Comment by orbital-decay | Hacker News Reader

Comment by orbital-decay | Hacker News Reader

>The inevitable has occurred

This makes it sound like it was some sort of an unique event. ISS has huge surface area, and MMOD impacts are practically routine, damaging all sorts of equipment - radiators, batteries, pumps, solar panels, and even heatshields and windows (Cupola windows got hit by debris a couple times, so now they are kept closed when not in use).

https://www.hou.usra.edu/meetings/orbitaldebris2019/orbital2...

>The ISS impact database is maintained at the NASA/JSC by the Hypervelocity Impact Technology (HVIT) group. The database contains over 1,400 records of impact damage from ground-based observations of space-exposed hardware returned from ISS

>MMOD damage areas of interest acquired from EVA and IVA sources mentioned here are collected in an image database managed by the Image Science and Analysis Group at the Johnson Space Center (JSC). There are currently 380 records tagged as “MMOD” in the database, although it should be noted that some of these records include multiple MMOD damages (i.e., there are more than 380 MMOD impacts represented in this database).

And that's only the detected ones. Even detecting the strikes in orbit is hard; automation of all sorts is being developed for this job. (strain sensors, microphones, ML-assisted visual analysis etc)

> Cupola windows got hit by debris a couple times, so now they are kept closed when not in use

You'd think that opening the windows in space was a bad idea anytime.

Window shields were open

Storm shutters?

Context: https://en.wikipedia.org/wiki/Cupola_(ISS_module)

Thanks, I thought it was an unusual colloquialism for "couple of"

I find it funny that someone wrote bulletproof in the specifications of the windows. Is the bulletproof term used in the space industry?

The funny part is that what they actually need is much stronger than merely "bulletproof," if only it had been invented.

"spaceproof" would sound much cooler, to be honest.

"Earthlings thrash proof" would be more accurate.

Did you mean to say trash?

Yes..yes i did ;)

Meteorite proof?

Bullet proof is a little open ended for a spec.

Meteor may be a tad vague. “What do you mean it’s not Chicxulub proof?”

I think the closest would be "hypervelocity-impact resistant".

But what if it gets too warm?

I know it's not a real question, but it is actually the bigger problem to cool the ISS then to heat it.

Also to distribute it ~evenly around the station.

https://science.nasa.gov/science-news/science-at-nasa/2001/a...

Wow, it is just so cool we’ve created a little alcove up in space for us fragile humans to live in.

Yes it's impressive how many problems occur in a space-station.

Fun-fact: The training bicycle needs to be suspended otherwise the whole station would start to wiggle/vibrate which can damage the solar-panels...because of one little human on a bike ;)

https://www.youtube.com/watch?v=bG3hG3iB5S4

Little humans in good shape can sustain for several seconds bursts of 1000W+ on a bike. Not so little after all.

Little Ant's and Bee's are even more impressive...well not on a bike but otherwise.

The cost-optimized mundane everyday machines that we expect to move are endowed with 150x that energy output -- and with the ability to sustain it rather than burst it. 1kW is large for a human but small for moving a big chunk of metal. Since the sort of resonant motion would be thoroughly damped if, say, you built a full scale ISS in your backyard, I tend to agree with them that it's notable.

> The cost-optimized mundane everyday machines that we expect to move are endowed with 150x that energy output -- and with the ability to sustain it rather than burst it.

A perfect example is a large water pump, a 250hp electric pump draws approximately 150kW (480v 3ph, around 300-310 amps).

I make Sustainable Sound (1),a bicycle powered sound+light+robot interactive experience… can confirm the impressive power a human can create.

(1) http://sustainablesound.org/ (Deep apologies for how behind my sites are - recovering and working on it)

Not just that, but the mere fan vibration is enough to make ISS unsuitable for some particularily sensitive 0g experiments. There was an entire co-orbital module for ISS in the plans (that never came to fruition, sadly) to provide the station with a separate volume with high-quality microgravity, that would be in the same orbit, docking with the station from time to time.

>This makes it sound like it was some sort of an unique event.

I don't think unique events are generally described as inevitable?

"The inevitable has occurred" says "we all knew this was coming one day, and now it finally has".

Whereas the reality here is "this happens all the time, including a minute ago".

They're very different messages.

I figured inevitable in this case referred to damage that was significant, the inevitability of the damage being due to the very commonness of the event that causes it.

But the damage appears to be not significant? And this isn't mentioned in the paragraph under discussion. They just say 'A piece of space debris too small to be tracked has hit and damaged part of the International Space Station'

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