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tater

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Posts posted by tater

  1. Just now, mikegarrison said:

    So by that definition there has not yet ever been any reusable space launch?

    NO. Did you not read my post you replied to?

    "When was the last 100% reusable (actually reusable, unlike Shuttle) rocket tested by anyone? "

    100%. What part of that is unclear? That means, um 100%. So never been done by anyone, ever.

     

    Nixon announcing the Shuttle program:

    https://www.nasa.gov/history/president-nixons-1972-announcement-on-the-space-shuttle/

    Quote

    The new system will differ radically from all existing booster systems, in that most of this new system will be recovered and used again and again—up to 100 times. The resulting economies may bring operating costs down as low as one-tenth of those present launch vehicles.

    So from inception designed to be (aspirationally) 1/10the cost of expendable LVs.

    Quote

    The general reliability and versatility which the Shuttle system offers seems likely to establish it quickly as the workhorse of our whole space effort, taking the place of all present launch vehicles except the very smallest and very largest.

    So replacing all launch except maybe Saturn V sized stuff and... smallsat scaled launchers?

     

    I should add that it will not have been done by anyone, ever, until a landed system is restacked, and reflown. Still a LONG pole for SpaceX.

     

  2. Definition would be that what sat on the launchpad gets restacked (or whatever, might be SSTO), and reflown with no major components having to be new by design.

    Just now, mikegarrison said:

    The Space Shuttle was a fully functioning small space station that could house more than half a dozen people for a week in orbit, and you are comparing it to the cost of a titan launch?

    The POINT of shuttle was to replace expendable LVs back in the day. That was the sales pitch.

    Regardless, you are arguing a straw man. I said 100% reusable. That means 100%, I didn;t say "largely reusable" or "partially reusable." So show me that Shuttle was 100% reused every launch, or you're making a nonsense argument.

  3. 18 minutes ago, mikegarrison said:

    the only thing that wasn't was the external tank.

    The last External Tank contract was I think 2007. They were $172M each. In 2024 dollars that's $257M.

    So the only part thrown away cost ~2.5X the entire Starship launch stack.

     

     

    2 minutes ago, Meecrob said:

    To be a jerk nit-picker: The aerodymanic engineering of the shuttle airframe is definitely re-useable. The Soviets did it first, and now the Chinese and Indians have reused the shuttle design, because without hypothetical quantum CFD supercomputers, the airframe shape is as close to optimized as you can get for the mission.

    That's not what "reusable" means in this context. Loads of IDEAS are useful across many regimes. We're talking about a vehicle—and he's nit-picking when I EXPLICITLY said 100% reusable. So Shuttle definitionally does not count even if someone's definition of "reusable" includes Shuttle because he says in the reply except the external tank... so not 100% of Shuttle was reused—they are trying something completely new here.

    On 3/26/2024 at 2:41 PM, tater said:

    When was the last 100% reusable (actually reusable, unlike Shuttle) rocket tested by anyone?

     

    ^^^Point stands.

  4. 9 minutes ago, mikegarrison said:

    Why do people in this forum continue to take potshots at the Space Shuttle?

    It was a fantastic system, that absolutely pioneered the practical reuse of space vehicles. Nearly every part of a shuttle was reused -- the only thing that wasn't was the external tank.

    I never said it wasn't fantastic—but it was not reusable in the sense that they are attempting with Starship (or even F9 boosters). Sorry, that's simply fact.

    $1.3B per flight is not a real reusable vehicle. When Shuttle was proposed, they literally talked about flying it enough to make it cheaper than Titan—which required a cadence of about 1 per week on the nominal budget... that in the real world flew just a few times a year. I don't care how many parts were "reused," it needs to result in cheaper use, and higher cadence or it's a waste of time. It must be economical to reuse.

    That's ACTUAL reuse. Cars are reusable. Planes are reusable. Ships are reusable. Shuttle wasn't. Orion isn't, DRAGON isn't, either. They are refurbishable.

  5. I looked it up, they also put "dolphins" in front of those structural elements to protect them. I'd assume the idea would be not RIGHT in front but enough of a distance to slow a larger vessel. Bridge apparently from 1977.

    When they rebuild it, would make sense to have a much wider span, and put the piers where the water is too shallow for large vessels. Ie: they run aground before they get close enough to damage the bridge. This from someone who knows exactly zero about any of this. A shame those construction workers died, that's just awful.

  6. 15 minutes ago, Nuke said:

    no. physics wins every time. if it could fold a bridge tower like that, what do you think its going to do to an over zealous guard rail. those might be useful for small boats though. tug boats at least add some redundancy in the event of power failure on the main vessel. it also sounds like the ship was over speed, so you might also see a reduction in speed limits. this would increase time to handle problems like these and reduce stress on the ship's power grid (these kinds of vessels tend to have electric omnidirectional thrusters, as a rudder is slow on a ship of this size, titanic effect).

    Dunno about those sorts of bumper designs, but you'd think with a sharp point, the bow would then glance off—and the barrier can be at some distance. Have such barriers been built at any other port?

  7. 36 minutes ago, kspbutitscursed said:

    Maybe they could do full flight duration at the Masseys new Static fire stand that is under construction?

    Possibly, not sure what they gain. It risks a pad RUD, and out of 3 test flights, two had the ship perform nominally for the engines‚ the issue being related to flight environment for the IFT-2 failure apparently. So maybe they learn something, maybe not.

    Might be mostly to double test possibility on closure days with 2 sites far apart (and limited road closures).

  8. 19 minutes ago, Ultimate Steve said:

    I think Exoscientist might be concerned about SpaceX deliberately and maliciously using this ambiguity to mislead. Maybe a dumb investor would fall for that, but nobody in the know would see "full duration" next to a video 20 seconds long and think "gee, I should buy a mission from them because they are firing the upper stage for a full 8 minutes/their upper stage is so powerful, it can enter orbit in 20 seconds!"

    It's not a public company. The people who invest know what they are getting into—remember Isaacman tried to invest directly, with deep pockets, and was turned down, hence Polaris. The caliber if investors is such that they get a sit down, it's not randos on the interwebs.

  9. 9 minutes ago, PakledHostage said:

    I just think there's a lot of jumping to conclusions going on here. The TSB supposedly hasn't even gotten on-site yet, because rescue crews are still looking for the missing road workers. It seems in poor taste to wag fingers now already.  But that's just my opinion.  As you were. 

    I wasn't wagging any fingers, I was saying that it's plausibly operator error at some level (that's usually the case I think). Given the air/water temp, the road crew had a few minutes before hypothermia, so I already assumed they were gone (which their company has now said officially). That's really sad.

    Interesting that Baltimore protected the power lines better than the bridge piers. Odd choice, the bridge is apparently not very old, seems like sufficient bumpers would have entirely prevented the accident.

    Image

  10. 9 minutes ago, PakledHostage said:

    The engines were built by Boeing... Seriously people.

    https://en.wikipedia.org/wiki/MV_Dali

    Quote

    Dali is propelled by a single low-speed two-stroke crosshead diesel engine coupled to a fixed-pitch propeller. Her main engine, a license-manufactured 9-cylinder MAN-B&W 9S90ME-C9.2[7] unit manufactured by Hyundai Heavy Industries, is rated 41,480 kW (55,630 hp) at 82.5 rpm.[2] Her service speed is 22 knots (41 km/h; 25 mph).

    She was commissioned in 2015. How often do these vessels get maintenance on important mechanical systems? Is that ll done in port, or does engineering crew do some of this? I know literally nothing, but it might have had issues that were allowed to get worse (either by the crew, or the company operating her).

  11. 3 minutes ago, PakledHostage said:

    I don't think that's fair. The New York Times says that the ship lost power and radioed (presumably to VTS or the Coast Guard) with sufficient lead time to get the bridge closed to traffic. That's why there are *only* 6 people missing.  Question might equally be asked why the ship wasn't accompanied by a tug? What were the regulatory requirements for that? And did they have a pilot on board? I suspect that they did. 

    Why did the ship lose power in the first place? Lights off, then on, then off (then on right before impact?)?

    Maintenance clearly slack, which could be crew quality related?

  12. 36 minutes ago, Exoscientist said:

      SpaceX repeating the same mistakes over and over again does not make those mistakes correct.

    What mistakes? When was the last 100% reusable (actually reusable, unlike Shuttle) rocket tested by anyone?

    ...

    Yeah, NEVER.

    What company in the US right now has more experience building, flying, and reusing any part of any rocket? Yeah, none.

    322 F9/FH flights is 322 upper stages built/flown—so even Centaur, the only possible thing that might have flown as much in the US, and in existence for 62 YEARS? How many times has Centaur flown? 271 times as of Vulcan Cert). So again, "the industry" right now in terms of experience is: SpaceX and "also ran."

     

    So you claiming it's a mistake how they are prodceeding... yeah, that's irritating, tbh.

    How about we just stipulate that you think everything they are doing is wrong, and skip the posts? When HLS lands on the Moon, we can all simply assume that according to you it's wrong, or tested the wrong way, whatever. When they land on Mars? Same thing, making the same mistakes all over again, this time on Mars! Pikers!

     

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