NSEP Posted May 30, 2018 Share Posted May 30, 2018 3 hours ago, Bill Phil said: But I think the intent is to create a refueling infrastructure on the lunar surface. That, combined with a transportation system for LEO-LLO and vice versa, is probably the plan... Yes, if they want to send humans to the Moon and back they would have to use ISRU for return. It makes me think, if they are going to send humans to the Moon, are they going to make their own manned deep-space capsule, build a commercial space gateway for other commercial spaceflight buddies to join the fun or are they going to use the already existing ISS. Quote Link to comment Share on other sites More sharing options...
wumpus Posted May 30, 2018 Share Posted May 30, 2018 3 hours ago, Bill Phil said: Apollo got away with less than 5000 kg, for the LM ascent stage. But I think the intent is to create a refueling infrastructure on the lunar surface. That, combined with a transportation system for LEO-LLO and vice versa, is probably the plan... That looks like one mind boggling difficult engineering trick after another, with everybody on board dying on a single failure. You have the delivery of fuel or ISRU to the Moon (landing. High mass landing gets tricky, although you can try again without people dying. On this one only). You then get to load the fuel into a rover. The rover moves the fuel to the land. The lander refuels (likely compressing the fuel). The lander ignites and uses the fuel to return to Lunar orbit. This isn't a bad plan if you have another 'gassed up and ready to go' old-school pressure fed hypergolic lifter nearby to be used if one of those steps fail. In fact, the first thing I'd leave as cargo on the Moon would be a backup ascent stage. Of all the ways NASA feared Apollo astronauts dying, a failed ascent stage topped the list (more delta-v had to be budgeted to that stage than any other, so mass was kept to a minimum, and possibly below that). Quote Link to comment Share on other sites More sharing options...
Bill Phil Posted May 30, 2018 Share Posted May 30, 2018 25 minutes ago, wumpus said: That looks like one mind boggling difficult engineering trick after another, with everybody on board dying on a single failure. You have the delivery of fuel or ISRU to the Moon (landing. High mass landing gets tricky, although you can try again without people dying. On this one only). You then get to load the fuel into a rover. The rover moves the fuel to the land. The lander refuels (likely compressing the fuel). The lander ignites and uses the fuel to return to Lunar orbit. This isn't a bad plan if you have another 'gassed up and ready to go' old-school pressure fed hypergolic lifter nearby to be used if one of those steps fail. In fact, the first thing I'd leave as cargo on the Moon would be a backup ascent stage. Of all the ways NASA feared Apollo astronauts dying, a failed ascent stage topped the list (more delta-v had to be budgeted to that stage than any other, so mass was kept to a minimum, and possibly below that). Well, just about anything society does on a regular basis is a series of mind-boggling engineering tricks one after another. Only difference is that we have an atmosphere we can live in, so death isn't as likely. It's difficult engineering. But that's kind of the point. If money is behind it, then it'll probably happen. No bucks, no Buck Rogers. Having a back up is always good. Quote Link to comment Share on other sites More sharing options...
wumpus Posted May 30, 2018 Share Posted May 30, 2018 1 hour ago, Bill Phil said: Well, just about anything society does on a regular basis is a series of mind-boggling engineering tricks one after another. Only difference is that we have an atmosphere we can live in, so death isn't as likely. It's difficult engineering. But that's kind of the point. If money is behind it, then it'll probably happen. No bucks, no Buck Rogers. Having a back up is always good. The problem isn't the difficulty itself. It is the difficulty, the issue of testing under actual conditions (.2g) , and the failure conditions (dead astronauts). Failure conditions often matter a lot more than actual difficulty in engineering. If you have to use the backup the first 10 times (and it is there and works), and then you finally get the ISRU going isn't a problem. If you get it going the second time but you didn't have a backup ascent vehicle the first time, that is a huge problem. Engineering tricks are one thing, but *reliable* engineering tricks almost always involve redundancy, and that means mass. Ascent vehicles require a total of 16,800 m/s delta-v (typically carried on other vehicles for all but the ascent, but it adds up), so there is a strong desire to keep said extra mass to a minimum (and yes, this includes spare ascent vehicles). Quote Link to comment Share on other sites More sharing options...
Bill Phil Posted May 30, 2018 Share Posted May 30, 2018 1 hour ago, wumpus said: The problem isn't the difficulty itself. It is the difficulty, the issue of testing under actual conditions (.2g) , and the failure conditions (dead astronauts). Failure conditions often matter a lot more than actual difficulty in engineering. If you have to use the backup the first 10 times (and it is there and works), and then you finally get the ISRU going isn't a problem. If you get it going the second time but you didn't have a backup ascent vehicle the first time, that is a huge problem. Engineering tricks are one thing, but *reliable* engineering tricks almost always involve redundancy, and that means mass. Ascent vehicles require a total of 16,800 m/s delta-v (typically carried on other vehicles for all but the ascent, but it adds up), so there is a strong desire to keep said extra mass to a minimum (and yes, this includes spare ascent vehicles). I don't think humans will be involved until rather late in the process. Getting more mass up there is easier once costs go down, which is the idea behind NG, afaik. Depots and tugs may help as well. Redundancy is the name of the game. Redundancy. Redundancy. Redundancy. Quote Link to comment Share on other sites More sharing options...
wumpus Posted May 31, 2018 Share Posted May 31, 2018 22 hours ago, Bill Phil said: Redundancy is the name of the game. Redundancy. Redundancy. Redundancy. Redundancy is great until you realize you are accelerating redundant systems by 16,800m/s. Obviously, all kinds of sneaky ways should be used to create redundancy where it might not be so obvious. Like sending all the ascent vehicles before the first human, so even if the first n fail there is still another. But I suspect there will still be way too many ways for an ISRU system to fail that will either have all systems fail (typically a design error) or have a choke point that was unavoidable. Expect at least some human required repairs. Just think how hard it is to make sure that ground based docking lines up in KSP: you can test them on the runway, but that doesn't mean their suspensions will line up on Minmus. Now imagine doing it in real life. Quote Link to comment Share on other sites More sharing options...
sh1pman Posted May 31, 2018 Share Posted May 31, 2018 5 hours ago, wumpus said: Just think how hard it is to make sure that ground based docking lines up in KSP: you can test them on the runway, but that doesn't mean their suspensions will line up on Minmus. Now imagine doing it in real life. (Job interview at BO) - What experience with space technology do you have? - I did extensive computer simulations of lunar surface docking and fuel transfer operations in the program called Ker... - You’re hired! Quote Link to comment Share on other sites More sharing options...
Ultimate Steve Posted May 31, 2018 Share Posted May 31, 2018 49 minutes ago, sh1pman said: - I did extensive computer simulations of lunar surface docking and fuel transfer operations I'm going to put this on my future job application to whatever aerospace company I apply for in 6 years time. Quote Link to comment Share on other sites More sharing options...
StrandedonEarth Posted June 1, 2018 Share Posted June 1, 2018 3 hours ago, sh1pman said: Job interview at BO) Job posting at BO / SpaceX / NASA in five years time: ”Must have completed (BO/SX/NASA) Application Mission in KSP:MH v1.64 with a minimum score of...” Quote Link to comment Share on other sites More sharing options...
HebaruSan Posted June 1, 2018 Share Posted June 1, 2018 31 minutes ago, StrandedonEarth said: Job posting at BO / SpaceX / NASA in five years time: ”Must have completed (BO/SX/NASA) Application Mission in KSP:MH v1.64 with a minimum score of...” "Attach craft file here:" Quote Link to comment Share on other sites More sharing options...
Ultimate Steve Posted June 1, 2018 Share Posted June 1, 2018 4 minutes ago, HebaruSan said: "Attach craft file here:" "Please also list the number of quickloads it took." Quote Link to comment Share on other sites More sharing options...
Racescort666 Posted June 1, 2018 Share Posted June 1, 2018 KSP is kind of a bad example for surface buildings. Trying to get docking ports lined up is not at all like how you would do fluid transfer on the lunar surface. Considering that current assembly robots have sub-millimeter precision over a 2 meter reach and the canadarm essentially already does this with berthing modules, connecting 2 parts together on the surface seems pretty straight forward and consistent. I suspect the problem would be keeping the connections clean followed by chilling in the lines and tanks for transfer. Quote Link to comment Share on other sites More sharing options...
sevenperforce Posted June 1, 2018 Share Posted June 1, 2018 29 minutes ago, Racescort666 said: KSP is kind of a bad example for surface buildings. Trying to get docking ports lined up is not at all like how you would do fluid transfer on the lunar surface. Considering that current assembly robots have sub-millimeter precision over a 2 meter reach and the canadarm essentially already does this with berthing modules, connecting 2 parts together on the surface seems pretty straight forward and consistent. I suspect the problem would be keeping the connections clean followed by chilling in the lines and tanks for transfer. Not to mention pumping fluid in microgravity. Quote Link to comment Share on other sites More sharing options...
cubinator Posted June 1, 2018 Share Posted June 1, 2018 45 minutes ago, sevenperforce said: Not to mention pumping fluid in microgravity. On the Moon it's not so bad. Quote Link to comment Share on other sites More sharing options...
tater Posted June 25, 2018 Share Posted June 25, 2018 Quote Link to comment Share on other sites More sharing options...
Xd the great Posted June 25, 2018 Share Posted June 25, 2018 I cant wait for jeff and elon to do a friendly project... Or just scream into each others ears on twitter... Well, there must be sufficient infrastructure if we use the mining and return method. Aka a bunch of autunomous robots. Plus we must also consider the chemical composition of the moon... Quote Link to comment Share on other sites More sharing options...
tater Posted June 27, 2018 Share Posted June 27, 2018 (wish they'd start launching more so we'd have something real to post here) Quote Link to comment Share on other sites More sharing options...
wumpus Posted June 27, 2018 Share Posted June 27, 2018 Sounds like BO engine is entering reality with its "25 reuse" engine. Didn't that used to be claimed in the hundreds? I know Falcon was supposed to be rated for 10, any *maybe* one flew three times. Also Musk's numbers on BFR pricing assumes something like 1000 flights per rocket. Quote Link to comment Share on other sites More sharing options...
Ultimate Steve Posted June 27, 2018 Share Posted June 27, 2018 2 minutes ago, wumpus said: Sounds like BO engine is entering reality with its "25 reuse" engine. Didn't that used to be claimed in the hundreds? I know Falcon was supposed to be rated for 10, any *maybe* one flew three times. Also Musk's numbers on BFR pricing assumes something like 1000 flights per rocket. The 25 seems to be an estimate for how well they expect the first version of this engine to perform. If BO goes places (which they have a good chance of IMO) the engine will undoubtedly be upgraded along with New Glenn itself to have a better chance of meeting the initial goal. And no Falcon has flown more than twice yet, they just now launched their first rocket actually designed to be reused ten times. Quote Link to comment Share on other sites More sharing options...
tater Posted June 27, 2018 Share Posted June 27, 2018 22 minutes ago, wumpus said: Sounds like BO engine is entering reality with its "25 reuse" engine. Didn't that used to be claimed in the hundreds? I know Falcon was supposed to be rated for 10, any *maybe* one flew three times. Also Musk's numbers on BFR pricing assumes something like 1000 flights per rocket. Did you read the article? They are saying NG good for 25 reuses, with the engines good for 100. So they are either planning on moving engines to new airframes every 25 flights, or they are planning to do a serious refurb on the airframe after 25 flights. Falcon 9 Block 5 plans assume a rebuild after 10 flights. BFR numbers have varied. BFS was said to be 100 (tanker/cargo), and the booster was 1000, since the stresses are lower on it (based on the ITS stuff from the first presentation). The cost numbers for BFR work out even with only a few flights, actually. Total BFR/BFS cost for production was something like 350 M$. Even with just 10 flights, that's only 35M$/launch, and launch costs are under a million. Blue CEO giving talk at New Space Conf right now, apparently. Quote Link to comment Share on other sites More sharing options...
tater Posted June 27, 2018 Share Posted June 27, 2018 Quote Link to comment Share on other sites More sharing options...
mikegarrison Posted June 27, 2018 Share Posted June 27, 2018 6 hours ago, tater said: Did you read the article? They are saying NG good for 25 reuses, with the engines good for 100. So they are either planning on moving engines to new airframes every 25 flights, or they are planning to do a serious refurb on the airframe after 25 flights. Falcon 9 Block 5 plans assume a rebuild after 10 flights. I assume the reusable launcher industry will eventually develop A-checks, B-checks, C-checks, etc. if they actually get that far. https://en.wikipedia.org/wiki/Aircraft_maintenance_checks Quote Link to comment Share on other sites More sharing options...
Streetwind Posted June 28, 2018 Share Posted June 28, 2018 22 hours ago, tater said: (wish they'd start launching more so we'd have something real to post here) Apparently their next flight is supposed to be "this summer". So, sometime in August maybe? Fingers crossed. Quote Link to comment Share on other sites More sharing options...
insert_name Posted July 5, 2018 Share Posted July 5, 2018 https://futurism.com/moon-colonization-blue-origin-2023/ Quote Link to comment Share on other sites More sharing options...
tater Posted July 11, 2018 Share Posted July 11, 2018 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.