Old Man Posted September 27, 2016 Report Share Posted September 27, 2016 Watching Elon present his Mars spacecraft now. The rocket is frickin' huge. Mars vehicle itself like a stubby rocket with fins.Deep cryo methalox for propellant, partially because it could possibly be manufactured on Mars. Takes advantage of booster landing to enable rapid refueling--basically one launch for the vehicle, quick turnaraound, second launch for additional fuel. Elon wants to get the "ticket price" for a Mars trip from $Billions to $200k. No mention yet of recent "rapid uncontrolled deconstruction" events. Or of funding--even Musk can't possibly afford this on his own dime. Quote Link to comment Share on other sites More sharing options...
Old Man Posted September 27, 2016 Author Report Share Posted September 27, 2016 Jesus, he wants to put a million people on Mars. He's talking about mass production of these ginormous rockets. I can just hear the Martians shouting "To arms! To arms!" Quote Link to comment Share on other sites More sharing options...
Old Man Posted September 27, 2016 Author Report Share Posted September 27, 2016 SpaceX is going to gasify the propellant itself to pressurize the tanks, rather than use the helium tank system that has apparently destroyed two Falcon 9s so far. Quote Link to comment Share on other sites More sharing options...
Old Man Posted September 27, 2016 Author Report Share Posted September 27, 2016 Now he has a slide up showing the Mars vehicle next to a Saturn V. Wasn't kidding when I said it was ginormous. 3x the thrust and 4x the payload of Saturn V. Quote Link to comment Share on other sites More sharing options...
Old Man Posted September 27, 2016 Author Report Share Posted September 27, 2016 Quote Link to comment Share on other sites More sharing options...
Old Man Posted September 27, 2016 Author Report Share Posted September 27, 2016 42 Raptor engines in the first stage! Quote Link to comment Share on other sites More sharing options...
Old Man Posted September 27, 2016 Author Report Share Posted September 27, 2016 550 tons to LEO. 450 tons to Mars. Quote Link to comment Share on other sites More sharing options...
Old Man Posted September 27, 2016 Author Report Share Posted September 27, 2016 Aerobraking initial reentry at both Mars and Earth. I'll have to take a closer look at the Mars reentry profile later--typically that is a very difficult problem. Quote Link to comment Share on other sites More sharing options...
Old Man Posted September 27, 2016 Author Report Share Posted September 27, 2016 The funding slide is really underwhelming. Kickstarter? Really? Profits from a SpaceX that is not yet profitable? Admittedly he's trying to drive costs down to $140k/ton to Mars, which puts each launch in the mere tens of millions... if it works. This is going to take some significant federal government assistance, I think. Quote Link to comment Share on other sites More sharing options...
Old Man Posted September 27, 2016 Author Report Share Posted September 27, 2016 They've actually built one of the fuel tanks for this already. It, too, is ginormous. Quote Link to comment Share on other sites More sharing options...
L. Marcus Posted September 27, 2016 Report Share Posted September 27, 2016 The man is a visionary loony. Quote Link to comment Share on other sites More sharing options...
Lawnmower Boy Posted September 27, 2016 Report Share Posted September 27, 2016 Quote Link to comment Share on other sites More sharing options...
Old Man Posted September 27, 2016 Author Report Share Posted September 27, 2016 Well... the man can think pretty big. I'm definitely not writing this guy off. In 14 years SpaceX has gone from a garage startup to reusable orbital launch vehicles. He and Bezos have thoroughly disrupted a stale aerospace field that was perfectly happy using Atlases forever. For that alone he has to be given a lot of credit. Funding this particular project is going to take one hell of a sales pitch, and indeed, I'm already seeing this described as just the beginning of a fundraising effort that will last for decades. Getting to Mars is going to take a repeating cycle of sales pitching, fundraising, technological success, and perceptions. It's certainly helpful that Musk is already putting 5% of SpaceX income towards the Mars vehicle and has already built a carbon fiber fuel tank, one of the key components. In fact, a lot of what he showed is already existing tech, especially the Raptor engines and booster return. That takes a lot of the uncertainty out of the equation--it's just a question of scaling up. On the other hand, SpaceX has been pretty aggressive in the past with launch schedules. For all the success that they've had, IIRC they're at least a few years behind schedule. Liveblogs were noticing that the timeline Musk put up today was already impossible given the recent Falcon 9 failure on the pad. Will the Mars vehicle still be viable if you push all the dates out 5 years? Maybe, maybe not. Lastly, I hear they're naming the first Mars vehicle the "Heart of Gold". Improbable indeed! (At least it wasn't the "Kobayashi Maru".) Quote Link to comment Share on other sites More sharing options...
Cancer Posted September 28, 2016 Report Share Posted September 28, 2016 42 Raptor engines in the first stage! Gaaaaaaaaah. Don't do that. Read up on the N1. Ganging many small motors is a complexity like n!. Small numbers of much larger engines, though it frontloads the engineering challenges into making those big motors, is the only real path. Quote Link to comment Share on other sites More sharing options...
Old Man Posted September 28, 2016 Author Report Share Posted September 28, 2016 But only the middle 7 are gimbaled! Quote Link to comment Share on other sites More sharing options...
megaplayboy Posted September 28, 2016 Report Share Posted September 28, 2016 Hey, the fun starts with the MUCH LARGER CRAFT taking 100-200 people at a time to Mars. I assume there will be some kind of floating launch platform for these, because an explosion on the pad by a multi-kiloton rocket would create, um, problems for Cape Canaveral. Quote Link to comment Share on other sites More sharing options...
Cancer Posted September 28, 2016 Report Share Posted September 28, 2016 Not to mention those on board. Quote Link to comment Share on other sites More sharing options...
L. Marcus Posted September 28, 2016 Report Share Posted September 28, 2016 Kablooie, so to speak. Quote Link to comment Share on other sites More sharing options...
Burrito Boy Posted September 28, 2016 Report Share Posted September 28, 2016 I think it's a lot of wasted effort. All you have to do to get to Mars is go to a certain cave in Arizona. Quote Link to comment Share on other sites More sharing options...
Old Man Posted September 28, 2016 Author Report Share Posted September 28, 2016 Canaveral will be underwater in ten years anyway. Initial reaction by government officials seems to be a bit frosty. The head of NASA said something to the effect of manned interplanetary spaceflight being the government's domain, not private enterprise. It's also being noted that the $10Bn price tag for the first BFR is more than Musk can afford, but within the reach of a Sergey Brin or an Apple. Still, we're talking about a project that would take at least ten years, if they started today. Quote Link to comment Share on other sites More sharing options...
Duke Bushido Posted September 29, 2016 Report Share Posted September 29, 2016 The man is a visionary loony. That's the best kind, really. Canaveral will be underwater in ten years anyway. Initial reaction by government officials seems to be a bit frosty. The head of NASA said something to the effect of manned interplanetary spaceflight being the government's domain, not private enterprise. and I would _totally_ believe them, if they'd done a single thing in the last decade to demonstrate that they were truly interested. Quote Link to comment Share on other sites More sharing options...
Old Man Posted September 30, 2016 Author Report Share Posted September 30, 2016 NASA is doing so well that they're looking at renting Soyuz seats for 2018. Quote Link to comment Share on other sites More sharing options...
megaplayboy Posted September 30, 2016 Report Share Posted September 30, 2016 I think a 200 passenger Mars rocket would have to be a vehicle on the order of 5-10 kilotons, and the rocket necessary to boost it past LEO probably several times larger than that. So, basically the size of an aircraft carrier or skyscraper. You might need a special crawler or ship to transport such a beast to a launch position. Quote Link to comment Share on other sites More sharing options...
Cancer Posted September 30, 2016 Report Share Posted September 30, 2016 Assuming you launch the whole thing as a monolith from Earth's surface in one blast. Quote Link to comment Share on other sites More sharing options...
megaplayboy Posted September 30, 2016 Report Share Posted September 30, 2016 Assuming you launch the whole thing as a monolith from Earth's surface in one blast. Well, true, though it would take multiple launches to get all that up into an orbital launching position. And Musk was talking about 10,000 flights to Mars to create a million strong settlement. So it'd have to be reusable, and you'd need a bunch of them. Quote Link to comment Share on other sites More sharing options...
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