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Japan’s Hayabusa2 spacecraft grabs close-up thirty feet above asteroid

cnet.com

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Re: Japan’s Hayabusa2 spacecraft grabs close-up thirty feet above asteroid

#71

Post by adrianmonk »

EdwardDiego wrote: post #69
melling wrote: post #50

Earlier quoted context omitted.

He’s probably referring to the time NASA lost the $125 million spacecraft because teams used different systems. https://www.wired.com/2010/11/1110mars-climate-observer-repo... It’s helpful when there’s only one system. In the US, it’s too costly to switch. HN readers are global and we’re technical so there’s no reason not to simply use metric.

> In the US, it’s too costly to switch. What is the estimated cost out of curiosity?

I estimate the cost to be 1 unit of national pride.

Re: Japan’s Hayabusa2 spacecraft grabs close-up thirty feet above asteroid

#72

Post by magduf »

justin66 wrote: post #54
SmellyGeekBoy wrote: post #40

Earlier quoted context omitted.

You mean the British-built one? I think us Brits are the worst of the worst when it comes to mixing units. Fuel is sold in litres but consumption measured in miles per gallon. Milk is sold in 1 pint or 2/4/6 litre bottles. Road signs to towns are in miles but in roadworks are in metres. And so on.

> I think us Brits are the worst of the worst when it comes to mixing units. McLaren recently failed to qualify for the Indy 500 (McLaren!) due in part to a unit conversion problem made prior to the last day of qualifying. https://autoweek.com/article/indy-500/mclaren-ceo-zak-brown-...

To be fair, from my reading of the article, this was a metric-to-imperial conversion problem, meaning McLaren was used to working in metric, but the Indy 500 is in the USA, which uses the backwards and archaic US customary units, so someone screwed up in converting to those. This could have happened to any non-American racing team, and doesn't serve at all as an example of Brits sticking with obsolete units, but rather the opposite.

It does seem that McLaren made a lot of boneheaded mistakes here, but this example just doesn't go with the "Brits are still using imperial units" theme of this thread at all.

Re: Japan’s Hayabusa2 spacecraft grabs close-up thirty feet above asteroid

#73

Post by Sharlin »

Nelson69 wrote: post #67
vvvv wrote: post #10

It bothers me (too much) that we are going to space and still using 'feet' as a unit of measurement.

I went all metric when we started the new millennium. I try to do all my personal measurements in metric. It has been my own personal battle to make progress, every little bit helps.. It's funny how life fights with you though. My wife and I share a scale in the bathroom, it's a fitbit wifi thing and she finally laid down the law, it uses pounds now. Chasing 130lbs is somehow more satisfying than 58.9 or 59Kg. Our el…

> Chasing 130lbs is somehow more satisfying than 58.9 or 59Kg.

I mean, chasing 60kg is more satisfying than 132.2lbs. There's nothing intrinsically important about 130lbs except that it's a round number in base 10. In metric you just pick a different round number to chase.

Re: Japan’s Hayabusa2 spacecraft grabs close-up thirty feet above asteroid

#75

Post by Sharlin »

merpnderp wrote: post #49
dls2016 wrote: post #31

Earlier quoted context omitted.

Given the distance to the sun and proximity to the asteroid, shouldn’t the vehicle and its shadow be essentially the same size?

I'd assume without an atmosphere to diffuse light, the sun is basically a point light for 95% of the Solar System.

It's a point light infinitely far away. So light rays are parallel, and shadows are exactly the size of the object.

Re: Japan’s Hayabusa2 spacecraft grabs close-up thirty feet above asteroid

#76

Post by melling »

adrianmonk wrote: post #71
EdwardDiego wrote: post #69

Earlier quoted context omitted.

> In the US, it’s too costly to switch. What is the estimated cost out of curiosity?

I estimate the cost to be 1 unit of national pride.

Everything has a cost. NASA estimated their cost was $370 million to switch to metric.

https://www.cnbc.com/2015/06/04/why-the-us-hasnt-fully-adopt...

The cost of switching road signs alone was quite expensive. Exit numbers, for example, are often the mile marker number.

Re: Japan’s Hayabusa2 spacecraft grabs close-up thirty feet above asteroid

#77

Post by stallmanite »

EdwardDiego wrote: post #68
cryptonector wrote: post #41

Earlier quoted context omitted.

Imperial pints are bigger than customary pints, for example.

In my country, NZ, we refer to beer as pints, and order them as such, but a pint isn't a legal unit of measurement, so it's accepted that your pint will vary. The good establishments have a chart on the wall explaining how many millilitres map to their "pint". And a pint of high alcohol beer will often be less than a pint of average alcohol beer. 473mL vs 568mL typically. It's not illegal to serve someone a "pint" if…

So at the same establishment you could order two pints of beer and the high ABV one would be smaller in volume? That would really bother me or anyone calculating the unit cost of ethanol.

Re: Japan’s Hayabusa2 spacecraft grabs close-up thirty feet above asteroid

#78

Post by GordonS »

GordonS wrote: post #42
SmellyGeekBoy wrote: post #40

Earlier quoted context omitted.

You mean the British-built one? I think us Brits are the worst of the worst when it comes to mixing units. Fuel is sold in litres but consumption measured in miles per gallon. Milk is sold in 1 pint or 2/4/6 litre bottles. Road signs to towns are in miles but in roadworks are in metres. And so on.

To add to the mix, some signs are in yards - who even knows what one of those equals these days?!

I don't usually complain about downvote... but seriously? Someone really thinks it's OK to have signs in all of miles, metres and yards?!

Re: Japan’s Hayabusa2 spacecraft grabs close-up thirty feet above asteroid

#79

Post by dang »

vvvv wrote: post #10

It bothers me (too much) that we are going to space and still using 'feet' as a unit of measurement.

"Eschew flamebait. Don't introduce flamewar topics unless you have something genuinely new to say. Avoid unrelated controversies and generic tangents."

https://news.ycombinator.com/newsguidelines.html

Re: Japan’s Hayabusa2 spacecraft grabs close-up thirty feet above asteroid

#80

Post by TylerE »

_Microft wrote: post #30

The above image comes from a 600-kilogram, refrigerator-sized robot travelling at about 15 miles per second, around 170 million miles from Earth. They can be glad that the asteroid is also around 170 million miles from earth, travelling at 15 miles per second and this even in the same direction. Relative motion is smaller though: The gravitational force between the probe (660kg) and asteroid (4.5 * 10^11kg) is just 0…

I'm kinda surprised an orbit that low as been stable for a year. Is this an unusually circular asteroid or is there a fair bit of eccentricity?
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