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#40
by
baldusi
on 06 May, 2014 01:58
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All ACES papers I seen talk about a 4.6m diameter which the internal diameter of the 5m fairing. Thus I would assume that the 4m version would a straight 4m fairing atop with the Common Upper Stage exposed but in the 5m case it would be enclosed.
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#41
by
vapour_nudge
on 06 May, 2014 12:51
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I was reading a ULA document from 2010, I wasn't aware of the design life of the engine. I knew they'd looked at re-usability, but I didn't know it was designed for 10 uses.
From the document: "The booster engine on the Atlas V, the RD-180, has several other features that enable practical reuse. It is a compact object fabricated with robust structures, as seen in Figure 1, yet it is not excessively heavy.
Most importantly, it is an evolved version of the RD-170 engine designed for 10 operational uses. This last fact provides the foundation for economical reuse."
Anway, I thought I'd throw it out there that if they had have successfully pursued this and had it now been operational, then the current crisis would have been much less of a problem - even if they could re-use the existing engines just one more time.
http://www.ulalaunch.com/uploads/docs/Published_Papers/Evolution/EELVPartialReusable2010.pdfMaybe worth a re-look? ("too late", she cried)
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#42
by
TomH
on 07 May, 2014 23:54
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I was reading a ULA document from 2010, I wasn't aware of the design life of the engine. I knew they'd looked at re-usability, but I didn't know it was designed for 10 uses.
From the document: "The booster engine on the Atlas V, the RD-180, has several other features that enable practical reuse. It is a compact object fabricated with robust structures, as seen in Figure 1, yet it is not excessively heavy. Most importantly, it is an evolved version of the RD-170 engine designed for 10 operational uses. This last fact provides the foundation for economical reuse."
Anway, I thought I'd throw it out there that if they had have successfully pursued this and had it now been operational, then the current crisis would have been much less of a problem - even if they could re-use the existing engines just one more time.
http://www.ulalaunch.com/uploads/docs/Published_Papers/Evolution/EELVPartialReusable2010.pdf
Maybe worth a re-look? ("too late", she cried)
But wouldn't you need some way of recovering the engine without it ever going into salt water. AV doesn't have that F9 pattern with 3/9 engines for boost back and 1/9 for landing. Ejecting the engine for mid-air parachute snag is pretty dicey and would require a heck of a lot of re-engineering. Just not quite sure how you'd recover it so that you could reuse it. BTW, the passage you quoted has awkward syntax and is not grammatically clear.
As written:
Most importantly, it is an evolved version of the RD-170 engine designed for 10 operational uses.Possible meanings:
Most importantly, as an evolved version of the RD-170, it is designed for 10 operational uses.
Most importantly, it is an evolved version of the RD-170, which was designed for 10 operational uses.
Most importantly, it is a evolved version of the RD-170, and both were designed for 10 operational uses.Nevertheless, the phrase
most importantly as a modifier of
it implies the RD-180 is designed for 10 uses.
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#43
by
kevin-rf
on 08 May, 2014 01:19
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Let's eat grandma... Commas, they save lives
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#44
by
floss
on 01 Jun, 2014 16:51
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With the ban on the rd 180 seeming to become apparent would the F1 be the only man rated engine available without a massive investment in a brand new engine for Atlas 6 seeing as a rapid replacement is needed ?
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#45
by
edkyle99
on 01 Jun, 2014 17:23
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With the ban on the rd 180 seeming to become apparent would the F1 be the only man rated engine available without a massive investment in a brand new engine for Atlas 6 seeing as a rapid replacement is needed ?
As near as I can tell, an actual RD-180 "ban" seems less apparent every day.
F-1 is not available, and hasn't been since 1973 or thereabouts.
- Ed Kyle
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#46
by
floss
on 01 Jun, 2014 17:40
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Yup but a 2 or 3 billion to build a new factory to build something that has already been built is far easier than starting a whole new high technology lab plus factory that costs about 10 billion .
US Congress might decide that having their precious voters at risk to a foreign despot might not be sensible.
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#47
by
edkyle99
on 01 Jun, 2014 19:52
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Yup but a 2 or 3 billion to build a new factory to build something that has already been built is far easier than starting a whole new high technology lab plus factory that costs about 10 billion .
US Congress might decide that having their precious voters at risk to a foreign despot might not be sensible.
OK, lets assume that there is an F-1B. What happens when one is stuck onto an Atlas 5 in place of an RD-180?
First , the big F-1B engine adds 3 tonnes of dry mass to the first stage, a nearly 14% increase.
Second, since F-1B produces twice as much thrust as RD-180, it will tear the Atlas 5 apart unless it can be massively throttled - something that F-1 did not do for Saturn. At its fixed full thrust it will produce more than
15 g acceleration near the end of the first stage burn.
Finally, since F-1B is a less efficient gas generator cycle engine, Atlas 5 payload to GTO will be cut by one-third. This assumes that the LOX and RP tanks can be resized to account for the different LOX to RP ratio of the engine.
The billions spent to create this engine would result in a rocket unable to even match Atlas 3A performance.
- Ed Kyle
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#48
by
floss
on 01 Jun, 2014 20:01
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Yup but a 2 or 3 billion to build a new factory to build something that has already been built is far easier than starting a whole new high technology lab plus factory that costs about 10 billion .
US Congress might decide that having their precious voters at risk to a foreign despot might not be sensible.
OK, lets assume that there is an F-1B. What happens when one is stuck onto an Atlas 5 in place of an RD-180?
First , the big F-1B engine adds 3 tonnes of dry mass to the first stage, a nearly 14% increase.
Second, since F-1B produces twice as much thrust as RD-180, it will tear the Atlas 5 apart unless it can be massively throttled - something that F-1 did not do for Saturn. At its fixed full thrust it will produce more than 15 g acceleration near the end of the first stage burn.
Finally, since F-1B is a less efficient gas generator cycle engine, Atlas 5 payload to GTO will be cut by one-third. This assumes that the LOX and RP tanks can be resized to account for the different LOX to RP ratio of the engine.
The billions spent to create this engine would result in a rocket unable to even match Atlas 3A performance.
- Ed Kyle
Thanks but I was talking about LEO not GEO a manned launcher to carry astronauts is what I was talking about.
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#49
by
edkyle99
on 01 Jun, 2014 22:27
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Thanks but I was talking about LEO not GEO a manned launcher to carry astronauts is what I was talking about.
Similar conclusions can be drawn about a LEO mission, though the payload reduction would be one fourth instead of one third. This of course assumes use of a 2xRL10 Centaur.
- Ed Kyle
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#50
by
floss
on 01 Jun, 2014 22:39
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So it would be an ok starter rocket but would cost way too much to construct a cheaper knockoff of the rd 180 is needed preferably with a bit more thrust .
I wonder what the next us manned rocket will look like ?
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#51
by
edkyle99
on 01 Jun, 2014 23:35
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So it would be an ok starter rocket but would cost way too much to construct a cheaper knockoff of the rd 180 is needed preferably with a bit more thrust .
I wonder what the next us manned rocket will look like ?
I think that it is already flying (including the RD-180 Atlas 5 possibility).
That aside, there would be a much better, though still imperfect, solution for Atlas 5 than F-1. Six Merlin 1D engines on a CCB carrying the same propellant mass as the current first stage would create a rocket that lost only 12.8% of its LEO performance and 14.2% of its GTO performance.
- Ed Kyle
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#52
by
floss
on 02 Jun, 2014 13:29
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So it would be an ok starter rocket but would cost way too much to construct a cheaper knockoff of the rd 180 is needed preferably with a bit more thrust .
I wonder what the next us manned rocket will look like ?
I think that it is already flying (including the RD-180 Atlas 5 possibility).
That aside, there would be a much better, though still imperfect, solution for Atlas 5 than F-1. Six Merlin 1D engines on a CCB carrying the same propellant mass as the current first stage would create a rocket that lost only 12.8% of its LEO performance and 14.2% of its GTO performance.
- Ed Kyle
But would that not give Space X Monopoly on human spaceflight which is what NASA is trying to avoid .
Bet there will be a fantastic high teck program to develop the replace the rd 180 and the nk33 .
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#53
by
watermod
on 02 Jun, 2014 17:30
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Another way of looking at the situation.
Manufacture of the RD-180 is questionable because by 2022 licensing comes into question. Well industry has a traditional way of dealing with situations like that. Change the design just enough so it doesn't legally violate the patents.
That's why, as an engineer, I was encouraged to make my patents as broad and generic as possible. I noticed most people don't patent things that way or think about it in that manner.
Each patent has claims that limit it in the n-tupple space of all possible patents. From the point of view of patent lawyers a "good" patent grabs as large a region of n-tupple space as it can get away with. However, if it can be proven that a firm used an existing device and worked around it their claim is not as good. But, if a 3-party behaves as a clean room and comes up with a solution that they then use, why the patent is worked around.
That is what is done with much of the OpenSource software that gets around copyrights and patents. Then if put under a GNU license framework anybody can use the concept.
It can get rather close to "dirty" too and still be safe. For an example of that look at the Canon Hackers Tool Kit . CHDK, Google it.
The source of CHDK was frustration of the software folk doing the Matrix movies. In some of the scenes they needed to network tens of thousands of cameras. The miraculous appearance of CHDK, from Hungary with its weak cleanroom laws, let them network up to 64,000 Canon PowerShots. With the nature of the net, who knows if the real hack was in Hollywood or Hungary and nobody will ever know but now its a fine tool that millions of photographers have been using to do all sorts of amazing things you can't do with a stock camera. (Oh and I will point out that if SpaceX had used a hacked Canon Powershot instead of a MPEG-4 camera they could of recorded and transmitted much more useful information than the landing video now being restored)
So if 3rd parties including Patent lawyers looked the RD-180 and its patents over then published their analysis somewhere where LM, ULA and others could read it, I am sure all the patent issues could be worked around to make a legal patent free RD-180 derivative.
Taking it further a design patent is just change a look. A functional patent is a bit more but with thought tools like TRIZ (another Russian gift to the world) make it quite easy to figure out another method to achieve the same function.
It would be safe to make it "OpenSource" as so few in the world would be able to build one. Maybe, India, Japan, China and the EU. Plus the cost of creating such a production line would be more than most would dare. If they do then one has a situation akin to chip foundries and they have turned out okay for the market.
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#54
by
baldusi
on 02 Jun, 2014 18:05
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Is the AJ-1E6 project to green as a replacement? The propulsion module is quite self-contained in the Atlas V and Antares.
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#55
by
Lobo
on 03 Jun, 2014 18:24
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Is the AJ-1E6 project to green as a replacement? The propulsion module is quite self-contained in the Atlas V and Antares.
Yea, the interesting thing is AJR now has the NK-33 designs for their AJ engines. I think they'll have any info left over from PWR's RS-84. As I assume that info stayed with Rocketdyne.
And then they should/would be the one's with the RD-180 IP. Between those 3 different, but similar in performance, kerolox ORSC engines, they should be able to produce an engine that will be a drop in replacement for the russian RD-180 on Atlas V, but they'd call it something else, and it'd be different enough than RD-180 that they could get around the patent and licensing issues that watermod mentions.
It wouldn't be an RD-180, but it would be a drop in replacement. And built specifically to interface with the A5 mounts, propellant lines, and avionics with no core changes.
If there's money for that anyway.
