SpaceX aims big with massive new rocket

http://www.flightglobal.com/news/articles/spacex-aims-big-with-massive-new-rocket-377687/?

by someperson • 14 years ago

117 49 14 years ago

someperson3• 14 years ago

This was submitted 11 hours ago (http://news.ycombinator.com/item?id=4661364), but only got 9 upvotes so was probably missed by many people. I sincerely believe this is strong Hacker News material that wasn't successful due to an unfortunate submission time, so it's worth resubmitting. This news deserves quality HN discussion.

someperson3• 14 years ago

> Musk declined to say what 'MCT' stands for, and declined to answer further questions on the project.

There's some speculation [1] that MCT stands for Mars Crew Transporter (or Mars Cargo Transporter).

(The comments on [1] are very interesting, speculating on Musk's aims for a rocket that currently doesn't have that much value to private industry)

[1] http://nextbigfuture.com/2012/10/spacex-developing-larger-en...

robbiep5• 14 years ago

aaah my dreams are coming true. How exciting, even from this far off speculative point.

benzofuran• 14 years ago

I was thinking the same thing - either Moon or Mars Crew / Cargo / Colony Transporter. It's an exciting time around these parts, and as I understand it the Merlin concept is pretty scaleable.

Perhaps the new fuel he's speaking of is some sort of hypergolic mixture (Hydrazine etc) that can be used for just about everything once the vessel arrives somewhere without much available oxygen.

TeMPOraL• 14 years ago

SpaceX - because screw FTL, we'll just build a better rocket. ;).

Jokes aside, they're doing really impressive job and I'm very happy to see visible progress in what I thought was a stale industry.

robbiep5• 14 years ago

possible payload range of the new rocket is 150-200t to low Earth orbit (LEO). A vehicle of that size would easily eclipse NASA's proposed Space Launch System, which will eventually be capable of launching 130t to LEO

This really allows you to begin to grasp the economics of what Musk et al are doing -

* The Space Launch System has been funded to the tune of $17Bn through to 2017 (Wiki)

* SpaceX got through the Falcon 1 and Falcon 9 development to where we are now (Viable launch system with paying clients) on around ~$1Bn

Even assuming that they have to start the development from scratch, new tooling, new plant and equipment, you could extrapolate out at a stretch that perhaps it would cost a cool $3Bn (And likely well under this) if they are planning on having some form of prototype 'MCT' up and running in around 3 years

so that would be around 1/6th the cost of a bloated government program for an extremely heavy lift capability, potentially re-usable if they are able to complete the engineering of that little monkey, making production of a space elevator within the realms of possibility (and maybe making earth rocket launches redundant!) as well as cheap heavy launch capability to mars.

The solar system is getting a lot smaller, it seems.

jacquesm2• 14 years ago

> making production of a space elevator within the realms of possibility

Rocketry has little to do with a space elevator, the materials science for a space elevator does not even exist.

robbiep5• 14 years ago

you're right, they are completely different fields.

However one of the more likely methods of construction (from this distant point anyway) would be a launch of lots of material, tie it all to some asteroid or other large counterweight that has been put in space a good 90,000+km away, and then unspool it all to the surface, which would require a good and cheap heavy launch capacity

(I suppose you could say if we are going to do such an undertaking as build a space elevator, with all the billions it may entail, then launch costs to get it going will probably be the least of our worries, but as far as I see it, every little bit helps!)

DennisP• 14 years ago

The material doesn't exist, but the materials science certainly does. Carbon nanotubes are theoretically strong enough, and a ribbon made of nanotubes several centimeters long with a good epoxy gluing them together would do the trick, according to a NASA study by Bradley Edwards.

Nobody's achieved it yet, but plenty of people are working on it.

precisioncoder• 14 years ago

The really exciting thing is that they're working on making things reusable since that seems to be the major barrier to affordable launches. Things like reusable rocket stages: http://spaceflightnow.com/news/n1209/24grasshopper/ and reusable spacecraft: http://en.wikipedia.org/wiki/Dragon_(spacecraft)

I always found it mindblowing that we spent billions on systems that we then destroyed to get things out of our gravity well. I'm really exited about what the future will bring, what a great time to be alive.

sbierwagen• 14 years ago

"Elon Announces He Might Be Building A New Rocket, Provides Absolutely No Details At All."

6m's pretty big, though. Falcon 9 is 3.66m. Ares V (the space shuttle replacement) is 10m. Saturn V was 10.1m.

I'm really not sure why they're not using RP-1, though. What's the alternative propellant? LH2 has all sorts of problems.

cdash• 14 years ago

My guess is that they will be using a methane engine.

Gravityloss2• 14 years ago

That's an interesting point.

Methane is sort of halfway between kerosene and hydrogen. No operational space launcher has used it, though, as far as I know, some engines like the venerabe RL-10 hydrogen upper stage work horse have been modified to run on it on a test bench.

ballooney5• 14 years ago

If we're playing 'guess-the-acronym', I'm going to depart from something Mars-based and suggest that the 'C' is to do with 'Cryogenic', and that now that they are more confident with engines they might be switching to a harder, but much higher performance, fuel combination like liquid oxygen with liquid hydrogen.

Whereas LOX+Kerosene has a Specific Impulse (crudely the amount of 'go' you get from a pound of propellent) of about 340s, LOX+Hydrogen engines have an Isp of about 450. That's really a huge increase in terms of what you can launch with a given size of rocket.

Tom Mueller, the head of propulsion at SpaceX, previously worked for TRW (the company that did the US's ICBMs in the 50s) and while there he worked on a LOX+Hydrogen engine, the TR106 ( http://en.wikipedia.org/wiki/TR-106 ), which was a beast.

It's harder to work with - both propellants are very cryogenic - but any rocket engine designer will be very aware that LOX+Hydrogen is hovering at the top of the evolutionary ladder looking mighty attractive for those that have the resources to take it on - a position Space X find itself in as they become more mature and heavyweight. They're already looking at it for their replacement Upper stage vacuum engine for Falcon 9 - the Raptor ( http://en.wikipedia.org/wiki/Raptor_(rocket_stage) ).

Also, almost any Mars mission would involve a lot of heavy lifting into low earth orbit to construct a vehicle that would transport people there and back. A space vehicle that can support several people for say 2 years, and move itself to and from Mars, is going to by way bigger than anything that can be launched by a single rocket all at once. A big heavy-lifter whose engines have a much improved Isp (which rather relaxes the expensive mass saving measures you need in the rest of the rocket to launch a given payload, or alternatively lets you launch a much heavier payload for the same vehicle) is consistant with a mars road map.

I doubt they would undertake something like this just for Mars - developing rocket engines is hecka expensive. SpaceX got started by inheriting most of the cancelled FastTrac project from Nasa ( http://en.wikipedia.org/wiki/Fastrac_(engine) ) and indeed still outsource their turbopumps (the hardest bit of an engine) to Barber Nichols, who did the design for Fastrac. That was a great move on their part - starting with a blank sheet would have been madly expensive and very slow - a working baseline engine design is a very high-dimensional optimisation problem, before you even get to cutting metal. My point is, if they're now starting clean-sheet engine design, I'm sure they must have in mind some way for it to pay for itself because it's a hugely costly business.

We live in interesting times!

nkoren5• 14 years ago

Hydrogen brings absolute oodles of troubles with it. For upper stages, where it is much more critical to minimise the wet weight, that trouble is generally worthwhile. For lower stages, not so much -- it's generally FAR more cost-effective to just build a heavier stages which will do the same job, but with lower ISP. In the past, SpaceX has always made the (correct, IMHO) decision to optimise the cost-efficiency of their rockets, rather than the propulsion efficiency, and hopefully they won't stray from that path.

(They've said in the past that they're working on a LH2 upper stage already, so if you see them building up a cryogenic capacity, that would explain why).

Also, I kinda miss the days when they could get away with calling their next generation rocket the "BFR", and no true geek needed to even ask what that stood for.

ballooney5• 14 years ago

Indeed, as I say it's very much harder to work with, but it's worth a revisit with 2012 technology, I think. I also am involved with oxygen+hydrogen rocket propulsion research but can't really discuss it much here. But things have come on a bit in the last 30 years :)

Re: 'BFR', well I have a few hypotheses about 'MCT' in a similar vein but I reasoned they might be a little bit blue for HN!

Edit: A better reason for first stage hydrogen occured to me over a cup of tea:

> "SpaceX has always made the (correct, IMHO) decision to optimise the cost-efficiency of their rockets, rather than the propulsion efficiency, and hopefully they won't stray from that path."

I think the economics change when you try and go reusable in the way that they are. Lox Hydrogen engines and tankage might be more expensive, which is obviously a factor in an expendable vehicle, but if you reuse the vehicle, and have to keep enough fuel back to land, as SpaceX plan, I think actually the equation goes far more back towards optimising for propulsion efficiency in order to get the cost efficiency. The launcher cost metric is basically dollars per kg into orbit, and for a given reusable rocket, lox+hydrogen will get many more kgs into orbit than lox+kerosene - you need to keep much less fuel back in reserve to land the various rocket stages, and the extra fuel you can use on the ascent is also a lot more thrusty per unit mass. I wouldn't be surprised, assuming you sell at a dollar/kg price, if lox+hydrogen ended up being much more profitable in reusables than lox+kerosene, everything else being equal. I have not done the sums though.

someperson3• 14 years ago

Heh, I didn't realise Musk used to do that.

I found a well written and interesting article from that period of time (2005), it's not his first announcement of "BFR" but it's worth a read just to remind ourselves how far SpaceX has come. Also it has some tidbits on his roadmap for the vehicle's development: http://www.thespacereview.com/article/497/1 (Fairly sure he's talking about the super heavy lift, using the Merlin 2 and all)

>Musk said he that while he would like to slow down the rate of growth the company has experienced since its inception over three years ago, he envisions that SpaceX could grow as large as 400-500 people, but no larger. “Companies do change once they grow beyond a certain level,” he said. “Once everyone doesn’t know everyone, the company becomes slightly different.”

SpaceX now has more than 1800 employees.

baq• 14 years ago

I'm going to add a link to this most excellent book about rocket propellants called Ignition!: http://library.sciencemadness.org/library/books/ignition.pdf. Foreword by Asimov himself, who was friends with the author. It's an entertaining description of years of work on the topic.

ballooney5• 14 years ago

My comment serves no purose other than to say YES. I love this book dearly, it's probably the best written and most enjoyable niche technical book ever written. It's an absolute gem. I high commend it to people as an excellent short read. One of those instances where you say 'why on earth would I be interested in the history of liquid rocket propellents?' but you should read it anyway - it's massively enjoyable, some bits are laugh-out-loud funny, and a tour de force in technical writing and communicating complex ideas to non specialist readers.

It actually got me into rocket propulsion research, having been a signal processing, ML and control theory person by background. May I offer it my highest commendation to the curious HNer and thank you baq for providing a link to it.

ommunist• 14 years ago

We lived in much more interesting times. N1 rocket 40 years ago had better isp. And "Energia" single unit (up to 8 could be equipped in a single complex) had isp of 476s 20 (yes, twenty) years ago. This enabled the USSR to send 20t to Mars or 8t to Jupiter in 1991.

But the USSR falled, and this tech will never be recovered.

subsystem• 14 years ago

The Antares rocket uses, or is about to use, NK-33 engines recovered from the N1 program. The reason these engines are so efficient is that they are closed loop. But that doesn't mean they are overall cost efficient. Of course when you're going beyond orbit the calculations change.

http://en.wikipedia.org/wiki/Staged_combustion_cycle_(rocket... http://www.orbital.com/Antares/

kamaal2• 14 years ago

>>But the USSR falled, and this tech will never be recovered.

Ugly fallout of politics. By the way what happened to all the technology and intellectual power?

I mean shouldn't Russia still have it?

avar• 14 years ago

    Also, almost any Mars mission would involve a lot of heavy lifting
    into low earth orbit to construct a vehicle that would transport
    people there and back.

I keep seeing this assertion but I'm genuinely curious to know why this is the case.

If you're going to assemble the vehicle in LEO anyway before you send it off to Mars why is it so much better to do so by lifting up X pieces for assembly with X huge rockets instead of lifting up X * N pieces on X * N smaller rockets?

Sure you get into engineering problems eventually if your rockets are too small, since any single component can't be larger than those rockets can carry. But if nobody even has a design for such an in-orbit-assembled vehicle, then just starting out by making a really big rocket seems to be a case of putting the cart before the horse.

robbiep5• 14 years ago

My guess, and I'm sure someone more knowledgable will chime in, would be efficiencibutton a larger rocket/lift capability- Defintely with the current 'throwaway' model, where whole rocket costs are ~95%+ cf. fuel; but I believe even with re-usable rockets (as they are aiming for) you have significant cost advantage per kg (or pound if you prefer) from a larger rocket.

So, as I see it, less cost, less launches, less messy construction (larger modules/however the beast turns out)

stcredzero• 14 years ago

Actually, someone came up with a variant of Zubrin's Mars Direct plan that involves in-orbit assembly of pieces launched by existing rockets.

masklinn• 14 years ago

> During an April interview, SpaceX president Gwynne Shotwell discussed a project with similar characteristics, describing engines with "more than 1.5 million pounds" of thrust.

For comparison, 6.7MN (1.5 million pounds) was roughly the thrust of Saturn V's F-1 engines (it had 5 on first stage and that many J-2 — at a mere 4.4MN each — on second stage), and it had an LEO payload quite a bit under those asserted here (120t).

Going beyond that means SpaceX is going to compete with the Zenit's RD-171 (~8MN), which is the current holder of "most powerful liquid-fuel rocket engine" title (the shuttle boosters are the holder of "most powerful rocket engine" title at more than 12MN each).

The Merlin page[0] seems to confirm that, suggesting the Merlin 2 is planned for around 8.5MN. That's absolutely enormous.

You still have to wonder how many of these things they'll put on a rocket to get it to push the expected 200t to LEO: the original Energia only lifted 100t to LEO with 4 zenit boosters (so 4xRD-170) and its own engines (4xRD-0120 at 2MN each), there were plans to have a 200t-lifting Energia… by strapping 8 zenits to it

[0] http://en.wikipedia.org/wiki/Merlin_(rocket_engine)#Merlin_2

Gravityloss2• 14 years ago

How many launches per year?

I don't see the economics here. Not with expendable, not with reusable.

Plus, if you have fewer big engines, you can't land on them as their thrust is too high.

JulianMorrison• 14 years ago

Are they building Sea Dragon?

danieldrehmer• 14 years ago

A few days before this article, a redditor reported a conversation where Elon Musk tells his friend that Dragon is just an appetizer for what he called "Mars Colonial Transport"... MCT?

http://www.reddit.com/r/space/comments/11bpvi/elon_musk_just...

bejar37• 14 years ago

Eaoq

teeja• 14 years ago

Given Musk's vision for the future, MCT clearly means Mars Colonization Transport.

SpaceX aims big with massive new rocket

Related Stories