Something I haven't seen posted WRT to 6 and 7. Elon is CEO and Director of a certain company that almost certainly has the most mature and capable machine learning algorithms yet developed for navigation, terrain/object recognition, and minute trajectory management. Add in SpaceX's literally unprecedented experience with autonomously landing rockets, and it shouldn't be hugely difficult to implement AI, radar, and imaging that can prepare BFS' legs or safely choose a landing site during the late stages of reentry. HiRISE imagery has basically blanketed Mars with 0.5m resolution coverage and will continue to do so until it dies, and that global imagery (stereoscopic in many cases) is almost without a doubt enough to roughly point to a landing spot small enough for onboard sensors to be able to autonomously choose a landing site in the last 10-30 seconds before touchdown. The real issue with 6 and 7 is FOD avoidance and tolerance - that's gonna be hugely difficult to successfully integrate with goals of reliable and total reuse, as well as economically viable lifespans between serious refurb.
Quote from: vaporcobra on 02/07/2018 11:24 pmSomething I haven't seen posted WRT to 6 and 7. Elon is CEO and Director of a certain company that almost certainly has the most mature and capable machine learning algorithms yet developed for navigation, terrain/object recognition, and minute trajectory management. Add in SpaceX's literally unprecedented experience with autonomously landing rockets, and it shouldn't be hugely difficult to implement AI, radar, and imaging that can prepare BFS' legs or safely choose a landing site during the late stages of reentry. HiRISE imagery has basically blanketed Mars with 0.5m resolution coverage and will continue to do so until it dies, and that global imagery (stereoscopic in many cases) is almost without a doubt enough to roughly point to a landing spot small enough for onboard sensors to be able to autonomously choose a landing site in the last 10-30 seconds before touchdown. The real issue with 6 and 7 is FOD avoidance and tolerance - that's gonna be hugely difficult to successfully integrate with goals of reliable and total reuse, as well as economically viable lifespans between serious refurb.I will be honest -- I don't think nearly as much of Mars has been imaged at 50cm resolution as you seem to think. HiRISE is a great instrument, but its highest resolution strips are fairly narrow, and Mars is still an entire planet. With land area equal to Earth's -- just without the intervening oceans/seas.There is likely 3- to 20-meter resolution photography covering 80% of the planet, and down to .5-meter resolution coverage on another 20%. Enough to offer a lot of very high resolution looks at candidate landing sites, but not covering every portion of the planet.Not even the Earth is mapped at .5-meter resolution to that large of an extent...
Getting a bit too deep in the weeds here, my main point is more simply that imagery and safe, autonomous landing and last-mile touchdown decisions are almost certainly not the biggest hurdles ahead of BFS.
I am a little surprised we have not heard about plans for a concept vehicle, especially for Mars EDL This is what I thought Red Dragon would do this year.
I am a little surprised we have not heard about plans for a concept vehicle, especially for Mars EDL This is what I thought Red Dragon would do this year. It could be an itty-bitty balsa wood thing (well, not literally, just making a point), but just if your little spam-covered vehicle can actually get there and land. That's been a hard enough challenge for NASA spacecraft as it is.
Something I've been curious about what others think - I think some amount of the Merlin's iterative improvements and reliability can be traced to the fact they built so many of them. If the booster is successfully reused from the getgo - they just won't have as many chances to iteratively test changes. With the Merlin every launch likely had a small incremental improvement to the engine. You won't have that opportunity with Raptor - which means changes will get grouped together in large sets - increasing risk.
But they have 38 engines per BFR/BFS, all of which will be tested. During development, testing will probably include individual engine FOD and RUD containment tests as well. I think it will be done similar to turbine engine development.
Maybe they have learned a lot and won't need to iterate as much - but that remains to be seen. If they need to iterate - it's going to be a lot more expensive to iterate BFS than Falcon.
But they have 38 engines per BFR/BFS, all of which will be tested. During development, testing will probably include individual engine FOD and RUD containment tests as well. I think it will be done similar to turbine engine development.John
Not a viable solution. SpaceX has already stated complete unwillingness to use FH for any Moon or Mars missions.
Quote from: Proxima_Centauri on 02/18/2018 10:01 pmNot a viable solution. SpaceX has already stated complete unwillingness to use FH for any Moon or Mars missions.huh? I'm pretty sure they said "we can do it, just send money" like they do for everything.
Quote from: livingjw on 02/18/2018 12:37 pmBut they have 38 engines per BFR/BFS, all of which will be tested. During development, testing will probably include individual engine FOD and RUD containment tests as well. I think it will be done similar to turbine engine development.JohnDo you expect that they will do tests analogous to the blade-out test that is done on commercial turbofans, i.e. intentionally cause a turbopump failure to test the engine controller shutdown response and the containment system? I seem to recall hearing that spacex has already done a "nut ingestion" test.