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Thread: Heavy-lift boosters?

  1. #241
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    The aeroshell would be a payload in its own right, with something smaller towards the center. All the Mars craft I have seen have a wide disk with the payload much less wide.
    That's Bezos call as to how he wants to spend his money.

  2. #242
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    Quote Originally Posted by publiusr View Post
    The aeroshell would be a payload in its own right, with something smaller towards the center. All the Mars craft I have seen have a wide disk with the payload much less wide.
    That's Bezos call as to how he wants to spend his money.
    Bezos doesn't want to spend his money on a 30 m diameter rocket for giving small payloads big non-inflatable aeroshells. If he ever builds a 30 m rocket, it'll be for big payloads which, if they were destined for Mars, would need inflatable decelerators or other approaches more than ever.

    Come on. The whole reason people are looking at inflatable decelerators is because of how the relationship between volume and cross sectional area changes as you scale up. If you're going to scale up to 30 meters, you can do a lot better than just scaling up capsules and parachutes (never mind that packed volume is way down on the list of obstacles to scaling up parachutes). And Bezos isn't even interested in Mars right now, he's talking about lunar landers.

  3. #243
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    Comparison of Falcon Heavy VS. Delta IV Heavy.

    http://theavion.com/falcon-heavy-vs-delta-iv-heavy/

    While the Falcon Heavy and the Delta IV Heavy may have similar structural designs, there are two very distinct differences. The first being the Falcon Heavy has three launch cores, each fitted with nine Merlin engines. Whereas the Delta IV Heavy also has three cores, but only one Aerojet Rocketdyne RS-68 engine per core. The second difference is that the Falcon Heavy’s cores can return to earth and are reusable, while the Delta IV Heavy boosters are non-reusable, and fall into the ocean.
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  4. #244
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    While initially planned for it to make it to Mars orbit, it, unfortunately, overshot its target. However, this proves the capabilities of the Falcon Heavy for future launches to come.
    Or if you prefer the correct version: the Tesla never was going to go to mars or even into mars orbit, it was planned to go into an elliptical orbit that hopefully had an apogee as far as the mars orbit. To test the capability of the rocket they burnt the engines till fuel ran out, and as the rocket performed better than expected, the Tesla is now in an orbit with apogee beyond mars orbit.


    Anyway, is there already a concrete mission for F9H? I'd love to see another launch of the triceratops.

  5. #245
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    The 1st launch of the Long March 9 has been brought forward by 2 years - 2028.

    https://gbtimes.com/china-aims-to-la...as-sls-in-2028

    China is working on a super-heavy-lift rocket, named Long March 9, which will allow the country to carry out a number of major robotic interplanetary and crewed lunar missions.

    Li Guoping, director of the Department of System Engineering at the China National Space Administration (CNSA), said at the World Conference on Science Literacy 2018 on Tuesday in Beijing that the Long March 9 would be capable of lifting 140,000 kilograms, or 140 metric tonnes, to low Earth orbit (LEO), according to the preliminary design.

    Reiterating previously stated dimensions, Li said that the length of the launch vehicle will be over 90 metres, with a core stage diameter of 10 metres.
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  6. #246
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    Quote Originally Posted by Nicolas View Post
    >
    Anyway, is there already a concrete mission for F9H? I'd love to see another launch of the triceratops.
    ArabSat 6 for the Saudis, USAF STP-2, and now that Falcon Heavy has been certified by the USAF it can be bid for military launches. NASA also has it in their online mission planning tool, and it beats Delta IV Heavy up to C3=100.

    And BFR is maybe 3-4 years out, and they've announced the first stage could be upgraded from 31 to 42 engines.
    Last edited by docmordrid; 2018-Sep-22 at 03:29 AM.

  7. #247
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    Russia proposed new super-heavy rocket Yenisei.

    https://spacenews.com/rogozin-teases...ocket-yenisei/

    With the collapse of a major U.S.-Russia arms treaty last week, much attention is being paid to new Russian rockets. In Moscow, the Kremlin has ordered its generals to begin crash development of an array of intermediate-range missiles. But while all of this was going on, President Vladimir Putin has also been reviewing other ambitious rocket programs.

    On Feb. 4, Roscosmos Director Dmitry Rogozin went to the Kremlin to sit down with Putin for a check-in on the state of the Russian space program. Much of the meeting focused on Roscosmos financials, which are bleak. But toward the end of the publicized portion of their discussion, Rogozin provided an update on three key rocket projects.

    The first was Soyuz-5, which is being promised as the future flagbearer of the Russian crewed space program. Everything is in position to move forward with the project, he said, and promised a first flight by 2022. That flight, he added, will feature Russia’s long-promised next-generation Federation spacecraft, a replacement to the solid old Soyuz capsule.

    Rogozin also reported that Russia’s other major rocket program, the Angara family of boosters, will see another test flight this year — again demonstrating the heavy A5 variant with four strap on boosters. But of greater interest was a super-heavy rocket for missions to the moon, one that will fuse Soyuz-5 with Angara to save countless rubles in development costs.
    I am because we are
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  8. #248
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  9. #249
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    With regard to the "Oops" article (damaging oscillations in the rocket engine), "pogo oscillations" also were a problem in early Saturn F1 designs. My understanding is that the cause wasn't well understood and fixes were ad hoc. My understanding is that they're very hard to avoid and the best "fix" is to make sure the oscillation frequency doesn't correspond to a structural resonance. That's what the Wikipedia article at https://en.wikipedia.org/wiki/Pogo_oscillation seems to claim, anyhow.
    Selden

  10. #250
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    Quote Originally Posted by selden View Post
    With regard to the "Oops" article (damaging oscillations in the rocket engine), "pogo oscillations" also were a problem in early Saturn F1 designs. My understanding is that the cause wasn't well understood and fixes were ad hoc. My understanding is that they're very hard to avoid and the best "fix" is to make sure the oscillation frequency doesn't correspond to a structural resonance. That's what the Wikipedia article at https://en.wikipedia.org/wiki/Pogo_oscillation seems to claim, anyhow.
    No there was pogo problems in the Saturn V, the F1 suffered from combustion instability, causing the fuel/oxidizer to rotate inside the nozzle faster and faster until they had sufficient force to destroy the engine. The pogo in the Saturn V was fixed by installing pulsation dampeners in the fuel lines.

  11. #251
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    Tonight at 9:00 pm Eastern on PBS

    Dr. Chris Riley @alifeofriley
    "Rise of the Rockets" - my new film with @SellaTheChemist, @Astro_Ferg, @elonmusk, @TimFernholz, @Reneehortonphd, @Lori_Garver, @JasonKalirai, @Peter_J_Beck and many more... premieres tonight on @novapbs - https://t.co/WcjAlRiIxA

    https://twitter.com/alifeofriley/sta...37586696122368

  12. #252
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    Looks like one of the names of the next Russian rocket comes from a river:

    The Don
    https://www.rt.com/russia/451448-rus...y-rocket-moon/

    Speaking of heavy lift, this was to ferry Buran:
    https://edition.cnn.com/travel/artic...ine/index.html

    Even larger versions were planned
    https://falsesteps.wordpress.com/201...e-tupolev-oos/
    Last edited by publiusr; 2019-Feb-15 at 09:29 PM.

  13. #253
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    Quote Originally Posted by docmordrid View Post
    Tonight at 9:00 pm Eastern on PBS

    Dr. Chris Riley @alifeofriley
    "Rise of the Rockets" - my new film with @SellaTheChemist, @Astro_Ferg, @elonmusk, @TimFernholz, @Reneehortonphd, @Lori_Garver, @JasonKalirai, @Peter_J_Beck and many more... premieres tonight on @novapbs - https://t.co/WcjAlRiIxA

    https://twitter.com/alifeofriley/sta...37586696122368
    The show underwhelmed me.

  14. #254
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    Me too.

  15. #255
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    Quote Originally Posted by docmordrid View Post
    Tonight at 9:00 pm Eastern on PBS

    Dr. Chris Riley @alifeofriley
    "Rise of the Rockets" - my new film with @SellaTheChemist, @Astro_Ferg, @elonmusk, @TimFernholz, @Reneehortonphd, @Lori_Garver, @JasonKalirai, @Peter_J_Beck and many more... premieres tonight on @novapbs - https://t.co/WcjAlRiIxA

    https://twitter.com/alifeofriley/sta...37586696122368
    Coincidentally I just read Richard Feynman's dissenting report on the Challenger Disaster (STS 51-L) when he was a member of the Rogers Investigation Commission. In his efforts while on the Commission Feynman also researched the development and production of the SSMEs, the RS-25 Aerojet Rocketdyne engines. Feynman was trying to determine if the NASA culture led to issues with the SSMES and was there a lurking problem (he concluded there were issues although none ever surfaced before the end of the program or else were addressed post-Challenger).

    In the NOVA special the RS-25D was shown as part of the re-purposed hardware for the SSL. Seeing those new engines made me wonder about the development and improvements since the shuttles last flew. And, more to the point, has any of the bottoms-up design and engineering taken place that Feynman recommended rather than the top-down approach that NASA took when it designed and built the SST. (I also noted that the Shuttle RS-25s were re-flown, albeit with major overhauls between missions. The RS-25Ds shown in the NOVA special will be flown once and dumped in the Atlantic.) The engines were used as a segue to the sections on Space X and others which are trying to build reusable equipment.

    The section below is from Feynman's report. It's a bit lengthy but might be interesting to those who haven't seen these remarks (click the link above for the full report):

    Appendix F - Personal observations on the reliability of the Shuttleby R. P. Feynman

    <snip>

    The engine is a much more complicated structure than the Solid Rocket Booster, and a great deal more detailed engineering goes into it. Generally, the engineering seems to be of high quality and apparently considerable attention is paid to deficiencies and faults found in operation.

    The usual way that such engines are designed (for military or civilian aircraft) may be called the component system, or bottom-up design. First it is necessary to thoroughly understand the properties and limitations of the materials to be used (for turbine blades, for example), and tests are begun in experimental rigs to determine those. With this knowledge larger component parts (such as bearings) are designed and tested individually. As deficiencies and design errors are noted they are corrected and verified with further testing. Since one tests only parts at a time, these tests and modifications are not overly expensive. Finally one works up to the final design of the entire engine, to the necessary specifications. There is a good chance, by this time, that the engine will generally succeed, or that any failures are easily isolated and analyzed because the failure modes, limitations of materials, etc., are so well understood. There is a very good chance that the modifications to the engine to get around the final difficulties are not very hard to make, for most of the serious problems have already been discovered and dealt with in the earlier, less expensive, stages of the process.

    The Space Shuttle Main Engine was handled in a different manner, top down, we might say. The engine was designed and put together all at once with relatively little detailed preliminary study of the material and components. Then when troubles are found in the bearings, turbine blades, coolant pipes, etc., it is more expensive and difficult to discover the causes and make changes. For example, cracks have been found in the turbine blades of the high pressure oxygen turbopump. Are they caused by flaws in the material, the effect of the oxygen atmosphere on properties of the material, the thermal stresses of startup or shutdown, the vibration and stresses of steady running, or mainly at some resonance at certain speeds, etc.? How long can we run from crack initiation to crack failure, and how does this depend on power level? Using the completed engine as a test bed to resolve such questions is extremely expensive.

    <snip>


    The Space Shuttle Main Engine is a very remarkable machine. It has a greater ratio of thrust to weight than any previous engine. It is built at the edge of, or outside of, previous engineering experience. Therefore, as expected, many different kinds of flaws and difficulties have turned up. Because, unfortunately, it was built in the top-down manner, they are difficult to find and to fix. The design aim of a lifetime of 55 mission equivalent firings (27,000 seconds of operation, either in a mission of 500 seconds, or on a test stand) has not been obtained.

    The engine now requires very frequent maintenance and replacement of important parts, such as turbopumps, bearings, sheet metal housings, etc. The high-pressure fuel turbopump had to be replaced every three or four mission equivalents (although that may have been fixed, now) and the high-pressure oxygen turbopump every five or six. This is at most ten percent of the original specification. But our main concern here is the determination of reliability.

    In a total of about 250,000 seconds of operation, the engines have failed seriously perhaps 16 times. Engineering pays close attention to these failings and tries to remedy them as quickly as possible. This it does by test studies on special rigs experimentally designed for the flaw in question, by careful inspection of the engine for suggestive clues (like cracks), and by considerable study and analysis. In this way, in spite of the difficulties of top-down design, through hard work many of the problems have apparently been solved. A list of some of the problems follows. Those followed by an asterisk (*) are probably solved:

    Turbine blade cracks in high pressure fuel turbopumps (HPFTP). (May have been solved.)
    Turbine blade cracks in high pressure oxygen turbopumps (HPOTP).
    Augmented Spark Igniter (ASI) line rupture.*
    Purge check valve failure.*
    ASI chamber erosion.*
    HPFTP turbine sheet metal cracking.
    HPFTP coolant liner failure.*
    *Main combustion chamber outlet elbow failure.
    *Main combustion chamber inlet elbow weld offset.
    HPOTP subsynchronous whirl.*
    Flight acceleration safety cutoff system (partial failure in a redundant system).*
    Bearing spalling (partially solved). A vibration at 4,000 Hertz making some engines inoperable, etc.

    Many of these solved problems are the early difficulties of a new design, for 13 of them occurred in the first 125,000 seconds and only three in the second 125,000 seconds. Naturally, one can never be sure that all the bugs are out, and, for some, the fix may not have addressed the true cause. Thus, it is not unreasonable to guess there may be at least one surprise in the next 250,000 seconds, a probability of 1/500 per engine per mission. On a mission there are three engines, but some accidents would possibly be contained, and only affect one engine. The system can abort with only two engines.

    Therefore let us say that the unknown surprises do not, even of themselves, permit us to guess that the probability of mission failure due to the Space Shuttle Main Engine is less than 1/500. To this we must add the chance of failure from known, but as yet unsolved, problems (those without the asterisk in the list above). These we discuss below. (Engineers at Rocketdyne, the manufacturer, estimate the total probability as 1/10,000. Engineers at Marshall estimate it as 1/300, while NASA management, to whom these engineers report, claims it is 1/100,000. An independent engineer consulting for NASA thought 1 or 2 per 100 a reasonable estimate.)

  16. #256
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    I like the Energiya RD-0120 better. Channel wall, and all: http://www.astronautix.com/r/rd-0120.html

    "Kosberg engine used in the Energia core stage. In 1987 it became the first operational Russian LOx/LH2 engine system, built to the same overall performance specifications as America's SSME, but using Russian technology....The channel-wall nozzle is a proposed replacement for the current SSME nozzle. Employing a process developed in Russia and used for the Russian RD-0120 rocket engine, flat stock is roll formed into a conical shape, which serves as the nozzle liner. The liner is slotted to form channels for the nozzle's liquid hydrogen coolant to flow through. A jacket is then installed over the liner and welded at the ends. The entire assembly is then furnace brazed. The channels in the liner take the place of the 1,080 tubes that regeneratively cool the current SSME nozzle. The channel-wall nozzle is a relatively simple design that has fewer parts and welds than the current complex SSME nozzle. (The current SSME nozzle takes two-and-one-half years to build, costs $7 million, and is currently flown no more than 12 to 15 times because of safety concerns related to hydrogen leaks.) "


    I seem to remember some scuttlebutt about how MSFC almost got their hands on an RD-0120, before things began to get frosty again...

  17. #257
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    Quote Originally Posted by schlaugh View Post
    Coincidentally I just read Richard Feynman's dissenting report on the Challenger Disaster (STS 51-L) when he was a member of the Rogers Investigation Commission. In his efforts while on the Commission Feynman also researched the development and production of the SSMEs, the RS-25 Aerojet Rocketdyne engines. Feynman was trying to determine if the NASA culture led to issues with the SSMES and was there a lurking problem (he concluded there were issues although none ever surfaced before the end of the program or else were addressed post-Challenger).

    In the NOVA special the RS-25D was shown as part of the re-purposed hardware for the SSL. Seeing those new engines made me wonder about the development and improvements since the shuttles last flew. And, more to the point, has any of the bottoms-up design and engineering taken place that Feynman recommended rather than the top-down approach that NASA took when it designed and built the SST. (I also noted that the Shuttle RS-25s were re-flown, albeit with major overhauls between missions. The RS-25Ds shown in the NOVA special will be flown once and dumped in the Atlantic.) The engines were used as a segue to the sections on Space X and others which are trying to build reusable equipment.

    The section below is from Feynman's report. It's a bit lengthy but might be interesting to those who haven't seen these remarks (click the link above for the full report):
    The first few flights of SLS will use refurbished RS-25D's left over from the Shuttle program, tossing the reusable engines after one last use. After that they'll switch to a redesigned non-reusable RS-25E.

    Chris Bergin at NASASpaceflight. com did an article,

    https://www.nasaspaceflight.com/2016...25-production/

    Also of interest, the reusable AR-22 to be used in Boeing's Phantom Express reusable flyback booster/spaceplane is based on RS-25. Phantom Express us for smallsats, but very rapid response - once a day..

    https://www.nasaspaceflight.com/2018...imes-ten-days/

    https://www.boeing.com/space/phantom-express/index.page

  18. #258
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    Quote Originally Posted by publiusr View Post
    Looks like one of the names of the next Russian rocket comes from a river:

    The Don
    https://www.rt.com/russia/451448-rus...y-rocket-moon/

    Speaking of heavy lift, this was to ferry Buran:
    https://edition.cnn.com/travel/artic...ine/index.html

    Even larger versions were planned
    https://falsesteps.wordpress.com/201...e-tupolev-oos/
    I've seen the operational AN-225 in person when it visited Paine Field in Everett, WA years ago, on its way to an airshow somewhere else. I worked at the adjacent Boeing factory and we went over to see it at lunchtime. Very impressive. And oh, my, so many wheels! We all wanted Boeing to tow a 747 over to park next to it for scale, but of course they didn't.

    Quote Originally Posted by bknight View Post
    The show underwhelmed me.
    You can add me to the list. How many times did we need to see Delta Clipper falling over?
    Cum catapultae proscriptae erunt tum soli proscript catapultas habebunt.

  19. #259
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    Quote Originally Posted by Trebuchet View Post
    I've seen the operational AN-225 in person when it visited Paine Field in Everett, WA years ago, on its way to an airshow somewhere else. I worked at the adjacent Boeing factory and we went over to see it at lunchtime. Very impressive. And oh, my, so many wheels! We all wanted Boeing to tow a 747 over to park next to it for scale, but of course they didn't.



    You can add me to the list. How many times did we need to see Delta Clipper falling over?
    I had a conversation with an Apollo hoax believer and his contention was the LM could not land vertically on the Moon because NASA did not possess the skills/knowledge to land vertically. Then he offered the Delta Clipper as his evidence. I told him that he totally ignored the fact that the DC had a leg buckle/collapse while landing causing the explosion.

  20. #260
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    The DC leg actually just didn't extend. And it had landed successfully multiple time before.

    I often wonder why they don't use five legs on F9 and such, as is universal on office chairs these days. One can fail and it can still be stable. Obviously the answer is weight, but I think about pretty much every time I watch one land. SpaceX did lose at least one F9 due to a leg failure.
    Cum catapultae proscriptae erunt tum soli proscript catapultas habebunt.

  21. #261
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    Quote Originally Posted by Trebuchet View Post
    The DC leg actually just didn't extend. And it had landed successfully multiple time before.

    I often wonder why they don't use five legs on F9 and such, as is universal on office chairs these days. One can fail and it can still be stable. Obviously the answer is weight, but I think about pretty much every time I watch one land. SpaceX did lose at least one F9 due to a leg failure.
    Weight, wider attachment base with 4 legs making the legs stronger against twisting, symmetry matching up with the Falcon Heavy booster arrangement, one fewer leg to deal with in ground handling, etc. And if one of 5 legs fails, there's very little margin of stability in the direction of that leg, so a vehicle with 1 failed leg out of 5 is pretty likely to topple on landing anyway...you need more than 5 legs to get a real benefit from redundancy.

  22. #262
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    Quote Originally Posted by Trebuchet View Post
    >
    I often wonder why they don't use five legs on F9
    >
    Because 5 doesn't divide into 8 evenly.

    F9's Octaweb thrust structure has 8 engines in the outer ring, and each engine is mounted inside an armor cell to prevent engine fratricide if one fails. The hard points where leg forks attach is where the cell walls meet the outer ring.

    The red triangles are "legs," each spanning 2 cells, and the close-up is a dual leg hinge which attaches to an Octaweb cell hard point.

    I *guess* they could use 8 legs by each leg spanning just 1 cell, but now the system is much heavier and requires more gas (with larger tanks) to operate all those pistons.

    octaweb leg arrangement 2.jpg

    octaweb leg arrangement 1.jpg
    Last edited by docmordrid; 2019-Feb-17 at 08:54 AM.

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