Wow. I didn't realize the schedule had such a dour outlook. One option that wasn't discussed in the article was using the same configuration for EM-1 to launch Europa Clipper. Is this possible or is the Exploration Upper Stage needed for its performance?
Any estimates for when the probe itself can be ready?I remember reading that it's being designed so that it fits on smaller launches and what the SLS provides is a faster trajectory. This might be nullified if it has to wait several years for SLS to be ready.There is also a lot of risk in launching a 2B flagship mission on a new launcher config.
Great article!It would be interesting to understand what the factors are driving the 33 months to do the conversion, because that is a long time. As a comparison it took 6 years from starting to dig the foundation of the world's tallest building, the Burj Khalifa, until it opened - so is the SLS ML only half as complicated as the Burj Khalifa? It would seem to be far less complicated, but they have different functions so maybe that is a factor.Is it money?Is it that the ML has to be disassembled and then reassembled?
Due to U.S. Federal laws written by Congress, SLS is the only vehicle that can launch Europa Clipper unless the law is changed.
Probable realistic launch plan schedule for SLS:EM-1 May 2020SM-1 July 2023EM-2 June 2024EM-3 June 2025SM-2 2026 (whenever the launch window in this year occurs) (plus this is the first flight of the RS-25Es, ASAP will want a unmanned flight of these engines first before a manned one) (this engine set will not be available to support a flight until this time anyway so it could not be done any earlier)EM-4 2028 (it takes 2 years to deliver 4 RS-25Es on the current contract) (It will require a bigger budget and a new contract to increase the build rate to deliver 4 engines per year instead of the current contract delivery rate of 2 engines per year)Unless the engine build rate is increased there is no more launches in the 2020's.
SM-2 2026 (whenever the launch window in this year occurs) (plus this is the first flight of the RS-25Es, ASAP will want a unmanned flight of these engines first before a manned one) (this engine set will not be available to support a flight until this time anyway so it could not be done any earlier)
Over the course of the Space Shuttle program, the RS-25 went through a series of upgrades, including combustion chamber changes, improved welds and turbopump changes in an effort to improve the engine's performance and reliability and so reduce the amount of maintenance required after use. As a result, several versions of the RS-25 were used during the program:[9][22][24][25][30][31][32][33][34]FMOF (first manned orbital flight) – Certified for 100% rated power level (RPL). Used for the orbital flight test missions STS-1—STS-5 (engines 2005, 2006 and 2007).Phase I – Used for missions STS-6—STS-51-L, the Phase I engine offered increased service life and was certified for 104% RPL.Phase II (RS-25A) – First flown on STS-26, the Phase II engine offered a number of safety upgrades and was certified for 104% RPL & 109% full power level (FPL) in the event of a contingency.Block I (RS-25B) – First flown on STS-70, the Block I engines offered improved turbopumps featuring ceramic bearings, half as many rotating parts and a new casting process reducing the number of welds. Block I improvements also included a new, two-duct powerhead (rather than the original design, which featured three ducts connected to the HPFTP and two to the HPOTP), which helped improve hot gas flow, and an improved engine heat exchanger.Block IA (RS-25B) – First flown on STS-73, the Block IA engine offered main injector improvements.Block IIA (RS-25C) – First flown on STS-89, the Block IIA engine was an interim model used whilst certain components of the Block II engine completed development. Changes included a new large throat main combustion chamber (which had originally been recommended by Rocketdyne in 1980), improved low pressure turbopumps and certification for 104.5% RPL to compensate for a 2 seconds (0.020 km/s) reduction in specific impulse (original plans called for the engine to be certified to 106% for heavy International Space Station payloads, but this was not required and would have reduced engine service life). A slightly modified version first flew on STS-96.Block II (RS-25D) – First flown on STS-104, the Block II upgrade included all of the Block IIA improvements plus a new high pressure fuel turbopump. This model was ground-tested to 111% FPL in the event of a contingency abort, and certified for 109% FPL for use during an intact abort.
The problem is there was no alternative in the Shuttle program. You flew manned or not at all.It could have flown unmanned but the state of the art was yet to be trustworthy for accomplishing this, hence the requirement to always be manned flights.Since then the safety community has become more risk averse when it comes to a manned program. This not to say it could not be done just less likely in the current safety environment for manned flight.
Quote from: rockets4life97 on 11/03/2017 05:34 pmWow. I didn't realize the schedule had such a dour outlook. One option that wasn't discussed in the article was using the same configuration for EM-1 to launch Europa Clipper. Is this possible or is the Exploration Upper Stage needed for its performance?SLS Block 1B w/ EUS is the only thing that can inject Europa Clipper into the desired direct trajectory to Jupiter with no gravity assists.
Quote from: ChrisGebhardt on 11/03/2017 05:59 pmQuote from: rockets4life97 on 11/03/2017 05:34 pmWow. I didn't realize the schedule had such a dour outlook. One option that wasn't discussed in the article was using the same configuration for EM-1 to launch Europa Clipper. Is this possible or is the Exploration Upper Stage needed for its performance?SLS Block 1B w/ EUS is the only thing that can inject Europa Clipper into the desired direct trajectory to Jupiter with no gravity assists.Is there something fundamentally wrong with using gravity assists? I know it takes longer, but I believe all missions to the outer planets so far have used them.
Quote from: spacetraveler on 11/05/2017 07:37 pmQuote from: ChrisGebhardt on 11/03/2017 05:59 pmQuote from: rockets4life97 on 11/03/2017 05:34 pmWow. I didn't realize the schedule had such a dour outlook. One option that wasn't discussed in the article was using the same configuration for EM-1 to launch Europa Clipper. Is this possible or is the Exploration Upper Stage needed for its performance?SLS Block 1B w/ EUS is the only thing that can inject Europa Clipper into the desired direct trajectory to Jupiter with no gravity assists.Is there something fundamentally wrong with using gravity assists? I know it takes longer, but I believe all missions to the outer planets so far have used them.They want to launch direct to increase SC Life Expectancy during transit and in the Jupiter System at Europa. Also Congress said so.
....You could take the hundreds of millions that are going to be spent on this useless ML redesign and use it to do something useful, like figure out how to produce SLS cheaper so you can actually launch it at a reasonable cadence.
Also, to reduce the human costs of maintaining a highly-trained, highly-PAID staff of hundreds?/a few thousands, and their support mechanisms in working order while the Flagship-class spacecraft is in transit to its destination.The New Horizons team created some creative solutions around these issues (launch in 2006, flyby Pluto/Charon 9 years later), but there's no substitute for launching a mission, and then getting on with the exploration ASAP, via direct trajectory!
Quote from: zubenelgenubi on 11/05/2017 09:11 pmAlso, to reduce the human costs of maintaining a highly-trained, highly-PAID staff of hundreds?/a few thousands, and their support mechanisms in working order while the Flagship-class spacecraft is in transit to its destination.The New Horizons team created some creative solutions around these issues (launch in 2006, flyby Pluto/Charon 9 years later), but there's no substitute for launching a mission, and then getting on with the exploration ASAP, via direct trajectory! I don't think so. Cost reduction is definitely not an advantage of this approach. It will cost MUCH more to launch via SLS with direct trajectory than it would with a smaller launcher using gravity assists and paying the ground support team for a few additional years during transit.
Probable realistic launch plan schedule for SLS:EM-1 May 2020SM-1 July 2023EM-2 June 2024EM-3 June 2025SM-2 2026 (whenever the launch window in this year occurs) (plus this is the first flight of the RS-25Es, ASAP will want a unmanned flight of these engines first before a manned one) (this engine set will not be available to support a flight until this time anyway so it could not be done any earlier)EM-4 2028 (it takes 2 years to deliver 4 RS-25Es on the current contract) (It will require a bigger budget and a new contract to increase the build rate to deliver 4 engines per year instead of the current contract delivery rate of 2 engines per year)Unless the engine build rate is increased there is no more launches in the 2020's.Assumptions:a) That ML-1 is modified to be a cargo only SLS-1B support.b) That an ML-2 is constructed with lessons learned to make a crew version of the ML with a budget funded at a level allowing it to be constructed in 5 years starting Oct 2018. This gets a ML available to support the June 2024 EM-2 date at better than 6 months prior to launch date plus a few months of margin. c) That EC is ready for launch by 6 months prior to its launch date in July 2023.d) That Europa Lander is ready for launch 6 months prior to its window in 2026.
that SLS launch will be part of the 1b validation (meaning it would have to be flown regardless).
Quote from: Khadgars on 11/06/2017 09:35 pmthat SLS launch will be part of the 1b validation (meaning it would have to be flown regardless). Sending your most expensive probe on a test flight, what could possibly go wrong...
There seems to be an assumption peeking out behind most of the negative posts here -- that the SLS will almost inevitably fail on its first flight.What, exactly, is the track record on first flights of new large boosters? I don't want to count smallsat launch vehicles that are built out of old, degrading solid rocket motors handed down from ICBM programs, or things like that. Just new large booster systems.I'm aware of Ariane 5's first flight -- which, IIRC, was an issue with the flight software not being modified from Ariane 4. Not a hardware issue at all. More an issue of the programming staff not being willing to give up one of their 12 weeks of paid vacation for that year... Now, *second* flights, I'm aware of issues, most recently with the CZ-5, and going back at least to to the Saturn V. But, again, out of large, multi-billion-dollar development programs, how many first flights have failed?You gotta fly it first at some point, guys -- and ASAP is gonna push hard against flying the first iteration of a given configuration with crew on board. If it's gonna cost 4 or 5 billion USD to fly the first one, doesn't it make sense to put *something* on it?And, thinking about it, SLS isn't a Saturn V. It's not featuring several previously-unflown engine designs (or, in the case of the J-2, previously unflown in a clustered configuration) -- heck, the first several flights of SLS will use previously flown engines. Has OrbitalATK been pushing to revert the SRB segment joints to the original faulty Shuttle design, or something?In other words why would people assume that Musk and Bezos can create new engines and boosters that will be perfectly wonderful from the get-go, but SLS, featuring extremely mature engine technology, is a horrendous risk that should never be attempted?I am not speaking of cost, or suitability of the booster for specific missions -- just an increasingly-less-unspoken assumption that SLS is inherently likely to fail, especially on its first flight. I'm just not seeing any basis for that prejudice against this launch system.
They are really going to redesign the entire mobile launchers because it will end up with a safety factor of 3.75 instead of 4.0 for the block 1B configuration? Seriously? And that's going to take 3 years?
Quote from: the_other_Doug on 11/07/2017 03:45 pmThere seems to be an assumption peeking out behind most of the negative posts here -- that the SLS will almost inevitably fail on its first flight.What, exactly, is the track record on first flights of new large boosters? I don't want to count smallsat launch vehicles that are built out of old, degrading solid rocket motors handed down from ICBM programs, or things like that. Just new large booster systems.I'm aware of Ariane 5's first flight -- which, IIRC, was an issue with the flight software not being modified from Ariane 4. Not a hardware issue at all. More an issue of the programming staff not being willing to give up one of their 12 weeks of paid vacation for that year... Now, *second* flights, I'm aware of issues, most recently with the CZ-5, and going back at least to to the Saturn V. But, again, out of large, multi-billion-dollar development programs, how many first flights have failed?You gotta fly it first at some point, guys -- and ASAP is gonna push hard against flying the first iteration of a given configuration with crew on board. If it's gonna cost 4 or 5 billion USD to fly the first one, doesn't it make sense to put *something* on it?And, thinking about it, SLS isn't a Saturn V. It's not featuring several previously-unflown engine designs (or, in the case of the J-2, previously unflown in a clustered configuration) -- heck, the first several flights of SLS will use previously flown engines. Has OrbitalATK been pushing to revert the SRB segment joints to the original faulty Shuttle design, or something?In other words why would people assume that Musk and Bezos can create new engines and boosters that will be perfectly wonderful from the get-go, but SLS, featuring extremely mature engine technology, is a horrendous risk that should never be attempted?I am not speaking of cost, or suitability of the booster for specific missions -- just an increasingly-less-unspoken assumption that SLS is inherently likely to fail, especially on its first flight. I'm just not seeing any basis for that prejudice against this launch system.If you're talking about EM-1, it does have the largest single stage and the largest solid motors ever. But the highest risk item is probably avionics and software, which are harder than hardware to test realistically and are all new, to my understanding.Europa Clipper would not be on the first flight of SLS, but the second. It would be the first flight of EUS, which is a new stage, again with new software.
Also, use of EUS and the matching-size PLF would allow a more massive (larger propellant tanks = more propellant = longer mission/greater mission flexibility at mission target), taller, and wider spacecraft, to accommodate the radiation shielding and multiple-instrument payload, would it not?(One of our resident experts would be able to express this better than me, I think.)
They are really going to redesign the entire mobile launchers because it will end up with a safety factor of 3.75 instead of 4.0 for the block 1B configuration? Seriously? And that's going to take 3 years? 4.0 is just a made up round number in some spec somewhere, there's nothing magical about it. Plus, it's not like this structure is going to see a high number of duty cycles where additional structural margin is required to actually build a safe structure with launches taking place off of it once every two years at best. The Saturn V second stage was supposed to be designed to a safety factor of 1.5. North American did a really good job of designing it to 1.5, and it broke pretty much right at 1.5 in integrated loading testing. So, rather than go redesign the entire stage, NASA changed the requirement for manned spaceflight factor of safety to 1.4 and called it good. Since then, every launch vehicle built in the US has been designed to 1.4. We would never have reached the moon by 1970 if NASA of the 60's was ruled by the bureaucrats who have their noses stuck in specification manuals like they do today. If they would have followed the letter of the specification and made North American go redesign the stage to 1.5, we'd never have made it to the moon in '69. Good engineering management requires understanding what is vitally important and what doesn't matter. You have to build additional margin into the areas of critical with high uncertainty, and you can accept significantly less in areas where the loads are extremely well understood (i.e. ground support equipment like the mobile launcher). You could take the hundreds of millions that are going to be spent on this useless ML redesign and use it to do something useful, like figure out how to produce SLS cheaper so you can actually launch it at a reasonable cadence.
This makes the Europa Clipper mission cheaper while not affecting SLS budget at all since it has to be flown before EM-2.
1. In other words why would people assume that Musk and Bezos can create new engines and boosters that will be perfectly wonderful from the get-go, but SLS, featuring extremely mature engine technology, is a horrendous risk that should never be attempted?2. I am not speaking of cost, or suitability of the booster for specific missions -- just an increasingly-less-unspoken assumption that SLS is inherently likely to fail, especially on its first flight. I'm just not seeing any basis for that prejudice against this launch system.
Quote from: oldAtlas_Eguy on 11/04/2017 04:48 pmProbable realistic launch plan schedule for SLS:EM-1 May 2020SM-1 July 2023EM-2 June 2024EM-3 June 2025SM-2 2026 (whenever the launch window in this year occurs) (plus this is the first flight of the RS-25Es, ASAP will want a unmanned flight of these engines first before a manned one) (this engine set will not be available to support a flight until this time anyway so it could not be done any earlier)EM-4 2028 (it takes 2 years to deliver 4 RS-25Es on the current contract) (It will require a bigger budget and a new contract to increase the build rate to deliver 4 engines per year instead of the current contract delivery rate of 2 engines per year)Unless the engine build rate is increased there is no more launches in the 2020's.Assumptions:a) That ML-1 is modified to be a cargo only SLS-1B support.b) That an ML-2 is constructed with lessons learned to make a crew version of the ML with a budget funded at a level allowing it to be constructed in 5 years starting Oct 2018. This gets a ML available to support the June 2024 EM-2 date at better than 6 months prior to launch date plus a few months of margin. c) That EC is ready for launch by 6 months prior to its launch date in July 2023.d) That Europa Lander is ready for launch 6 months prior to its window in 2026.6 launches by 2028.... By then we would have spent >$40 billion on the SLS program.good god$6.7 billion per flight. That's $20 from every man, woman, and child in America to throw one of these up.
Quote from: ZachF on 11/07/2017 04:36 pmQuote from: oldAtlas_Eguy on 11/04/2017 04:48 pmProbable realistic launch plan schedule for SLS:EM-1 May 2020SM-1 July 2023EM-2 June 2024EM-3 June 2025SM-2 2026 (whenever the launch window in this year occurs) (plus this is the first flight of the RS-25Es, ASAP will want a unmanned flight of these engines first before a manned one) (this engine set will not be available to support a flight until this time anyway so it could not be done any earlier)EM-4 2028 (it takes 2 years to deliver 4 RS-25Es on the current contract) (It will require a bigger budget and a new contract to increase the build rate to deliver 4 engines per year instead of the current contract delivery rate of 2 engines per year)Unless the engine build rate is increased there is no more launches in the 2020's.Assumptions:a) That ML-1 is modified to be a cargo only SLS-1B support.b) That an ML-2 is constructed with lessons learned to make a crew version of the ML with a budget funded at a level allowing it to be constructed in 5 years starting Oct 2018. This gets a ML available to support the June 2024 EM-2 date at better than 6 months prior to launch date plus a few months of margin. c) That EC is ready for launch by 6 months prior to its launch date in July 2023.d) That Europa Lander is ready for launch 6 months prior to its window in 2026.6 launches by 2028.... By then we would have spent >$40 billion on the SLS program.good god$6.7 billion per flight. That's $20 from every man, woman, and child in America to throw one of these up.A LEO flight of ~3 mT of logistics or crew costs every man, woman and child in the U.S. about $1 on average. SLS is almost an order of magnitude bigger(70-130 mT vs 7 mt - 22 mT LEO).
Also, use of EUS and the matching-size PLF would allow a more massive (larger propellant tanks = more propellant = longer mission/greater mission flexibility at mission target), taller, and wider spacecraft, to accommodate the radiation shielding and multiple-instrument payload, would it not?
There seems to be an assumption peeking out behind most of the negative posts here -- that the SLS will almost inevitably fail on its first flight.
Quote from: the_other_Doug on 11/07/2017 03:45 pmThere seems to be an assumption peeking out behind most of the negative posts here -- that the SLS will almost inevitably fail on its first flight.I'm a critic of SLS, but I don't expect it or EUS to fail on first, but surely it's beyond dispute that launching the very expensive EC on SLS is much riskier than launching it on the very well proven Atlas V.
Plus, it's not like this structure is going to see a high number of duty cycles where additional structural margin is required to actually build a safe structure with launches taking place off of it once every two years at best.
And every launch vehicle built in the US has been designed to 1.25 and not 1.4
Quote from: zubenelgenubi on 11/05/2017 09:11 pmAlso, use of EUS and the matching-size PLF would allow a more massive (larger propellant tanks = more propellant = longer mission/greater mission flexibility at mission target), taller, and wider spacecraft, to accommodate the radiation shielding and multiple-instrument payload, would it not?(One of our resident experts would be able to express this better than me, I think.)The spacecraft size is already fixed. It is dual compatible with SLS and other existing launch vehicles.
Quote from: Proponent on 11/07/2017 09:58 pmI'm a critic of SLS, but I don't expect it or EUS to fail on first, but surely it's beyond dispute that launching the very expensive EC on SLS is much riskier than launching it on the very well proven Atlas V.Were you this adamant that the billion dollar New Horizons probe not use the first Atlas 551(7th Atlas V overall) and instead use a smaller flight tested vehicle even if it took longer? And that was a nuclear payload.
I'm a critic of SLS, but I don't expect it or EUS to fail on first, but surely it's beyond dispute that launching the very expensive EC on SLS is much riskier than launching it on the very well proven Atlas V.
Quote from: ncb1397 on 11/07/2017 10:46 pmQuote from: Proponent on 11/07/2017 09:58 pmI'm a critic of SLS, but I don't expect it or EUS to fail on first, but surely it's beyond dispute that launching the very expensive EC on SLS is much riskier than launching it on the very well proven Atlas V.Were you this adamant that the billion dollar New Horizons probe not use the first Atlas 551(7th Atlas V overall) and instead use a smaller flight tested vehicle even if it took longer? And that was a nuclear payload.By the time an Atlas V 551 launched New Horizions, the Atlas V core had already flown 6 times, as you point out, the SRBs had been flown 7 times, and the Centaur had flown many times. Flying 5 with 5 SRBs when at most 3 had flown before was a risk factor, but a small one compared to flying on the second ever SLS and first ever EUS.
Quote from: Proponent on 11/10/2017 01:16 amBy the time an Atlas V 551 launched New Horizions, the Atlas V core had already flown 6 times, as you point out, the SRBs had been flown 7 times, and the Centaur had flown many times. Flying 5 with 5 SRBs when at most 3 had flown before was a risk factor, but a small one compared to flying on the second ever SLS and first ever EUS.By the same logic, the RS-25 & solid boosters will have flown on 136 missions (135 STS, 1 SLS), and the core stage will have been flight proven one (1) SLS mission. The RL-10 engines on the EUS have been flown since 1963.
By the time an Atlas V 551 launched New Horizions, the Atlas V core had already flown 6 times, as you point out, the SRBs had been flown 7 times, and the Centaur had flown many times. Flying 5 with 5 SRBs when at most 3 had flown before was a risk factor, but a small one compared to flying on the second ever SLS and first ever EUS.
I buy the logic for the RS-25s, but they are not the same engines that have flown previously. Designs and details are different (and I think even from the previously flown engines to be used on the SLS).The SRBs are a new 5 segment design, different chemical make up (as I recall), and a different nozzle, with only 2 test firings, not under flight conditions plus 2 for the first flight of SLS.The RL-10s are not the same as flown in 1963, but do have more recent flight heritage.
Quote from: mike robel on 11/10/2017 02:32 pmI buy the logic for the RS-25s, but they are not the same engines that have flown previously. Designs and details are different (and I think even from the previously flown engines to be used on the SLS).The SRBs are a new 5 segment design, different chemical make up (as I recall), and a different nozzle, with only 2 test firings, not under flight conditions plus 2 for the first flight of SLS.The RL-10s are not the same as flown in 1963, but do have more recent flight heritage.Just a correction, 5-segment SRBS have been test fired 5 times, 3 development test fires (in 2009, 2010, and 2011) and 2 qualification test fires (in 2015 and 2016).
1. If you see the various presentations that Papalardo has done on Europa Clipper, Atlas V is both weight and volume limited. It is not just that it will take a series of flybys to get to Jupiter and Europa, Clipper is running into the maximum weight limit of Atlas V and into the volume limit of its shroud.
Thanks -- can you give me a pointer to the relevant presentations?
Quote from: Proponent on 11/12/2017 08:52 pmThanks -- can you give me a pointer to the relevant presentations?Check out the link below. I don't know if all the trajectory options are still valid with the current masshttps://sites.nationalacademies.org/cs/groups/ssbsite/documents/webpage/ssb_172023.pdf
The lecture is about Europa, with details about Clipper in the end. The most recent news I heard in there is that apparently during flyby Clipper will generate so much data the processing system will not be able to handle it so they will use a more primitive system instead. Alas, I would like that explained: will they record everything a then process it afterwards before transmitting it to Earth, or will they not record it when it goes above the system's capability.
Quote from: Proponent on 11/10/2017 01:16 amQuote from: ncb1397 on 11/07/2017 10:46 pmQuote from: Proponent on 11/07/2017 09:58 pmI'm a critic of SLS, but I don't expect it or EUS to fail on first, but surely it's beyond dispute that launching the very expensive EC on SLS is much riskier than launching it on the very well proven Atlas V.Were you this adamant that the billion dollar New Horizons probe not use the first Atlas 551(7th Atlas V overall) and instead use a smaller flight tested vehicle even if it took longer? And that was a nuclear payload.By the time an Atlas V 551 launched New Horizions, the Atlas V core had already flown 6 times, as you point out, the SRBs had been flown 7 times, and the Centaur had flown many times. Flying 5 with 5 SRBs when at most 3 had flown before was a risk factor, but a small one compared to flying on the second ever SLS and first ever EUS.By the same logic, the RS-25 & solid boosters will have flown on 136 missions (135 STS, 1 SLS), and the core stage will have been flight proven one (1) SLS mission. The RL-10 engines on the EUS have been flown since 1963.
Since I am more familiar with the Science part of NASA (though still a learned amateur) than the launcher part here are a few answers about the payloads:1. If you see the various presentations that Papalardo has done on Europa Clipper, Atlas V is both weight and volume limited. It is not just that it will take a series of flybys to get to Jupiter and Europa, Clipper is running into the maximum weight limit of Atlas V and into the volume limit of its shroud. Now the other lesser alternatives beyond Atlas V are Delta IV Heavy and Falcon Heavy. Delta IV Heavy also has a shroud volume issue, though not the weight issue. It does not really get mentioned that much in the presentations, most likely if like with the Parker Solar Probe they run into a weight problem while designing for Atlas V they can switch, and become the third NASA mission on Delta IV Heavy after EFT-1 and Parker Solar Probe. They have asked SpaceX what is the payload shroud and lifting power limits for Falcon Heavy. As per the most recent presentation I saw in the summer (I have not seen yet the November 2nd presentation on LPI) SpaceX had not given a formal answer to the Europa Clipper team.
Quote from: AegeanBlue on 11/07/2017 10:14 pmSince I am more familiar with the Science part of NASA (though still a learned amateur) than the launcher part here are a few answers about the payloads:1. If you see the various presentations that Papalardo has done on Europa Clipper, Atlas V is both weight and volume limited. It is not just that it will take a series of flybys to get to Jupiter and Europa, Clipper is running into the maximum weight limit of Atlas V and into the volume limit of its shroud. Now the other lesser alternatives beyond Atlas V are Delta IV Heavy and Falcon Heavy. Delta IV Heavy also has a shroud volume issue, though not the weight issue. It does not really get mentioned that much in the presentations, most likely if like with the Parker Solar Probe they run into a weight problem while designing for Atlas V they can switch, and become the third NASA mission on Delta IV Heavy after EFT-1 and Parker Solar Probe. They have asked SpaceX what is the payload shroud and lifting power limits for Falcon Heavy. As per the most recent presentation I saw in the summer (I have not seen yet the November 2nd presentation on LPI) SpaceX had not given a formal answer to the Europa Clipper team. There are no volume issues with existing fairings. EC is designed to fly in them. Even if EC flies on SLS, it still could be in a 5m fairing
Check out the link below. I don't know if all the trajectory options are still valid with the current masshttps://sites.nationalacademies.org/cs/groups/ssbsite/documents/webpage/ssb_172023.pdf
Very interesting --I had not known about the possibility of trajectory with a major post-departure delta-V. I wonder if any particularly stage is in mind for that.
However… this is the desired plan with no money – at present – to execute as Congress must approve the additional funds needed to build a brand new ML, and with such funds becoming available before the start of FY 2019 on 1 October 2018 an extremely unlikely possibility, the ML-2 desire is – at present – just that. A desire.
Quote from: oldAtlas_Eguy on 12/01/2017 10:07 pmBut there is one question that was not answered in the article and that was how long would it take to build a new ML once the work started? How long has it taken/will take for the first ML to be built?The Mobile Launcher contract was awarded to Hensel Phelps in May 2008.source: https://www.nasa.gov/home/hqnews/2008/may/HQ_C08025_Ares_MLP_contract.htmlAres 1X launched from it in October of 2009. The Ares 1 mobile launcher is simpler than the SLS mobile launcher though.
But there is one question that was not answered in the article and that was how long would it take to build a new ML once the work started? How long has it taken/will take for the first ML to be built?
Quote from: ncb1397 on 12/01/2017 10:21 pmQuote from: oldAtlas_Eguy on 12/01/2017 10:07 pmBut there is one question that was not answered in the article and that was how long would it take to build a new ML once the work started? How long has it taken/will take for the first ML to be built?The Mobile Launcher contract was awarded to Hensel Phelps in May 2008.source: https://www.nasa.gov/home/hqnews/2008/may/HQ_C08025_Ares_MLP_contract.htmlAres 1X launched from it in October of 2009. The Ares 1 mobile launcher is simpler than the SLS mobile launcher though.The basic item was when was the work started to modify the ML for SLS-1A (EM-1). I do know the ML is still under construction (modification). With a target completion date of June 2018. What I do not know is when its actual work started.
The Mobile Launcher, completed in August 2010 at a cost of$234 million, consists of a two-story base, a 355-foot-tall launch umbilical tower, andfacility ground support systems that include power, communications, and water.
If it takes more than 3 years to build it would not support the EC launch date window of June 2022. Because a 3 year build time with completion of ML occurring soon enough for the EC SLS stacking to start in Jan 2022 the build has to start on or prior to Dec 2018. Meaning it will either take 3 years or it might as well take 4 years. Since the next window is July 2023. A larger cost ($300M more) than that for the modification 33 month effort usually means a longer time frame as well. All of the time frames all point to the same goal post of support for an EC launch July 2023. And unlikely will support a EC launch date with the modified or a new ML of June 2022.
NASA weighs new mobile launcher for SLS
Bob Cabana, director of the Kennedy Space Center, also supports building a new mobile launcher rather than modifying the existing one. He said earlier at the NASA Advisory Council committee meeting that he took Bill Gerstenmaier, NASA associate administrator for human exploration and operations, on a tour of the current launcher “so he could appreciate the complexity of this thing and why I believe we need a second mobile launcher rather than modifying this one.”Cabana offered an analogy for the work needed to modify the mobile launcher for the SLS Block 1B. “I’m going to cut off my head and add six inches to my body,” he said. “That’s essentially what you’re doing. You’re taking a very complex system — all the wire systems and everything else that is on that thing — and raising it up to extend it for the larger vehicle.”
Hill said a more detailed discussion about the tradeoffs of modifying the existing launcher versus building a new one could take place at the committee’s next meeting, which would be around March 2018 based on the schedules of previous meetings. “By then,” he said, “we should know whether we’re going with modifying this mobile launcher or having the authority to go get a new one.”
Love this quote from Gen. Hyten, “I’m worried about the future. Somehow this country lost the ability to go fast. I don’t know how that happened,” he said. “We take four years to study a problem before we do anything. We do four years of risk reduction on technologies we built 50 years ago.”http://spacenews.com/battle-brewing-in-the-pentagon-over-military-space-investments/Pretty much sums up the entirety of the SLS program. I'd de-manifest EC from SLS at this point. NG, Vulcan, Block5 based FH, BFR(?)....
Love this quote from Gen. Hyten, Im worried about the future. Somehow this country lost the ability to go fast. I dont know how that happened, he said. We take four years to study a problem before we do anything. We do four years of risk reduction on technologies we built 50 years ago.http://spacenews.com/battle-brewing-in-the-pentagon-over-military-space-investments/Pretty much sums up the entirety of the SLS program. I'd de-manifest EC from SLS at this point. NG, Vulcan, Block5 based FH, BFR(?)....
So, built a mobile launcher for Ares X-1, built a mobile launcher for EM-1, and now going to build another for EM-2. Even the mobile launchers are expendable.
Quote from: AncientU on 12/05/2017 09:27 pmSo, built a mobile launcher for Ares X-1, built a mobile launcher for EM-1, and now going to build another for EM-2. Even the mobile launchers are expendable.Ares I-X used the Space Shuttle MLP-1. youtube.com/watch?v=1Gcn-5nZKwkEM-1 is using the MLP originally designed for Ares I, but heavily modified for SLS Block I.Its not yet decided if EM-2 will use a new MLP.
http://spacenews.com/nasa-budget-proposal-continues-debate-on-when-and-how-to-launch-europa-clipper/NASA is study two launch version one with ULA Atlas V and Gravitational Swing by maneuver for $432 million other SLS direct to Jupiter for around $600 million now Capitol Hill is questioning the Europa Clipper budget, special the use of SLS in june 2022 Hey, NASA you look like intelligent organisation you look like someone who would be interested in a bargain. Wanna buy this rocket, NASA ?*just $150-90 million launch cost and bring space probe direct to destinations, no need for Gravitational Swing by maneuver
not a viable candidate
Quote from: Jim on 02/26/2018 01:05 pmnot a viable candidateCan you please expand on this (I assume you are talking about FH)? Not viable direct or at all? Why? What about Atlas V (can Atlas V 552 do direct?)?
And, there is not just risk Class A certification, it is also nuclear certification.
Quote from: Jim on 03/01/2018 01:55 pmAnd, there is not just risk Class A certification, it is also nuclear certification.Launches of nuclear materials aren't so much certified as approved on a case-by-case basis by the executive.Specifically, for NASA missions involving launch of nuclear materials, NASA and DOE spends some years preparing a risk analysis. This analysis is then reviewed by an Interagency Nuclear Safety Review Panel (INSRP) representing more agencies than NASA and DOE. The INSRP then forwards a recommendation to the White House, which approves or disapproves the launch.I was involved in the White House review of the INSRP recommendation for the Cassini launch, described in this press release:https://www.jpl.nasa.gov/releases/97/casok.htmlGoogle "INSRP" for more.
Just being stupid here, how can SLS be certified if the first one has not been produced and/or flown?
yes, I know and I supported INSRP for MER and MSL. The analysis has been done for Atlas V (twice and will be for a third time) and hence it is "certified"
NASA no longer seeking to develop second mobile launcher for SLS:http://spacenews.com/nasa-no-longer-seeking-to-develop-second-mobile-launcher-for-sls/So does that mean that the Atlas V wins by default for the Europa Clipper mission?
1. Using the exact same A5 (or other LV) configuration may save some analysis on the launch side.2. But unless the s/c are exact duplicates launching from the same location on the same trajectory under the same conditions -- and those factors are never identical -- the nuclear and health analysis is always unique to that mission and launch.3. Just because a LV configuration launched a short-lived rover with RHUs a couple years ago does _not_ mean that the same LV configuration is "certified" (or cleared, endorsed, etc.) to launch a long-lived rover with RTGs now (for example).
Provided further, That $895,000,000 shall be for Exploration Ground Systems, including $350,000,000 for a second mobile launch platform and associated SLS activities
It's interesting they spent more than 800 Mio. $ in refurbishing an existing MLP, while a new one is estimated to cost 350 Mio. $....
Quote from: Bananas_on_Mars on 03/22/2018 06:05 amIt's interesting they spent more than 800 Mio. $ in refurbishing an existing MLP, while a new one is estimated to cost 350 Mio. $....Well they originally thought modifying the existing ML would only cost $54 million....
The articlehttp://spacenews.com/nasa-weighs-new-mobile-launcher-for-sls/puts the cost of a new ML at $300M + the cost of what it takes to modify the ML-1 in which a new ML-2 that supports SLS 1B but the ML-1 would only support SLS 1A since it would no longer be modified due to lack of funds.The start date would be if it is requested in the next budget FY2019 of 1 Oct 2018 at earliest. It is always possible for if there is some funds to start it earlier but you still need Congressional authority to obligate the government to any across FY projects. At the current rate of legislation that authority may be sometime in Jan 2019. But there is one question that was not answered in the article and that was how long would it take to build a new ML once the work started? How long has it taken/will take for the first ML to be built?That value could be used as a way to evaluate whether a new ML can meet the schedules needed (available earlier than a ML-1 reworked and a delayed to June 2020 EM-1 launch date. That would be a time to build of < 53 months. Any longer and a new ML does not solve schedule problems but causes more schedule problems.
Gerstenmaier also said that from procurement to delivery, it will take 5 years to build the second Mobile Launch Platform.
Am I missing something besides my marbles lately? 5 years to build a gantry? They built most of the KSC complex faster. I was big SLS-fan, but this is starting to resemble something out of an old "Mad" magazine...
Quote from: eric z on 04/25/2018 09:59 pm Am I missing something besides my marbles lately? 5 years to build a gantry? They built most of the KSC complex faster. I was big SLS-fan, but this is starting to resemble something out of an old "Mad" magazine...Not just the gantry, but also the big boxy launch platform. And it's that glorious red tape. All NASA projects have to be open competition, studied, an environmental assessment done, etc. Then the work orders are "signed in triplicate, sent in, sent back, queried, lost, found, subjected to public inquiry, lost again, and finally buried in soft peat for three months" to quote HHGTTG.
Am I missing something besides my marbles lately? 5 years to build a gantry?
Quote from: eric z on 04/25/2018 09:59 pm Am I missing something besides my marbles lately? 5 years to build a gantry? Not a gantry, but an umbilical tower.
The key problem is a design that meets the total weight constraints for the crawler.That was the main driver towards a second MLP or a very long duration upgrade to SLS 1B for MLP1.If it was just a stationary tower and platform the design could be quickly done as well as the construction.