...one of these ->
for all concerned. Top marks.
Elon Musk's SpaceX has successfully landed a rocket on Earth, after first using it to launch satellites. The Falcon 9 craft left the US on Monday night, local time, packed with 11 satellites. The rocket launched at 20:28 from Cape Canaveral in Florida. At 20:32 the rocket's first stage engines shut off. Two minutes later, the …
By which I presume you actually mean landed on "Of course I still love you" somewhere out at sea?
Which makes the landing all the more impressive.
Congratulations to Elon and his crew.
(The icon? Not This Time at least.)
The fire was pointing in the correct direction so it did go to space today.
@ Morrie Wyatt
"By which I presume you actually mean landed on "Of course I still love you" somewhere out at sea?"
Nope it took off and landed at the cape, as in Cape Canaveral, USA where they generally launch rockets from.
Truly remarkable especially as it also deployed its cargo of 11 satellites (i'm guessing tiny ones) too.
good job Elon's team!!
It was on land. See the pic in the graunidad - towards bottom of the article:
From this pic it is also very clear that they could pull this one off because they had a HUGE quantity of excess fuel on this launch. You can see both curves quite clearly there (it is a 5 min "open shutter" pic). The rocket had to compensate for the delta v acquired curving on a ballistic towards the horizon to fly back. You cannot do that if you are short on fuel, so those barges will still see action from time to time for heavy payload and/or high orbit launches.
That makes it even more impressive that landing on a barge. The first stage had to change it's delta-v completely, so it's a prolonged burn with the rocket pointing the wrong way to whatever atmospheric drag it's experiencing. With a heavy load of fuel in the tanks - I think that this is a lot more difficult than the barge landing.
The boostback was definitely making things difficult, as they had to carry more fuel to revert delta-V . However, one thing that made barge landing so difficult, which you do not experience on terra firma, is the movement of the landing surface caused by waves. I think SpaceX is aiming to eventually start its rockets in Texas and land in Florida, so they have "best of two worlds" i.e. non-floating landing surface and no need to revert all of delta-V = less fuel for landing, which translates to more capacity.
You can launch from Texas as long as you don't mind taking out New Orleans if the launch goes wrong! There's a reason that they launch out across the ocean. If not the best place to launch from is from a rocket sled up the side of the rockies (you can make a single stage to orbit rocket easily doing that!)
"You can launch from Texas as long as you don't mind taking out New Orleans if the launch goes wrong!"
Hardly. You don't launch from Houston. You launch over the gulf from somewhere between Corpus and Brownsville -- that way the landing pad is straight East _over_the_ocean_. New Orleans wouldn't be in any danger.
they must take bit of a battering from launch forces and re-entry...
I would also assume that any residual fuel/oxidiser makes them quite hazardous to work on once landed too.
I havent seen much published on the practicalities.
All that said, great job and well done.
Looking at the state of it on the ground (video clip here), it looks like it really will need a good wash. Check out the difference in colour between the bottom, and the parts that were covered up by the landing legs.
And how exactly do you scrub a rocket anyway? Stick it on a low loader and go through a car wash? Or perhaps one of the ones they use for cleaning trains.
Sadly, I can't remember where I read this, but in an interview with Musk from earlier this year he said that the engines should be reusable between 20 and 40 times. Apparently the engine is the really valuable bit that they care about. Presumably replacing struts and fuel tanks that may be showing signs of wear is a lot cheaper than replacing the actual engines, which I suppose makes sense.
they must take bit of a battering from launch forces and re-entry...
The first stage is basically to get the thing off the ground to what are better thought of as very high aircraft heights and speeds, which is why there are projects to use rockets released by aircraft as the first stage. At this point the first stage is jettisoned as dead weight, and the second stage takes the rocket to low/mid space sort of heights, at which point it's jettisoned so save weight so the now lighter third stage can make it to orbit sort of heights.
At very high aircraft speeds and heights, you are looking at more aircraft levels of friction heat (ie < Mach 5) than "spacecraft free falling from orbit" levels (Mach ~25), which is presumably why they are only recovering the first stage.
Basically, this marks the start of the traditional "throw away the first stage" rocketry model having it's days numbered. With Space X actually able to reland their first stages and various approaches (SABRE etc) in development competition is about to bring down the cost to orbit quite a lot.
I suspect this first successfully landed 1st stage will be stripped down to the last nut and bolt for testing and analysis to see what stress and wear have occurred. The engines, being the most expensive bits may well get re-used eventually, possibly only as spare poarts, but I expect they will be subject to highly invasive testing, not least to satisfy the FAA that used engines are safe to re-use.
Alister: "Isn't it curious how we've seen spaceships land like this for decades in Sci-Fi films and TV shows, but to see it actually happen for real somehow is just so much more awesome."
Space vehicles landing vertically has been done before.
At least six times.
On the Moon.
Starting in the 1960s.
Bezos's accomplishment was impressive, for sure, although it's important to remember that the man is a bona fide independent billionaire. It's reasonably easy to do things when you don't have commercial constraints.
Aside from the massive technical differences, which you alluded to, what strikes me is that Musk has achieved this on a commercial launch with a company that actually has customers and makes money.
I also happen to think that Bezos is a total dick, but that's just personal.
"Aren't we comparing apples with oranges in this article? Bezos' vehicle is for taking people up to have a look and bring them back down again"
Nah - this is just cover for developing a vehicle to deliver heavier Amazon Prime payloads. Only to people who have decent sized lawns of course. Lawns you won't have to cut again at no extra charge.
That's by design. Even a single motor is very over-powered for the remaining booster mass, and those big motors are not easily throttled down. So they have to bring it to a halt just above the pad and kill the motor all in one motion. Otherwise the thing would only go back up with no way to bring it down while the motor is running.
Although I thoroughly agree with you and I thought exactly that as I watched it, on reflection I think the next big step is really going to be something like Reaction Engines Sabre in a runway to runway space plane.
I suppose it depends on if that system can ever cope with larger payloads to a decent orbital height. Returning 1st and maybe even 2nd stages back to Earth for re-use for all it's fantastic achievement, might well be just a minor blip in the history of re-usable rocketry. And before anyone hits that downvote button, I am TOTALLY GOBSMACKED and in AWE at this latest success by SpaceX.
Peter Ford asked about Stage 2.
It flames through the atmosphere at 17,000 mph and what's left splashes into the ocean in a traditional manner.
They mention that they intentionally deorbit it (retro-burn), which is nice since it was some 630 km up. Otherwise it'd be space junk for nearly forever.
"They mention that they intentionally deorbit it (retro-burn), which is nice since it was some 630 km up. Otherwise it'd be space junk for nearly forever."
Na, maybe 2 years, tops, before it fell back down without any sort of station-keeping. But yes, it's in their own interest to de-orbit their junk!
Stage 2 burns up on re-entry. From what I remember, S1 cuts out between 60-80km depending on where it's released (for a ground-based landing, it's 60km - for water based, it's around 80km, due to it being probably closer to Europe than the US at this height and not able to make it all the way back).
The S2 component might be doing "tricky" bits, but is far smaller/cheaper than the S1.
The more I think about this, the more difficult I realise it is...
First, there's all the rocket science which is, well, rocket science. So very difficult.
Then there's the turning it round in space.
Then there's the aiming it at the right spot.
Then there's adjusting for Earth's rotation.
Then there's the bringing it back through the atmosphere.
Then there's the actually slowing enough to land without smashing.
Then there's the landing.
Then there's the refurbishing.
And all of this had to be thought up and designed and amended and refined even before a single piece of metal was bent in a complicated way.
This has got to be the achievement of the century, if not the millennium.
So pretty much what the space shuttle did last century?.. ;-)
I'm not saying it's not impressive, but it's on the same level as how difficult it is just to get into the correct orbit in the first place. The analogy during the moon landings was along the line of hitting a moving bullet, with another bullet, at a range of 10 miles.
The S1 doesn't turn around "in space" though - it's well below the Karman line (which many would argue is nowhere near space to begin with).
Yes it's impressive, but it's rooted firmly in 20th technology. It's all been doable for a while, but only recently become justifiable in terms of cost. I'd argue the Mars Curiosity landings were more advanced than these.
"This has got to be the achievement of the century, if not the millennium."
Purely in terms of the maths, I think maybe the Voyager missions slingshotting around multiple planets over a period of decades may just trump that. Or the Rosetta mission. Or landing a nuclear powered laser armed tank on Mars by lowering it from a rocket powered skyhook :-)
Admittedly, Voyager is last century even if still on going, but I think we may be a bit early in the current century to call anything "achievement of the century," just yet :-)
It's good to be alive now. We've seen moon landings and the birth of the WWW amongst other amazing things.
I find it interesting that they find this a better economic trade off than either (a) parachutes and fishing it out of the sea, like the shuttle boosters, or (b) gliding, perhaps using some sort of air-breathing engine. It would be interesting to hear how they decided on this method, despite its obvious challenges.
@Phil Edecott - salt water corrosion is the problem with sea landings. That and structural stress - bear in mind that even if the rocket came to a stop just bove teh waves, it is then going to fall sideways, and building it to withstand those forces and salt water corrosion adds weight which decreases performance... - frankly, it's easier to just land it back on land (or a barge!).
The Why and How is obvious in the final design.
1) a little bit extra fuel (not as much as you think since it's nearly empty and thus low mass)
2) those steering vane thingies
3) deployable legs
5) ITAR grade GPS (due to altitude and speed)
6) Engines that don't mind operating close to a surface
7) Multiple redundant C&C, self-destruct and abort systems (due to aiming back at the Homeland)
All you have to do is think about it, and you'll soon see that any other solution is less optimal.
The only tricky bit is the software, and that's not THAT difficult if you give the coder drones and physics/math geeks sufficient time to think it through.
Until SpaceX can deliver proper results every time, they are still one hit wonders.
They've succeeded in 19 of 20 Falcon 9 launches, even with an in-flight engine explosion. In terms of profit-generating flights, they're no longer one-hit wonders but a going concern. Further, the Falcon 9s ($62M/flight) are also comparable in cost with the competing Soyuz launcher, cheaper than the Long March 3B ($72M), and much cheaper than the Ariane V, Delta IV, and Atlas V (all $160M and up).
Cost is relevant to the "one hit wonder" point because these reusability demonstration flights - which, yes, have succeeded once - are designed to lower costs further. SpaceX has already succeeded in being competitively priced, and even a modest cost reduction after several more landing wrecks would purely be a bonus.
I love night launches. The clouds were annoying, but during the ascent the Falcon 9 peeked through gaps and was visible from 100km away. And the clouds were thin enough that sometimes the rocket lit them up like the sun behind lace.
The local TV crews had their cameras at just the right distance for a dramatic flair (or is flare the correct term for a rocket?): as the first stage was settling on the ground, the sonic boom reached the cameras and visibly rocked them. The reporter was having a space geek moment gushing about how long it'd been since the Space Coast had heard a sonic boom from a returning spacecraft. Much agreed, sir, I got a little teary eyed to see this stuff happening again.
Something I noted: even when local stations were using SpaceX camera feeds from the rocket, they were 1.5-2 minutes ahead of the webcasts. How much buffering do webcasts need?
"And now we have two companies capable of pulling off this awesome trick! ®"
SpaceX and... who else? Bezos' rocket can go straight up and down but can't get the sideways speed needed for orbit, so it can't pull off the trick, not even close.
It is a real shame when the science section of a tech news site has such poor understanding of the basic concepts of a frequently reported subject.
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