Battle of the Heavy Lift Rockets

schwit1 writes: Check out this detailed and informative look at the unspoken competiton between NASA's SLS rocket and SpaceX's planned heavy lift rocket. It's being designed to be even more powerful than the Falcon Heavy. Key quote: "It is clear SpaceX envisions a rocket far more powerful than even the fully evolved Block 2 SLS – a NASA rocket that isn't set to be launched until the 2030s." The SpaceX rocket hinges on whether the company can successfully build its new Raptor engine. If they do, they will have their heavy lift rocket in the air and functioning far sooner than NASA, and for far less money.

Comments

Competition is good.

[Z00L00K]

There have been way too little competition in this area the last decades. Considering that the Russian RD-180 engines designed in the 70's&80's are still seen as state of the art it is obviously a stagnant situation.

Re:Competition is good.

[tomhath]

Much of the progress in propeller driven aircraft happened during the 1930's by racers like Howard Hughes

Re:Competition is good.

[Ol Olsoc]

But that's government "progress" for you. Compare 60 years of spaceflight technology from 1955 to 2015 (OK, the years were cherry-picked) and it's still basically the same: LOX/Kerosene or LOX/LH2 and some engines are bigger and some are smaller.

It's short of amazing that you can attempt to attack the evul guvmint on this one. And be so mind bogglingly wrong at the same time.

There are many different types of engines out there. Aluminum perchlorate mixture engines, Hybrid nitrous oxide/polymer engines, some really interesting combos where the fuel is paraffin and with mixed other additives like Al, or Li. Hydrazine rockets, Ion thrusters, solar sails, there are hundreds of designs. Many of which haven't happened yet due to one or another limitation.

The Kero-LOX and Liquid Hydrogen-LOX rockets are just examples of the most powerful liquid fueled rockets.

Lot's of different types of rockets out there.

And lack of any new and more powerful engines that exist that exist are almost certainly not caused by jackbooted thugs, just itching to put loyal citizens in FEMA Death camps while installing a new world order. where we all pay 300 percent of our salary in taxes that go to urban thugs.

It is a matter of physics, which turns out to be remarkably resistant to the invisible guiding hand of the free market. We can build the biggest, bad-assed, Chuck Norris rocket engine that we can dial up the power the whole way to 11, but if we can't pump in the fuel quickly enough, or the resultant temperatures are beyond the melting point of any available material, And neither Grover Norquist not Ayn Rand can fix that.

Maybe the answer is in teaching Intelligent design in school?

Anyhow, I went off the deep end on your idea to illustrate just how silly the idea that the government is holding back progress on rocketry. Hopefully humorously, but that's for others to judge. None of the engines in use by the commercial outfits are some dramatic new design, and it's all physics and material design, not ideology. Now look at aircraft development from (another cherry-picked 60 years): 1910 to 1970. That went from wooden biplanes to the 747. Sure, there were a few "helpful" eras in between - like 2 major wars and lots more lesser ones, which kicked development up by several notches. But those developments were still the result of commercial companies, just as NASA contracts out work, today.

Re:Competition is good.

[khallow]

Anyhow, I went off the deep end on your idea to illustrate just how silly the idea that the government is holding back progress on rocketry.

Like the US banning private launch vehicles through to 1984? Or maintaining a launch oligopoly funded on the public dollar through to the last decade? Or paying a few tens of billions to develop a huge rocket while not paying a few billion to get someone like SpaceX to develop said rocket.

Re:Competition is good.

[TubeSteak]

Or maintaining a launch oligopoly funded on the public dollar through to the last decade?

It took two world wars and one cold war to get us to where we are today.
Feel free to complain about the oligopoly, but don't pretend like Boeing, North American, and Douglas were going to build the Saturn V rocket on their own dime.

Or paying a few tens of billions to develop a huge rocket while not paying a few billion to get someone like SpaceX to develop said rocket.

"Or paying a few tens of billions to develop a huge rocket " to who?

Boeing is the prime contractor for the design, development, test and production of the launch vehicle cryogenic stages, as well as development of the avionics suite.

You had a three sentence post and two of them were full of ignorance.

Re:Competition is good.

[fustakrakich]

"Spaceflight" technology goes back to 1926.

And the 747 still burns kerosene. Progress in that respect has remained static since the first steam engine. However, think about the fact that man spent thousands of years on horseback, makes the present rate of progress look pretty good.

Re:Competition is good.

[khallow]

You had a three sentence post and two of them were full of ignorance.

I was disabusing the previous poster of some pretty misguided notions. I guess you need some help as well. I notice, for example, that you don't actually disagree, you just choose to characterize my short observations as "full of ignorance". Do you have a reason why you think so?

I'm quite aware how NASA operates - by writing large checks to private contractors who make sure the money gets spent in the right congressional districts. But that sort of activity hasn't resulted in a viable launch platform since the 70s, when the Space Shuttle was developed.

And rather than continue to do something that hasn't worked in around four decades (and really, the Space Shuttle and the Apollo programs were just money sinks) maybe we could look at things that do work, like SpaceX's approach?

Re:Competition is good.

[petes_PoV]

Anyhow, I went off the deep end on your idea to illustrate just how silly the idea that the government is holding back progress

unfortunately when you went off the deep end, you missed the pool completely.

This was never about government consipracy. It was simply that governments have no need of improved performance or improved efficiency - when they have (as near as dammit) infinite amounts of money available to "solve" the problem with.

The commercial aircraft makers, being subject to both competition and finite resources *had* to make things better to stave off their competitors who were in the same race for betterment and profit and to meet clients' expectations of improved performance: speed, reliability, payload capacity and lowered cost. Governments do not have those drivers, hence they have no need to improve the vehicles they use.

splash!

Re:Competition is good.

[Ol Olsoc]

Like the US banning private launch vehicles through to 1984?

I'm not allowed to have an unshielded reactor in my backyard either. Fucking liberals.

Yours is just more of the Science as ideology. How about a couple minutes for you to understand exactly why it wasn't allowed.....playing that time passing song....

Times up, BZZZZT! - No it wasn't evul democrats or Beyonce flashing the Illuminati sign at a burning man festival. Not even free birth control for women.

1. Understand that the amount of energy let loose in even a small rocket launch is pretty impressive. So it sort of makes sense to limit especially early private launching, as failure was not only an option, it was pretty likely.

Note of course, if you support second amendment rights to own artillery and hand grenades, you might have an argument there. I mean come on - Just assault rifles does not make for a well armed militia. Sheesh - next thing you know, we won't allow little children to mess with fully automaitic weapons.

Sorry - had one too many cups of coffee this morning. But rocketry is dangerous work, kinda accidentally kills people once in a while. That's no biggie, but it might level a job creator's house, and then the economy will fail , you betchya.

2. There were some hatey people who wanted to kill us, thad they were launching these flamey explodey things. Perhaps we were a little afraid that we might accidentally set off World war 3 when an early private launch of our own, unfettered by government regulations, failed and wiped out a town?

Eventually though, we'd all settle back down and figure out the sticks and stones we were going to fight World War 4 with.

Or maintaining a launch oligopoly funded on the public dollar through to the last decade? Or paying a few tens of billions to develop a huge rocket while not paying a few billion to get someone like SpaceX to develop said rocket.

So what you are telling me is that for some odd reason, despite private rocket launches in their own facilities using their own rockets is now considered okay, and done on a regular basis, you are still in a white hot seething astrorage anger and feeling much butthurt because of the way it used to be a long time ago?

Do you have any newsletters about the evil radical-diabolical Communist Franklin Delano Roosevelt and how he is spreading soclialism from his gravesite? It's important to get that news out.

Think I'm making fun of you? You got that right.

Re:Competition is good.

[Anonymous Coward]

"Or paying a few tens of billions to develop a huge rocket " to who?

Boeing is the prime contractor for the design, development, test and production of the launch vehicle cryogenic stages, as well as development of the avionics suite.

TFA: "However, it is clear SpaceX envisions a rocket far more powerful than even the fully evolved Block 2 SLS â" a NASA rocket that isnâ(TM)t set to be launched until the 2030s."

The difference isn't private/gummint. All companies strive to make money.

The difference is in the objectives of the organizations involved. The objective of Congress is to get re-elected by keeping the pork flowing. The objective of Boeing is to take as long as possible to build anything because the longer it takes, the more pork flows in. Congress doesn't give a fuck if it ever flies. Boeing would be delighted if the project is funded to 2030, and even more delighted if cost overruns and delays pushed it out to 2050. Everybody has well-paid jobs for life!

The objective of SpaceX is Mars, bitches.

Musk needs an HLV long before 2030 if he is to live long enough to be able to retire on Mars. Because he is effectively self-funded, he not answerable to the whims of Congressmen and their pork allocations. Because he is interested in living long enough to see it fly, he is not interested in delaying things to pull as much pork out of the project as possible. He will build the fucking thing himself, and it will fly.

Re:Competition is good.

[backslashdot]

NASA should wait until July/August 2015 before proposing a new launch system. That's around the same time the New Horizons space probe NASA launched back in 2008 will be reaching Pluto. I believe, hopefully, that the pictures from Pluto will capture the imagination of the public and, by proxy, Congress. That way NASA can propose a totally Giga launch system and get it approved.

Frankly SLS is lame. We're going to be stuck with whatever launch system for a few decades -- possibly longer given politics, so we better get it right. We need to be looking to build something that can scale to sustainable colony establishment class stuff.

Re:Competition is good.

[khallow]

How about a couple minutes for you to understand exactly why it wasn't allowed.....playing that time passing song....

It was because NASA needed funding for the Space Shuttle. It had nothing to do with safety. Merely, requiring private companies to post bonds prior to each launch covers your safety concerns without requiring a decade long ban.

Further, it's worth noting that many of the companies which by your reckoning can't be trusted to run a safe commercial launch vehicle are the same ones that were building and running NASA's Space Shuttle (as well as having decades of launch experience under their belts).

Further, it is monumentally stupid to claim that commercial launches can be confused with a nuclear attack. One launch isn't going to take out the USSR. For example, here's a story written shortly after the fall of the Shuttle monopoly.

Some of the agency's likely tactics are already evident. One strategem, reported by several observers close to the Shuttle/ ELV controversy, has been to apply pressure on contractors sup- plying major components to NASA to keep them from entering the ELV business. Although nothing has appeared in official docu- ments, it is said that NASA officials have suggested to possible private competitors that their contracts for Shuttle components might be endangered if these firms engaged in private launches. Another tactic has been to try to delay implementation of "full cost recovery," so that NASA could charge Shuttle customers less than the full cost of launches for long enough to capture the market, with the cost picked up by the taxpayer. This could close down production lines for a number of the components needed to construct and launch ELVs, making their later development far more expensive than would otherwise be the case.

What is most disturbing is that NASA's anti-competitive activities could undermine the President's broad initiative on space commercialization by undermining private sector efforts before they can acquire a firm financial footing. The agency would thereby undercut a number of key benefits for Americans that the initiative would otherwise yield.

The first thing you should do before writing stupid drivel is ask yourself, "Gee, is there really a problem here?" But no, you just had to get that anti-libertarian straw man in without regard for the history.

So what you are telling me is that for some odd reason, despite private rocket launches in their own facilities using their own rockets is now considered okay, and done on a regular basis, you are still in a white hot seething astrorage anger and feeling much butthurt because of the way it used to be a long time ago?

And you should too. Because history has a habit of repeating itself. What's going to happen when NASA has the SLS supply chain and SpaceX has the Falcon Heavy, a cheaper and more reliable competitor?

Well, that SLS supply chain, being better connected politically, are going to use their connections to sabotage SpaceX, just like Space Shuttle proponents did commercial space launch back in the 70s or the launch oligopoly did to various would-be competitors in the 80s and 90s.

They're already playing games with the Commercial Orbital Transportation Services (COTS) program which was an attempt by NASA to encourage commercial launch services, including SpaceX, to supply ISS with supplies and personnel. The number of competitors was reduced from six competitors to two by interference from Congress. There's also fishing expeditions for "anomalies" from recent Falcon 9 launches. Notice that nobody else was targeted by that demand for info

Re:Competition is good.

[ppanon]

As someone pointed out, the physics of building rocket engines hasn't significantly changed in the last 60 years. That's why the F1 engine is still the most powerful rocket we've ever designed. What has changed are manufacturing techniques like sintering laser 3D printing techniques and computer modeling to allow us to build F1 engines that are slightly more powerful and a lot cheaper than what was built for Apollo. And yet somehow we don't build them. Why? Because there's no demand for it.

There has been a lot of demand for faster, more agile, and more fuel efficient aviation - from combat aircraft for wars to civil aviation in the face of rising fuel prices. That pressure isn't as significant for the launch market because: a) there are only so many safe, useful orbits for satellites where they aren't going to interfere with eachother (in terms of signal transmission - which is what many are used for) and a lot of them are already in use; b) fuel costs are a small portion of launch costs.

So the moral of the story is a) development happens according to demand and changing requirements/conditions and b) supply-side economics is BS - consumption is limited by demand.

Re:Competition is good.

[k6mfw]

And rather than continue to do something that hasn't worked in around four decades (and really, the Space Shuttle and the Apollo programs were just money sinks) maybe we could look at things that do work, like SpaceX's approach?

Apollo succeeded because the politicos (those in power) realized if Soviets land on the moon first, they will plant the Hammer and Sickle flag on the surface that will enslave the world in Communism (not really but that's what they thought). So with that in mind, do whatever necessary to prevent that from happening otherwise their goose is cooked (strong motivator like 25 years before when threatened by Nazi Germany and Imperial Japan).

Then after what next? Shuttle was left over from more ambitious missions of orbiting stations, lunar bases, mission to Mars, etc. And it could have easily not happened. see Dale Myers on MIT OCW video in 2005 when he said at time it looked like last HSF by US would have been the Skylab missions, Apollo-Soyuz was not scheduled at that time (sorry too lazy to get link but it's on youtube). Nixon realizing many people laid off in states with lots of electoral votes (CA and FL) so give them a big program to continue, in 1972 he said to OMB stop objecting to NASA plans for Shuttle and approve it.

Fast forward to 21st century and progress made by SpaceX and others is result of wealth inequality. Few billionaires have some billions they can put into to what they want rather than meeting political objectives (war, votes, whatever).

Argue all you want, you still have to deal with the tyranny of the Rocket Equation.

Re:Competition is good.

[0123456]

Even a small percentage increase in fuel efficiency results in a significant increase in the payload that can be boosted.

Which, as I said elsewhere, is irrelevant if that 'small percentage increase' doubles the cost of the engines. It's like putting a Lamborghini engine in a truck so you can pull more cargo.

Re:Competition is good.

[HanzoSpam]

With apologies to Ernest Lawrence Thayer

The outlook wasn't brilliant for the student march that night;
The quads were filled with rent-a-cops and not a picket sign in sight;
With Cooney busted for possession, and Barrows, the riot laws;
A sickly silence fell upon the supporters of The Cause.

A straggling few got up to go, in deep despair. The rest
Clung to that hope which "springs eternal in the human breast;"
They thought, If only Gay Ol Olsoc could be rallying that mob,
We'd put up even money now, with Ol Olsoc at the quads.

But Flynn preceded Ol Olsoc, as did also Jimmy Blake,
And the former was a no-good and the latter was a fake;
Forlorn, that stricken multitude discouraged by the odds,
For there seemed but little chance of Ol Olsoc's getting to the quads.

But Flynn let fly a bottle, to the wonderment of all,
And Blake, the much despised, set a bomb off in the hall,
And when the dust had lifted and men saw what had occurred,
Jimmy beaned the Dean of Students, while the bombed out library burned.

Then from five thousand throats and more there rose a lusty yell,
It rumbled through the valley, it rattled in the dell,
A Harley roared up from the street, and was tearing up the sod,
And Ol Olsoc, Gay Ol Olsoc, was advancing through the quads.

There was ease in Ol Olsoc's manner as he wheeled into his place;
There was pride in Ol Olsoc's bearing and a smile on Ol Olsoc's face,
And when, responding to the cheers, he lightly gave a nod,
No stranger in the crowd could doubt `twas Gay Ol Olsoc at the quads.

Ten thousand eyes were on him as he gunned the throttle loud;
Five thousand tongues applauded as he signaled to the crowd.
And while the nervous officers grabbed the night sticks from their hips,
Defiance gleamed in Ol Olsoc's eye, a sneer curled Ol Olsoc's lip.

And now a can of tear gas came hurtling through the air,
And Ol Olsoc stood a-watching it in haughty grandeur there,
Close by the haughty Ol Olsoc , the can unheeded sped --
"That ain't my style," said Ol Olsoc . "Break it up!" the coppers said.

From the streets, black with people, there went up a muffled roar,
Like the beating of the storm waves on a stern and distant shore.
"Kill them; kill the pigs!" shouted someone from the mob;--
And Ol Olsoc guns his engine, and wipes-out on the lawn.

With a fist of protest shaking, Ol Olsoc's visage shone;
He jumped back on his Harley; he bade the march go on;
The Harley takes off through the quads, 'till it hits a vicious bump;
And Ol Olsoc sails through the air, landing smack upon his rump.

"Fascists!" he screeched, "Capitalist, Imperialist, Racist, Sexist pigs!"
"If I must I'll ride a tricycle, but we'll have this march - you dig?"
They saw his face grow stern and cold; they saw his muscles strain,
And they knew that Gay Ol Olsoc wouldn't lose that bike again!

The sneer is gone from Ol Olsoc's lip; his teeth are clenched in hate;
He sniffs with cruel derision as he lets go of the brake.
And now he throws it into first, the clutch he now he lets go,
And now the air is shattered as the bike takes off - alone.

Oh! somewhere there's a campus town where they drum and chant all night.
They protest for the rain forest, and demand the polar bear’s rights.
And somewhere bongs are being passed, and somewhere radicals shout;
But there is no joy at Old State U -- Gay Ol Olsoc has Wiped Out!

Re:Competition is good.

[Rockoon]

It took two world wars and one cold war to get us to where we are today.

Let me translate this for everyone:

"Yes, the government really did outlaw private space flight, and when the ban was lifted it still used its influence in order to raise barriers to entry to prevent competition with the oligarchy, but I think that it had a good reason to."

..and this true statement without the fucking spin is a far cry from negating any argument about how government held us all back yet again. The government did in fact hold us back.

The facts are that a private company can come along and get things done better and cheaper. If we were to believe the argument that the government does it better, then the government would have already done what SpaceX is doing. It didn't, therefore the government did not do it better. It had MANY decades to do so. Instead it prevented better from happening.

Define Heavy?

[danknight48]

Mr. Mueller then later updated his numbers at a follow-on conference to portray 6,900 kN of sea-level thrust, and 8,200 kN of vacuum thrust.

That took me 20 seconds to find.

Come on, its Slashdot, at least give us some technical information to back up the story.

This is the Congressinal Rocket not NASA.

[trout007]

NASA never wanted to build this rocket. It was forces in them from Congress. Plus NASA doesn't build rockets it overseas other aerospace contractors.

Re:This is the Congressinal Rocket not NASA.

[TwoUtes]

That is it in a nutshell. NASA programs have always been subject to the whims of politicians. I'd bet that the next administration/congress cancels SLS after the next presidential election, and NASA will again look inept and directionless.

Re:This is the Congressinal Rocket not NASA.

[tomhath]

The rocket they really wanted was Constellation, but Obama cancelled that one.

Re:This is the Congressinal Rocket not NASA.

[Bo'Bob'O]

And in it's place we got the commercial cargo and commercial crew programs, which have been highly successful so far. So much so that NASA is now looking to duplicate the process in other endeavors: http://spaceflightnow.com/news/n1407/27marstelecom/#.VANoxEi0b0c

Meanwhile the Orion capsule, which was the part of the constellation project that actually put humans on top of those rockets to get them into space, was kept. It's still over budget, under speced and years off from putting anyone in space.

Re:My money is on SpaceX

[Anonymous Coward]

NASA never had agility. Vision sure, but the entire institution was intentionally designed to be scattered and resistant to change. It's difficult to be institutionally agile when you're operations are spread out into as many political jurisdictions as possible.

Why does it take so long?

[tekrat]

I mean seriously, look at the SLS, it's almost entirely composed of re-used space shuttle parts. It has the main engines on the bottom of the tank re-purposed from the shuttle. it has solid rocket boosters which already exist from the shuttle -- it entirely looks like it could be cobbled together in a few month's time because it uses almost entirely existing components.

So what exactly requires so many years to make it al work when it's all basically existing tech from the shuttle? I hate to say this, but this ain't rocket science.

Re:Why does it take so long?

[db48x]

Unlike in Kerbal Space Program, when you stack rocket components on top of each other you have to reengineer the bottom one to hold up the top one; they say that they're reusing the main tank, but that might be true in a narrow sense if they reuse the H2 tank inside the orange Space Shuttle External Tank. Then you have to engineer the manufacturing processes and factories for producing any new components (and there will be lots of those), plus the modified one (easier, but still plenty to go around), plus you have to engineer the test facilities for all the components, and you have to test the test facilities, and then test the components, and then test-launch the vehicle, etc. Don't forget to document everything, and to design training procedures so that you can hire new people to build these things, and test them, etc, etc. It actually is rocket science.

Re:Why does it take so long?

[db48x]

For the most part it's a difference in magnitude. The speeds the rockets achieve are much higher than any airplane, let alone car, ever manages. The thrust of the engines is stupendous, the liquid H2 and O2 fuels are cryogenic, the flame temperatures in the engine are extreme. In fact, they're so extreme that the engines use precise control over the flow fuel and oxidizer entering the engine to create a layer of cooler gasses around the inside of the engine nozzle, so that it doesn't melt or ablate entirely away. Everything has to work in vacuum and at ambient air pressure and at max Q during flight.

All of this and more adds up to a much harder design problem, much more stringent test requirements, much tighter manufacturing tolerances, etc. The principle is the same, however; any change to one component of a system may require changes to every other component.

The one thing that all forms of engineering from (whether software, civil, aerospace, or other) have in common is the management of complexity. The automotive engineer designs the engine mounts in your car to accept a wide range of engines, so that they can manufacture several variants of the same car with different engines without having to redesign every component. Similarly, SpaceX has greatly reduced their cost and risk by reducing the complexity of their rockets; one way they did this was to use the same engine for both the first and second stages of their rockets (the first stage simply uses more of them). Another way was to avoid cryogenic fuels; they have a lower specific impulse (fuel efficiency), but a much greater space efficiency (liquid H2 is very light; that orange tank is huge, and 80% of it is for the H2 tank) plus you avoid having to deal with cryogenic fuels, and the complicated materials engineering that goes into designing the tanks to hold them.

If you want to know more, MIT has some great lectures on the subject, even ones suitable for non-engineers. A good one is An Electrical Engineering View of a Mechanical Watch . The description of this lecture only touches on superficial matters; Sussman's real point is that the means of abstraction present in an engineered system can be applied to any other engineered system, and that it's only by designing the right abstractions that engineers make continual progress in designing newer and better systems. He states this directly in the first two minutes, which is quite handy. You might also check out the video lectures for the Structure and Interpretation of Computer Programs , the first lecture of which goes into much the same topics in the realm of software engineering.

Re:Why does it take so long?

[db48x]

I got distracted and broke my links. An Electrical Engineering View of a Mechanical Watch is at http://video.mit.edu/watch/an-..., and the SICP lectures are at http://ocw.mit.edu/courses/ele...

Re: Why does it take so long?

[kellymcdonald78]

While the "Shuttle Derived" messaging was used to sell the program, it's hardly anything but. The first few flights will use left over RS-25Ds from the shuttle program, but they are far too expensive for new ones to be built and throw away each flight, so the RS-25E and RS-25F engines needed to be developed. The 4 segment SRBs from the shuttle aren't powerful enough for SLS so they've had to develop a 5 segment SRB with a new type of solid fuel with a completely new grain. The casings are also being redesigned to be expendable. While the tank is shuttle derived, it needs a completely redesigned aft section to support the engines, plumbing is completely different, and the a new interstate to support the upper stage and payloads. It would have been cheaper and faster to start from scratch, but that doesn't keep the trough filled.

No Competition Here!

[Irate Engineer]

NASA would be very happy to let SpaceX build a heavy lift booster for them. Really.

The only reason SLS exists is to keep the congresscritters from the former shuttle supply chain districts happy. That's it. NASA is desperately trying to keep funding going, and they ain't interested in pissing that money away on designing big dumb rockets, but politics says that they must to survive. Rockets are rapidly becoming a commercial technology, which is a good thing.

NASA would be very happy to buy rockets from Elon Musk and/or whoever else can put up competing articles. NASA would much rather be doing and spending its hard-fought budget on things that they do well, pushing the envelope on technologies for hard problems, like getting our asses to Mars, and science missions.

Re:No Competition Here!

[confused one]

I've come to the conclusion that this may be the unspoken official plan. Congress is driving NASA to do what they're doing; but, the Administration is sort of sitting back quietly saying very little. Note how you don't hear much from the Obama administration about SLS; but, they keep pushing Commercial Crew. I think it is possible they're just waiting for SpaceX (or one of the other commercial contractors) to fill the void and provide commercial launch capability. NASA has leased launch facilities to SpaceX and Boeing already, including pads 39A and 40 at Canaveral. Heavy lift is the next logical step. Musk has made a lot of noise publicly and given the presentation to Congress and the Administration. They're taking him seriously enough that members of Congress are trying to derail his efforts to protect their constituency. I believe the Administration is giving them the same serious consideration, standing back and waiting to see if they can pull it off.

No miracles

[nojayuk]

There are no miracles in rocket engine design. The RD-180 has pretty much the best performance to be wrung out of a sea-level-to-altitude LOX/RP-1 motor in terms of efficiency. SpaceX is still playing catchup in that area, trading off the lower cost per Merlin motor for a lower Isp from a simpler design.

As for the Raptor the "new" liquid-methane/oxygen fuel mix it will burn has the potential to produce a higher Isp than the current mainstream LOX/RP-1 mix used in motors like the Merlin, the RD-180 etc. but it comes with downsides -- it means a redesign of the rocket structure to support fully cryogenic tankerage (although not requiring the sorts of extreme temps or processing LH needs), launchpad facilities for fuelling and defuelling rockets will need to be revamped, liquid methane is half the density of RP-1 so the tanks and the rocket structure need to be larger and heavier to contain equivalent amounts of fuel and so on.

Re:No miracles

[0123456]

Efficiency is irrelevant when fuel makes up about 1% of the cost of a launch and bigger tanks are cheap. When you're throwing engines away every time, and they make up a large fraction of the cost of a launch, a low-cost engine that burns 10% more fuel can be a massive win.

Government rocket engineers have been fixated on efficiency because they rarely have to worry about cost. They can just steal more money from taxpayers.

Re:Delay is good. congress operating as designed.

[queazocotal]

'One spectacular explosion' - One explosion would be 92% reliability. (one failure in 12 launches)

Nasaspaceflight.com

[jpfulton]

For those of you who visited the link, Nasaspaceflight.com has a very well-informed stable of posters, many of whom are professionals in the space industry, and there is the L2 section where you will find much that is not available anywhere else.

Re:Rockets suck

[db48x]

A rocket is a mass driver, and all of the "scifi" types of propulsion break the laws of physics one way or another. Space elevators would be pretty nice, but we still haven't found a material strong enough. Carbon nanotubes are the current hope, but we can't make them long enough yet; they'd have to be very long indeed to make a strong enough elevator. Short nanotubes have to be glued together and then you're down to the strength of the glue.

Re:My money is on SpaceX

[0123456]

NASA went from the first suborbital manned flight to putting men on the freaking Moon in eight years. They were pretty agile back then.

Now they're spending longer than that just building a rocket that largely uses existing hardware, and has no funded missions that would require it.

Re:My money is on SpaceX

[cytg.net]

Well, when talent begins leaving NASA for SpaceX, then we know its in business...