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.
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 11/07/2017 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.
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.