The thread for space cadets!

[hobbsyoyo]

Glad I didn't know that stuff before I saw the film :haha:

I didn't know all that at the time either. I learned about this when working on super dracos the next summer.

Did anyone read anything non-sensational about that radio signal that was people were so quick to say "it's not aliens"? I thought for sure Phil Plait would have written about it by now, but he hasn't. He's pretty much my go-to for debunkings.

I haven't seen anything about any radio signal. Do you have a link?

 

[hobbsyoyo]

Funny story about that summer:

I was in a clean room and we were inspected a super draco rocket engine after the Dragon 2 pad abort test. The engines come in an assembly called a jetpack (for obvious reasons - see below) and we had one of them out on our work bench. The unit had already been scrubbed of propellants but we had this thing called a draeger next to it on the table just in case. Draegers look and act like geiger counters - they beep when they detect toxic propellants.

So we're working on it on the bench and I walked away to retrieve some tools and in the background I can hear this klaxon going off like it's a red alert. I assumed it was someone's ring tone going off but grew concerned as the technicians I had been working with began running for the exits. One of them grabbed me by the bunny suit and practically dragged me out of the room exclaiming, The draeger's gone off!

So we enter the vestibule and begin stripping out of our bunny suits when in walks the lead technician at a slow pace. He pulls down his beard cover and begins to absolutely destroy the technicians. He screamed that they could have tripped and hurt themselves or tripped and damaged one of the Dragons being worked on in the clean room.

But the alarm went off - we had to escape the poison, the technicians protested.

The lead explained to them that the draegers were keyed to detect concentrations in the parts per billion - completely harmless but requiring attention. If the levels of toxins had actually been dangerous, running would not have saved them, they would have died where they stood.

Spoiler Our nemesis that day :

 

[Kaitzilla]

The alarm is not cause for alarm!

It is calibrated to only cause concern or play a funeral dirge.

 

[Imaus]

Watching billion dollar rovers fail because there's no one to wipe off the dirt on their solar cells or knowing that none of the billion dollar rovers we've sent over has been able to turn over a rock and smash it open with a hammer like any field geologist can is the counterargument.

They have a role to play for sure in space exploration but I think it will be a few more decades before we can send robots that make adequate substitutes for people. We've only just now, a decade in, driven our Martian rovers for a distance that is further than a human could cover in a single day. They are sophisticated for sure and we should keep sending them but the amount of science they can return pales in comparison to what a few boots on the ground could do.

Zubrin's explanation about 'bots still holds true thirty years*!!!! later. You want anything really done, like digging through billions of years of dirt buildup or the like, you send either 1) huge construction robots or 2) a crew of people.

 

[peter grimes]

I love the engineering is aerospace. Like, let's cast in a gusset, but distribute the force over a wide area!

(Crap, cantc attach file from mobile. I was looking at the "descent trees" at the top of the combustion Chambers)

 

[Kaitzilla]

*snip*
Wrong thread!

Let's see, space space.
The moon took a meteor hit last week, kinda neat to see.

 

[peter grimes]

Ok, here is a Guardian article that, I think, is talking about the same thing that was buzzing on r/space a week or so ago. Can't be sure because searching Reddit is peculiarly difficult:

https://www.theguardian.com/science...-from-dwarf-galaxy-3bn-light-years-from-earth

So apparently these are FRBs (fast radio bursts) - the interesting thing here is they are from a previously observed source first discovered in 2012. Because there is uncertainty as to the mechanism behind FRBs, and repeating ones especially, reddit jumped to Aliens.

I really doubt it's aliens.

But I'm glad I'm still donating processing time to SETI@home!

 

[r16]

it's aliens ... End of the world , right ? So , they have doubled the distance , from the previous 1.5 billion light years .

 

[Bootstoots]

Funny story about that summer:

I was in a clean room and we were inspected a super draco rocket engine after the Dragon 2 pad abort test. The engines come in an assembly called a jetpack (for obvious reasons - see below) and we had one of them out on our work bench. The unit had already been scrubbed of propellants but we had this thing called a draeger next to it on the table just in case. Draegers look and act like geiger counters - they beep when they detect toxic propellants.

So we're working on it on the bench and I walked away to retrieve some tools and in the background I can hear this klaxon going off like it's a red alert. I assumed it was someone's ring tone going off but grew concerned as the technicians I had been working with began running for the exits. One of them grabbed me by the bunny suit and practically dragged me out of the room exclaiming, The draeger's gone off!

So we enter the vestibule and begin stripping out of our bunny suits when in walks the lead technician at a slow pace. He pulls down his beard cover and begins to absolutely destroy the technicians. He screamed that they could have tripped and hurt themselves or tripped and damaged one of the Dragons being worked on in the clean room.

But the alarm went off - we had to escape the poison, the technicians protested.

The lead explained to them that the draegers were keyed to detect concentrations in the parts per billion - completely harmless but requiring attention. If the levels of toxins had actually been dangerous, running would not have saved them, they would have died where they stood.

Spoiler Our nemesis that day :

Wait, what propellant is that toxic? I looked up MMH and UDMH - they're both nasty but Wiki has LC50 values in the tens of ppm for exposures of ~4 hrs and hundreds of ppm for ~30 min of exposure. I briefly poked around but couldn't find any propellant that is more toxic than this in common use. It's also kind of strange that the dose-response curve would be so steep that there's little ground between "harmless" and "dead where you stand".

 

[Timsup2nothin]

Wait, what propellant is that toxic? I looked up MMH and UDMH - they're both nasty but Wiki has LC50 values in the tens of ppm for exposures of ~4 hrs and hundreds of ppm for ~30 min of exposure. I briefly poked around but couldn't find any propellant that is more toxic than this in common use. It's also kind of strange that the dose-response curve would be so steep that there's little ground between "harmless" and "dead where you stand".

I just want a picture of @hobbsyoyo in a bunny suit!

 

[hobbsyoyo]

Wait, what propellant is that toxic? I looked up MMH and UDMH - they're both nasty but Wiki has LC50 values in the tens of ppm for exposures of ~4 hrs and hundreds of ppm for ~30 min of exposure. I briefly poked around but couldn't find any propellant that is more toxic than this in common use. It's also kind of strange that the dose-response curve would be so steep that there's little ground between "harmless" and "dead where you stand".

It's not, that was the point. The alarms go off to let you know it's still got some residue somewhere in it but it was in no way dangerous. The techs did not know that and just panicked and ran. The lead was exaggerating about dead where you stand but I have seen rrcordings of some incidents that really would have killed people had they not been wearing full hazmat suits (more like spacesuits than the bunny suits we wore).

 

[hobbsyoyo]

I just want a picture of @hobbsyoyo in a bunny suit!

No photos allowed :-/

 

[Thorgalaeg]

That remembers me a day at the laboratory in my first year of chemistry. Some clumsy guy (i am no going to say any names ) burnt his sample which included a large amount of acetic acid, the feel was like having an awl in your nostrils. Everyone ran out of the laboratory in panic. Later the professor said us acetic acid vapors, while unbearable, are not dangerous but probably there was some phosgene in the air too, since there was some compound with clorine in the burnt mix, so we did the correct thing running away even without knowing. Moral of the story: when messing with chemicals, in case of doubt, run.

 

[Timsup2nothin]

That remembers me a day at the laboratory in my first year of chemistry. Some clumsy guy (i am no going to say any names ) burnt his sample which included a large amount of acetic acid, the feel was like having an awl in your nostrils. Everyone ran out of the laboratory in panic. Later the professor said us acetic acid vapors, while unbearable, are not dangerous but probably there was some phosgene in the air too, since there was some compound with clorine in the burnt mix, so we did the correct thing running away even without knowing. Moral of the story: when messing with chemicals, in case of doubt, run.

Hmmmm. Maybe in a classroom setting, where learning rather than knowing is basically the intent. On the job, "in case of doubt" means you aren't qualified and shouldn't have been there. If you are on a job and don't know when it's time to run you need to be shuffling papers or something, not working with chemicals and equipment.

 

[Thorgalaeg]

The sample was supposed to be warmed in a water bath, this clumsy guy didnt read the recipe correctly and applied the bunsen burner directly. Such newbie errors shouldnt happen in a professional environment, but anyway nobody can foresee all possible situations.

 

[Timsup2nothin]

The sample was supposed to be warmed in a water bath, this clumsy guy didnt read the recipe correctly and applied the bunsen burner directly. Such newbie errors shouldn't happen in a professional environment, but anyway nobody can foresee all possible situations.

That always sounds so obviously true, but often serves as a sidetrack. For example, if these techs said "well, you can't have a plan for every possibility," the immediate response should be "if you don't have a plan for 'alarm goes off on the provided chemical sniffer,' is there anything that you do have a plan for?" I mean, "well, we didn't anticipate a meteor strike on the lab" is pretty reasonable, but if you don't have a plan for dealing with a provided alarm what's the point of providing the alarm?

 

[Thorgalaeg]

True, but alarms are alarming and we humans are a bunch of cowards. Maybe one like this would have worked better:

 

[Timsup2nothin]

The alarms on the reactor plant control panel of my submarine were all connected to a siren. It was immediately audible, but if you didn't acknowledge it and gave it time to wind up to speed it would split your eardrums, or perhaps your skull. No one, to my knowledge, ever determined how loud it could really get.

 

[Thorgalaeg]

Biggest danger was the alarm itself then. An alarm to warn about the alarm was needed.

 

[Timsup2nothin]

Biggest danger was the alarm itself then. An alarm to warn about the alarm was needed.

I liked it. Dealing with a nuclear power plant, as proven by Three Mile Island, the worst thing you can do in most cases is get in the way of the protective systems. When I trained reactor operators I would tell them "First thing, silence the alarm. Now, since you probably had to stand up to do that, grab your ass with both hands and sit down on them until you know what's going on." The siren on wind up provided great incentive to get it acknowledged before it got too far along, especially since it also required some amount of time to wind back down after all the alarms were acknowledged.

There's only one casualty where operator speed is critical to preventing damage to the core. You call the alarms off as you acknowledge them, and if by the time you get the siren to start winding down you've called 'reactor scram,' 'reactor low pressure,' and 'pressurizer level,' in any order, then you are banging the stops and starting fast primary leak isolation. Otherwise, there's time.