The Pod Bay

kim holder

01:56

NUCLEAR PROPULSION IN SPACE 25192

►

sometimes the really old-school space docs are super good

this one was made before even Apollo 11

geoffc

02:20

@Hohmannfan sudo Get Me a Sandwich.

Proper User Policy apparently means Simon Says.

geoffc

02:38

Drone shot of drone ship incoming.

XKCD

05:03

The failures usually don't hurt anything, and if it installs several versions, it increases the chance that one of them is right. (Note: The 'yes' command and '2>/dev/null' are recommended additions.)

kim holder

14:31

i'm trying to decide what parameters to add based on a comment by uh-oh

>Would a very large orbit around both of them count, e.g. 1E+05 to 1E+06 km, or are you looking for either/or? Would 1E+06 years count as stable?

i'm putting that it has to be just around pluto, or charon, but not the system, and now i'm trying to decide what time frame to put

i think 50 years is a good time, considering how long other probes have lasted, and the low data rate from pluto. but maybe that is too easy.

@Hohmannfan certainly based on the figures in your answer, over such a long time the orbiter would need to do a lot of station-keeping.

Hohmannfan

@kimholder I am not so sure about that, somebody has to do the actual 3B-calculations to answer how long it is really stable. I have only answered by "yes it is possible, because it is within the realm of what we already manages".

I would really like to see a orbital mechanics wiz answering that question in an exact way.

kim holder

Alright, i put it at 50 years. Of course i just threw out the question as from a naive standpoint it seemed like it could be challenging. If one wanted to talk in terms of fuel budgets and payloads, maybe the fuel for adequate station-keeping would be onerous, i guess.

I had really thought it would be less stable than it is.

kim holder

16:41

@TildalWave hey, your supposed country hasn't signed the Outer Space Treaty! Oh dear.

TildalWave

@kimholder the map is wrong because it was apparently made by a mercan :P

Slovenia didn't exist then, we signed it as Yugoslavia which has been later "inherited" and we're definitely among the signees

kim holder

yeah, i remember yugoslavia...

TildalWave

actually that map is quite bad also elsewhere

OK, I said Slovenia didn't exist ... that is incorrect, but we weren't an independent state, just a federal one

pretty well defined tho, with borders mostly still the same, our language, yada yada

kim holder

16:59

i doubt that @duzzy will let you off so easily

TildalWave

kinda like Catalonia

or Scotland

they do exist :P

kim holder

i haven't picked up on other errors in the map...

@TildalWave couldn't the same be said of several other former bits of Yugoslavia?

recent history would seem to suggest so

TildalWave

@kimholder Moldova is among signees through Romania

and it's shown as red

all other ex Yugoslav republics are also shown in red instead of green

kim holder

hm, that article could use some editing then

TildalWave

ex Soviet republics also look suspicious

especially the Baltic states

it shows Latvia in red, which I don't believe is right

@kimholder yeah not just that page, the whole "space law" on Wikipedia is presented as if it was last discussed 40 years ago

kim holder

17:07

(which it kind of was...)

at least in the public's mind

TildalWave

kinda, but there's been many addendums

and some later documents were ratified in the meantime

and some are now being drafted still

I mean, even OST itself isn't some dead thing from the past

it reads quite a bit different by now than it did in its initial form

kim holder

but it's a mess. and it is hard to think of a good way forward.

TildalWave

yes it's a mess, but that's not something that will ever change

that's why we have lawyers as a profession

otherwise I wouldn't have any need for them, not even for a decoration

kim holder

i think of the treaty for the ISS

or - not a treaty... whatitcalled

TildalWave

resolution?

kim holder

17:12

sure, sounds good

TildalWave

I think it's just an agreement tho

kim holder

it really depends on diplomacy, because if there is a serious disagreement up there, you are already screwed

i think that is a good summary of space in general

TildalWave

some have said that the reason we haven't seen any other intelligences in the Universe is exactly because of our space law :)

yes, it is off-putting

kim holder

david livingstone had encouraged me to read up on Article IX in relation to today's show, and i'm just not seeing even the relevance

TildalWave

OST is basically just "general directive" and it can't possibly be anything more, it's up to individual state member signees to expand on it

so then you really have to read implementations of several dozens of states, and there would be more if others actually bothered with it

kim holder

17:17

i don't know... international law of this kind seems pretty abstract to me

TildalWave

@kimholder what show is it?

kim holder

really if different states have a disagreement, they haggle

Catherine Connely

TildalWave

well, there's more than just the OST really ... you have to look at all of them in context

kim holder

head of NASA planetary protection

starts in 15 minutes but i have to go out

TildalWave

> In the exploration and use of outer space, including the moon and other celestial bodies, States Parties to the Treaty shall be guided by the principle of co-operation and mutual assistance and shall conduct all their activities in outer space, including the moon and other celestial bodies, with due regard to the corresponding interests of all other States Parties to the Treaty.

> States Parties to the Treaty shall pursue studies of outer space, including the moon and other celestial bodies, and conduct exploration of them so as to avoid their harmful contamination and also adverse changes in the environment of the Earth resulting from the introduction of extraterrestrial matter and, where necessary, shall adopt appropriate measures for this purpose.

> If a State Party to the Treaty has reason to believe that an activity or experiment planned by it or its nationals in outer space, including the moon and other celestial bodies, would cause potentially harmful interference with activities of other States Parties in the peaceful exploration and use of outer space, including the moon and other celestial bodies, it shall undertake appropriate international consultations before proceeding with any such activity or experiment.

> A State Party to the Treaty which has reason to believe that an activity or experiment planned by another State Party in outer space, including the moon and other celestial bodies, would cause potentially harmful interference with activities in the peaceful exploration and use of outer space, including the moon and other celestial bodies, may request consultation concerning the activity or experiment.

That's article IX

kim holder

17:22

i'd certainly have a lot to say about that in another context, but planetary protection?

TildalWave

it mentions harmful contamination

and protection of the Earth

Earth is a planet too :)

kim holder

yeah, but this isn't an issue that will every come up while she's in the post

and when i listened to the previous show with her, there seemed to be no current issues at all

TildalWave

if they're gonna discuss sample returns, then yes it might

kim holder

the nations capable of that are in agreement as to the rules

TildalWave

there's been some development regarding Mars 2020 Rover sample caching and later return to Earth discussed during the recent MEPAG meeting

kim holder

17:25

the policy as it applies to sample return is certainly an interesting topic

TildalWave

there's possibilities that it'll be done internationally

kim holder

but i don't see some big issue with article ix like the message i was getting

TildalWave

actually I very much doubt that NASA will manage this on their own

@kimholder yeah that's just a broad overview

kim holder

more like they have to work out the details amongst themselves of the protocol

but they are all in agreement as to the principles

TildalWave

anyway, search UNOOSA for more documents unoosa.org and NASA has a planetary protection office too

kim holder

17:27

oh, i had already read it

nice to have it up there as a reference, tho

TildalWave

@kimholder yes that's the gist of it

kim holder

and i'd have plenty to say about it in another context, the military context

TildalWave

absolutely

it's only applied so far when it comes to international projects

otherwise who's to say

kim holder

i loved it when i checked and found that conventional weapons are allowed

only weapons of mass destruction are banned

which doesn't include missiles (unless they are nuclear), mines, artillery...

TildalWave

oh if there was a Woodworm on a collision trajectory with the Earth, that part about no WMD would be quickly forgotten too

Russell Borogove

17:31

Is a tungsten rod reentering from orbit a WMD?

TildalWave

why? because it would turn the Earth into an incandescent light bulb? :)

Russell Borogove

Kinetic bombardment

A kinetic bombardment or a kinetic orbital strike is the hypothetical act of attacking a planetary surface with an inert projectile, where the destructive force comes from the kinetic energy of the projectile impacting at very high velocities. The concept originated during the Cold War. The typical depiction of the tactic is of a satellite containing a magazine of tungsten rods and a directional thrust system. When a strike is ordered, the satellite would brake one of the rods out of its orbit and into a suborbital trajectory that intersects the target. The rod picks up speed as it approach...

TildalWave

c'mon I was joking, surely you picked up on it

Russell Borogove

I have no sense of humor that I'm aware of

TildalWave

kinetic bombardment is not so easy... unless you listen to Brian Cox, in which case it's apparently as easy as "dropping it" :))

kim holder

17:35

how about flinging just anything from the moon? i don't see any particular need for it to be tungsten.

well, of course we've covered this before

TildalWave

rocks and boulders are not classified as weapons of mass destruction ... I'm not saying they can't be, just that by definition they aren't

Russell Borogove

Well, if it's big enough it doesn't have to be dense.

TildalWave

besides, OST specifically says "nuclear weapons"

PearsonArtPhoto

It doesn't take much tungsten to survive from space...

TildalWave

...or any other kinds of weapons of mass destruction or from installing such weapons on celestial bodies.

details LOL

PearsonArtPhoto

17:39

I'm familiar with satellites that had a few kg of tungsten to serve as ballast launched with them. They had to get a FCC waiver to launch.

TildalWave

@PearsonArtPhoto it's also rather pointless to even launch it to space only to later have to deorbit it so it reaches terminal velocity that it could just as well reach on a ballistic trajectory

TL;DR is that OST doesn't protect us from "unfavorable weather"

Russell Borogove

The Sword of Damocles doesn't have the same psychological effect if you just throw it at a dude.

3

PearsonArtPhoto

Launching from Earth to space is a poor kinetic bombardment weapon. The idea is to use asteroids or other space rocks.

TildalWave

it would also be nice to know is there's any Earth-crossing NEOs that were made aware of it :D

kim holder

it just doesn't seem like any significant settlement of space would be possible without it including the ability to execute a devastating attack, using basic equipment they'd have to have.

TildalWave

17:43

there's been some nice / interesting discussions about asteroid redirection

basically, the problem is that when you start moving its trajectory, you're moving impact zone

kim holder

yeah, there's a thread on that on the moonwards forum

the moon has a lot of options for affecting the trajectories of NEOs

so now we officially sit at 4 ways the moon could conquer the world.

TildalWave

just 4? :O

kim holder

well, four good ones...

that we've thought of...

PearsonArtPhoto

Paint the moon white?

kim holder

mirrors that are very flat and carefully aimed, that was covered...

TildalWave

17:47

OK so beamed weapons

what are the other three?

PearsonArtPhoto

Even just painting the moon white would have a pretty significant impact.

TildalWave

hurling boulders?

blocking the Sun?

kim holder

@PearsonArtPhoto really? i'm instantly thinking question on the site...

PearsonArtPhoto

Well, the moon is about the color of asphalt.

If you painted the moon white, it would make it something like 10 times brighter.

kim holder

@TildalWave yeah, you have three now, and then also nudging an asteroid onto a collision course for earth

TildalWave

17:48

@kimholder I thought that falls under the "nudge / hurl boulders" category

kim holder

pretty different mechanism. different infrastructure would be needed

TildalWave

sure but for the same end effect

kim holder

@PearsonArtPhoto would that really have a big impact on life here?

@TildalWave i don't know, sound sufficiently different, like the difference between artillery and missiles.

PearsonArtPhoto

If it was white enough, it could be almost like a second Sun I think. Maybe I'm a bit exaggerating, but...

TildalWave

some, but I'd dare guess that it would balance at a bit more cloud cover

kim holder

17:51

but if you don't have your giant laser yet, mirrors could do the same thing but concentrate on a much smaller area

PearsonArtPhoto

Yeah, I suppose so.

TildalWave

How about painting it black, making people of the Earth so depressed they deal with themselves?

PearsonArtPhoto

It's a small, subtle way to get at Earth a bit, but probably not really cause any damage.

The albedo is .12, so at most it'd be 9 times brighter. That would really mess up life on Earth, but probably not end life.

kim holder

nocturnal life, especially simple life, i can see it messing with them.

PearsonArtPhoto

I know I've seen something along those lines before...

kim holder

17:54

the cloud balance possibility is interesting

PearsonArtPhoto

reddit.com/r/askscience/comments/2z527h/…

Never mind, it pretty quickly degrades...

kim holder

oh good - i was trying to figure out how to do a keyword search on it

yeah, i did it anyhow using 'life'. nothing interesting came up.

Transcript for