Referring back to the shuttle SRBs again, they had to be almost completely disassembled for refurbishment, and many parts couldn't be reused. It was only barely worth doing.
- Parachutes are less accurate. Their goal is to actually land back at the launch site. Once they work out the kinks, a powered landing strategy will allow them to make very precise landings, putting the rocket exactly where it needs to be for rapid re-use. Parachutes are much harder to control, especially in winds, so they wouldn't be able to achieve the same accuracy.
- Replacing/repacking parachutes is more costly than replacing a little bit of fuel.
- Perfecting powered landings is part of their very-long-term goal of shuttling people to and from other planets. You can't land on Mars with just parachutes.
perfectchaos007
Member
Hopefully their next attempt is sooner rather than later.
Dragon on final approach. 40 minutes to go.
http://www.spacex.com/webcast/
Espresso machine almost at the ISS: http://www.mynews13.com/content/new...articles/cfn/2015/4/17/spacex_dragon_iss.html
http://www.spacex.com/webcast/
Espresso machine almost at the ISS: http://www.mynews13.com/content/new...articles/cfn/2015/4/17/spacex_dragon_iss.html
I know nothing about rocket science, so if everyone could indulge my ignorance a little here... but why don't they have something at the landing site assist with the landing, to guide it to a soft and stable landing? wouldn't that be easier than letting it land without "holding its hand"?
CyclopsRock
Member
There has been talk of this, but there are a few reasons. The first is that they believe they can do it without this. If they can, that'd be ideal, because it reduces to required infrastructure for landing to basically nothing, just a flat bit of ground (or, indeed, a barge). Long term this is great because if this sort of travel becomes more normalised, there'll be countless places you could land (as opposed to just a handful around the world). Short term, it means they don't have to build anything to catch it. This thing that catches it would also be complex and another potential source of error and malfunction. And, arguably most "important" from a more long term stand point, is the fact that they want to land on other planets like this, and perfecting the technology is vital to doing that. You can't land on Mars if you require infrastructure already in place to do so (and if this technique works on Earth, it should work basically anywhere).
yep, makes sense. thanks for the explanation.
CyclopsRock
Member
Well one of SpaceX's competitors ULA is actually going to try exactly what you suggested:
http://www.popularmechanics.com/spa...ed-launch-alliance-helicopter-rocket-recover/
So we'll have a nice comparison to see which works out best!
all it has to do is direct the parachuting rocket/engine to a specific GPS location, intercept it while falling back to earth by a helicopter dangling a heavy cable/hook, and then somehow the helicopter has to hook onto it without getting its rotors fucked up in the parachute? Sounds like the helicopter would need to intercept at altitude and then descend rapidly after the parachute passes in order to catch it up? Nice idea but sounds messy - also less refactorable for future space exploration - being able to land on other planets/surfaces could be a nice secondary revenue source for SpaceX
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