Posts by imanidiot

Re: Historically

Air quality is certainly improving. It's still shit though (and Shanghai was at times worst than Beijing).

As to independence for maintenance, that's only possible if you also have domestic supply for the spares. Which they currently still don't have. Domestic production of powerplants is still severely lagging behind RR and GE.

Re: Historically

He's right though, both cities are objectively shit to live in based on air quality alone

Re: Seeing back in time

Since the entire universe came into existence at the same time, "here" and "over there" have always been "here" and "over there". The position within the (probably infinite) universe for either position hasn't changed since the big bang. Just the distance between the two points as measured by the time required for a photon traveling near the maximum velocity of a photon in vacuum to get from "over there" to "here"

Because of the expanding universe "over there" has been getting further and further away (or we've been getting further and further away from "over there", or both have been moving away from a point in between depending on reference frame as everything is moving away from everything else at the same time.

Re: Seriously?

Huh, apparently I was wrong, the only requirement to receive a refund is to send them the motor controller*. Indeed in that case it would be a very simple matter to retrofit any of dozens of 3rd party motor controllers

(*See the recall FAQ)

Re: Rollover protection?

They claim that research in other countries points to the rollbar being a bigger hazard (snagging on trees, or causing injury to the rider because they prevent the rider from coming off the bike. The UK's/Northern Irelands HSENI for instance recommends against ROPS) Australian research seems to point to people coming off the bike being rare and it being nearly impossible for roll-bars to cause injuries greater than would be sustained in the accident if the rollbar wasn't there.). Mostly it seems like it was a heavy handed attempt at coercing AUS into not implementing the rules because they fear they won't sell enough of them after making the chances to recoup cost (because there's too many people being very vocal and buying into the repeating talking points against the devices about how it would impede work or how it would be dangerous)

Re: Seriously?

I doubt the disabling of the vehicle will involve only the electronics. Good chance they'll require photographic evidence of something far more drastic (like a removed section of frame tube) to prove the disabling. Potentially even proof that it was dismantled and anything metal crushed beyond repair.

Probably not. The Corona program catching returning film capsules from spy sats needed the cargo aircraft (They also used C-119s, C-123s and some other aircraft beside Hercs iirc) with longer loiter times because their target was in a larger area of uncertainty and tracking tech wasn't as advanced. The target was also usually a lot further out to sea. The program for retrieving people/spies from the ground similarly had a fairly large range requirement, plus the added speed was welcome if having to penetrate behind enemy lines. Rocket Lab has a pretty good idea of where their target will be and it's a lot closer to shore. On top of that the aircraft used in the US programs had all sorts of additional equipment to then haul the retrieved cargo into the back of the aircraft. That simply won't work for the much more voluminous first stage of Rocket Lab and it's kinda hard to land an aircraft with such a payload trailing on a cable behind it without damaging said payload.

People here laugh, but for larger boosters it's not a terrible idea and not the first time it's been proposed. Especially Russian rocket engineers were rather keen on the idea and it surfaced several times

As a booster for the follow up to the soviet space shuttle Energia booster (Urgan/Energia II)

https://www.reddit.com/r/WeirdWings/comments/b3oyd7/the_zenit_flyback_booster_a_fully_reusable_rocket/

More recently proposed as a booster to the new Russian Angara rocket:

http://www.russianspaceweb.com/baikal.html

A video with some more info and pictures:

https://www.youtube.com/watch?v=QVNIaC10MDg&t=360s

Re: On what scale?

The actual mission is launching the payload. That went off without a hitch. Catching the first stage was only a very minor part of said mission and it failing to snatch the rocket in mid-air doesn't make the overal mission a failure. Since the payload went to space.

Not an option

They're using all their fuel to get the payload where it needs to go. They don't have the margins like SpaceX does to do a return, re-entry and landing burn. Basically the only option they have is to open a parachute after the rocket did it's thing and starts falling. Since it's flight path doesn't pass over the Delmore Downs, there's no option to land there. They have to either pluck it out of the air where it falls, or pick it up out of the ocean where it falls. Mid-air aircraft refueling is a lot simpler. Both aircraft are actively controlled and it's relatively easy to take the time to set up a rendezvous, keep both aircraft on the same flight path and get close, etc. In the case of catching a rocket stage, it falls under parachute where the flight path and prevailing winds take it. The helicopter pilots have the time between the chutes opening and getting the first position fix until it hits the ocean to get to it and make a pass over the top with the hook on the trailing line in the right position to catch rocket. That's really no easy feat. *magnets* aren't magic or miraculous and are not going to help here.

Slight problem there, that helicopter is about 1/3 of the way around the planet. It'd take several thousand of the longest flights it's made so far to even get there. (If it could. Likely it would do it's best impression of an upturned turtle long before that)

I did the math in an earlier thread about the InSight Lander, copied here for your reading pleasure: "That little helicopter is roughly 3450 km away. It's highly unlikely it could even GET to the InSight lander and IF it could make it it would be an epic trek across the planet that would likely take years to complete, by which time it would be pointless. The longest flight of Ingenuity to date iirc was about 700 meters during flight 25. At 3450 km distance that would take nearly 5000 flights to complete!"

Re: Use inclined solar panels

You could have these upside-down and dust would still cling to them.

Re: Use inclined solar panels

Complicated, heavy, can damage the panels and probably not nearly as effective as you'd think (try brushing dust off of a statically charged balloon, you'll probably just end up adding more).

Re: Use inclined solar panels

Working with HV equipment in a vacuum that needs to be super clean I can say that the experiments have been done and have been less than successful. Once particles like that stick it's REALLY hard to persuade them to leave again. Your repelling charge might just shake them loose a little bit, only for them to then get attracted back to your surface at even higher charge levels

Re: It’s not just the cost of SLS

This has nothing to do with new car vs existing car, it's really that bad for SLS. The rocket is brand-new (and will always be brand-new since the whole thing splats into the ocean after launch). Rolling back the vehicle from the launch pad is a multi-day operation in itself. If it's rolled back lots of stuff like flight-abort-system batteries have to be replaced (because they can't be charged while SLS is on the pad and have a limited lifespan) and then the thing has to be rolled back out to the pad and prepped for launch (requiring a weather window long enough to get safely from VAB to pad and prep for launch)

SLS isn't built for fast launch (or for launch in the first place it seems)

Google cardboard was and is a nice gimmick. Most of those "Smartphone in a headset" contraptions equally so. VR or AR really only works with proper 6DOF tracking of sufficient fidelity and accuracy. We're still a very long way off from smartphones having enough ooomph onboard to make that happen.

Re: China's Moon Mining is a better idea

"You do little more than rant, but if you think for a minute that the Rover and the Rocket will be acting autonomously while everyone is cozy sleeping at night, perhaps you should take a lesson from Tesla autonomous driving cars,"

Pretty much all Mars rovers since the cutest of them (Sojourner) have been to a large degree "autonomous" (pre-programmed asynchronous control is probably a better name for it). For early rovers it was mostly a sequence of commands boiling down to "Turn X degrees, drive forwards Y meters, turn Z degrees take photo" which were sent to the rover, then waiting for the results to come back in, spend the rest of the day deciding how to move next and making a command sequence for it, then at the end of the day upload the command sequence, and overnight the data for the result would be received and the next day they could analyse, make a new sequence, send that, wait for results, analyse those, send a new command sequence and go home, repeat ad nauseam.

For newer rovers there's more autonomy, and commands from earth are more along the lines of "drive to this location, preferably along this route". The onboard navigation systems then mostly follow the route but will make autonomous (without human intervention) small course corrections to steer around larger rocks and gullies to prevent wheel damage and optimize travel time.

The claims about moving Dimorphos' orbit around Didymos are very well substantiated and there's plenty of data out there if you care to look. A lot of the data doesn't even come from NASA but from observatories (both optical and radar/radio) in multiple countries. Proving an orbit changed is rather simple. If you know the orbit (and we did) then you can easily predict where something should be after a certain amount of time has passed. If you take a photo after exactly one orbital period (barring some precession wobble and such) the object will be in exactly the same spot around the parent object. When that lines up well for all shots pre impact you know you have a good fix on the orrbit. Post impact the object suddenly isn't where you know it should be based on it's previous orbit. In other words, it's orbit has shifted.

As to the whole space shuttle debacle, that's a discussion in itself and one we can't blame ONLY on NASA.But that requires so much history and program knowledge I'm not going to bother.

Re: China's Moon Mining is a better idea

Mining the moon is largely pointless. There's currently nothing up there that we need and can't get cheaper and easier here on earth (Earth and Moon share pretty much the same mineral composition. And don't say Helium-3 because we can't actually do anything with it here and won't be able to for at least another decade, probably even longer. First we'd need to get Deuterium-Tritium fusion working. After that we can start trying MAYBE to get up to helium fusion temperatures but we're a VERY long way from achieving that).

The Rover is using a Plutonium power cell, we know exactly how long it's going to live based on the half life of plutonium and previous experience with RTGs (The Voyager probes and the curiosity rover being notable ones).

The sample tubes are not glass, they are titanium (Grade 5 iirc) with gripping and locking provisions designed in. Loading and unloading these will be almost entirely autonomous and certainly none of it will be manually controlled. There would be no human intervention anywhere in the process as the time delay simply doesn't allow for it. Of course a way for the robot to align to the lander and an allowance for minor misalignment is designed into the system. None of that is particularly hard to solve. Getting there safely and dealing with the dust will be the biggest challenges

If you're going to spout bullshit, read up on what you're spouting bullshit about.

Re: Here's hoping that it will work out

Just to be that guy, WELL AHHCHKTUALLY, they no longer plan to send a rover but now not one but two helicopters intended to provide backup capability to recover the tubes and carry them to the lander, which will then load them into the ascend module, which will in turn dock to an orbiting return module where the sample tubes get transferred from the ascend module to the return module, after which the return module departs to earth (This complicated "pass the parcel" chain is so that nothing that touched the surface of mars gets brought back to earth outside the sample capsule, just in case there IS life on Mars and it's hostile to humans. Viral or bacterial life is the big threat there). The primary method for returning sample tubes to the lander will be Percy itself. If Perseverance is somehow unable to perform the function then the helicopters will be used. The tubes the helicopters would recover are the ones left behind on the surface by Perseverance as it sampled different sites. They would explicitly not be able to retrieve the sample tubes retained on-board the rover. (Current WOW is that they take 2 samples at each location, with one sample tube being left behind and one retained aboard the rover.

(Source

And this is why proprietary car interface systems are a bad idea. Alternative to buying a new car for reasons akin to the ashtray being full use something like a CarLinkIt to convert your wired setup to wireless (No idea how well that works).

Re: consistent with my experience

If I HAD owned an NFT it's not something I would consider admitting to in polite company. I'd sooner talk about having some disease or show them my baby pictures, much less embarassing.

AI or Ali G. innit?

Re: There's a reason

The only true Philips made Philips products remaining are the shavers and the healthcare products. Everything else is designed, marketed and sold by companies other than Philips with a branding deal so they can put the Philips name on it.

And yeah, I'm currently working for a company that used to be Philips, supplying equipment to another company that started as Philips, and having regular encounters with people who worked for other (now succesful) companies that used to be Philips and the culture of that company still resonates and hampers progress so many years later it's so unfunny it's become funny again. Within our own company I sometimes refer to the former Philips employees as the Philips Fossils. Philips Healthcare honestly makes some very good products (just maybe not their ventilator/breathing products) and their electric shavers are imho also top of the market. Everything else is overpriced and "a bit shit". Even their lighting products (Now made by spun-off Signify. The Hue range was very early to the smart lighting market) haven't really been able to stay relevant as far as I can see.