https://www.thetimes.co.uk/article/iss-nasa-warns-of-danger-after-international-space-station-robotic-arm-struck-by-orbiting-debris-9xzhwnklq

 

Looks like space junk travelling at 17,500 mph hit the robotic arm

I would not trust that "17500 mph" figure without supporting evidence. Since that is roughly the velocity of objects in low Earth orbit, I get the feeling that the writer of the article has assumed that this was the impact velocity.

Edited June 3, 20215 yr by Christopher Low

Yes, I see your point. The ISS is in low Earth orbit and orbits at that speed I recall. So any debris that hit couldn't be the same velocity or there would be no impact.

It would only require a slight diference in velocity for an impact to occur and it wouldnt hit at that speed.

Edited June 3, 20215 yr by martin-w

It's also critically important to understand that the orbital path mechanics dictates not only speed, but altitude. Any object orbiting in the same direction cannot be much faster (or slower) than the ISS.

Now non-orbital objects on the other hand are much more problematic and unpredictable!

Whilst it's obviously not good, I can't help feeling it's not going to make for a very exciting big summer blockbuster movie. I can see it now...

Cue jump cuts of people whizzing through the connecting tunnels on the ISS with alert sirens and rotating warning lights flashing and wailing away. An emotionless bitching betty voice repeats 'warning, incoming debris, proximity alert'. The impossibly young and good-looking crew head to the non-existent control room on the ISS, where the non-existent radar scope with a beeping proximity alert is going crazy accompanied by a bombastic Hans Zimmer soundtrack as more jump cuts of people assault our senses. They shout technobabble phrases: 'Shut down the number four reactor and seal off the cryogenics lab!' and 'I'm on it, Commander!', etc. Then we get a close up as a discarded screwdriver bumps into a solar panel at about ten miles per hour, dents it a bit, bounces off, then scrapes a bit of paint off the Canada crane armature before disappearing off into void.

'This summer... Strap in for the ultimate space thrill ride aboard the ISS. Minor Inconvenience, rated R. In cinemas from Friday.'

Edited June 3, 20215 yr by Chock

3 hours ago, n4gix said:

It's also critically important to understand that the orbital path mechanics dictates not only speed, but altitude. Any object orbiting in the same direction cannot be much faster (or slower) than the ISS.

Now non-orbital objects on the other hand are much more problematic and unpredictable!

The velocity of two orbiting objects in a circular orbit will be pretty much the same, but that "same direction" caveat cannot be safely assumed--not all space objects orbit at the same inclination (direction, relative to the equator).  An object in a polar orbit at that altitude and an object in an equatorial orbit can be at the same altitude and speed, but in different directions.  Think broadside collision at something a wee bit higher than highway speeds...

Also, orbits are generally not perfectly circular...you can have objects with dissimilar orbital geometries (e.g. one in an elliptical orbit and one in a more circular one) even in the same plane collide with a significant velocity delta.

At 17,500 mph, all it takes is a ~5 deg difference in direction to produce a crossing velocity equal to that of a 30.06 bullet!

Not the first time... not the last time either.

Even though the impact was on the RMS, I guess I shouldn't be surprised that the article is using the word "punctured" when describing the strike. As Chock says - whatever it takes to evoke the mental image of air leaking into space and astronauts in grave danger...

Funny...I was just watching Moonraker last night on DVD (one of my least favourite Bond Movies!). There was plenty of space junk when Drax's satellite went kaput!

I guess it's time to watch Gravity again!  What could be better than Sandra Bullock dangling on the end of the robotic arm attached to nothing??

Loved Gravity !

14 hours ago, Penzoil3 said:

Loved Gravity !

 

Barely any plot, astronauts playing silly devils with MMU's... Hated Gravity. 😑