Quote from: Robotbeat on 05/13/2016 02:17 amQuote from: aameise9 on 05/13/2016 12:33 am1) Mars surface is reached by a larger version of the Dragon, with engines suitable for precision landing.2) Mars surface is reached by a larger version of the F9R, with engines suitable for both orbital launch and precision landing.Neither. Or rather, something in between.You need maybe 6-7km/s to return to Earth from the surface of Mars. You can do that in a single stage with TPS, though it is hard.Thank you! So something in between a squat capsule and a pencil-shaped booster.Presumably with short, stubby legs to support the weight of a fully tanked craft?Presumably with engines angling outward (Dragon-style) to direct blast debris away from craft?I am not sure that I understood the relevance of TPS (temperature protection system)?
Quote from: aameise9 on 05/13/2016 12:33 am1) Mars surface is reached by a larger version of the Dragon, with engines suitable for precision landing.2) Mars surface is reached by a larger version of the F9R, with engines suitable for both orbital launch and precision landing.Neither. Or rather, something in between.You need maybe 6-7km/s to return to Earth from the surface of Mars. You can do that in a single stage with TPS, though it is hard.
1) Mars surface is reached by a larger version of the Dragon, with engines suitable for precision landing.2) Mars surface is reached by a larger version of the F9R, with engines suitable for both orbital launch and precision landing.
I am not sure that I understood the relevance of TPS (temperature protection system)?
Cars on Earth don't have to carry their own oxygen. As RB said, you are letting your experience on Earth mislead you.
Solar electric propulsion has vastly better "range" than any chemical rocket.
Solar panels still work during dust storms. (Dust is actually easier for modern solar panels than water-droplet clouds on Earth.)The power generated will drop, of course. But most of the power required on Mars will be for ISRU. You simply suspend power hungry ops during the worst of the storm. (Which, judging by MER-Opportunity, is only a few days even in a month long dust storm.)
Question: what is the best material to make MCT out of?The options that I come up with are:1) Aluminum - Lithium alloy just like Falcon.2) Carbon Fiber composite using a honeycomb core.3) Titanium single shell.4) Titanium double shell with a core of some kind.Considerations include heat tolerance, insulation needed, corrosion on Mars and Earth.Stiffness when not pressurized. Thick core walls are much stiffer.The material that I like is Titanium with hollow spaces to form a a 2 wall Ti sandwich with a Ti honeycomb core.Obviously this is very difficult to make as it is hard to weld Ti alloys in air. But if that could be worked out it would seem to be the most durable. Insulation is needed not only on Earth, but on Mars when accumulating ISRU propellants, so an inner layer of insulation is needed. For Carbon Fiber or Al-Li an outer layer of insulation would also be needed.
@SpaceXTripToday I celebrate nine years @SpaceX! It's amazing how much it's changed, and I am excited for what the future holds https://t.co/oNLgPQM9my
Picard:"Somehow I doubt this will be the last ship to carry the name Enterprise."
Trip Harris is celebrating 9 with SpaceX today, and is currently is Manager of Falcon landings. The YouTube clip he chose to link to his celebratory tweet is....interesting. https://twitter.com/SpaceXTrip/status/733869950067036160Quote@SpaceXTripToday I celebrate nine years @SpaceX! It's amazing how much it's changed, and I am excited for what the future holds https://t.co/oNLgPQM9myQuotePicard:"Somehow I doubt this will be the last ship to carry the name Enterprise."
I don't know if it's been talked about yet - but what about MCT/BFS and the hoverslam? As F9R is showing, hoverslam can be pretty damn rough/tough on the rocket. So what would MCT/BFS face during descent on Earth or Mars, and would hoverslam be feasible? Or are you just going to need much more deeply throttleable engines?
Quote from: sanman on 05/25/2016 06:52 amI don't know if it's been talked about yet - but what about MCT/BFS and the hoverslam? As F9R is showing, hoverslam can be pretty damn rough/tough on the rocket. So what would MCT/BFS face during descent on Earth or Mars, and would hoverslam be feasible? Or are you just going to need much more deeply throttleable engines?It's not necessarily the hoverslam that is rough on the rocket, it's the reentry. Shield from reentry heating, and hoverslam is simply a more efficient way to land (though maybe a bit sketchy with crew).
...Hopefully (going out on a limb to say certainly) BFS will have a lower thrust-to-weight ratio compared with a F9 stage one.
What do you mean 3.8g and 4.5g, thouse are incredible acceleration rate and likely beyond what crew could tolerate,
Humans can handle 8-9 gees just fine if oriented the correct way.