Say what you like about Elon Musk, he's not boring. ®
I thought we had to be somewhat careful with our comments here ;)
Rocketry upstart SpaceX has said it's new "Falcon Heavy" launcher – which will be the most powerful on Earth when it comes into service – has been grounded by further delays. The news comes as part of a briefing given by SpaceX chief Elon Musk and other company executives outlining their plans following the explosion of a …
As per the end of the article I do think reuse and the knock on effect on price are the key. As long as Musk/SpaceX have the financial reserves/income stream to keep on with the Falcon Heavy (and XX) programme then their launch cost per Kg will be tiny in comparison to the SLS which is completely thrown away.
The maximum payload difference may not be such an issue either: one use of such a heavy lift is to take up multiple things, in which case multiple, dramatically cheaper lauches are better. The other is to take up a single heavy thing (duh!) - but what is the demand for that? Any realistic manned Mars mission is likely to need multiple launches of bits and pieces and likely some in-orbit assembly at which point what is the difference between joining 3 things together and joining 5? Well, obviously _some_ difference but enough to be worth spending the entire SLS development cost on? (when they should be spending the money on e.g. working out how to assemble stuff in orbit ....)
"Any realistic manned Mars mission is likely to need multiple launches of bits and pieces and likely some in-orbit assembly"
The reason that the USA shitcanned doing that for the moon is that there's too much potential for things to go wrong. The more you can put on one launcher the easier it is to keep them together in orbit.
Mars is different to the Moon though. The ship's just going to be too big to send on one rocket. You'll need more people, more shielding, more accommodation, more storage, more fuel, several landing craft etc.
I'd have thought the best method in the end will be to build some sort of ISS like truss (but stronger ovbiously), with an engine bolted to one end, and crew accommodation and whatever mission stuff you needed strapped along it. Then you could test it by going to visit an asteroid - or a mission to fix some of those useful satellites in L1 - and strap different payload to it for a trip to Mars. i assume we can find something worth visiting that's a quicker trip than Mars, to test out shielding, isolation, and the like.
Musk and SpaceX had at once time appeared to be in with an outside chance of doing this job, replacing the cripplingly expensive 1970s-era hydrogen technology of the Shuttle and the SLS with new kerosene- or methane-powered kit. Plans have been discussed for new SpaceX "Raptor" engines, more powerful than the Merlins in the 9 and the Heavy, which could power a new class of super-Falcons - like the SLS, as big as oldtime Saturn Vs but more powerful than either.
As it is, the Heavy will probably be doing well to step into the Delta IV Heavy's shoes lifting US spy satellites - and if it can do that, Musk will no doubt be happy enough.
All this presupposes that NASA and Friends can bring the SLS in on time and on budget, not something they have much past history of doing.
"All this presupposes that NASA and Friends can bring the SLS in on time and on budget, not something they have much past history of doing."
Absolutely. Based on recent form, there's a very good chance NASA could be stood with a still-not-ready SLS in 2018 whilst Musk smiles and waves calling:
"I say chaps, we've got this Heavy over here if you need something big lifting? Anything? Give us a shout if you need us! Oh, you do? Well, step into my office..."
It also remains to be seen how re-uesable the SpaceX first stages are. How many re-uses can you get out of them? How costly are they to re-furbish? How reliable are they? etc
There's going to be some reticence around loading up your multi-million dollar satellite on a slightly used rocket.
I hope it works out the way SpaceX intends it to...
"It was never clear that the cost of recovering, refurbishing and transporting the boosters ever made sense"
It didn't - but that had more to do with the company building them being halfway across the country, necessitating the booster diameter being constrained by what would fit through rail tunnels and segment length by what would fit on rail wagons (They really should have been twice the diameter they were)
The whole program was institutionalised pork, as is SLS - and if NASA have it operating within a decade of the schedule I'll be surprised, let alone man-rating the thing (NASAs solid launchers have so much vibration that IMO they'd liquify an astronaut's brain in short order, plus once lit you can't put them out.)
Elon is being _extremely_ cautious in his rocketry program and it's paying dividends. Heavy is ready when it's ready. It doesn't matter when that is, there will be a market for the thing (bigger payloads to GEO are always in demand for starters).
Regarding shuttle engine reusability: SMEs were stressed within a whisker of breaking point at every launch and built by companies which didn't lose money if they blew up on the test stand (several did) or shut down during a launch (several did). Merlins are far more conservatively designed and being a commercial outfit, SpaceX only get paid for successful launches. This brings its own incentives for reliability.
Comments pooh-poohing Falcon's reliability are majorly misguided. It's had an unprecedented success rate for a new launcher. I'd imagine that "words were exchanged" about a defective component but quite frankly that's an absolutely minor failure cause(*) compared to most other launch failures in the last decade.
(*) As in: easily remedied, not a fundamental engineering or software issue.
Anon for this because I work in the industry (research side, not commercial) and we've put hardware on almost every launcher available.
The solid rocket boosters got parachuted into sea water every launch. Which is horrible for re-use, but the thing was supposed to be a shuttle, so they did it.
As they were also woefully under-powered, the shuttle main engines regularly got run up to 115% of power, every launch. Which can't have been good for longevity.
I also can't believe that metallurgy hasn't vastly improved since the shuttle designs were done in the 60s, in combination with SpaceX landing under power, on legs, on dry land, they ought to be able to save some cash. However, even if the engines aren't saving much cash, they're also recycling the rocket body, plus electronics. And if they can survive one launch, they should be reuseable for several.
"Comments pooh-poohing Falcon's reliability are majorly misguided. It's had an unprecedented success rate for a new launcher"
Nonsense. Ariane 5 had a couple of failures in its first test flights, and since then has managed 78 launches with one failure and one partial failure. Delta IV (including heavy variant) has managed 29 launches with one partial failure. Falcon 9 has so far had 19 launches with one failure and one partial failure. Even including Ariane 5's test flight failures, Falcon still has the worst failure rate of the three. Of current launchers only Proton and Zenit are worse. Falcon's certainly not terrible (if you want to see terrible, check out the Delta III), after all Proton is the most used launcher ever even with an 11% failure rate, but it's nothing close to unprecedented.
The failures weren't directly due to reuse of the parts but they WERE due to the parts being reusable.
The shuttle had it's large and fragile heatshield with very brittle tiles because it needed to be reused. The SRB contruction that led to the Columbia disaster was also largely due to it needing to be disassembled and reused. There were better designs possible if the booster was throwaway hardware.
"The shuttle had it's large and fragile heatshield with very brittle tiles because it needed to be reused"
Nope, the shuttle had a fragile heat shield because during development the Airforce (who paid for most of the development BTW) wanted cross-range capability with a steep glide path.
This required the heat shield to withstand much higher temperatures, the fragility is a combination of this and weight reduction.
"Of course they are also a good example of how re-use didn't provide the expected cost savings."
Of course, soft-landing a SpaceX 1st stage back on the pad might well mean slightly less refurbishment will be required as compared to a fairly hard landing under a parachute followed my a few hours immersion in salt water.
There's going to be some reticence around loading up your multi-million dollar satellite on a slightly used rocket.
The same reticence there is about loading it on a rocket with a short track record, or one that's suffered a recent failure. Which will be balanced against the reduced launch fee for early flights or multiply-reused launchers. Market forces really do work!
Also one would hope that a bathtub curve might emerge, and that a second, third, ... launch might actually have a lower failure rate than the first one. But it's never been done before, and it'll take a good while to accumulate anything like useful statistics. So to start with it'll involve a lot of guesswork by all parties.
I consider it to be the same sort of vaporware as NOVA, which was the enormous direct-ascent variant of the Saturn V. I'll believe it when I see it. However I have also learned to not bet against Elon Musk. He might not be on-time, but he usually eventually delivers.
> There's going to be some reticence around loading up your multi-million dollar satellite on a slightly used rocket.
Well the idea is that the "slightly used rocket" has a proven track-record of making a successful flight, which includes stresses and regimes that you just can't test for. So it should be more trustworthy than a shiny brand new one.
"the "slightly used rocket" has a proven track-record of making a successful flight, which includes stresses and regimes that you just can't test for. "
I'm not quite sure where to factor into that possible metal fatigue / starting hairline cracks / wire harnesses on the verge of getting interrupted / shorted / abraded / melted in hard-to-reach places etc. It clearly wouldn't be practical to unbolt every single nut after every single launch, although I'm sure that's exactly what they'll do for the first time...
"It clearly wouldn't be practical to unbolt every single nut after every single launch"
Getting an engine back after a launch, intact, allows the things to be torn down to see where the stresses are, etc etc - and by the time you finish that kind of inspection the parts can't be flown again.
Even the ones Elon's had back in bits have been useful.
Don't expect to see a used Merlin flying a commercial payload anytime soon (or if they do, it will be on a no-liability hitchhiking basis). The prime use of the first few flights he gets back will be redesigning components to ensure they can survive multiple cycles. That's the kind of data you can't get from pogoing out of a cow paddock.
"adding more struts"
More struts == more mass == less payload.
It's a delicate balancing act.
The strut in question failed at less than 1/2 of its specified strength. If it was a NASA design the thing would probably have been designed so that was 80% of specified strength.
Two downvoters don't follow SpaceX twitter and don't play Kerbal Space Program. Thanks for the downvote for referencing both companies and "adding more struts" being their own in joke.
And one upvote for the person who did get the joke! :D
Downvotes, because no better way to know more about others than yourself.
and you land on the surface. How exactly do you get back? Mars although smaller than Earth with less gravity, you still need a fair amount of thrust to achieve orbit and you won't have any support systems on Earth to help prep the ship or make any repairs in case of a heavy landing. Going to Mars is a one way trip unless we improve the tech.
It's one of the minor reasons for switching to Methane for the fuel. It's not hard to process the Martian atmosphere into Methane and Oxygen which you can use to refuel your lander for the trip back up. Takes power and time but saves a huge amount of payload lifted from Earth.
Mars has a Carbon Dioxide Rich atmosphere. With electricity from Solar Panels a robotic rover could assemble the solar array and generate methane and liquid oxygen from the atmosphere. Thus they could conceivably have all the fuel made and stored away prior to a human leaving planet earth for the trip to Mars. For that matter they could have a reserve craft standing by and one in orbit to bring back the away team in case their craft is damaged in some way. That same robotic technology could erect a greenhouse and grow and store away fresh fruit and vegetables long before arrival of the away team. Fresh water is more difficult but not beyond current technology. IMHO Nasa and SpaceX should be choreographing the entire project here on earth, perhaps in Antarctica as a kind of dress rehearsal for the project.
To get the water you've got to be at the poles or have equipment a bit more complicated than "suck in air." Wikipedia is suggesting 4% water down to 60cm. That's going to take churning up soil and probably means a rover rather than a static base.
And correction, Wikipedia suggests 15 ppm H2. (And for those who were asleep in chemistry: you need hydrogen to make methane which is why we're talking about it.)
Mars (or just about anywhere in the solar system) would be a lot easier with a nuclear-powered ion drive interplanetary stage. Assemble (fuel) it in Earth orbit, so there's never a critical mass or anything more radioactive than Uranium at risk to a rocket failure in Earth's atmosphere. Of course, you'd still need to lug along a conventionally powered lander.
Pity about the mindless politics concerning "nuclear".
Nobody is rooting for SpaceX to succeed more than me, but your dismissal of the SLS reveals a lot of slant to your opinion.
70mt is FEEBLE? That's with no upper upper stage (budget constrained, not technology constrained). Pointing out the obvious, the shuttle only had a max payload capacity of 25mt.
As for 70's technology, name an engine, any engine that is more powerful than the RS-25 (SSME)? Sometimes technology stays around because it's the best technology, not just the newest.
As an analogy, noticed the other day how an F-35 got it's butt handed to it by an F-16 during a dogfight test.
Also noticed that both Orbital and SpaceX had their rockets blow up. Not a cheerleader for NASA and their lack of direction but there's a lot more to rocket science than you portray.
The SLS is doomed. Not to say anything against NASA (they build good space probes) but they are at the mercy of presidents and congress. And those change every few years. The things they want built (and the places they want them built) change every few years. And every politician wants his/her name on a NEW something, not a maintained or improved something. Whenever NASA is in danger of completing a more powerful rocket, they are told to drop it and do something even better.
There's no real doubt that a SpaceX alternative would be cheaper and probably better
I would say there is considerable doubt. As for the 1970s technology jibe: all rockets are 1940s technology.
Yes, the Space Alliance is beholden to the behemoths but that doesn't mean that they can't eventually come up with the goods: it's not as if they don't have damn good engineers. Part of the historic problem of cost-plus overrun was politician-driven mission creep. Though on some of the really pioneering work you can't really do anything other than go cost-plus, which is why DARPA still does it.
In any case, any discussion of launch vehicles really ought to include Ariane which continues to quietly go about the business of commercial satellite launch. But also as the space programmes in China and India progress we can expect to see even more fruits of "lean innovation" across the industry. Who's to say that the Chinese won't be offering 150 tonne launchers 10 years from now?
Much more troubling than the broken part, or even the loss of a rocket is the broken management style of SpaceX. Management of SpaceX designed a rocket without a fail safe part or redundant parts doing the job of that failed strut. Management of SpaceX built a system that evidently didn't even test that critical part to see if it met the needs for the task. Management of SpaceX failed to put the software into the payload capsule to deploy its parachutes in an emergency. The self admitted complacency among employees is strictly a SpaceX management issue. I have to wonder how many other single points of mission failure exist in this design. I am not worried about building and installing a better strut, even I could do that in a single trip to Home Depot. I am worried about SpaceX's ability and willingness to fix it's management. Without a shift in the Management Ethos of SpaceX I have no doubt other failures are just waiting to happen.
I wouldn't put it this strongly - Musk himself mentioned complacency, and it's easy to ascribe blame from outside. But I think in this general sense, you have a point. Until now, SpaceX has benefited from 'lean and mean', entrepreneurial style systems but with this failure, and especially as they progress toward man-rated systems, both the hardware and the systems for building and launching will inevitably have to move somewhat toward more rigorous systems with additional checks at every stage in the process, which will likely increase their operational and launch costs, although I don't expect them to go as far as the 'old school' methodologies. But at the same time, additional analysis may discover additional cost savings in other areas, as their technology matures, so it may be a wash.
SpaceX has already revolutionized the cost structure of orbital launches with the fixed price approach and roughly 50% cut in that price from traditional ones - ULA, Orbital ATK and Boeing are all working on reorganizations that will allow them to cut their costs to be more competitive.
Finally, assuming SpaceX gets the reusable first stage working with a 30% or better success rate, that will reduce the costs some more. I assume that SpaceX pricing will take into account the success rate so SpaceX will eat the costs of the failures to return the first stage. So in the long run, even with the increased carefulness, launch costs will continue to come down. ... I hope! :)
The payload survived. It could have landed and been recovered. They are adding the software to do so in the next attempt.
It was also a failure in manufacturing/supply. I suppose sourcing from 3 suppliers can help, as you'll only get 1 in 3 failure rate if a supplier tries to give you sub standard parts.
They have also considered "adding more struts" as an option. So yes, they can and do have failsafes. The previous failures showed they can, when one engine fails the rest can throttle up or the flight path be adjusted (1 deployment on a 2 bus/satellite delivery).
"The self admitted complacency among employees is strictly a SpaceX management issue"
You may have a point about complacency, but you have to remember that even NASA didn't get the "tough and competent" attitude that they achieved during the latter half of the Apollo programme until after the deaths of Grissom, White and Chaffee in the Apollo 1 fire, with the subsequent and very public arse-chewings of senior NASA management in front of a US Senate committee. As Flight Director Gene Kranz said at the time, "We were too 'gung-ho' about the schedule and we blocked out all of the problems we saw each day in our work."
SpaceX has just had their first proper 'rocket-science' life lesson handed to them on a plate, but this time no-one died, expensive kit was lost, but kit is replaceable. Whether they learn the lesson or not is up to them, but if I were to choose words to describe Elon Musk, 'complacent' certainly wouldn't be one of them.
Musk has been hit with a serious reality check after last months expensive disaster. It's going to take more than smoke and mirrors to fix SpaceX and Tesla's problems. Musk is hyping EV performance so as to generate a lot of sales to pay for the unprofitable EV operations now that he doesn't have revenues from the SpaceX project to underwrite Tesla. Musk's entire Biz portfolio depends on tax payer provided public grants to even exist. None of his current deals are actually profitable.
SpaceX doesn't have problems. Their first mission rocket has exploded. No-one else has a better safety record though. So as long as they don't make a habit of it, they have secure work from NASA and the airforce for years. Plus they appear to be cheaper than the competition, and have a strategy to become cheaper still, which still leaves them ahead for a few years, even if reusabiliy fails. They just need to win a bit more commercial satellite work. The Russians are having worse problems.
I don't know enough about Tesla to have an opinion.
Having watched the lovely launch video, I'm intrigued as to how the reusable bits all come down nicely on the same site, and I wonder where that site might be.
For one thing, the launch supposedly takes place from Canaveral, and presumably heads east, in the normal rocket-heading-for-orbit way. This means that the first stages would detatch somewhere over the Atlantic - so after they detach and spin round, in order to return to what appears to be a land-based landing platform, they must be carrying enough fuel to burn off all the eastward velocity and then fly all the way back west to Florida. That's in addition to the fuel they need to burn off the westward return velocity when they reach the landing site, and the fuel they need for the soft descent.
Even wierder is that the middle reusable stage burns for much longer than the outer two, so it detaches waaay further downrange - yet it returns to the same landing stage.
I guess we're not supposed to get picky about something which is essentially a sales video, but they must realise that anyone interested enough to watch this stuff must have at least the most basic acquaintance with them pesky laws o' physics.
Either I'm a total muppet, or they are...
Overall, SpaceX fuel tanks are the lightest in the industry, and the engines have amazing thrust to weight ratio. All this means that without the payload, the booster stages are amazingly light, meanjng the fuel goed muuuuch much further.
The side boosters will be pumping fuel to the central core booster during flight, which means they'll detach earlier than what the first stage does now on vanilla Falcon 9, so for the side boosters, return will be easier and will require less fuel.
The central core, however, will need more fuel than current F9. For some missions they'll have to barge land or discard the central core, or all 3, depending on load and deployment orbit.
The published capacity (and price list!) for F9 takes into account fuel reserve needed for recovery. SpaceX has flown heavier loads than that though, without recovery attempts on first stage.
The other thing and probably minor but important is the earth is rotating. So the launch pad will be a bit (for some value of "bit") closer. As I recall, Canaveral is at the 600mph point for the earth's rotation. So for a 5-10 minute burn, it will be 30 to 60 miles closer the separation point which is something like 150 miles downrange... Every little bit helps in this.
Disclaimer: I'm not 100% sure of the maths or numbers and I recall reading somewhere that this was calculated in for positioning the barge so it is ending up under the 1st stage while anchored 100"+ miles off the coast.
"Overall, SpaceX fuel tanks are the lightest in the industry, and the engines have amazing thrust to weight ratio" - this also means, I believe, that one of the issues with landing is that even using a single engine at minimum thrust it still has net lift. So it cannot just gently lower itself down at whatever pace it feels like - it has to set a descent trajectory with positive vertical acceleration that happens to end with zero velocity exactly(*) on the pad/barge...
(*) obviously there is a certain amount of tweaking you can do, there are cold gas thrusters and the legs can take a certain range of non-zero landing speeds, but, still, it's tricky...
"For one thing, the launch supposedly takes place from Canaveral, and presumably heads east"
The first stage separates less than 30km downrange - by which stage it's so light that turning around is fairly easy. Ground horizontal speed isn't particularly high (The first stage's primary job is to get the stack clear of the lower atmosphere, not to get it to orbital velocity)
This is covered at https://www.reddit.com/r/spacex/wiki/faq/reusability and there are launch profiles for sea and land recovery linked from that point.
Second stage return would require a "once around" profile. It's also doable.
Eliminating jobs is progress and ought to be encouraged!
Government interference in the economy ought to be prohibited. I think it's unconstitutional, as it DAMAGES the "general welfare".
Since when does the United States Constitution empower the Federal Government to intentionally harm the entire American people, for the benefit of elites who have corrupted the political system - not just some firms or wealthy people, but ALL the damn pressure groups plus the activists in both political parties?
We ought to execute those corruptors for Treason, not screw the public for their benefit!
... with 1960s-era kerosene technology? (Saturn V first stage used kerosene, the other two hydrogen).
Just a note: without hydrogen technology, there would have not been any New Horizon near Pluto last week. The Centaur upper stage is so efficient because it uses hydrogen. And the reason nor Russia nor Europe or anybody else can send probes beyond Mars (without complex gravity assists) is exactly the lack of this kind of powerful upper stages. Sure, it's not a cheap nor simple technology - it's just the most powerful available.
Liquid hydrogen is a fantastic fuel but its density is less than a tenth of that of kerosene, so you need comparatively huge fuel tanks to store it. Huge fuel tanks generate lots of atmospheric drag, so to get through the lower parts of the atmosphere, hydrocarbons or solid boosters are typically used. The propellant used in modern solid rocket motors is about 25 times the density of liquid hydrogen, which is partly responsible for their popularity as boosters.
I should also point out that LH2 powered engines are the most efficient, but they're not the most powerful, not by a long shot. Of engines that have actually been used, the most powerful kerosene engine produces just over twice as much thrust as the most powerful hydrogen engine, while the most powerful solid rocket motor produces four times as much.
Are you suggesting that Europe and Russia don't have the ability to send hydrogen fuelled rockets? Because they certainly do. Ariane 5 for example is LH2 all the way, with solid boosters to help it out of the atmosphere.
LH2 is a sixth the density of RP-1 kerosene, not a tenth. It's still bulky and difficult to produce, handle on the launchpad and burn in a rocket motor but it produces much better performance than LOX/RP-1 during most of the flight once it's out of of the atmosphere as the jet velocity is a lot higher. At low altitudes rockets aren't travelling very fast so drag isn't that important and by the time they're going fast they're almost out of the atmosphere and drag is again not an important factor.
The most advanced liquid fuelled engines are LOX/LH2 -- the Ariane V Vulcain 2, the Japanese H2 series engines and the RS-68 that powers the largest launcher currently available today, the Delta 4 Heavy which is a pure LOX/LH2 launcher whereas the others use solid boosters as an assist during the early part of the flight.
Even SpaceX want to move forward from RP-1, developing the Raptor engine burning liquid methane (which is less dense than RP-1 necessitating larger tanks and with theoretically similar performance to LH2 without its deep cryogenic problems). However others have tried liquid methane before and abandoned it. I've heard there's a problem with coking up of the injectors and damage to the turbopumps using methane due to decomposition of the fuel.
LH2 is a sixth the density of RP-1 kerosene, not a tenth.
That density calculation was from the numbers quoted by Wikipedia.
LH2: 70.9 kg/m³
RP-1: 810 kg/m³
I can believe it being one sixth if you're looking at the complete propellant system however, i.e. including the LOX that they typically both use as oxidiser.
At low altitudes rockets aren't travelling very fast so drag isn't that important and by the time they're going fast they're almost out of the atmosphere and drag is again not an important factor.
Maximum dynamic pressure generally occurs early during the first stage of most multi-stage rockets. For example the Falcon 9 v1.1 first stage burns for ~180 seconds while the vehicle reaches max Q at ~80 s. In the case of the Shuttle, max Q was limited by the strength of the vehicle. A less bulky rocket provides a benefit in such a situation.
One thing worth bearing in mind is that when it comes to deep space missions, launch costs are largely irrelevant. The total cost of the Mars Science Laboratory, including the laser tank El Reg is so fond of, is around $2.5 billion to date, with more to come if the rover and orbiter continue working. The cost of an Atlas V launch is around $200 million. A Falcon Heavy launch is around $100 million. Obviously reducing costs isn't a bad thing, but when you're dealing with programmes that cost billions, and overrun by billions (MSL cost over a billion more than it was supposed to), any savings on launch costs are little more than rounding errors.
This is not to knock Falcon and Musk, when it comes to the far more common and useful uses for such launch systems, getting some competition involved and bringing prices down is great. It's just that people always seem to start talking about missions to Mars and the like, and at that point any possible cost savings are just not relevant.
If you are sending a single probe to Mars that took 10years to design and build and will be operated for years - that's true.
If you want a permanent base and need to lift 1000t of supplies to Mars in 100s of launches then the delivery charge starts to become significant.
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