And what are the benefits? Does it really make it that much easier to stack the stages
My first question is: How long do people think it will be until Chopstick operations are "routine" enough to no longer require pad clear for lifts?
Quote from: Hamish.Student on 10/12/2022 02:58 amMy first question is: How long do people think it will be until Chopstick operations are "routine" enough to no longer require pad clear for lifts?Anyways will be a requirement.
Sticks were connected, but the ship was stacked, no?
Quote from: Jim on 10/13/2022 03:53 pmQuote from: Hamish.Student on 10/12/2022 02:58 amMy first question is: How long do people think it will be until Chopstick operations are "routine" enough to no longer require pad clear for lifts?Anyways will be a requirement.As always, your one liners are wrong.Already wrong, in this case, as yesterday they had Starship on the chopsticks with men on lifts poking around at the QD.
The only issue I see is that the booster is pressurized when the ship is lifted, but this again probably just means don't hang around the pad for no reason...
Quote from: meekGee on 10/14/2022 04:38 amThe only issue I see is that the booster is pressurized when the ship is lifted, but this again probably just means don't hang around the pad for no reason...If the booster must be pressurized for stacking, then it should remain pressurized while Starship remains stacked, shouldn't be? Does it mean that people are not supposed to walk around while stacked?
Quote from: geza on 10/14/2022 04:59 amQuote from: meekGee on 10/14/2022 04:38 amThe only issue I see is that the booster is pressurized when the ship is lifted, but this again probably just means don't hang around the pad for no reason...If the booster must be pressurized for stacking, then it should remain pressurized while Starship remains stacked, shouldn't be? Does it mean that people are not supposed to walk around while stacked?Yes, but the lift adds the risk of dropping the ship or colliding or whatever was imagined upthread, and so a pressurized booster is more dangerous.I still think it'll be normal operations at some point, but I also think once the booster is there and you're loading a ship, there won't be a lot of people there anyway.
Sort of like the vertical road transport of the SH or SS that just needs to make sure that the area around is clear (or mostly clear-restricted access) if it topples over. It is not going to explode just toss some pieces a few meter out from where it impacts mostly due to the fall and less about the pressurization.
Quote from: oldAtlas_Eguy on 10/14/2022 05:24 pmSort of like the vertical road transport of the SH or SS that just needs to make sure that the area around is clear (or mostly clear-restricted access) if it topples over. It is not going to explode just toss some pieces a few meter out from where it impacts mostly due to the fall and less about the pressurization.It's a question of scale. An SH is 234 feet tall. Depending on your conversion factor, that's about as tall as a 20-story building. If it topples it can hit you if you are within 234 feet of it even if it's sitting on the ground and does not throw any debris. In contrast with a building, it will topple as a unit, especially if a bit of pressure helps it retain its structural integrity.
Quote from: meekGee on 10/14/2022 01:30 pmQuote from: geza on 10/14/2022 04:59 amQuote from: meekGee on 10/14/2022 04:38 amThe only issue I see is that the booster is pressurized when the ship is lifted, but this again probably just means don't hang around the pad for no reason...If the booster must be pressurized for stacking, then it should remain pressurized while Starship remains stacked, shouldn't be? Does it mean that people are not supposed to walk around while stacked?Yes, but the lift adds the risk of dropping the ship or colliding or whatever was imagined upthread, and so a pressurized booster is more dangerous.I still think it'll be normal operations at some point, but I also think once the booster is there and you're loading a ship, there won't be a lot of people there anyway.A positive pressure of a non explosive gas such as nitrogen is a safety factor for humans around it than a danger. So long as the positive pressure amount gains the needed structural integrity without increasing risk of structural failure creating a lowering risk of danger from a structural failure. Having that pressure can give the humans around the area that added extra time to get away from the vehicle as it does a slow collapse vs a faster one. The Atlas always had a positive pressure and humans crawled around around it all the time including non-worker visitors that walked up to and put their hands on the vehicle skin. It is as Nomad mentioned the movement of the vehicle that is a clear the area event and was so for the old Atlas as well except the horizontal road travel which was in a special hard frame but uncovered. Sort of like the vertical road transport of the SH or SS that just needs to make sure that the area around is clear (or mostly clear-restricted access) if it topples over. It is not going to explode just toss some pieces a few meter out from where it impacts mostly due to the fall and less about the pressurization.
Quote from: oldAtlas_Eguy on 10/14/2022 05:24 pmQuote from: meekGee on 10/14/2022 01:30 pmQuote from: geza on 10/14/2022 04:59 amQuote from: meekGee on 10/14/2022 04:38 amThe only issue I see is that the booster is pressurized when the ship is lifted, but this again probably just means don't hang around the pad for no reason...If the booster must be pressurized for stacking, then it should remain pressurized while Starship remains stacked, shouldn't be? Does it mean that people are not supposed to walk around while stacked?Yes, but the lift adds the risk of dropping the ship or colliding or whatever was imagined upthread, and so a pressurized booster is more dangerous.I still think it'll be normal operations at some point, but I also think once the booster is there and you're loading a ship, there won't be a lot of people there anyway.A positive pressure of a non explosive gas such as nitrogen is a safety factor for humans around it than a danger. So long as the positive pressure amount gains the needed structural integrity without increasing risk of structural failure creating a lowering risk of danger from a structural failure. Having that pressure can give the humans around the area that added extra time to get away from the vehicle as it does a slow collapse vs a faster one. The Atlas always had a positive pressure and humans crawled around around it all the time including non-worker visitors that walked up to and put their hands on the vehicle skin. It is as Nomad mentioned the movement of the vehicle that is a clear the area event and was so for the old Atlas as well except the horizontal road travel which was in a special hard frame but uncovered. Sort of like the vertical road transport of the SH or SS that just needs to make sure that the area around is clear (or mostly clear-restricted access) if it topples over. It is not going to explode just toss some pieces a few meter out from where it impacts mostly due to the fall and less about the pressurization.I have no problem with people next to a pressure tank, for all the reasons you stated.I have no problem with the safety of the chopsticks - they will be much safer than any crane op.I only added that during motion, when there's some non-zero chance of Starship hitting SH, then the stored energy in SH can add risk, if the skin is punctured.Overall though, I'm fully with those thinking that Chipstick lifts will not require a "pad clear".
As always, your one liners are wrong.Already wrong, in this case, as yesterday they had Starship on the chopsticks with men on lifts poking around at the QD.
Quote from: InterestedEngineer on 10/14/2022 03:20 amAs always, your one liners are wrong.Already wrong, in this case, as yesterday they had Starship on the chopsticks with men on lifts poking around at the QD.Wrong again on both points as usually. "Pad clear" doesn't mean all personnel. It means all non essential personnel. That is basic work knowledge. It applies to spacecraft fueling, lifts of fueled spacecraft, lifts of large hardware, etc. BDA clears are usually when going into launch vehicle people propellant loading and that clears all personnel.