Why is the Delta IV Heavy bigger than the Falcon Heavy yet FH has nearly double the payload and costs nearly 5x less...

>ULA has plenty of money from their previous contracts. If they need to take a loss on a few rockets to shut up the competition then they will do it.

all the money made goes back to its parents, and if lockheed and boeing feel like it they'll sprinkle a little on ula from time to time

>>Why is the Delta IV Heavy bigger than the Falcon Heavy yet FH has nearly double the payload and costs nearly 5x less per launch?
>ULA has plenty of money from their previous contracts. If they need to take a loss on a few rockets to shut up the competition then they will do it.
That's not remotely true, and doesn't correspond at all with what you're replying to.

The ULA rocket is the one that costs five times as much but carries half the payload. They can't afford to cut prices and become competitive. ULA was founded in the failure of either of the two parent companies to produce a cost-effective rocket that could compete in the commercial market. They merged their operations as part of a deal in which they set aside their litigation shitstorm and were unofficially made into cost-plus contractors.

Furthermore, the gap is only set to grow in the future. ULA has announced its plans for at least five years into the future, and none of it comes close to keeping pace with SpaceX as its reusability matures.

Not only is Vulcan going to take years to develop and has no potential to compete with Falcon 9/Heavy, but the way things are going, BFR may be flying before Vulcan. ULA lacks any engineers experienced in developing a new vehicle. The EELV program started in the mid-90s, over twenty years ago. The main people who developed those rockets have retired. ULA is fundamentally a custodial organization, taking care of the vehicle production lines and operational procedures handed down from its parent companies. When they go to build a new vehicle, you have to think of them as a startup, and the vast majority of rocket startups fail to produce a working vehicle.

And you need 5-6+ engines to be able to have one engine throttle low enough to land an empty booster.
BFR will have even more because they want engine out capability for LANDING

Honestly, I don't believe SpaceX's approach for reusability with Falcon 9 is optimal, it just fit their incremental development path.

You can always add specialized landing engines, and also use them on lift-off so they're not dead weight during the ascent phase. There are a lot of advantages to having the landing engines sized to enable hovering when empty, and also well above the pad during landings (so it doesn't kick up a lot of debris). The old concept (and placement) of vernier engines would work well.

Hovering isn't required for computers to be able to land. If your control programs are fine tuned, a hover-slam/'suicide' burn works just fine.

If it works with the main engines doing landing, why change it.
Slow landings are for people, they aren't any benefit for computers.

Sure if they can scale the raptor as easily as they claim, then they could produce a 1/10th thrust version, specifically for landing/precision burns.
They are going to make those methane/oxygen thrusters after all.

>They are going to make those methane/oxygen thrusters after all.
Sure but those are just gas-gas fueled RCS thrusters, and even though they'll be a lot more powerful than Draco thrusters for example that's still not close to what these vehicles would need to land.

In any case, the landing burn needs to be completed as fast as possible to reduce the fuel requirements. More thrust means greater acceleration, and since the rocket is actively fighting gravity during landing, it is experiencing gravity losses. An ideal landing burn would take place in an instant, and would use the minimum amount of fuel/energy. Hovering is the worst possible option, because while hovering you are expending delta V without changing your velocity, you're just counteracting gravity and using fuel in the process.

>Sure but those are just gas-gas fueled RCS thrusters
Just like in the FFSC engines

These raptor engines are going to be a little too large for landing on the moon too.

>An ideal landing burn would take place in an instant
You aren't working around ideals though, you are working around never losing the vehicle to high winds or your GPS/altitude sensors being off.

>Just like in the FFSC engines
No, the gas feeding those maneuvering engines is very low pressure by comparison.

>These raptor engines are going to be a little too large for landing on the moon too.

Elon says they won't be too much for landing on the Moon. The Mars landing burn takes about 40 seconds, the Moon landing burn (assuming they don't deorbit and land in the same burn) would take less time. The way SpaceX does their landings is they calculate how long it will take for the rocket to cancel all vertical and horizontal velocity at full throttle, then they start the burn early at a lower throttle setting. The computer keeps track of that predicted burn time, the burn time they will get at their current throttle setting, the altitude etc, and keeps the rocket technically on a crash course up until the final few meters of descent, slowly throttling the engine up as speed decreases and the ground gets closer, and cutting the engine when everything hits zero. Landing on the Moon they would need to start the engine either lower or faster than on Mars or on Earth, but the same software would figure out the correct landing burn time and throttle settings. It'd be nearly impossible for a human, but for a computer it's easy. Oh, and I should mention that with only the landing engines on and with cargo and fuel aboard, the Spaceship landing on the Moon should have a lower maximum TWR than a Falcon 9 here on Earth, and they've landed those things close to 20 times in a row now, with rough seas and wind to deal with.

>You aren't working around ideals though

Correct, which is why the Falcon 9 (and future SpaceX vehicles) don't/won't use all main engines to land. That would technically be the most efficient, but offers the least safety margin. The margin they get currently, with a single Merlin providing TWR>1, is plenty for a computer to compensate for serious turbulence/wind/waves. The margin they will have with BFR is greater.

>those are just gas-gas fueled RCS thrusters
You've been listening to fan theories over official statements. They're going to be simplified and scaled down Raptor engines, without the main compression turbines to generate high chamber pressure.

Low specific impulse, but they can be made with as high thrust as is needed, and you don't need orbital-launch-class specific impulse for a landing burn. They need fairly high thrust even for RCS on something as big as BFR, that will carry such heavy payloads.

>Hovering is the worst possible option
The capability of hovering gives the best possible range of options to ensure a safe landing, and the required propellant is not that high.

Nothing SpaceX has said would indicate that they're going to use anything other than Raptor to land either stage of BFR (both are big enough to use the landing technique they've proven and matured on Falcon 9), but if they make a reusable smaller stage, like a single-Raptor upper stage for Falcon Heavy (as I think is likely before BFR), it would need to land on some kind of other thruster.

Everything SpaceX has said for the past 8 months has indicated that they will no longer pursue second stage reusability for Falcon 9 or Heavy, because the R&D would be wasted on a soon-to-be outdated system. Not only that, a hypothetical new reusable second stage would need to be man rated all over again, requiring the old design to continue to be built for manned flights until they could freeze the design of the reusable stage and get it qualified. This would all come at a lot of expense and would delay BFR, all for a reusable second stage that would have an even smaller payload ceiling than the current reusable Falcon 9 has. I know the USAF paid for some small percentage of Raptor development as a precursor to maybe paying for a reusable upper stage for FH using Raptor, but so far there's little indication that they will actually develop that stage either.

>They're going to be simplified and scaled down Raptor engines, without the main compression turbines to generate high chamber pressure.
So, an entirely different engine? Elon said (when asked if the thrusters would resemble methane powered Superdraco engines) that the thrust chamber would be more similar to Raptor. My understanding is that he was talking about the fuel injection and ignition system being similar, since both engines are burning the same chemicals and have the same issue with getting everything mixed and lit. He said the thrusters will have no turbopumps, they're going to be entirely pressure fed so there's zero spin delay. The nozzle expansion ratio will be different due to the much lower chamber pressure, and it will also be truncated to fit into vehicles they're going to be installed on. The thrusters will of course take into account what SpaceX ha learned in developing Raptor, but it's not the same as taking Raptor and scaling it down, they're going to be completely different engines except for propellant choice.

It should be noted that virtually all competition relies on spacex failure rather than on development of cost-effective and capable vehicles. And on stunted market that will not grow of course. Ariane 6 for example is designed to compete with expendable falcon 9, from 2020 on. Others even pretend spacex doesn't exist.
Depending on how things turn out, it might bite them in the ass very badly.

>Everything SpaceX has said for the past 8 months has indicated that they will no longer pursue second stage reusability for Falcon 9 or Heavy, because the R&D would be wasted on a soon-to-be outdated system.
1) They've announced the intention to start upper stage recovery tests in 2018 on Falcon 9.
2) They're currently in the middle of spending $30+ million from the USAF on a contract to develop Raptor as an upper stage engine for Falcon 9/H.
3) They've said they'll (only) develop a Raptor upper stage if a customer pays for it.
4) The "suborbital test vehicle" for the BFR upper stage, with all sea-level Raptors, would be the right size to serve as a booster replacing the three cores of Falcon Heavy.
5) The plan to develop BFR and then simply abandon Falcon 9/Heavy leaves a huge hole in their product line for smaller payloads that don't need a super-heavy launch vehicle, particularly deep-space probes that need affordable high-energy departure stages that won't be coming back.

My interpretation: they badly want to develop a Raptor-powered reusable upper stage for Falcon Heavy, as an incremental step toward BFR, but they also want the US government to pay for it, and for negotiating leverage are taking a strong pose of intending to skip this step unless they get their government funding.

By my estimates, a single-Raptor upper stage refuelled in low-Earth orbit could land a manned Dragon 2 on the moon and return it directly to Earth, no other stages or iffy deep-space rendezvous required, no development or qualification of new crew vehicles required. The same stage could also land a 20-tonne payload on the moon surface, one-way (enough to land a full B330 inflatable habitat, for instance). A reusable version of the same stage, flying on a reusable Falcon Heavy booster, could launch and refuel it without expending any hardware.

This is the fastest, cheapest way for the Trump administration to reach its goal of putting men back on the moon.

The only way to put humans back on the Moon is for joint mission based on international cooperation between US-Russia-China.

Trump's wishes to raise his approval ratings have nothing to do with it, and if anything they will prevent all attempts until he's out of office one way or another.

They've announced that they are going to try a few things like maintain stability during the 2nd stage reentry, but no recovery or hardware changes will be made. It's just to gather data.

I already mentioned that, $30 million is not even close to enough to develop an upper stage, it was just funding incentive to develop Raptor in case the USAF wants to pay SpaceX to build a Raptor upper stage later. No current plans are in place.

Yes, but that customer needs to be willing to pay several hundred million dollars to get the stage developed and built. So far it doesn't seem likely.

The suborbital test vehicle will have the same shape as the BFS, and won't be suited to carry a Falcon upper stage. Developing a suborbital test vehicle that looks and acts nothign like the final spaceship would be a meaningless waste of resources compared to just developing the BFS and using Falcon boosters to launch Falcon rockets.

Not really. The whole point of BFR is that it's roughly ten times cheaper to launch than Falcon 9, and a few hundred times cheaper per kilogram payload. A 1 ton satellite could be launched more cheaply on BFR than on Falcon 9, despite taking up only ~0.6% of the potential payload mass. As for higher energy payloads like interplanetary probes, a cargo BFS carrying a 1 ton probe could be refueled in orbit and boosted onto a departure orbit, let go of the payload, and burn again to slow back down onto an elliptical Earth orbit, to land and be reused later. That's the magic of on-orbit refueling, high mass fractions, and small payloads on large vehicles.

lol. If they wanted the US Gov. to pay for it they would have put together a coherent proposal with estimates, rather than pretend to want to skip it. The incremental step to BFR has been the Falcon 9, they don't need to asymptotically approach BFR like people seem to suggest. If you want to take Vienna, take Vienna.

>Elon said (when asked if the thrusters would resemble methane powered Superdraco engines) that the thrust chamber would be more similar to Raptor.
No, he said that the whole thing would be based on Raptor components. And I've already pointed out that the main turbines would be omitted and the whole thing would be scaled down, making it a significantly different configuration.

>they're going to be completely different engines except for propellant choice.
SpaceX loves to save time and money by having commonality between different parts of a vehicle. They're not going to do a full redesign when they can simply scale and repurpose necessary Raptor components to make a pressure-fed thruster.

Pressure-fed components make sense for Raptor start-up. They need to spin up the turbines, and there's no helium in this system to do it with. The tank pressure isn't likely to be high enough, and in any case, they need to boil it to use it efficiently. They're going to have to have something like a pistonless pump, where they fill a pair of smaller, higher-pressure tanks and use a heat source (burner or electric element) to pressurize them and generate gas, either boiling the methane and oxygen as it flows out of them or just heating them way above boiling in the tanks (which would require larger tanks, but would also mean there are no concerns about orientation or propellant settling).

For the full Raptor, they'll scale the pressure tanks and burners to what's needed for the startup procedure for the main turbopumps. For the thrusters, they can scale them to whatever thrust and maximum burn duration they need, omit the main turbopumps, and just use this pressure feeding directly to the main combustion chamber.

>By my estimates, a single-Raptor upper stage refuelled in low-Earth orbit could land a manned Dragon 2 on the moon and return it directly to Earth, no other stages or iffy deep-space rendezvous required, no development or qualification of new crew vehicles required. The same stage could also land a 20-tonne payload on the moon surface, one-way (enough to land a full B330 inflatable habitat, for instance). A reusable version of the same stage, flying on a reusable Falcon Heavy booster, could launch and refuel it without expending any hardware.

Maybe, but even if you are right, BFR can land a spaceship on the Moon with more than 100 tons of payload and enough propellant to boost back to Earth. Developing rockets takes roughly the same time whether they're small or large, and that applies to single rocket stages as well. To develop a reusable Raptor powered upper stage for Falcon Heavy you're looking at 2-3 years of intensive development. To develop BFR you're looking at 4-5 years of intensive development. The Saturn V design was selected in 1962 and the first flight took place in 1967, and that's with 1960's era technology, today we have high fidelity computer modelling and better manufacturing and prototyping ability.

For SpaceX, it makes more sense to stop perpetually developing Falcon 9 and Falcon Heavy, and instead freeze the design and shift focus to BFR R&D. BFR is a launch vehicle to render all others that currently exist into impossibly expensive, slow, and risky alternatives. It'd be cheaper to launch than anything today except for the very smallest of launch vehicles, and nothing beats it on minimum price per kilogram. Why wouldn't SpaceX want BFR as soon as possible? In the beginning they don't need to sell BFR flights for $6 million right away, hell they can sell them for a few million less than a Falcon 9 and make bank with a sky high profit margin. They'd want to do this until the launch market expanded anyway.

>No, he said that the whole thing would be based on Raptor components
source on that, I'm interested if true.

All rocket engines have pressure fed components. If the fuel tanks weren't pressurized there would be cavitation in the pumps at much lower rpm and the maximum thrust the rocket could achieve with a given pump size would be lower.

We don't know anything about the autogenous pressurizing system yet, but we do know the main tanks will be constantly above a couple bar of pressure. That should be enough to start the turboprops because they're staged, the spin up only needs to be able to work with a low flow rate at which point the engine can self power and spin up to operating rpm with the right torque. I imagine that the RCS thrusters will be fed off a smaller set of higher pressure tanks, separate from the main fuel tanks. When the main engines are burning and supplying hot gas to re-pressurize the fuel tanks some portion of that high pressure gas can be used to refill the RCS tanks. That higher pressure fuel would lose some pressure as the gasses cooled and condensed, but if the tanks aren't kept at cryogenic temperature the leftover pressure should still be high. During landing the RCS engines could be fed directly off of the hot pressurized gas supply rather than from the tanks, but it's probably simpler to avoid plumbing hell and just route all RCS fuel into the tanks first. As long as the tanks are large enough to supply enough propellant for all the maneuvering required during a Mars transit there shouldn't be any issues there. Like I said, I agree that SpaceX will want to reuse designs for Raptor on these thrusters, but in my opinion that can only extend as far as the injector design and the igniter design, since in both engines gaseous methane and oxygen are going to be the reactants. Otherwise there's not a lot of design commonality there.

>They've announced that they are going to try a few things like maintain stability during the 2nd stage reentry, but no recovery or hardware changes will be made. It's just to gather data.
Stop pretending to remember this stuff, and look it up before you post, instead of filling in the gaps in your memory with stuff that's non-embarassing for you after shooting your mouth off previously.
forums.teslarati.com/threads/spacex-will-attempt-falcon-9-upper-stage-landings-in-2018-says-shotwell.4784/

As recently as September, they've announced they're planning recovery, but not reuse, of the current Falcon 9 upper stage. Hardware changes will, of course, be necessary. It will need heat shielding and landing thrusters added on.

SpaceX is a very incremental company. Modifying the Falcon 9 upper stage is the least expensive, nearest-term way to experiment with upper stage recovery, even if the Falcon 9 upper stage is unsuitable for reuse. Similarly, a single-Raptor Falcon Heavy upper stage is the least expensive, nearest-term way to test their BFR components in space and get practical experience with a reusable upper stage, which is why I believe they're going to do it. It's consistent with the way they do things.

I've already explained how I think they're going to get the US government to pay for it: it's also the least expensive, nearest-term way to build a manned moon base.

>Shotwell clarified that SpaceX would not attempt to reuse Falcon 9’s upper stage, even if recovery efforts succeed.

this is the important bit.

>Similarly, a single-Raptor Falcon Heavy upper stage is the least expensive, nearest-term way to test their BFR components in space and get practical experience with a reusable upper stage, which is why I believe they're going to do it.

no, it's a waste of resources when they can develop a suborbital hop vehicle using the BFS fuselage design and kill several birds with one stone.

>it's also the least expensive, nearest-term way to build a manned moon base

Regular Falcon Heavy not good enough for you? It's real now, btw. Even with an expendable upper stage, Falcon Heavy is fine for sending landing craft and habitat modules to the Moon for hundreds of millions rather than billions. Any NASA Moon base architecture is realistically going to be hundreds of millions per module anyway. With BFR people can comfortably live in the ship that brought them there, and have over a hundred tons of machinery and building materials to play with.
Besides that, getting to the Moon as fast and for as little up front cost as possible shouldn't be the goal. The goal should be setting up a transport system that allows for real work to be accomplished on the Moon, which is what BFR can do but Falcon Heavy cannot.

>Developing rockets takes roughly the same time whether they're small or large, and that applies to single rocket stages as well.
That's not really true even with unlimited resources, and a single-Raptor upper stage would be a reasonable incremental step in developing BFR.

Consider: the full BFR, capable of orbital flight, requires 38 Raptor engines per prototype, and an all-new launchpad. The suborbital BFS test unit requires 7 Raptor engines per prototype, and an all-new or heavily-modified launchpad, and can't do any useful work. The subscale BFS requires only 1 Raptor engine per prototype and only minor pad modifications for supplying a modest amount of subcooled liquid methane, and can do very useful work.

9-meter stages require a new factory (the cost of transporting them out of LA is prohibitive, due to the requirement to take down traffic lights, etc.). 5-meter stages can almost certainly be built in the existing SpaceX factory.

A mini-BFS would take half as long to develop, cost a small fraction as much, and the experience gained would likely mean it saves money (and possibly even time) over going directly to the full-scale BFR without gaining any subscale orbital experience. They can start building it as soon as they have the first flightworthy Raptor, and don't need to wait on the construction of a new factory. They can afford to fly a few expendably (and maybe even make money doing it, by carrying risk-tolerant payloads).

>The Saturn V design was selected in 1962 and the first flight took place in 1967
N1 was selected in 1965 and it was cancelled in 1976 with no successful launches. The Titan II development contract was signed in 1960, the first flight took place in 1962, and it served the manned launch needs of the 1964-1965 Gemini program.

Though rockets scale well, it seems that increasing rocket size by an order of magnitude roughly doubles or triples the development time, and development/tooling cost goes up linearly.

>Regular Falcon Heavy not good enough for you?
Falcon Heavy by itself is not capable of landing anything on the moon.

The mini-BFS with its ability to store propellant, landing thrusters, and orbital refuelling capability, would serve as an Earth-departure stage far more capable than Saturn V's, would work as a one-way lunar lander capable of landing 20 tonnes in one launch (enough to build a moon base), and together with Dragon 2 would also serve as every part of the Apollo spacecraft.

It would be an extremely cost-effective way to put men on the moon.

The space x has microchips...

They are not attempting to practically recover the Upper Stage they are just experimenting with reuse
Same reason they experimented with the F9 booster.

Flying truly jerryrigged and experimental hardware is likely too much of a risk for SpaceX
Same reason they cancelled the whole F9R thing, it's very hard to get permits to fly rockets.

REKT

Umm user I would pull up a live feed of pad 39A right now if I were you...