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Thread: Mars

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    Default Mars

    Moving away from the interesting pics thread, watching the latest landing on Mars made me think.
    The entire operation is fully automated, as signals from Mars to us take between 5 and 20 minutes (i suppose if landing is on far side of Mars from us, signals take 20 minutes, otherwise 5 min). So, when they shout "Eagle has landed" or whatever, the damn thing has already been on surface for 20 min

    Say something goes wrong and has to be rectified from here, the initial advice that pawpaw is in fan, takes 20 min to reach Nasa. Then a split second decision taken at Nasa would take another 20 min to reach the spacecraft, thus 40 min after pawpaw occurred Plan B reaches the spacecraft.

    Sounds like me being directed to reverse a trailer i cannot see
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    Default Re: Mars

    Why did they only have cameras showing the parachute and looking down, they should of had side cameras so you could of seen the Nevada desert from the side I mean Mars
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    Default Re: Mars

    The difference in time has to do with two things.
    • The elliptical shape of Mar's orbit (so sometimes it is closer and sometimes further away from our orbit) - but more importantly
    • Sometimes we are on the same side of the sun, and at other times we are on opposite sides of the sun, that is when the time stretches to its maximum.


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    Default Re: Mars

    Quote Originally Posted by clivemd View Post
    Why did they only have cameras showing the parachute and looking down, they should of had side cameras so you could of seen the Nevada desert from the side I mean Mars
    Only the hazard avoidance landing cameras were used for the landing. The other scientific cameras were covered to protect them during landing. You don't want a stone thrown up by the engines chipping the lens of a several million Dollar camera.

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    Default Re: Mars

    Quote Originally Posted by C Africa View Post
    The difference in time has to do with two things.
    • The elliptical shape of Mar's orbit (so sometimes it is closer and sometimes further away from our orbit) - but more importantly
    • Sometimes we are on the same side of the sun, and at other times we are on opposite sides of the sun, that is when the time stretches to its maximum.


    C
    Yip, thanks, i recall seeing their plan to travel and reach Mars when the two orbits get planets as close as possible. Thus delay would be in shorter region for signals, but still a lot can go wrong in 5 min plus 5 minutes. That's now when they remotely drive their vehicle and also the drone they have that will fly there. When i fly my drone i turn Confucious when drone is flying towards me and left is now right and right is left
    Last edited by julius caesar; 2021/02/28 at 09:05 AM.
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    Default Re: Mars

    Quote Originally Posted by julius caesar View Post
    Yip, thanks, i recall seeing their plan to travel and reach Mars when the two orbits get planets as close as possible. Thus delay would be in shorter region for signals, but still a lot can go wrong in 5 min plus 5 minutes. That's now when they remotely drive their vehicle and also the drone they have that will fly there. When i fly my drone i turn Confucious when drone is flying towards me and left is now right and right is left
    The difference is that a robotic pilot has the point of view the vehicle has. They cannot see their vehicle like you can see your drone. The drivers of the mars vehicles are on Earth and due to the distance and time taken for radio signals every move command is only sent after hours or days of deliberation by the team. You don't want to realise the decision was a mistake a minute after sending the move command and realising you will see the results only in 10 minutes time.

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    Default Re: Mars

    I'm convinced that there is serious technology at play here.
    During the descend phase, the NASA commentator was mentioning the "heartbeat" they get from the vehicle. It didn't contain any data, but confirmed that the vehicle was still alive. From the commentary I got the distinct impression that it was real time. My mind boggles at these space mission technology.

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    To add to these complexities, the mini copter/drone will autonomously do 90 sec flights covering 50m at 1m/1,5m with those blades spinning 5 times faster than earth bound drones. Sure we will hear those blades spinning on earth!! I assume the boundaries will be stretched after a few flights. Cant wait for that footage.

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    Default Re: Mars

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    Default Re: Mars

    Quote Originally Posted by RoelfleRoux View Post
    I'm convinced that there is serious technology at play here.
    During the descend phase, the NASA commentator was mentioning the "heartbeat" they get from the vehicle. It didn't contain any data, but confirmed that the vehicle was still alive. From the commentary I got the distinct impression that it was real time. My mind boggles at these space mission technology.


    No the delay at that time was still around 12 minutes, the only reason why they didn't keep mentioning it was to not confuse the viewers and in fact themselves.
    Those guys deal with everything as if it's in real time to keep confusion and mistakes out of it, when they announced that it landed, it was in fact already down for over 10 minutes. I believe the official times they record which goes in to the history books is also the time they receive the signals here on earth and not the actual time things are happening up there.

    I can't remember exactly how it works, the people working on the mission also now have constantly moving work schedules which they refer to as Mars time, basically the window in which they can communicate with the rover and perform tasks constantly moves, so your 8 to 5 work day is different today than what it will be next week and next month.
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    Default Re: Mars

    Quote Originally Posted by TonyC View Post
    To add to these complexities, the mini copter/drone will autonomously do 90 sec flights covering 50m at 1m/1,5m with those blades spinning 5 times faster than earth bound drones. Sure we will hear those blades spinning on earth!! I assume the boundaries will be stretched after a few flights. Cant wait for that footage.
    I don't think they can stretch the boundaries. That little chopper is just a test unit and I believe the battery is too small to offer more. I actually get the impression that NASA isn't 100% convinced it will fly. If it does fly, then we can expect bigger units on future missions.
    There is also a small oxygen generator on the rover as a test unit, in preparation for manned missions.

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    Default Re: Mars

    Imho, I'm sure they programed different situations into the module and counter measures to be taken... Not an IT expert but imho similar to Excel formulas when setting up a spreadsheet.

    I say this because if said space pod is flying into a mountain, 5 min delay means bang, hence radar picks up mountain, pod moves etc etc.
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    Default Re: Mars

    The rover landed in a pre-determined spot by identifying the spot from high definition photographs.
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    Default Re: Mars

    Quote Originally Posted by RoelfleRoux View Post
    I don't think they can stretch the boundaries. That little chopper is just a test unit and I believe the battery is too small to offer more. I actually get the impression that NASA isn't 100% convinced it will fly. If it does fly, then we can expect bigger units on future missions.
    There is also a small oxygen generator on the rover as a test unit, in preparation for manned missions.


    In one of the interviews I heard, the leader of the helicopter experiment said should it work and should they be able to successfully complete the initial 30 day I think helicopter mission, then they will be able to try go even further and push its limits.

    If that thing works it will be a mind boggling achievement and I'm sure just as with the rover itself, NASA did everything possible to make it a success, but it is after all a experiment and a first, so nobody knows.
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    Default Re: Mars

    This stuff is so mind boggling and really exciting. You wonder where we will be in five hundred years. my name is on Mars so Im chuffed about that.

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    Default Re: Mars

    Quote Originally Posted by julius caesar View Post
    That's now when they remotely drive their vehicle and also the drone they have that will fly there. When i fly my drone i turn Confucious when drone is flying towards me and left is now right and right is left
    They don't drive the rover like one would drive a RC car by LOS (obviously) or by looking through the camera.

    The way it works is, they first look at photographs taken by the rover at it's current position. They pick a spot and tell the rover, go there.
    The rover then drives itself there using all it's obstacle avoidance camera's and AI.

    Then once the rover has reached that first waypoint, they repeat the process.

    Edit: One can deduce this method by looking at the distance the Curiosity rover traveled since landing in 2012....a whopping 24km in say 8 years.
    Last edited by IcePick88; 2021/03/01 at 08:08 AM.
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    Default Re: Mars

    Years back I was on one engineering forum. There was an ex NASA engineer. He said at the time that they write all calculations on their own - from scratch. Maybe they use today some commercial programs but better than Excel

    For the next trip to Moon they wrote new programs to calculate engine burns etc. Complicated. To check the program they dug out old Apollo calculations. They were correct.

    They do make mistakes...
    https://www.latimes.com/archives/la-...%20translation.


    Quote Originally Posted by hunter26 View Post
    Imho, I'm sure they programed different situations into the module and counter measures to be taken... Not an IT expert but imho similar to Excel formulas when setting up a spreadsheet.

    I say this because if said space pod is flying into a mountain, 5 min delay means bang, hence radar picks up mountain, pod moves etc etc.
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    Default Re: Mars

    ;d

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    Default Re: Mars

    I am qualified as an ROV (Remotely Operated Vehicle) Pilot, so I am very impressed by the achievement of the Perseverance mission.

    The difference is that I operate in real time, although every mission is preplanned taking hazards, approach paths, escape paths and no go areas into consideration. When more than one vehicle are operating together, planning becomes more intricate and communication is key.

    Much of the robotics of the Mars rovers has been pioneered on Earth for many years in the offshore oil industry where the depths are far too great for divers. The start was with what are now considered very primitive vehicles and presently advanced vehicles are used. As a point of interest I include some pics of a heavy work class vehicle rated to operate at up to 3000 metres deep that I was part of the crew on.

    As a matter of interest and not to detract from the Mars rover, an insight into some of the technology that led up to the Mars mission:

    A new generation Heavy Work Class Remotely Operated Vehicle

    Click image for larger version. 

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    The pilot and co-pilots seats in the control room

    The vehicle has a crew of three. The co-pilot tends to be far busier than the pilot keeping the pilot informed, performing navigation, operating the sonar and transponders, recording client requested information, operating the spatially controlled arm, checking alarms and vehicle health, communicating with control and other vehicles on the mission and ensuring the trainee pilot/junior pilot keeps the log book and photo/video register up to date.

    The pilot flies the mission and is responsible for the safety of the vehicle.

    Click image for larger version. 

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    The pilots chair.

    Note the foot pedals, joysticks and touch screen with multiple pages of controls.

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    An American colleague flying a mission.

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    The same colleague engaging in wishful thinking after fitting an hydraulically operated extension tool to the vehicle.

    It's a big socket spanner and torque wrench extension. The round buoyancies attached to the vehicle are to compensate for the weight of the tool.

    Click image for larger version. 

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    The business end of the vehicle configured for a specific mission.

    The pan and tilt zoom colour video and HD cameras with their LED light can be seen as can the thrusters and hydraulically controlled arms. All tools for the mission are attached to the arm on the right of the pic. They are attached in their preplanned sequence of use for the mission. All hydraulic hoses to the tools and the orange electrical cable are routed and tied in their preplanned sequences of use to prevent fouling on deployment.

    Click image for larger version. 

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    Hope this gives some insight into the difficulties of using remote vehicles like the Mars rover.

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    Default Re: Mars

    Quote Originally Posted by RoelfleRoux View Post
    I'm convinced that there is serious technology at play here.
    During the descend phase, the NASA commentator was mentioning the "heartbeat" they get from the vehicle. It didn't contain any data, but confirmed that the vehicle was still alive. From the commentary I got the distinct impression that it was real time. My mind boggles at these space mission technology.
    Njet, not real time.......
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