Posts by Alan Brown

An Army Watchkeeper drone tried to land. Then meatbags took over from the computers

Re: Army culture vs Air Force culture

"The Air Force will not buy a drone which does not require a pilot to fly it."

On the other side of the pond where the US Army and the USAF fly the same kit, but one group are hands on (USAF) and the other group have strict orders NOT to touch the kit whilst it's landing or taking off (Army), the human-flown units have a substantially higher rate of landing crashes.

The problem here isn't that the Watchkeeper operators intervened, but that they weren't told to leave it the fuck alone during the landing cycle and specifically _not_ to try and second-guess it.

In the case of real, honest to goodness "out of control", you should have a "Range Safety" option to blow the wings off/fire the recovery chute - and be prepared to explain to the board of enquiry why you hit that big red "bugout" button when you did.

Re: Crew Training

"But instead I guess they displayed a message more like"

It's the Army. You really don't want to know what happened to switches marked "Boot"

Donald Trump blinks in his one-man trade war with China: US govt stalls import tariff hike on Chinese phones, laptops, electronics

Re: inside the 'mind'

"the Tangerine Twerp uses backchannels ... to benefit from the stock market"

Objection.... Assumes intelligence and facts not in evidence.

He's been bankrupt multiple times and the only skill he's ever shown himself to be good at is pissing money against a wall and stiffing his smaller creditors whilst somehow convincing the larger ones to keep giving him wads of cash.

It smells like a money laundering operation to me (and not coincidentally, smelled like one to the Australian Federal Police in the 1980s, which is one of the reasons why they successfully objected to him being given an Australian casino license - the other being their thorough documentation of his mafia connections)

It's widely believed that Robert F Kennedy's father used his Mafia connections (moonshining) to get his son installed in the White House, but the Kennedys had some political history and intelligence. This is another level of cronyism and idiot cousin handling the accounts altogether.

"so buyers don't buy the thing as much"

where it gets even more pernicious is when _export_ bans are imposed.

These are hurting USA technology companies which depend heavily on sales to China and it would perfectly understandable if they took the time-honoured response to such stupidity of decamping their entire operation to jurisdictions which are more friendly to business operations - leaving thousands of USA workers with a choice of moving to another country or being unemployed.

Re: 'preventing further unfair transfers of American technology and intellectual property to China'

For a long time the USA was not enforcing IP laws on its own companies so they could steal or reverse engineer technology and sell it cheaper

There, fixed that for you.

Quite recent examples which spring to mind are:

- jet engine technology (centrifugual and axial - taken from British and german scientists respectively)

- nuclear weaspons research - borrowed from the Brits and then _refused_ to be handed back

- movies - stolen from the Lumiere Brothers.

- light bulbs - mostly stolen from Swan and Priestly.

The USA was notorious for pirating steam engine technology too, back in the day.

"It merely clears a field for the locals…"

Unfortunately for the USA, the country has been endlessly using and abusing protectionism - either directly with tariffs (light trucks and agricultural products ) or indirectly with technical rules such as the USA(LHD) vs UN(LHD) carmaking rules over the last 70 years to insulate local producers from world realities that the internal market is completely and utterly warped in its views of everywhere else.

Carmakers are screaming that having to make UN(LHD) standard vehicles is a trade barrier erected against them. Light truck makers are screaming that noone wants to buy their overpriced, oversized, overpowered, unreliable and thirsty vehicles outside the USA (except as boutique purchases). Farmers don't really care because they have a captive market that for the most part doesn't notice that the steaks are grey, not red, or that food poisoning traceable to chicken slaughtering is 100 times the level in the EU. Telcos have somehow managed to obtain abusive monopolies without the pesky Universal Service committments that AT&T used to have as a result of the 1932 FTC Antitrust settlement.

The USA is large enough to be a self-contained market, but the barriers it's erected against others entering tend to grate when it's demanding access everywhere else and demanding "free trade or else!"

Tariffs haven't been clearing fields for locals in the USA for a very long time. They're been allowing the incumbents to maintain their cushy lifestyles by shutting out new entrants - and whilst these kinds of misuses are the very thing that GATT and WTO rules are intended to try and tear down, the USA has been erecting more and more such barriers of late.

One thing that Trump is right about - he really is "Making America Grate"

WTF is Boeing on? Not just customer databases lying around on the web. 787 jetliner code, too, security bugs and all

Re: Agree... but

" in other words, Boeing admitted the flaws were there but tried to downplay the seriousness of them. "

Exactly this - and did so in ways which attempted to discredit Santamarta and friends, which speaks volumes about Boeing's motivations.

Re: Irresponsible

"If they need help in doing security reviews, there are plenty of suitably skilled consultants who can help them."

The same can be said about Huawei - Unfortunately the hardest part is not that help is available, but getting the to admit that they NEED to listen to externals in the first place.

I'm getting brushoffs about security even after waving the GCHQ report in people's faces - the people who really need to be listening are suffering a bad case of Dunning-Kruger (One Huawei Enterprise engineer told me today that TLS1.2 is totally secure therefore they don't need to do anything - neglecting all the factors that go into SSL connections such as key lengths and crypto types or that TLS1.2 is 11 years old, or that the piece of equipment in question - still being manufactured - CANNOT be SSHed to from RHEL7.6/Ubuntu 18.10 or connected to from current versions of Firefox/Chrome/Edge/IE due to use of obsolete cryptography - his stance (and hence Huawei's official stance) is "But it uses TLS1.2, so it's OK!")

At what point...

Do CASA and EASA join up, insist on impounding one of these aircraft and invite some of these code auditors to go over everything _without_ Boeing present to prevent them from finding "trade secrets" etc?

or even scarier for Boeing, let them be present, let them prevent the hackers from exploring certain areas, then start investigating WHY Boeing's crapping themselves about people poking into those areas.

(Incidentally it's not just Boeing that can be targetted here. Toyota's shown that their coding quality has gone to hell in a handbasket too, etc - it's just that Boeing have achieved regulatory capture and have been getting away with this shit for longer)

There's fraud, and then there's backdoor routers, fenced logins, malware, and bribing AT&T staff seven figures to unlock 2m phones

Re: Deliberate greed

"IMEI blacklists aren't shared worldwide"

That's being worked on.

LTO-8 tape media patent lawsuit cripples supply as Sony and Fujifilm face off in court

Re: Sure this will be great on the long term @Tomato42

>> "I pity future generations of historians when so much of todays information will no longer be available."

> I think they'll be fine on that score.

I point you to the time and effort required to retrieve a working copy of the BBC Domesday book.

Re: Sure this will be great on the long term

> > it has much longer data storage lifetime than (spun-up) hard drives.

> only as long as you have a working drive to read it.

This is why you have migration policies ensuring that the data moves long before the drives expire.

I've had data on DLT, LTO2, 4 and now 6 and I can retrieve it in an hour or less.

On the other hand I've had people show up with 9-track NASA tapes from the 1970s they're hoping to read (The answer is "sure - go see this company in Southhampton - the charge is about £400 per reel") and the guy with 3500 exabyte tapes he thinks I'm going to hand feed to a single drive (that's been dead for years) when he wants a restore is vastly outta luck (not my circus, not my monkeys)

Re: Sure this will be great on the long term

" If you have multiple petabytes to back up, you will need more than a single tape drive. "

Your rate of backup determines the number of drives you need for that task. It's usually a small number.

Your rate of disaster RESTORE determines the number of drives you need for that task. It's usually significantly higher.

Don't spec for #1 and find yourself caught badly short when #2 happens.

and $3000 is a _very_ cheap tape drive. they're closer to $16k apiece for LTO7 when in a quantum library and if you're backing up anything more than 1-200Gb/day you WILL need a robot.

Re: Sure this will be great on the long term

"But that's about the same number of tape cartridges shipped, too"

The difference being that tape cartridges only "consume power" when installed in a drive. The rest of the time they're passive pieces of plastic which are remarkably resistant to abuse.

Not that I trust iron Mountain. My preference is to pay £5k a pop for fireproof datasafes holding 850 tapes.

Re: Sure this will be great on the long term

"but its margin over hard drives is falling due to innovation in disk and lower demand for disk "

The corollary to that is as disk sales fall it becomes uneconomic to make them and the price will either climb or they'll go out of production (probably both)

As for tape sales falling: dollar sales yes, but capacity per dollar keeps going up - and if you stay a couple of generations behind it can be surprisingly cheap (or just hold off for 12 months - the initial tape price usually halves)

Re: Aitor is correct

China's the coming provider of those nuclear plants - ironically using technology the USA threw away in 1972.

Re: Aitor is correct

"You can patent something and sit on it if you like, as say an oil company might do if someone found a way to build Back to the Future's "Mr. Fusion" device"

Or if you're an oil company you can buy up and sit on critical Nickel-metal hydride battery patents, forcing automotive battery development down the more dangerous lithium-ion path instead and taking Toyota's entire californian fleet of RAV-4 EVs off the road.

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

Microsoft cofounder Paul Allen's personal MiG-29 fighter jet goes under the hammer

Does it come in leather?

Researchers find development and conservation aren't mutually exclusive

Re: The elephant...

"and then there were a lot of rabbits, and much less vegetation."

And then (eventually) a lot less rabbits.

Carbon-reduction... "There's a lot of pressure to do it, because there's a lot of money to be made."

There's a lot of money to be made by certain groups. The pressure is coming largely because _so far_ just about every IPCC prediction of the range of possibilities of the future made 30-40 years ago has happened either "early" or at the "pessimistic" end of the scale, depending how you look at it and things seem to be accelerating.

The REAL elephant in the room is this:

If you want to understand why there's a real urgency in a lot of climate scientists' minds, look at the Laptev Sea - it shouldn't be bubbling methane to the surface - that was thought to be impossible, but it's happening (methane should be dissolving on the way up).

Furthermore it's been doing it in increasing volumes for the last 15 years and appears to be the source of the Global Methane Survey's rather famous 20% "we can't find this" error of 2011 (they weren't looking there).

The REALLY scary bit is what's still on the seafloor - if the methane clathrate deposits are weakened too much then a mudslide could set them off in one big hit - somewhere between 0.75-2 times (or more) the annual human carbon emissions hitting the atmosphere in one go. That happened 9,000 years ago off Norway (Storegga) and caused a near immediate 1-2C uptick in temperatures. This time around such an event might add enough warming to kick off a chain reaction of methane clathrate eruptions and last time THAT happened triggered a major mass extinction(*) - it's not known exactly how long it took to get underway due to the briefness of the fossil records but it was definitely less than a decade - possibly as short as a year for the last hurrah

(*) It wasn't global warming that killed off most of the land plants, it was acid rain from the massively elevated levels of CO2. Without plants, most animals followed within months. Without plants CO2 levels went higher and O2 levels fell as everything rotted and without plant cover erosion went crazy. In the meantime during the buildup to this the high acidity started killing off shell-forming organisms in the oceans (we are HERE) and as O2 levels fell in the water, most ocean animal life died off (Anoxic events - we may be on the leading edge of these already in some parts of the world). There were then a series of red tides - the algae from those formed most of the oil we've been burning. Oxygen levels went down to 11% and stayed there for about 100,000 years.

How bad was it? It took about 10 _million_ years before coal beds started forming again - the only time in earth history since land plants evolved that has happened. Life nearly got reset back to single celled organisms.

Windmills, tidal and solar are mostly scams. It's not that they can't generate enough electricity to replace existing carbon-sourced electricity generation (they can - just). but that they can't provide enough EXTRA electricity production to replace motor vehicles, gas/oil heating, carbon-intensive industrial processes - and provide sufficient extra energy to allow production of fuels for things like aircraft - which aren't going to be battery powered on anything other than journeys which could as easily made by a train anyway. (Biofuels are a scam too, when you start looking into the arable land they consume. Using waste products is a way of offsetting that but it's nowhere near enough and it frequently causes soil to be strip mined).

The result is that a lot of time effort and money is being put into "Green" solutions which are largely akin to rearranging the deckchairs on the Titanic. Either we figure out ways to produce 6-10 times more electricity than we were making in 2010 (and making enough to allow developing countries to do the same or they're just going to increase their carbon consumption) or we start seriously risking not only radical climate change and ocean level rises but a world where atmospheric oxygen content may drop so fast that our children won't live to see these things happen.

Re: Goodie-Goodies...

"but it's pretty obvious motorways are not good for badgers, foxes, bears or even packs of hounds..."

On the other hand building motorways in such ways that they don't attempt to go over the fences to get to the other side(*) is perfectly feasible - if implemented at the design stage pretty much cost neutral.

(*) And I don't mean by making the fences 30 feet high impossible barriers to pass. Wildlife/local population tunnels aren't that difficult and have paid dividends wherever used(**). Animals encountering a high fence tend to run along them until they find a place to dig through or jump over - and if the place happens to have a tunnel, Robert is an elder male relative.

(**) Both for the wildlife and in terms of reduced costs of crash cleanups when wildlife encounter high speed traffic.

Another rewrite for 737 Max software as cosmic bit-flipping tests glitch out systems – report

Re: Not Cosmic Rays

"the lead in tin lead balls on BGA devices contain a small amount of Pb210 (part of the uranium decay chain) that ends up as Pb206 (stable) via Po210 (Polonium) which is an alpha particle emitter"

Those are on the outside of the CPU/memory case. Alpha particles don't penetrate. Neutrons do.

What surprises me is that water-jacket shielding for high altitude avionics isn't standard.

Re: Strictly speaking the 737 max airframe is uncertifiable and no amount of code can fix that

The 737NG is dynamically unstable too and the 737-800 was pushing the boundaries of it,

Re: We have this saying...

"The FAA schills "earn" their stripes (and future private sector positions) and Boeing gets their craft certified by October."

Certified by the FAA perhaps.

EASA will look at the FAA's inspections and run their own sets if they're not satisfied, as will CASA (who don't have a dog in the fight as Australia/NZ don't build aircraft)

Re: So...

" It has some FBW elements bolted on to a mechanical control system."

Even fully mechanical systems in civil transports had (or should have) redundancy - usually dual and occasionally triple.

Re: This is strange an frightening.

They didn't even have them in master/slave mode.

Only ONE computer was active. The active one toggled between flights. Lose that and you have NO flight computer operating.

Two computers in master/slave mode isn't sufficient anyway. You always need an odd number in order to avoid voting deadlocks.

This stuff was solved 40+ years ago in avionics. If Boeing's screwed it up that badly then there are serious safety ramifications across their entire range.

"So it turns out the FAA is to blame as well as the manufacturer."

That's what happens when you get regulatory capture.

"Were all the other aviation authorities also sleeping at the wheel?"

The FAA was supposed to be independent. Making a big fuss and calling the FAA "captured" would have moved the trade wars the USA was already waging under the table into wide open mode.

This way, the FAA was publicly shown up and the other agencies simply have to fold their arms until it's sorted out - and ALL FAA decisions get to be second guessed for the forseeable future. It's a pity 300+ people had to die but their relatives can sue Boeing and the US government.

Don't worry, Boeing's software and hardware are (finally) going to be gone over with a fine tooth comb, just like the USA has been doing with everyone else's kit for years.

Our hero returns home £500 richer thanks to senior dev's appalling security hygiene

"This is why security needs to be made a legal requirement"

GDPR laws and insurance companies refusing to pay out in cases where security was lax have that effect.

The memo is finally starting to trickle up to management. Personal liabilities would help.

Re: Low quality coding

3 years olds are like a sponge - they willingly soak up every piece of information you throw in their direction and want more.

Treating management like 3 year olds is an unkind comparison to 3 year olds (Seagull management in any case)

Seagull managers don't WANT new information and they certainly don't want more after you've given them the bare essentials they didn't want, but did need.

Re: Ahhh passwords...

"If I had raised a concern, they would have blamed me for every thing!"

At that point I'd have not touched anything and found a good reason to not be there - reason being that the blamestorming was about to kick off.

Get ready for a literal waiting list for European IPv4 addresses. And no jumping the line

Re: Untill Mainstream ISP's...

At this point the only mainstream ISPs in the UK _not_ offering IPv6 are TalkTalk and resellers of their wholesale service.

It's about time Ofcom and/or the ASA clamped down and said that to call themselves an ISP, they have to offer IPv6 or it's misleading advertising.

Re: IPv6 was designed by theorists

"Had they simply added two octets and made 0.0.x.x.x.x map to IPv4 probably everyone would be using it today."

Spoken like someone who doesn't realise that the original intent of the octets was to show LOCATION in the first 2 bytes, not stuff as many IP addresses as possible into as few bits as possible.

Having longer prefixes makes things EASIER, not harder, as it cuts down the size of the routing tables dramatically. There are millions of IPv4 routes on the core networks today whilst the equivalent IPv6 implementation would only need a few hundred to a couple of thousand.

Having had to USE x.25 and X.400 addressing for many years before I came to the internet side of things, I can understand why the networking committee ran screaming into the night when confronted by it.

IPv6 isn't perfect, but it's a lot better solution than IPv4 and CGNAT - and perfect is the enemy of "good enough" - if you keep striving for perfect you'll never move off IPv4 despite it being manifestly unusable in many parts of the world - WE might not notice how bad it is, but I can assure readers that when you're in the wilds of Myanmar behind _3_ layers of CGNAT (I've done this many times, my wife is Burmese) things don't _turn_ to shit, they're simply shit all the time - that "1 IP for every 2600 citizens" in practice is more like 1 IP for 12-15,000 people (and the ISPs have never heard of IPv6)

Re: We need a new approach

Sheltering under a tree during a thunderstorm won't dry you out if there's a lightning strike.

The lightning boils the sap under the bark, making steam and usually causing the outer layer of trunk trunk to go off like a giant firecracker. If you don't get pulverised by the supersonic large sheet of bark you'll get some pretty nasty steam burns.

A similar fate awaits those who keep sticking with IPv4 and refusing to make plans for IPv6.

CGNAT is crap and if you don't have (and understand) IPv6 on the day you need it, your business is going to suffer.

Re: We need a new approach

Internet stream protocol used type 5 as its identifier, but it was never known as IPv5 or intended to be a successor to IPv4. It even used the same addressing structure as IPv4

Re: We need a new approach

"What happened to IPV5?"

IPv4 was a hacky kludge designed to last as long as it took for the "real" internet protocol that was being developed by Novell to roll out.

We know it as IPX (Internet Protocol Exchange) - and it's extremely difficult to route, which is why everyone stuck with IPv4

IPv4 was originally intended to use the first octet to show the SITE, second for local destination and 3,4 for local networking - whilst there are 4 billion possibilities the intention was a few thousand hosts at most and 10-20 routes.

IPv6 does something similar: the first section is country/major network, second= suballocation, etc all the way down to the /48 point. This means instead of _millions_ of routes that we see in IPv4 backbones, it will reduce to a few thousand.

Sparseness is good. It's an addressing table, not a stuffing competition.

Re: We need a new approach

NAT is not firewalling and firewalling is not NAT.

Just because NAT happens to achieve some parts of firewalling doesn't really make it an acceptable substitute and relying on it as a security wall is asking to be reamed - anything that gets behind your NAT wall can tunnel out and render your entire security model useless.

Re: Seriously, whats wrong with IPV6 ?

"I'm under the impression that most new routers support v6, although there's certainly a long tail of crap out there"

I haven't seen _anything_ less than a decade old that doesn't support IPv6 unless it's been deliberately crippled in the ISP's local masking of the OEM kit (ie: It's there, just not visible to the users)

Re: Seriously, whats wrong with IPV6 ?

"My ISP declared that they will never deploy IPv6 because they have a class B IPv4 range"

Your ISP misses the point - sooner or later there will be resources which are IPv6 ONLY and at that point their customers horizons start rapidly shrinking.

If Google announced that they were throttling IPv4 speeds, there'd be a stampede to IPv6.

Why do I say that? Barcodes.

For _decades_ there was much pissing and moaning from grocery manufacturers about how hard they were to implement despite governments in various countries trying to encourage their adoption. Then in the 1980s most supermarkets simply said "If it doesn't have a barcode on the package, we're not buying it" - at which point the objections disappeared overnight.

UK digital network Openreach takes 15 electric vans for a spin

"Are you sure about that? Source? "

Big Clive did a teardown of one on Youtube about a year ago:

https://www.youtube.com/watch?v=G32NYQpvy8Q

He starts pointing at the relay and discussing the way it may operate at 8:35

It's there, the existence of the things has been confirmed independently and it's interesting how many people start on personal attacks when I bring this up.

Who's been copying AMD's homework? Intel lifts the lid on its hip chip packaging to break up chips into chiplets

Re: Pentium II

"The earlier Pentium Pro was better than a PII"

And this was proven after a while. Contemporary pentiums are descendants of Ppro, not p2-4

Re: Chiplets?

Especially the vertically stacked one.

Transporting heat out of the middle layers _is_ going to be a significant challenge. There's a good reason that this is usually done in a flat plane.

Bored of laptops? Love 200Gb/s interconnects? Then you're going to hate today's Intel news

Re: 10nm

At the end of the day what matters most of the time is the speed from the CPU to ram and bus - MOST of the time that's still only running at a couple of hundred MHz (parallel equivalent) or with latencies around 40ns for random access - which is ~half what it used to be, but still a major bottleneck compared with how fast everything else has sped up.

time-of-flight matters too. 1ns per foot, more or less.

Re: I'm still waiting

They're getting way cheaper.

Check out fiberstore

Outraged Virgin slaps IP trolls over dirty movie download data demands

Re: Shome mishtake shurely?

The issue of "guardaley" - a rather shadowy "german" outfit which seems to be the real power behind all these 'lawsuites' needs to be addressed too.

https://www.techdirt.com/articles/20140603/18021127448/international-men-mystery-how-discredited-german-anti-piracy-company-may-secretly-be-behind-malibu-medias-copyright-trollery.shtml

He's coming for your floppy: Linus Torvalds is killing off support for legacy disk drive tech

Re: Using a hole punch....

"I forgot all about that hack of using a hole punch to convert floppies to being dual sided."

Just the thing, when you had $10, 70kB 5.25" floppy disks on your CBM 2008 (and $1200 floppy drives!)

"i just had to walk round the room checking computers and servers to see if i still had any floppies"

I had to have a standup argument with manglement to stop speccing floppy drives on systems.

Users hadn't touched the things for YEARS and whenever we tried use them they'd be so full of dust they'd fail immediately (which is where USB floppies have a distinct advantage), so i didn't see any point.

The tipping point was when motherboards stopped having FDD port connectors.

Re: Er, what do I do with my old 78s ?

"I would suggest, respectfully, listening to some 78s on a well set up acoustic gramophone."

Alternatively, using the right stylus on a high end turntable running at 33 or 45, transcribing to reel-to-reel tape and then replaying the tape at a (tweaked) higher speed, to equalise and transcribe to another open reel tape.

Which sounds longwinded (and was), but allowed us to prepare the things for broadcast on college radio without having a midrange screech that was like fingernails on a blackboard

Of course the grooves are so wide that you could probably scan them at 2800dpi and derive the audio from that, bypassing the whole snap-crackle-pop and inevitable high end loss caused by the ice skate effect of the stylus (Stylii exert pressures of several hundred tons per square inch, the vinyl or other media momentarily melts as it passes over, which means that high frequencies are lost with each pass AND dust gets pressed into the media. A scanner can pickup and integrate the entire groove)

Re: I remember floppy disks

"I remember paying over £100 retail for my first 5.25 drive"

newbie

Sleeping Tesla driver wonders why his car ploughed into 11 traffic cones on a motorway

Re: 2 points

I managed to regularly microsleep whilst riding a motorbike at 60-70mph on relatively twisty roads - aged about 19-22 or so

Didn't realise it at the time and the realisation many years afterwards that the tiny "blinks" in the background noise I was peripherally aware of in my hearing had actually been 10-15 second periods of unconciousness at the wheel scared the bejeezus out of me.

As I said, once diagnosed it's easily treated..... Once diagnosed.

Some estimates are that as much as 1/3 of the population are undiagnosed sufferers.

One of the major CPAP makers surveyed as many sports teams at one australian university as they could get to cooperate and found that 40% of the 18-25year olds they tested (They tested entire groups involved in sports, initial screening is pretty easy and involves wearing a pulse oximeter overnight) had some degree of problem and whilst some simply needed nose splints, most really did need CPAP machines - to the tune of about 35% of the participants - it surprised the hell out of the company as they'd been expecting 10-12% at most and ALL the participants were active, fit & healthy individuals.

The problem appears to be so widespread - and testing so easy - that screening should be automaticaly done - treatment is about 150 dollars a year, whilst non-treatment ends up costing hundreds of thousands in heart disease, major health complications and early mortality.

Re: the train willl bring itself to a gentle stop

"Only thing they bother about in UK is speeding"

You might be "happy" to know that the latest generation of speed cams are pitching up the ability to detect tailgaters - both at fixed locations (relatively easy) and at distances of up to 1km.

Satellites with lasers and machine guns coming! China's new plans? Trump's Space Force? Nope, the French

Re: Gravity

"the film was all special effects and barely any plot; the French plan seems quite similar."

The russians came to much the same conclusion about their cannon-weilding salyuts - the intention was to repel boarders when unoccupied but they proved supremely impractical the one and only time they were tested.