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#52
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Space X 2nd stage recovery
On 4/28/2018 2:29 PM, JF Mezei wrote:
On 2018-04-28 12:30, Jeff Findley wrote: Adding a service module to Dragon, in place of the simpler trunk, would be possible, but it would be adding to Dragon's primary mission capabilities and the crew's lives would depend on the proper functioning of the service module. As such, it would have to be fully "crew rated" in a way that relatively benign recovery devices simply do not. Yeah but what does "crew rated" mean outside of NASA? If say SpaceX were flying it's own customers not NASA astronauts? Also I fear "crew rating" when NASA is a primary customer is a bit of a political tool that can be used to hammer contractors in line in case they get too far out in front of SLS. Since BFR/BFS are being built in separate facility, would it really hurt BFR/BFS if NASA were to send mega pork money for SpaceX to build an upgraded Dragon with service module to do moon excursions? If the later is built at Hawthorne facility that is focused on Falcon/Dragon, it shouldn't hinder BFR/BFS much. Well I'm not going to speak for SpaceX. If such a thing were to happen it would be up to SpaceX to respond in a fashion that makes sense for SpaceX. My blathering about it without any knowledge of what is transpiring within SpaceX is pointless. Blathering about it WITH knowledge of what is transpiring within SpaceX (outside of being a journalist) probably would get me fired. Yes, it makes more sense for SpaceX to respond to RFP with BFR/BFS proposal for moon. The mega pork from NASA would help fund BFR/BFS development. Yes it does. I wouldn't call it pork. I'd call it a "public investment in the future". :-) But if BFR/BFS proposal would not win, then it is better for SPaceX to win with Dragon/Falcon so at least profits from that work go to fund BFR/BFS. (aka: better than nothing) Depends. Maybe, maybe not. Distraction of an engineering organization has its own costs. Longer term though, if BFR/BFS do to manned space travel what Fan[/l]con9 reusability has done for cargo costs, then eventually, it will win any/all NASA contracts for manned space travel. Maybe. Depends upon how the RFP is written. Sometimes they can be pretty specific and exclusionary. "Contracted vendor must be able to legally display "Boeing" name and insignia in highly visible portion of vehicle."... Well, usually not this bad... Dave |
#53
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Space X 2nd stage recovery
In article , says...
On 2018-04-28 12:30, Jeff Findley wrote: Adding a service module to Dragon, in place of the simpler trunk, would be possible, but it would be adding to Dragon's primary mission capabilities and the crew's lives would depend on the proper functioning of the service module. As such, it would have to be fully "crew rated" in a way that relatively benign recovery devices simply do not. Yeah but what does "crew rated" mean outside of NASA? If say SpaceX were flying it's own customers not NASA astronauts? Also I fear "crew rating" when NASA is a primary customer is a bit of a political tool that can be used to hammer contractors in line in case they get too far out in front of SLS. I believe the FAA has to sign off on crewed vehicles not flown by NASA. So, there will be a certification process, but it will be independent of NASA. NASA, of course, doesn't have to FAA certify anything because they're a government agency (like DOD). NASA gets to write their own rules and their own waivers to the rules! NASA gets to have their cake and eat it too! Take the failure to develop vertical landing of Dragon 2 as an example. NASA didn't want SpaceX testing vertical Dragon 2 landings on cargo delivery missions to ISS. To be fair to NASA, this sort of testing would have had a non-zero chance of NASA losing some of its hardware and experiments it was returning from ISS. This effectively killed propulsive landing because paying for a completely separate test campaign would have been completely on SpaceX's dime. They developed Falcon 9 booster landing in such a way, so SpaceX thought it reasonable for Dragon 2 as well. But booster landings have absolutely zero impact on the customers if they fail. Not so for Dragon 2 propulsive landings. So NASA wanted to stick with what they know, which arguably stifles innovation in the process. The moral of the story is that you have to do things "the NASA way" when NASA is paying the bills. BFR/BFS, however, is going to be developed on SpaceX's dime (and their investors, of course), so NASA won't have any say in the matter like they did with Dragon 2 and Falcon 9 Block 5. If BFR/BFS is successful, NASA will simply be a customer. If they don't like it, they don't have to fly on BFR/BFS, now do they? Jeff -- All opinions posted by me on Usenet News are mine, and mine alone. These posts do not reflect the opinions of my family, friends, employer, or any organization that I am a member of. |
#54
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Space X 2nd stage recovery
JF Mezei wrote on Sat, 28 Apr 2018
14:15:42 -0400: On 2018-04-27 23:32, Fred J. McCall wrote: Oh, I agree. SpaceX has no reason to undertake the diversion of developing and certifying a Service Module for Dragon V2 any more than they need to undertake the diversion of man rating Falcon Heavy. This week saw VP Pence name the new NASA administrator. In all the PR I heard, going back to the moon was mentioned. Also mentiond, working with commercial suppliers. Whether going to the Moon makes sense or not, if NASA wants to go and is willing to pay, should SpaceX pass on such an opportunity? Of course not. The bigger question is whether SpaceX should bid for such a project with Dragon and a glorified trunk/service module or bid with BFR/BFS. BFR/BFR Spaceship. For lunar missions, BFR Spaceship could (with an LEO refuel) fly to the Moon with enough cargo and personnel to establish a base, land, offload, and return to Earth without refueling. More likely 'commercial' application is for cargo. NASA is going to want to put people on SLS/Orion. I don't think they're going to pay for developing another manned system to replace their pet. Dragon V2 weighs about 6.4 tonnes 'dry' and around 10 tonnes loaded with cargo. That's what you need to get to TLI. Could the Super Dracos be used for a TLI burn? I don't know if they have enough fuel for that. If not, you need some sort of 'high energy upper stage' or a real Service Module engine to get you there. Falcon 9 doesn't have enough grunt, nor does Falcon Heavy in reusable mode (unless the Super Dracos are good enough, in which case it MAY be able to get 10 tonnes to TLI in reusable form). So you're likely using Falcon Heavy and throwing away three cores with every launch. Musk says this would take launch cost up to around $150 million (plus the cost of Dragon for cargo). Could 'Falcon Super Heavy' do the job in reusable mode? Maybe. NASA *SHOULD* ask what that would cost to develop, but they won't because it would probably wind up being a direct competitor to SLS if you're willing to expend the cores. From a components point of view (big picture) should SpaceX decide to get Dragon to the moon and back, would it be easier modify a 2nd stage to have bigger tanks and perhaps its own solar panels for longer autonomy as opposed to making a separate service module? No, and that wouldn't get the job done in any case. The problem isn't electrical power, although Dragon only produces about a fifth of what Orion Service Module does. The problem is all the consumables (water, air, etc). And before you say it, no, you can't just stuff all that in the trunk (and you don't have as much 'cargo capacity' as you think, anyway, since part of that is consumed by your 'people' cargo). Any connections of any size to the 'trunk' are going to require punching holes in the Dragon heat shield, which is probably NOT something you want to do, particularly on lunar returns. So even with a 'real' service module, you're going to have to do some reengineering on the Dragon capsule itself if you're sticking your extra consumables outside the capsule. Doesn't it become much easier to man-rate and upgraded man-rated model vs man rating something new? No. When you start making big modifications to hardware and how you're going to use it, that is "something new". And they'd still have to go down the road of 'man rating' Falcon Heavy AND assume they were throwing it away (because it can't get to the Moon with sufficient payload in anything but expendable mode). -- "The reasonable man adapts himself to the world; the unreasonable man persists in trying to adapt the world to himself. Therefore, all progress depends on the unreasonable man." --George Bernard Shaw |
#55
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Space X 2nd stage recovery
JF Mezei wrote on Sat, 28 Apr 2018
14:29:09 -0400: On 2018-04-28 12:30, Jeff Findley wrote: Adding a service module to Dragon, in place of the simpler trunk, would be possible, but it would be adding to Dragon's primary mission capabilities and the crew's lives would depend on the proper functioning of the service module. As such, it would have to be fully "crew rated" in a way that relatively benign recovery devices simply do not. Since BFR/BFS are being built in separate facility, would it really hurt BFR/BFS if NASA were to send mega pork money for SpaceX to build an upgraded Dragon with service module to do moon excursions? If the later is built at Hawthorne facility that is focused on Falcon/Dragon, it shouldn't hinder BFR/BFS much. Engineering talent to do designs for such things is just floating around available. Yes, it makes more sense for SpaceX to respond to RFP with BFR/BFS proposal for moon. The mega pork from NASA would help fund BFR/BFS development. But if BFR/BFS proposal would not win, then it is better for SPaceX to win with Dragon/Falcon so at least profits from that work go to fund BFR/BFS. (aka: better than nothing) You're assuming they're looking for 'commercial crew'. Given that that would compete directly with SLS/Orion, you probably shouldn't hold your breath waiting for that. Longer term though, if BFR/BFS do to manned space travel what Fancon9 reusability has done for cargo costs, then eventually, it will win any/all NASA contracts for manned space travel. Don't bet on it. They'll have some reason for wanting to use SLS/Orion. -- "Some people get lost in thought because it's such unfamiliar territory." --G. Behn |
#56
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Space X 2nd stage recovery
JF Mezei wrote on Sat, 28 Apr 2018
22:08:48 -0400: On 2018-04-28 19:42, Jeff Findley wrote: BFR/BFS, however, is going to be developed on SpaceX's dime (and their investors, of course), so NASA won't have any say in the matter like they did with Dragon 2 and Falcon 9 Block 5. If BFR/BFS is successful, NASA will simply be a customer. If they don't like it, they don't have to fly on BFR/BFS, now do they? If NASA sends some of its EMPLOYEES on a SpaceX ride, it is legally responsible for the safety of its employees and wants to ensure that ride is safe. No it isn't. Cite said law. This is different from SpaceX selling seats directly to tourists who are solely responsible for their own life when they sign the contract with SpaceX. Not so much, no. So the minute NASA buys transport for its employees, it will likely insist on "man rated" standards. How flexible NASA becomes in ensuring the transport meets standards is likely the bigger question. No. It will do that long before it 'buys transport' in order to avoid buying said 'transport' and keep funding SLS/Orion. If BFR/BFR Spaceship is flying commercial passengers when it does this it becomes pretty transparent and opens NASA up for a really big lawsuit for slandering a SpaceX business. -- "Some people get lost in thought because it's such unfamiliar territory." --G. Behn |
#57
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Space X 2nd stage recovery
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#58
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Space X 2nd stage recovery
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#59
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Space X 2nd stage recovery
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#60
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Space X 2nd stage recovery
JF Mezei wrote on Sun, 29 Apr 2018
01:52:03 -0400: On 2018-04-28 22:42, Fred J. McCall wrote: More likely 'commercial' application is for cargo. NASA is going to want to put people on SLS/Orion. If politicians send a message to NASA that after they run out of budgetted engines, they won't get additional money and that they should seek commercial launches, you'll find NASA will have a contest to pick 2 or 3 launch providers. If unicorns **** magic pixie dust we'll all be eating steak. Any connections of any size to the 'trunk' are going to require punching holes in the Dragon heat shield, which is probably NOT something you want to do, Don't they already have connections for power. As I recall they "wrap" around the heat shield and penetrate the capsule higher up. Yes, they do, AND THOSE ARE DESIGNED IN. You're now talking about doing the same thing with stuff like hypergolic fuel lines. All that stuff burns when you fire the Super Dracos, which kind of defeats the purpose of putting fuel down there in the trunk (and destroys the vehicle on engine fire into the bargain). have to go down the road of 'man rating' Falcon Heavy AND assume they were throwing it away (because it can't get to the Moon with sufficient payload in anything but expendable mode). SpaceX would likely compare the economics of multiple re-usable flights to assemble/fuel the lunar ship versus single flight which sacrifices a falcon heavy. (2 Falcon9 stages) You cannot refuel a Dragon capsule anywhere but on the ground. So you're now postulating an entirely new 'trunk', an entirely new capsule, an entirely new refueling vehicle, ... -- "Some people get lost in thought because it's such unfamiliar territory." --G. Behn |
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