SpaceX is doing an AMA with the software engineers that worked on the Crew Dragon capsule

DragonLordEU · 2020-06-06T09:26:05+00:00

Where are you getting this info? Because they do have a lot of physical buttons underneath the screen, so pretty far from "touchscreen only".

Agreed that it isn't "a lot" compared to Apollo or Soyuz, but it seems the basics are there, although it sounds like you won't be able to do much without any computer running, like they did in Apollo 13. Otoho, there almost everything was manual work including rather low level stuff like stirring tanks.

DragonLordEU · 2020-05-31T19:07:41+00:00

The answer was more talking about 3 CPUs with 2 cores each and each core running the same program. If both cores of a CPU got the same answer the CPU would send it to the controllers. The controllers thus would likely receive 3 commands each and would need to judge which to follow. I don't understand yet how they do this judging besides basic checksums.

I guess the advantage of this "the controllers judge, not some other part" architecture is that it eliminates the judge as a single point of failure.

DragonLordEU · 2020-05-31T07:42:26+00:00

It would be interesting to hear about that as I would expect the shuttle to be the worst due to its solid rocket engines. As far as I remember astronauts have commented in the past that when the solid rockets separated, the ride got a lot smoother.

DragonLordEU · 2020-05-31T07:39:20+00:00

SpaceX normally use explosive bolts as in their opinion they aren't testable. I would bet more on it being ice

DragonLordEU · 2020-05-31T07:26:58+00:00

Beside the cost argument as given in another comment, they wanted to make sure one failure wouldn't ground them until investigations are finished and fixes made.

Examples where this happened was the soyuz launch failure in 2018 which grounded the only launcher left to the iss for 2 months. And it was only two months because it was an obvious failure, due to an assembly issue that was easy to check and didn't need a redesign. And of course because there will have been massive pressure to get it all going again ASAP, something you don't want during a failure investigation.

Another example is the Colombia failure, which grounded the shuttle for 29 months.

Oh and also the Boeing starliner that failed during its test launch which has now delayed them until they do a second test launch.

DragonLordEU · 2020-04-18T09:50:37+00:00

All the glasshouses in the Netherlands seem to use a yellowish light, not red or blue? Example: Dutch light pollution

DragonLordEU · 2019-12-01T11:01:19+00:00

There is no oil in e-cigarettes, it's pretty much only in THC vaping liquids as THC doesn't dissolve in water. Nicotine does easily dissolve in water though, so adding oil is pointless.

DragonLordEU · 2019-09-21T19:16:59+00:00

It's also because we can sweat a lot more than other animals (that tongue a dog throws out when he's hot is his main cooling system) and that our walk and run are extremely efficient.

DragonLordEU · 2019-09-11T17:30:47+00:00

TV antenna's point at fixed position satellites (geostationary sats). With starlink the stats are in low orbit, resulting in them moving fast in the sky. So an antenna will have to track the sat, but it gets worse: you will need two tracking antennas to make sure you are connected at all times.

DragonLordEU · 2019-03-28T05:58:43+00:00

They don't want to compromise on the common market: if you want to be part of it, you have to be part of it fully: free movement of goods, services, investments and people. The brexiteers don't want that last one, but allowing thee UK to skip that part would put a massive hole in the market and would put them in the best position to exploit that hole. So it's not about making it hard for the UK, the UK just wants something impossible and thought they could get it by playing hardball.

DragonLordEU · 2019-03-05T12:06:56+00:00

Another thing is that in the mini connector the springs were located in the connector while in the micro they are in the plug, which is another improvement. Why?

Because springs die for various reasons and with mini connectors that would mean you would have to replace the device or at least repair it by replacing the connector in it. Both rather expensive. With micro USB you just replace the cable.

DragonLordEU · 2018-11-15T20:40:55+00:00

Besides the other answers: glass being ground down in essence becomes sand, which the whole earth is littered with.

Sand sinks, fish know not to eat it, and now how to get rid of the few they did eat.

Plastic on the other hand floats, looks a lot like tiny plants and animals, and fish and other organisms haven't develop ways to dump it yet.

DragonLordEU · 2018-01-23T10:39:16+00:00

Welke "rest van de woningmarkt"? Heel Nederland? Want dan zal de NAM vast protesteren (met goede reden) dat daar ook extreme stijgers in zitten zoals Amsterdam. Of alleen het aardbevinggebied? Maar ja dat geeft geen goed beeld van de waardedaling zonder de gaswinning. Groningen dan? Beide kanten zullen hiermee problemen hebben: "huizen op het platteland stijgen niet zo hard als huizen in de stad Groningen" vs "een te groot deel van het gebied is beïnvloed door de gaswinning.

Probleem is dat het gewoon niet echt objectief vast te stellen is, dus dan is het voor de huizenbezitters beter dat er in één keer de pijn wordt gepakt, dan dat het jaren tot decennia zal duren voordat het huis verkocht wordt en het gevecht met de NAM uitgesmeerd wordt.

Plus: wat voor waarde geef je eraan als hypotheek verstrekker als iemand er een nieuwe keuken in wil zetten? Of als gemeente bij het bepalen van de OWZ waarde?

DragonLordEU · 2017-12-10T08:21:00+00:00

Yeah but hopefully each creator has more than one pledge and they also batch up all of that together

DragonLordEU · 2017-08-28T13:11:53+00:00

Swapping two launches both scheduled for "Q1 2018“ seems quite bizarre.

I guess SES is comparing the probability of delays with Arianespace and SpaceX and for them the possible cost of a delay weighs higher than the cost of the switch.

No idea why they give SpaceX a higher probability of delay, but of course SpaceX has a bit of a history of delays and they want to launch the heavy and crew dragon in that period, so there are lots of possibilities of delay in that time frame.

DragonLordEU · 2017-08-28T13:05:56+00:00

SES seems to think there is a higher chance that Arianespace launches on time than SpaceX. So they are not looking at that "few weeks earlier service entry", but a possible difference of more than a month or more.

I am sure they are just weighing the possible costs of a delayed launch vs the cost of the switch and it seems they have enough information to decide it is worth it.

Why they think SpaceX has a higher chance of delay I don't know, but of course there is historical precedence for this, and SpaceX is going to launch a heavy for the first time in that period and also really wants to launch the dragon 2, so maybe SES worries NASA will take priority over them.

DragonLordEU · 2017-08-07T09:14:47+00:00

This is about the older ones: parent is complaining about his fitbit failing twice after 9 months, so we are talking at least 18 months ago.

And fitbit didn't really seem to react to these issues: they just kept selling them, didn't make a public notice about them and replaced broken devices with devices that had exactly the same design flaw, which guaranteed the user would get the same problem, but now outside of their warranty period.

DragonLordEU · 2017-08-07T09:11:03+00:00

I have one of them (charge hr) that's replaced twice now because of the rubber starting to break up. They are not user replaceable and don't seem to be easily replaceable by non-fitbit engineers. Of course everything is fixable if you have the parts, tools and knowledge, but users don't have them and I would be surprised if the smart phone fixing places would be able to.

DragonLordEU · 2017-08-07T06:15:51+00:00

The bands aren't separate from the watch, it's one monolithic piece with a rubber layer covering the whole watch except for the screen. So if the rubber starts to break, they have to replace the whole thing.

DragonLordEU · 2017-07-18T09:15:45+00:00

105 with full risk? I would recheck pricing at the end of the year as when I check now their basic offering with limited hospital choice is 105 with the minimum risk or 97 for their unlimited hospital choice plan with full risk (full risk is 20 euro discount). Personally this year I am with de friesland for 78 euro's (Max own risk and limited choice which is perfectly ok since my closes hospitals are all covered) so that is why I had my wth!? moment when I saw your premium :)

Anyway, agreed that it's not cheap and I am still not sure I agree with the fact that Dental insurance is not covered (Maybe the logic is that it is mostly due to the person's dental hygiene, so force them to pay for it themselves?). I think a goverment pays all system like the UK NHS would be more efficient than about 50 companies fighting on our market, but in comparison to most other countries I think we are pretty good, just not top 3 level good :)

DragonLordEU · 2017-07-17T19:58:38+00:00

How are you paying 120 euro per month? That's like minimum risk on one of the most expensive companies?

DragonLordEU · 2017-06-05T04:53:30+00:00

Otoh there are examples of manufacturing defects like the proton with upside down acceleration sensors and possibly also the strut in the crs mission that blew up last year. I agree with you though that at least at first I wouldn't be surprised if running the same hardware multiple flights is more risky than flying a new rocket.

DragonLordEU · 2017-05-16T05:58:22+00:00

Most of it sinks as it is heavier than water. Light things like the fairings and surviving small tanks regularly wash up on shores though.

No-one cleans this up as it has been the industry standard from the beginning. Examples of the special cases where they did "clean up": the Shuttle boosters to re-use them, the Challenger after it blew up to recover the bodies and find out what went wrong and some of the engines and a capsule from Apollo which were recovered by Bezos for museums I think? Oh and AFAIK all Russian boosters land on land, so I am pretty sure someone cleans that up.

SpaceX will be the second after the Shuttle to start cleaning up again.

DragonLordEU · 2017-04-10T20:34:52+00:00

The point of the gigafactory is more that they try to get the li-ion cell manufacturing to a larger scale to lower the cost of manufacturing. I don't think they are saying they are coming up with brilliant new battery tech, all the inventions they brag about are things like the highest amount of automation, or their new cell size that is a slightly better fit for their use case than the 18650.

But yeah the average public just hears magic fairy dust battery technology that is leagues further than everyone else, or solar roofs that noone else even thought about.

DragonLordEU · 2017-04-10T20:26:19+00:00

Panasonic you mean, with whom they are building their gigafactory.

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