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SpaceX granted injunction in rocket launch suit against Lockheed-Boeing

washingtonpost.com

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Re: SpaceX granted injunction in rocket launch suit against Lockheed-Boeing

#71

Post by Gravityloss »

dfc wrote: post #29
Gravityloss wrote: post #22

This is very ironic. IIRC when the EELV rockets were bidding for first launch batches, Boeing used some insider price information to win the majority for Delta IV. There was a big lawsuit about that and Lockheed Martin's Atlas V ended up getting more launches. http://www.staynehoff.net/boeing-eelv-punished.htm

Where is the irony?

The US Government attempted to create competition and a "market" with two competing launch providers. Boeing didn't play fair, and it was a big scandal. Finally when everything was put in proper order,the EELV providers couldn't compete with foreign launchers on the commercial market (commercial use was envisioned to lower costs for government launches as well). So the two competitors merged their rocket operations to form ULA. So despite the best efforts of the government, they just couldn't get the independent providers and free market thing to work.

But now SpaceX comes along. It's offering just what the government has been trying to create for decades.

Yet SpaceX has to sue the government, to get to play on a level field.

So the government had trouble with the companies trying to tilt the field. Now a new company has a problem with the government.

What an odd reversal of things.

Re: SpaceX granted injunction in rocket launch suit against Lockheed-Boeing

#72

Post by InclinedPlane »

mrfusion wrote: post #67
InclinedPlane wrote: post #66

Earlier quoted context omitted.

The Falcon Heavy uses 3 identical cores as the "first stage" of the vehicle. If each of the stages burns at the same rate and burns out at the same time then it's basically just one big stage and the Falcon Heavy would just be a 2-stage launcher. Adding more stages increases payload performance of launchers because you're dumping dead weight. The plan for the Falcon Heavy is to have cross feed between the engines so…

You might need to dumb it down a bit more for me :-( What's a core? Why would the stages burn at the same time? I thought the second stage wouldn't turn on until the first stage is jettisoned?

Right. OK. So with a simple 2-stage rocket like the Falcon 9 you have the first stage which has the 2nd stage stacked on top of it which has the payload stacked on top of it. During a normal flight the first stage (which is the biggest stage) lights, lifts the whole thing off the ground, and pushes the rocket up into the air and starts getting it up to speed. Then the first stage runs out of fuel, it separates and then the 2nd stage takes over, pushing the payload the rest of the way to orbit.

The Falcon Heavy uses the same "2nd" stage but it uses 3 first stages instead of just one, which are called "cores". Each core is just a Falcon 9 first stage, for the most part. The idea of the Falcon Heavy (similar to the way the Delta IV Heavy works) is that you have three times as many first stages pushing, which leads to increased payload.

With the cross-feed option you end up with effectively a 3-stage launcher. The outer two cores becomes like the first stage, and they are jettisoned when empty, then you have the inner core which now becomes a 2nd stage, and the previous 2nd stage is now a 3rd stage (or just "upper stage", to avoid confusion).

But, as mentioned, when you fly this way the 2nd stage core ends up way faster and way farther away when it's done thrusting, so in the prospect of having it keep around some extra propellant so it can thrust back to the launch site and land so it can be reused becomes much more difficult. But in a worst-case scenario all of the "cores" can be run at the same time, so they burn out the same distance away from land and can each return and be reused (saving a lot of money). You end up with only a 2 stage vehicle (3 1st-stages all running at the same time plus the upper stage) which would decrease performance, but because you recover all of the first stage cores (instead of only 2/3 of them) the cost benefit would probably be worth the payload reduction.

Re: SpaceX granted injunction in rocket launch suit against Lockheed-Boeing

#73

Post by Gravityloss »

mrfusion wrote: post #67
InclinedPlane wrote: post #66

Earlier quoted context omitted.

The Falcon Heavy uses 3 identical cores as the "first stage" of the vehicle. If each of the stages burns at the same rate and burns out at the same time then it's basically just one big stage and the Falcon Heavy would just be a 2-stage launcher. Adding more stages increases payload performance of launchers because you're dumping dead weight. The plan for the Falcon Heavy is to have cross feed between the engines so…

You might need to dumb it down a bit more for me :-( What's a core? Why would the stages burn at the same time? I thought the second stage wouldn't turn on until the first stage is jettisoned?

Falcon 9 (not heavy) has a first stage and a second stage. The first stage consists of one kerosene tank, one oxygen tank and nine engines. This is also called a core.

Falcon 9 heavy (no crossfeed) has a first stage and a second stage. But the first stage consists of 3 cores that run in parallel. All three cores start and stop at the same time. So 27 engines start at the pad.

Falcon 9 heavy with crossfeed has sort of two or three stages, depending how you count. Outwards it looks very similar to the no-crossfeed Falcon 9 heavy. The topmost stage is similar to the two already mentioned configurations. The three cores look pretty similar. All three cores start at the pad (27 engines running), but the propellant for the center core's engines is taken from the outer cores' tanks. This means the outer cores run out of propellants quite quickly. They can then be discarded in flight, and the center core starts using propellants from its own tanks. Now it can fly without the dead mass of the outer cores and as a result the rocket can carry a bigger payload.

Why start the core engine at the pad, and not make it a real second stage that starts up only higher? Because then you get more thrust, the engines are not dead weight during early flight.

Some rockets like Titan IV had a somewhat similar parallel configuration but they did not start their center engine except at high altitude.

Re: SpaceX granted injunction in rocket launch suit against Lockheed-Boeing

#74

Post by smackfu »

rayiner wrote: post #27

Note it's a preliminary injunction ( http://apps.washingtonpost.com/g/documents/business/spacex/9... ), which is basically a device that keeps the status quo from changing irreversibly while the parties figure out the merits of the suit. This doesn't mean that SpaceX has "won" but it does mean that they have demonstrated at least a "substantial likelihood for success on the merits" of the case.

It also only applies "until the court receives the opinion of the United States Department of the Treasury, and the United States Department of Commerce and United States Department of State, that any such purchases or payments will not directly or indirectly contravene Executive Order 13,661."

Re: SpaceX granted injunction in rocket launch suit against Lockheed-Boeing

#75

Post by dfc »

Gravityloss wrote: post #71
dfc wrote: post #29

Earlier quoted context omitted.

Where is the irony?

The US Government attempted to create competition and a "market" with two competing launch providers. Boeing didn't play fair, and it was a big scandal. Finally when everything was put in proper order,the EELV providers couldn't compete with foreign launchers on the commercial market (commercial use was envisioned to lower costs for government launches as well). So the two competitors merged their rocket operations t…

Yes, the market for rocket technology is not static--circumstances change. An "odd reversal of things" is not irony.

Re: SpaceX granted injunction in rocket launch suit against Lockheed-Boeing

#76

Post by mrfusion »

InclinedPlane wrote: post #72
mrfusion wrote: post #67

Earlier quoted context omitted.

You might need to dumb it down a bit more for me :-( What's a core? Why would the stages burn at the same time? I thought the second stage wouldn't turn on until the first stage is jettisoned?

Right. OK. So with a simple 2-stage rocket like the Falcon 9 you have the first stage which has the 2nd stage stacked on top of it which has the payload stacked on top of it. During a normal flight the first stage (which is the biggest stage) lights, lifts the whole thing off the ground, and pushes the rocket up into the air and starts getting it up to speed. Then the first stage runs out of fuel, it separates and th…

Wow thanks, between this and Gravityloss's comment, I'm really starting to get a clear picture.

So on the Falcon heavy, is the plan for all three cores to return to the launch pad independently? Just landing a few hundred feet away from each other?

Re: SpaceX granted injunction in rocket launch suit against Lockheed-Boeing

#77

Post by dfc »

rayiner wrote: post #27

Note it's a preliminary injunction ( http://apps.washingtonpost.com/g/documents/business/spacex/9... ), which is basically a device that keeps the status quo from changing irreversibly while the parties figure out the merits of the suit. This doesn't mean that SpaceX has "won" but it does mean that they have demonstrated at least a "substantial likelihood for success on the merits" of the case.

After reading the injunction it seems that the court believes that the test is "a reasonable likelihood of success on the merits" not "a substantial likelihood for success."

Re: SpaceX granted injunction in rocket launch suit against Lockheed-Boeing

#78

Post by Gravityloss »

monochr wrote: post #52
nkoren wrote: post #30

Earlier quoted context omitted.

Elon's response to that tweet was more than a little bit epic: https://twitter.com/elonmusk/status/461279062837968897 followed by: https://twitter.com/elonmusk/status/461283368693669888 Not sure what Rogozin thought about them apples, but this sure isn't boring!

"Not sure what Rogozin thought about them apples, but this sure isn't boring!" Probably nothing. The Soyuz rockets they use are so old they are literally still named after the Soviet Union. This might seem like a bad thing but in rocketry old means reliable and new means "Your payload will probably explode in one of the first 5 missions. Hope it wasn't important!" In short, it won't be sometime before 2018 before the…

They can fly Falcon 9 with cargo Dragons as well as unmanned Dragon 2 capsules many times before 2018. Demonstrated safety is hard to argue with.

There have been relatively recent failures with Soyuz launchers as well (though none with Soyuz FG). Russians have also been developing new things, both as upgrades to the Soyuz launcher and Soyuz spacecraft but also new developments. (Soyuz-2-1v and PTK)

Re: SpaceX granted injunction in rocket launch suit against Lockheed-Boeing

#79

Post by Gravityloss »

rst wrote: post #70
tanzam75 wrote: post #65

Earlier quoted context omitted.

The Chinese are developing an engine, the YF-100, based on the Russian RD-120. It's a staged combustion engine with an oxygen-rich preburner -- very similar technology to the RD-180. The YF-100 has already gone through a full-length test firing on the ground, and the CZ-7 rocket that it's mounted on is scheduled for a test flight later this year. If the Chinese have been able to make it, then I see no reason why we c…

You appear to be right about P&W. About the engines: heck, the Space Shuttle Main Engine was staged-combustion Oxygen-Hydrogen. The question isn't whether the US could produce such an engine. It's how soon, and how reliably. ULA has laid in what they say is a two-year stock of engines as a hedge against ... hiccups in the supply chain, but they'd need new engines after that. For a clean-sheet design, that would be a…

In a hydrogen engine, you can do fuel rich staged combustion.

With kerosene, you must go oxidizer-rich. Nobody has mastered that except Russia. Nobody really knows how much it costs, or how they came up with it.

SpaceX uses the far simpler gas generator cycle.

In staged combustion, you pump some of the propellants to some absurd pressure like 300 bars, burn them, put them through a turbine that extracts some power that lowers pressure to 250 bars or so. Then the turbine exhaust is put into the main combustion chamber, together with the other propellants that were pumped up to 250 bars. All propellant contributes to thrust.

In a gas generator, you pump all propellants to perhaps 70 bars, divert some small part to a gas generator that burns them, the exhaust is put to a turbine that exhausts to ambient air. The turbine powers the pump. So that part of the propellant flow does not contribute directly to thrust. If you go to higher pressures with a gas generator engine, you waste a larger portion of the propellant to run the pump and it's just not worth it. So gas generator engines are limited to much lower pressures than staged combustion engines.

Lower pressure means bigger engines are needed for the same thrust. Also the efficiency is worse. A large (tall) rocket can have problems with limited base area per mass, hence for example the low pressure engined Saturn V had an expanded base.

Space Shuttle's main engines ran with high pressure and could fit on the back of the relatively small reusable orbiter vehicle.

Re: SpaceX granted injunction in rocket launch suit against Lockheed-Boeing

#80

Post by Gravityloss »

huhtenberg wrote: post #55
JackFr wrote: post #20

Earlier quoted context omitted.

This is not space exploration, its a jobs program for missile scientists -- you know keep them off the streets, keep them from joining gangs, kind of like Boys Clubs or something. http://www.washingtonpost.com/sf/national/2013/09/14/the-ski... "The collapse of the Soviet Union created the final incentive to go forward. U.S. officials worried that Russian rocket scientists would go to work for rogue nations, spreading…

And that's of course the US version of the story. Very cute, but I can tell you from lots of anecdotal evidence that all that ISS work was a drop in the ocean as far as Soviet space program was concerned. Rocket scientists didn't go to work for rogue nations. You have to understand that Soviet space industry was (and still is) veiled in secrecy. Think of it as SkunkWorks but on a massive scale and with 100x of securi…

In my personal opinion, manned space flight (launchers, spacecraft, in space operations) has little technical overlap with solid fueled ballistic missiles.
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