Ozexpatriate Posted February 21, 2021 Share Posted February 21, 2021 On 18/02/2021 at 08:55, PaulRhB said: ... the only comparable system being various landers and the Apollo landers which were operating in lower gravity and not trying to land on pads or ships automatically but flown by astronauts. It puts me in mind of Neil Armstrong and the (almost) deadly 'flying bedstead' (more properly the Lunar Landing Research Vehicle or LLRV). This of course operated in full earth gravity and had a "Lunar Sim Mode" to emulate LM descent behaviour. Most of the potted histories of Apollo include Armstrong's ejection from the faulty LLRV which was grounded after that accident. There's a documentary where Aldrin talks about never wanting to fly it again. It was replaced by the LLTV (Lunar Landing Training Vehicle) which, while similar, was safer. Thrust-based VTOL is hard. Link to comment Share on other sites More sharing options...
rockershovel Posted February 21, 2021 Share Posted February 21, 2021 4 hours ago, Ozexpatriate said: It puts me in mind of Neil Armstrong and the (almost) deadly 'flying bedstead' (more properly the Lunar Landing Research Vehicle or LLRV). This of course operated in full earth gravity and had a "Lunar Sim Mode" to emulate LM descent behaviour. Most of the potted histories of Apollo include Armstrong's ejection from the faulty LLRV which was grounded after that accident. There's a documentary where Aldrin talks about never wanting to fly it again. It was replaced by the LLTV (Lunar Landing Training Vehicle) which, while similar, was safer. Thrust-based VTOL is hard. ... but much easier than previously, now it can be computerised and automated. Most of the problem revolves around handling lots of data, quickly and in the correct sequence and forming an appropriate response. The problem with VTOL is that the object has no natural dynamic stable state, except “in a heap on the ground” so constant input is required, controlling multiple vectors in multiple dimensions. Helicopters resolve this by having a cyclic pitch stick and pedals, plus a common pitch stick and throttle which don’t require constant attention. The Harrier “jump-jet” system .... well, like this .... The LEM had the further limitation of being operated by a standing pilot, who had to maintain their own balance and couldn’t operate foot pedals. So the training module had the same system. All that need be said, is that NASA never built another! Link to comment Share on other sites More sharing options...
RMweb Gold 57xx Posted February 22, 2021 RMweb Gold Share Posted February 22, 2021 NASA has released video of Perseverance's descent to Mars https://www.bbc.co.uk/news/science-environment-56158928 1 1 Link to comment Share on other sites More sharing options...
rockershovel Posted February 23, 2021 Share Posted February 23, 2021 8 hours ago, 57xx said: NASA has released video of Perseverance's descent to Mars https://www.bbc.co.uk/news/science-environment-56158928 That has certainly attracted my childrens’ attention. 1 Link to comment Share on other sites More sharing options...
RMweb Premium Reorte Posted February 23, 2021 RMweb Premium Share Posted February 23, 2021 Impressive stuff, pity the audio failed (that's two missions now which had a mic but they didn't get anything from AFAIK, although they say they've got one working now). It looks impressive enough in its own right but it's interesting in other ways - that they've got the bandwidth (or good compression algorithms) to get high quality video back from that distance. Looking forward to seeing what the helicopter does, and what the rover finds when it gets to the delta. Link to comment Share on other sites More sharing options...
woodenhead Posted February 23, 2021 Share Posted February 23, 2021 1 hour ago, Reorte said: Impressive stuff, pity the audio failed (that's two missions now which had a mic but they didn't get anything from AFAIK, although they say they've got one working now). It looks impressive enough in its own right but it's interesting in other ways - that they've got the bandwidth (or good compression algorithms) to get high quality video back from that distance. Looking forward to seeing what the helicopter does, and what the rover finds when it gets to the delta. You don't need sound, anywhere not on the Earth sounds like this: 1 Link to comment Share on other sites More sharing options...
Edwin_m Posted February 23, 2021 Share Posted February 23, 2021 2 hours ago, Reorte said: Impressive stuff, pity the audio failed (that's two missions now which had a mic but they didn't get anything from AFAIK, although they say they've got one working now). It looks impressive enough in its own right but it's interesting in other ways - that they've got the bandwidth (or good compression algorithms) to get high quality video back from that distance. Looking forward to seeing what the helicopter does, and what the rover finds when it gets to the delta. Perhaps they should have checked they weren't on mute? 2 Link to comment Share on other sites More sharing options...
RMweb Gold 57xx Posted February 23, 2021 RMweb Gold Share Posted February 23, 2021 3 hours ago, Reorte said: Looking forward to seeing what the helicopter does I'm looking forward to that too. Wonder if a lot of people don't know about that as it doesn't get much of a mention at times, yet it will be an amazing First when it flies. 1 Link to comment Share on other sites More sharing options...
rocor Posted February 23, 2021 Author Share Posted February 23, 2021 3 hours ago, woodenhead said: You don't need sound, anywhere not on the Earth sounds like this: Theremin needs some accompaniment. 2 Link to comment Share on other sites More sharing options...
Ozexpatriate Posted February 24, 2021 Share Posted February 24, 2021 17 hours ago, Reorte said: Impressive stuff, pity the audio failed (that's two missions now which had a mic but they didn't get anything from AFAIK, although they say they've got one working now). Have you not heard the recording of Martian wind? Link to comment Share on other sites More sharing options...
AndyID Posted February 24, 2021 Share Posted February 24, 2021 43 minutes ago, Ozexpatriate said: Have you not heard the recording of Martian wind? Don't need to. I doubt if it's a lot different from human wind and there's plenty of that in these parts. I might have to go skiing tomorrow just to clear the air 3 Link to comment Share on other sites More sharing options...
RMweb Premium Reorte Posted February 24, 2021 RMweb Premium Share Posted February 24, 2021 6 hours ago, Ozexpatriate said: Have you not heard the recording of Martian wind? Have now. The original plan was to record the sound during the descent too, that's what didn't work. 2 Link to comment Share on other sites More sharing options...
Ben B Posted February 24, 2021 Share Posted February 24, 2021 "...this is the voice of the Mysteronnnnnnssss... we know that you can hear us, earthmennn..." 1 Link to comment Share on other sites More sharing options...
Classsix T Posted February 24, 2021 Share Posted February 24, 2021 "please raise seat backs into the upright position..." C6T. 1 1 Link to comment Share on other sites More sharing options...
RMweb Gold 57xx Posted February 25, 2021 RMweb Gold Share Posted February 25, 2021 (edited) On 23/02/2021 at 09:58, Reorte said: It looks impressive enough in its own right but it's interesting in other ways - that they've got the bandwidth (or good compression algorithms) to get high quality video back from that distance. It's not 4k HD being live-streamed back. They can transmit it back at whatever bandwidth they need, which according to this site is 2kpbs Nice commentary on the footage from Scott Manley, giving insight that the earlier Beeb link would never get near to touching. Edited February 25, 2021 by 57xx Added new link 3 1 Link to comment Share on other sites More sharing options...
RMweb Premium Reorte Posted February 25, 2021 RMweb Premium Share Posted February 25, 2021 4 minutes ago, 57xx said: It's not 4k HD being live-streamed back. They can transmit it back at whatever bandwidth they need. Sure, but it's still a hell of a lot of data to return. After a bit of digging I found a value of 2 mb/s between the rover and the orbiters, and I think the equivalent back to Earth but I didn't find a definitive answer for that one, which is a pretty impressive rate considering the distance, even with the size of the receivers back on Earth. I'd also read that the raw data that went in to that video was 30 GB. 2 Link to comment Share on other sites More sharing options...
RMweb Gold 57xx Posted February 25, 2021 RMweb Gold Share Posted February 25, 2021 18 minutes ago, Reorte said: After a bit of digging I found a value of 2 mb/s between the rover and the orbiters, and I think the equivalent back to Earth but I didn't find a definitive answer for that one, 2kbps, you replied whilst I was editing and adding a link to that info. 1 1 Link to comment Share on other sites More sharing options...
rocor Posted March 1, 2021 Author Share Posted March 1, 2021 Elon Musk has a big ambition to ensure that Humans become an interplanetary species . This is seen as an insurance policy to ensure that the human race survives a possible extinction event such as a giant meteorite striking the Earth. His plan is to set up a human colony on the red planet. 1 Link to comment Share on other sites More sharing options...
RMweb Gold Dagworth Posted March 3, 2021 RMweb Gold Share Posted March 3, 2021 Well, it didn’t explode... Link to comment Share on other sites More sharing options...
RMweb Gold Dagworth Posted March 3, 2021 RMweb Gold Share Posted March 3, 2021 ...yet. Another attempt in two hours Link to comment Share on other sites More sharing options...
RMweb Gold Dagworth Posted March 3, 2021 RMweb Gold Share Posted March 3, 2021 (edited) Up and down perfectly. Superb to watch. Well done SpaceX. Edit: And then it exploded! And Edited March 3, 2021 by Dagworth 1 1 Link to comment Share on other sites More sharing options...
RMweb Gold PaulRhB Posted March 3, 2021 RMweb Gold Share Posted March 3, 2021 (edited) Oops second takeoff and landing weren’t ‘nominal’ though! Still they’ve got a sense of humour, image from this feed Edited March 3, 2021 by PaulRhB 1 2 Link to comment Share on other sites More sharing options...
RMweb Premium Reorte Posted March 4, 2021 RMweb Premium Share Posted March 4, 2021 Looks like the fire had got going before it landed. Link to comment Share on other sites More sharing options...
RMweb Gold PaulRhB Posted March 4, 2021 RMweb Gold Share Posted March 4, 2021 37 minutes ago, Reorte said: Looks like the fire had got going before it landed. The fireball as it first approached may have been the third Raptor engine switching off, the one they didn’t run as backup and ended in SN9’s crash, as you get similar one when they shut off at before the hover at altitude. Hopefully the next video from Scott Manley will answer some of these questions. Still looks like it came down hard and the gear either collapsed or failed causing the tilt. I wonder if that led to the fire cooking the fuel tank as it was so contained? 1 Link to comment Share on other sites More sharing options...
rocor Posted March 4, 2021 Author Share Posted March 4, 2021 It appears that the next prototype SN11, is already to roll, though SpaceX will obviously have to first conduct an autopsy upon SN10, and incorporate any modifications found to be necessary from this, before SN11 may be launched. 1 Link to comment Share on other sites More sharing options...
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