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.

[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.

[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.

[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.

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.

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.

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: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?

[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.