Two Big Rockets Launched Early Wednesday -- Then One Landed In High Seas (arstechnica.com) 81
Arianespace and SpaceX both launched rockets this morning between 7:25am ET (11:25 UTC) and 7:39am ET (11:39 UTC). The Ariane 5 ES rocket sent four Galileo satellites into medium Earth orbit (at an altitude of 22,922km) for the European Commission. "These satellites will form part of Europe's own global navigation system constellation," reports Ars Technica. As for SpaceX's Falcon 9 rocket, it launched from the West Cost to deliver 10 Iridium NEXT satellites into a polar orbit 625km above the Earth. Ars reports on how the launches went: Both rockets hit their instantaneous launch windows on Wednesday morning, with the Ariane 5 booster lifting off from Kourou, French Guiana under mostly sunny skies and the Falcon 9 rocket ascending from California through a thick fog layer. The upper stages of both rockets are now in their coast phases before deployment of their satellite payloads.
After the launches, attention turned toward SpaceX's attempt to recover its first stage and payload fairing. The atmosphere offshore, where the Just Read the Instructions droneship was stationed 235km away from the launch pad, had high wind shear. This means wind speeds and directions varied at different altitudes, making it a challenge to come back to the ground in a more or less straight path. This, combined with high seas, made for the "worst" conditions SpaceX has ever tried to land a rocket in, said launch commentator John Insprucker. The cameras on board didn't capture the landing clearly, but afterward SpaceX said the rocket did, in fact, make a safe landing on the droneship. Less certain was the fate of the payload fairing amid the poor weather conditions. "This is an experimental attempt; we're still learning how to catch a fairing out of the air," Insprucker said.
After the launches, attention turned toward SpaceX's attempt to recover its first stage and payload fairing. The atmosphere offshore, where the Just Read the Instructions droneship was stationed 235km away from the launch pad, had high wind shear. This means wind speeds and directions varied at different altitudes, making it a challenge to come back to the ground in a more or less straight path. This, combined with high seas, made for the "worst" conditions SpaceX has ever tried to land a rocket in, said launch commentator John Insprucker. The cameras on board didn't capture the landing clearly, but afterward SpaceX said the rocket did, in fact, make a safe landing on the droneship. Less certain was the fate of the payload fairing amid the poor weather conditions. "This is an experimental attempt; we're still learning how to catch a fairing out of the air," Insprucker said.
Sounds like a successful mission? (Score:5, Insightful)
It sounds like SpaceX's rocket successfully launched and they managed to recover the first stage. The Fairing is suppose to be a bonus recovery but it sounds like it was too windy to do successfully. Keep in mind the first stage actually has rocket power so it has some sort of control over where it is suppose to end up. The Fairing sounds like a huge piece of metal with a parachute. Good Luck catching that in random winds.
Re:Sounds like a successful mission? (Score:5, Informative)
The fairing has a steerable parachute. It's as big as a bus. They didn't manage to get the ship under it, but "they saw it come down".
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Makes me wonder why they don't try to snatch it with a grapple equipped helicopter, like they did with film canisters from spy satellites many years ago. I understand that it's a pretty large and heavy part (800Kg, I believe), but there should be helicopters that can manage that sort of maneuver, and then drop the load on a much smaller net before landing on their own barge.
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Maybe it sinks too fast or gets filled with water and becomes too heavy.
Re: Sounds like a successful mission? (Score:2)
How did you manage to misunderstand the word "catch"?
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https://www.instagram.com/p/Bf... [instagram.com]
No, it floats apparently. But they'd rather catch it then have to fish it out of the (saltwater) ocean.
I'm sure there's economic sense to it or they wouldn't try. $6mm isn't chump change to throw away on each mission and i'm guessing saltwater refurb costs > catchers mitt operation.
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https://www.instagram.com/p/Bf... [instagram.com]
No, it floats apparently. But they'd rather catch it then have to fish it out of the (saltwater) ocean.
I'm sure there's economic sense to it or they wouldn't try. $6mm isn't chump change to throw away on each mission and i'm guessing saltwater refurb costs > catchers mitt operation.
The lower launch cost from recovering the first stage makes the loss of the payload fairing a larger part of the launch costs so there is more incentive to recover it.
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A large helicopter, with pilot trained for such operations and insurance to cover the risks involved, and a separate ship for it to operate from would all be quite expensive. With the film canisters, it didn't matter if it cost a few million to arrange their recovery, but with these, the whole point is to save a few million.
Re:Sounds like a successful mission? (Score:4, Informative)
It's not just the grid fins and landing burns that make the first stage easier. The rocket does a boostback burn and a reentry burn, both of which help pointpoint where the rocket will end up. The fairing does no burns; the only control over where it will be when its parachute deploys is when it separates and the trajectory of the upper stage at the time. Errors in precision high up are amplified as the fairing descends and enters the atmosphere.
The terminal guidance with the parachute and catching that with a boat is yet another problem on top of that. At least the parachute slows the descent, giving the boat more time to position itself.
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I think the fairing also has some manoeuvring nozzles added, mainly for the early re-entry phase control.
polar versus geostat orbit (Score:2)
Hmmm.... don't know enough orbital mechanics to argue but getting heavier sattelites 8 times further away seems like it might take a much larger rocket than the space-X one. So is there much to compare here?
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The USA had done really great work with the DC-X https://en.wikipedia.org/wiki/... [wikipedia.org]
The Soviet union was considering Zarya https://en.wikipedia.org/wiki/... [wikipedia.org]
Re:polar versus geostat orbit (Score:5, Interesting)
Hmmm.... don't know enough orbital mechanics to argue but getting heavier sattelites 8 times further away seems like it might take a much larger rocket than the space-X one. So is there much to compare here?
The two rockets are very comparable. In expendable mode, the Falcon-9 has a greater payload capacity (to the same orbit) than the Ariane 5, 8.3 tons vs 7, but with reuse it is less, only 5.5 tons to GTO.
In rocketry, is is not about power, distance or energy, rather it is thrust and delta-V (change in velocity). Higher orbit means higher velocity.
You need around 10km/s to get to low-orbit, and another 2-3 for the higher Galileo orbit, similar to geosync transfer orbit. So the "8 times further" is misleading.
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Re: polar versus geostat orbit (Score:2)
Correct; the current model of the Ariane 5 can lift around 11 tonnes.
I wasn't sure about the cost, so I looked around. Holy crap. A launch on the Ariane 5 costs more than one on the Falcon Heavy, and the FH can lift more than twice as much.
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Thanks folks, I was quoting figures for the old model Ariane 5 from ten years ago.
It looks like the Falcon heavy can do 16 tons to GTO while recovering the side-boosters.
Recovering the core booster drops that to only 8 tonnes, similar to an expendable Falcon 9.
Note that SpaceX is quoting prices for fully reusable, but capacities for fully expendable.
So the $90m lowest price tag for FH comes with a lower capacity than the current Ariane 5. (but half the price)
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Ariane 4 used to have low launch costs. But most customers who use the Ariane 5 right now do it mostly because of the high reliability of the rocket vs large Russian rockets like the Proton. Of course SpaceX has been snatching away that market from all the other operators.
Both Landed in High Seas (Score:5, Insightful)
a cost compare (Score:2, Interesting)
Ariane cost: $165-220M per launch, 16,000 kg to LEO.
Falcon 9 cost: $50M per launch (2018), 22,800 to LEO.
Taking the middle of the Ariane cost, it is $12,000 per KG to LEO. The F9 is $2200 per KG to LEO.
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Ariane cost: $165-220M per launch, 16,000 kg to LEO. Falcon 9 cost: $50M per launch (2018), 22,800 to LEO.
Taking the middle of the Ariane cost, it is $12,000 per KG to LEO. The F9 is $2200 per KG to LEO.
Not to doubt you, but where did you find those numbers?
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Not to doubt you, but where did you find those numbers?
Sorry, i should have put the sources. All numbers sourced from wikipedia, but there are many other sources around the net too. Sidebars on the right:
Ariane 5 [wikipedia.org]
Falcon 9 [wikipedia.org]
Re:a cost compare (Score:4, Informative)
The Ariane 5 that launched four Galileo satellites yesterday is the ES variant, capable of putting about 21 tonnes into LEO. It's only flown that particular profile for ATV service missions to the ISS. This is the second ES-variant Galileo mission flown, putting a carrier with four satellites in elliptical orbit which is then circularised at GPS altitude (about 20,000km). Originally the Galileo satellites were being launched two at a time by Soyz-Fregat rockets but one launch went wrong and ESA decided to take the rest of the launches "in-house". It worked out cheaper to fly four satellites at a time on the heaviest-lift variant of the Ariane V compared to two at a time on the less-capable ECA variant.
As for the Falcon 9 FT it can only, IIRC, deliver 20-odd tonnes to LEO if it flies without recovery in mind -- no landing legs, no first-stage fuel reserve for landing etc. This makes for a more expensive launch cost.
Re:a cost compare (Score:4, Interesting)
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But Bruce, Ariane has lifted a number of 20 ton payloads to LEO. [wikipedia.org] Spacex cliams to be cheaper, but nobody in the 20 ton class gives a shit about Falcon9?
Since many real-world payloads are volume-limited rather than mass-limited, the 20 tonne capability of Falcon 9 is being seen as less relevant. For example, the 20-tonne ATV spacecraft would have never fit into Falcon 9's fairing. It was more than ten meters long at a 4.5 meter diameter but the F9 fairing stops being 4.5 meters wide internally before 8 meters of length. It fit nicely within the 40% larger Ariane 5 fairing.
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Re: a cost compare (Score:2)
Falcon 9 block 5 can lift 25 tons to LEO with recovery. Block 4 could only do that if expended.
Nonsense. Block 5 can do 22 tonnes in expendable mode, or about 13 tonnes with recovery.
No clue where you are getting your numbers, but the whole idea that block 4 can lift significantly more than block 5 is just wrong. The major improvements between block 4 and block 5 had to do with making the rockets more durable and easier to reuse; lift capacity was essentially unchanged.
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That was in short tons, and the stage-1-recoverable weight to LEO would be 22.8 tonnes for block 5.
SpaceX keeps changing the figures here [spacex.com] as they upgrade, you can look at the older versions on the Wayback Machine.
While block 4 quoted a 22 tonne mission in expendable mode, block 5 does all missions in recoverable mode and quotes that same weight for a recoverable mission. There is a quote here [businessinsider.com] of Musk on the engine difference: The most important part of Block 5 will be operating the engines at their full thr
Re: a cost compare (Score:2)
While block 4 quoted a 22 tonne mission in expendable mode, block 5 does all missions in recoverable mode and quotes that same weight for a recoverable mission.
No, it doesn't; the page you linked to gives performance and capability data and simply doesn't differentiate between the two modes. If you had clicked on the "pricing" link you would have seen that the following page lists a "standard payment plan" at $62 million, limited to 5.5 mT to GTO. This is consistent with Block 4 figures; it's the maximum lift of the rocket in reusable mode.
Below that they list a maximum lift of 8.3 mT to GTO, which, again, is consistent with Block 4. But they don't give a price
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There have been several power increments since the original Falcon 9, so yes, it's about twice as powerful. It is also more powerful than the original specifications for FH, which is why there aren't more missions for FH.
And I see that they are quoting the GTO missions in expendable and non-expendable mode, but they aren't quoting the LEO missions that way - and they used to. Also, they have learned a lot about landing the rocket and may be more confident now that they can do it on less fuel. So, until they
Re: a cost compare (Score:2)
There have been several power increments since the original Falcon 9, so yes, it's about twice as powerful. It is also more powerful than the original specifications for FH, which is why there aren't more missions for FH.
Now I know you're on crack. The FH is 3 F9 cores strapped together. I don't care what kind of "power increments" you're making, 1 core isn't going to be more powerful than 3. That would require a whole new engine design and a switch to a different kind of fuel entirely.
Please find me any reference anywhere which suggests that the FH was originally specified to lift less than 23 tonnes to LEO. No, you can't cite your imagination.
And I see that they are quoting the GTO missions in expendable and non-expendable mode, but they aren't quoting the LEO missions that way - and they used to.
They're not quoting missions at all; they're quoting maximum capabilities of
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You're being a troll or you just don't know anything about this. The current Falcon 9 is more powerful than the original specifications of Falcon Heavy. This is because of improvements in the rocket and a stretch in its height. All of the mis
Re: a cost compare (Score:2)
You're being a troll or you just don't know anything about this. The current Falcon 9 is more powerful than the original specifications of Falcon Heavy.
No, me pointing out that you're just making shit up is not "trolling". You clearly have no clue what you're talking about. Either provide a reference for this insane claim, or fuck off.
This is because of improvements in the rocket and a stretch in its height.
Those improvements were all done back in 2011-2013, when they went from Version 1 to the Version 1.1. In the intervening upgrades from 1.1 to 1.2 (aka "full thrust) to Blocks 3, 4, and 5, there has been no change to it's "stretch". Meanwhile the first FH didn't fly until 2018.
If the original design of the FH was based on
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Some quick math says that the FH based on the current F9 can lift about 2.8 times as much as a current F9. Applying that to the original F9 means that an FH based on the original F9 should have been able to lift 28 tonnes to LEO.
That is stupid quick math because the original Merlin engines are not throttleable. You can't just apply a multiplier like that if in one case, all the engines burn out at the same time and in the other case they don't. You have to do an entirely new performance calculation.
Re: a cost compare (Score:2)
I'm aware of that; I was keeping the math simple because it's a close enough approximation for my purposes, and it's still far better than anything that he has provided (that being nothing whatsoever).
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Putting the two together, the rocket can lift 5.5 tonnes to GTO in reusable mode, and 8.3 tonnes in expendable. Extrapolating that down to LEO gives the same numbers I quoted earlier; 22 tonnes expendable, or 13 tonnes reusable.
You're extrapolating wrongly then. In no way should you be getting a 1.5 ratio for GTO payloads but 1.7 for LEO payloads. Better outline your Tsiolkovsky calculations.
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The ECA variant is not "less capable" it is optimized for GEO satellites at higher orbits and has a LOX/LH2 powered upper stage. The ES variant is hypergolic powered so it's lower performance in terms of payload to higher orbits but it is capable of multiple restarts to insert satellites into multiple orbits. Had the ESC-B variant with the Vinci engine been introduced as supposed to that would have been LOX/LH2 with multiple restarts. i.e. high payload capable and capable of multiple orbit insertion. Intere
Re:More debris to space? (Score:5, Interesting)
Actually a very good question...
LEO satellites are usually orbited low enough that they will naturally re-enter with in a few years of "unpowered" flight, such as after it's run out of fuel or is no longer controllable. So LEO orbits are generally self cleaning over time.
For orbits that are higher, the natural decay times can be quite long (as in practically not going to happen) and in such cases the usual thing is to either plan to deorbit the satellite by putting it into a highly elliptical orbit where it drags in the atmosphere at the low point and letting gravity take it's course, OR you plan a parking orbit out of the way. Such things usually take fuel and active control of the satellite so they are not always successful. Also, some orbits have natural collection points due to the gravity between say the moon and earth. These points are often the final destination of space junk as it's a low energy way to get it out of the way into a place where it will naturally stay without help, which is a good thing.
So for LEO the issue of debris is naturally correcting, though still a bit of a risk to the satellites that operate there because of the relative speed differences which can be very high for objects in different but crossing orbits. However for LEO, there are all sorts of possible orbits and directions so you can usually stay out of each other's way. Form geosynchronous orbits the relative speed differences is quite low, given that the whole point is to make the satellites all stay in one place in the sky. This stacks up a lot of hardware in a very small space though so collisions would be more slow motion train wrecks that won't create a lot of debris than quick obliteration events that generate a lot of fast moving objects.
Of course there are all sorts of highly elliptical orbits used for various types of satellites and these are usually designed to be decaying over time, with their low points being at or near LEO levels. As in most of this stuff, they have a planned way to get the used up hardware out of the way somehow.
So no, we certainly don't convert them to debris, usually, though some have been used for target practice to prove anti-satellite weapons actually can work. Such weapons have been demonstrated by multiple countries, including the USA, China and Russia/Soviet Union.
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Form geosynchronous orbits the relative speed differences is quite low, given that the whole point is to make the satellites all stay in one place in the sky. This stacks up a lot of hardware in a very small space though so collisions would be more slow motion train wrecks that won't create a lot of debris than quick obliteration events that generate a lot of fast moving objects.
Only until an evil scientist sends a box of nails going in the opposite direction.
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Someone's been reading (Score:2)
Someone's been reading their Iain M. Banks. But I'd still like to see the cost/benefit analysis from a Ship Mind on adding the additional fuel/oxidizer, control surfaces, and other equipment + inspections and refurbishment costs to allow stage recovery. Intuitively it doesn't seem to make sense, but perhaps a great Mind existing partially in hyperspace sees what mere humans cannot.
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The extra fuel is dirt cheap compared to the cost of the booster. Estimates vary for the cost of a booster core, maybe $20-30M, but the price of that will come down anyway now that they're finalising their F9 design with Block 5. Musk has said that the cost of refurbishing Block 4 for reflight was less than half the new cost, so still definitely worth it - and Block 5 is designed to fly with minimal refurb (as little as 24 hour turnaround) so will certainly cost a lot less than that to refly. And the added
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the cost of carrying extra fuel isn't the purchase price of the material - which is usually low compared to the per kg cost of the rest of the vehicle - but the opportunity cost of the extra weight carried, the extra structure needed to carry that weight, the large control surfaces needed to manage the higher weight, and so on all the way down to the last turtle.
Re: Someone's been reading (Score:2)
The amount of extra fuel needed is relatively low but, regardless, all of that is included in the launch price. If you want to put 13 tonnes or less into LEO, it will cost you about $60 million, which is comparable or less than every other launch option. The cost of the extra fuel needed is included in that price, and results in a lower payload capacity.
If you want to use the rocket to it's full potential and put 22 tonnes into LEO, it will cost you significantly more than $60 million so that SpaceX can b
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You're not wrong, but in practice this is rarely an issue. Have a look at the payload masses on SpaceX's mission list [wikipedia.org] - the great majority of payloads didn't come close to their maximum capacity, meaning the mass overhead of recoverability is a non-issue most of the time.
While it's true they give up a tiny percentage of customers who need slightly more than their reusable rocket can now deliver, it's more than made up for by the savings of of reuse. They've also expended a handful of boosters that didn't ha
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Catching the fairing is fun and all... (Score:2)
But wouldn't it be more reliable to design a fairing that floats and can tolerate a few minutes/hours of contact with seawater?
Then instead of having to catch it in the air, the boat could just go to where it touched down and collect it.
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The do float, but they get water logged.
I'd take it, water logged and all, make it into a shed.
Argh, who's got a fast, ocean going, boat? We're going to pirate one of the next two off CA. Your boat, you get the first.
We'll stalk the recovery ship, they know about where they're coming down. We go for the one they don't go after, gone before they know what happened.
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It definitely floats. It is really light and rides astonishingly high in the water for something its size. It just gets damaged.
A fairing is 5 Million dollars of mainly carbon composite. If it's a pound heavier, that's a pound you can't have for payload. This gets really important with geosynchronous transfer orbit or (worst) direct geosynchronous, where the capability is much lower than LEO. Adding weight means there will be some missions you can't carry. I guess they could have heavier fairings for when t
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If it's a pound heavier, that's a pound you can't have for payload.
Not really, if they're discarded nowhere near orbital velocity. (However, if it's too heavy, it's impractical to land by means of parachute, etc. etc.) There's some loss but nowhere near 1:1.
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The fairing is dropped pretty close to the time that stage 1 ends its burn, and most of the delta-V is in stage 1
It's around 2 km/s for Falcon 9 with landing the first stage, with a total delta-v of around 10 km/s for GTO missions. So I'd say that most delta v is in the second stage, unless you were trying to say something else than I thought you were trying to say. The F9 throws away the fairing shortly after igniting the stage 2 engine (after expending around 15 tonnes of propellant in the latest flight), at the point when the total mass of the remaining stack is still around ~100 tonnes, so I'd be very surprised if
Re: and that, in a nutshell, is why... (Score:2)
Yep, there's a reason why NASA is using Soyoz rockets for crewed launches.
Yep, that reason being "because they have no other option".
Re: and that, in a nutshell, is why... (Score:3)
This is largely meaningless. Most rocket failures happen in the early stages of a program, while the bugs are being worked out. And the Ariane 4 was a derivative of earlier rockets in the same family. So, all in all, being able to have a streak of 40 success isn't at all unexpected.
The overall success rate for the Ariane 4 has been 97.4%. The Soyuz-U has a very similar 97.3% success rate, while the Falcon 9 has a success rate of 96.6% thusfar. Now, the Falcon 9 has not have had enough launches for that