
Missions could see NASA spacecraft heading to Uranus and Neptune - noinput
http://www.physics-astronomy.com/2017/06/nasa-wants-to-probe-uranus-in-search-of.html
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huangc10
Original Title: "NASA WANTS TO PROBE URANUS IN SEARCH OF GAS"

All jokes aside, these missions are still pretty far off and article doesn't
really go into depth of what this research can help accomplish for future
generations. Thoughts?

~~~
hrasyid
Just curious, was the word pronounced the same way as today when they picked
the planet's name? Or was it picked by non-English speaking people?

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dzink
It sounds bad only in English and partly because of the foreign spelling. In
Bulgarian it the name spells and reads “Uran”.

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JumpCrisscross
> _In Bulgarian it the name spells and reads “Uran”_

Uranus was discovered by British-Hanoverian William Herschel [1] and named
after the Greek god of the sky, Οὐρανός [2], which anglifies to Ouranos.

[1]
[https://en.wikipedia.org/wiki/William_Herschel](https://en.wikipedia.org/wiki/William_Herschel)

[2]
[https://en.wikipedia.org/wiki/Uranus_(mythology)](https://en.wikipedia.org/wiki/Uranus_\(mythology\))

~~~
dzink
The comical pronunciation is only comical when Our-/Ur- as a prefix resembles
a relevant word in your language. The second part of the joke comes from the
greek spelling/pronunciation which is also not used by all countries/languages
referring to the same planet.

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forapurpose
I wait and hope for someone with more planetary knowledge than I have to
explain the lack of interest in Venus as a habitable planet and thus the
center of NASA's attention ahead of Neptune, Uranus, and of course, Mars.

Based on what I've read, which includes a paper from a NASA (or was it JPL?)
engineer, Venus' surface is not very hospitabl, but at a certain altitude it
looks like an oasis in the Solar System:

Venus (at ~50-55 km altitude) / Mars (surface): (all stats from Wikipedia, and
yes not always complete or comparable)

* Gravity: 0.9G / 0.38G

* Pressure: ~1 atm / 0.00628 atm (prevents liquid water)

* Temperature: 27-75 deg C / -63 deg C (mean)

* Shortest distance from Earth (for logistics): 40M km / 55M km

* Sunlight (energy): More than Earth / 43% of Earth

Also, oxygen and nitrogen are lighter than the CO2-heavy atmosphere, so a
balloon of O2 and N2 would float conveniently at 50 km. The CO2 in the
atmosphere also could be a valuable resource.

~~~
vlovich123
I'm not an expert, but the wikipedia page alone doesn't paint that bright a
picture.

> Venus is shrouded by an opaque layer of highly reflective clouds of sulfuric
> acid.

We know very little about it. Also, I'm sure you'll need to coat any
probes/spacecraft to protect against the sulfuric acid.

> The water has probably photodissociated, and the free hydrogen has been
> swept into interplanetary space by the solar wind because of the lack of a
> planetary magnetic field.

So basically same chance of water (maybe worse) as Mars.

> Venus (at ~50-55 km altitude)

So we'd have to have floating habitats even if we knew this zone was actually
habitable (it's still a sulfurous environment). This also means much higher
energy costs along with other logistical challenges.

> Shortest distance from Earth (for logistics): 40M km / 55M km

Yeah, but you're fighting solar winds so the question is how much less are the
energy costs. Also, from a logistics perspective, communication might be
important & the unfriendly atmosphere may pose additional challenges/costs.

~~~
cstross
However, an interesting aspect of floating habitats in the Venusian
stratosphere is that a terrestrial breathable gas mix (80% N2 / 18% O2 / 2%
trace others) is a lifting gas that's about as effective as Helium here on
Earth. (Venus's atmosphere is > 90% carbon dioxide, which has a significantly
higher molecular weight than air.) And it's protected from solar UV and
radiation to a considerable extent by the layers of atmosphere above it. So
your entire balloon -- or, more likely, dirigible airship -- can be inhabited
volume, rather than just a cramped gondola slung underneath.

Photovoltaic power might sound problematic at first in view of the long
Venusian night (a single day lasts up to 116 Earth days), but at altitude
there are strong jet streams and winds circulate around the equator roughly
every hundred hours. So you're not stuck running on battery power for months
on end, but you may need some maneuvering capability.

This is not to minimize the problems associated with activity in the Venusian
atmosphere -- but it's not _quite_ the impossible hell-hole it's been
portrayed as.

~~~
TheOtherHobbes
You'd be floating in a haze of CO2 and sulphuric acid garnished with hydrogen
sulphide, battered by raging convective winds which would make it very hard
indeed to stay at a fixed altitude - which means the outer temperature would
fluctuate by 10C to 50C or so without massively powerful altitude control.

You can't just drift there as if you're in a hot air balloon eating sandwiches
and enjoying the view.

Venus might not be completely impossible, but it's still one of the less
hospitable destinations in the solar system.

Also, smelly because of the H2S.

~~~
azernik
On the other hand, Mars requires you to live in a radiation-shielded pressure
vessel.

I think the real killer is that it's hard to build and maintain infrastructure
when floating on balloons - much easier to run a spaceport on Mars, or to get
to all the useful surface resource deposits. On Venus you'd have to build
literal castles in the air, using only only what you can pull out of the
atmosphere or ship in from orbit.

Not to mention Mars is at the bottom of a much shallower gravity well.

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galaga99
Coincidentally this week Fermat's Library highlighted a paper about the
Voyager mission, the only spacecraft (Voyager 2) to visit Uranus and Neptune.

Super interesting paper. Turns out Voyager was the first spacecraft that could
be reprogrammed "mid flight". In fact, if it wasn't for that we would have not
gotten back images of Uranus or Neptune!

[https://fermatslibrary.com/s/voyager-mission-
telecommunicati...](https://fermatslibrary.com/s/voyager-mission-
telecommunication-firsts)

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LyalinDotCom
I can't in good faith upvote a story on a website that has more junk
advertisement then content per character and has stories like "VOYAGER 2 MAY
HAVE BEEN HACKED AS IT ENTERED DEEP SPACE" featured next to this.

~~~
akkat
The title of this linked article is "NASA Wants To Probe Uranus In Search Of
Gas

"

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Symmetry
I'm glad, we really need to better understand how the Ice Giants[1] in our
solar system work.

[1][https://en.wikipedia.org/wiki/Ice_giant](https://en.wikipedia.org/wiki/Ice_giant)

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TangoTrotFox
I really do wish NASA had a focus. The 60s showed the power of NASA given a
clear goal and direction, but now a days they feel like they're operating a
mile wide and an inch deep.

Probes are great, but I think many overestimate the amount of information they
can genuinely provide. Even on Mars where we have had multiple rovers on the
surface, there are still ongoing debates about things such as whether the
streaks on the planet's surface are water, which NASA made a large
announcement of, or indeed just sand which is where the latest interpretation
stands. And that's for a very peaceful and close planet (in comparison to
Uranus or Neptune) that we ostensibly have a great understanding of.

I don't really care what their goal would be, as long as it would be a goal
that they could work towards - a base on the moon, a base on mars, expanding
the ISS, or anything - preferably with a human element as that's what attracts
people to space, and thus gets the money to make these missions become
reality. But these probes are not really advancing society.

And here I would make an exception for things like the Kepler missions. Those
were a directed mission with a specific, valuable, and _new_ purpose that
could (and did) provide information that substantially advanced society. Let's
go shoot some probes off around Uranus and Neptune and grab some pics and
atmospheric readings is better than nothing but it feels like spending funding
for the sake of spending funding.

~~~
mturmon
Not a down voter, but: This isn't accurate. Planetary science (as in the OP)
tends to be more diverse and exploratory than Earth or Astrophysics, but it
still has a strategy. It's not just stamp collecting. See:
[https://science.nasa.gov/solar-system/focus-
areas](https://science.nasa.gov/solar-system/focus-areas)

~~~
TangoTrotFox
I'm not sure what your link is supposed to show?

~~~
mturmon
Well, you wondered,

"I don't really care what their goal would be, as long as it would be a goal
that they could work towards..."

and that link shows the basic four orienting science questions (right panel in
blue text) - how did life begin, how did the solar system evolve, how did the
planets originate, etc.

Those are the top-level questions that the National Academies panel doing the
Decadal Survey arrived at and that motivates the portfolio of planetary
missions that are planned. I would have linked to the Decadal Survey (overview
at
[https://en.wikipedia.org/wiki/Planetary_Science_Decadal_Surv...](https://en.wikipedia.org/wiki/Planetary_Science_Decadal_Survey)),
but the report itself is a very long pdf - and this gets into the strategy in
detail.

For instance, the next Mars mission (Mars 2020) is set up to address the
"life" question, and the "how did the planet [Mars] evolve" question, etc.

~~~
TangoTrotFox
Do you know what the Uranus probe's goals are? They're laid out here [1]. It's
to measure wind speed and atmospheric densities/temperatures. And that is
typical. This is what I was getting at when I said that these probes do not
achieve near what many people seem to think they can. We have a limited budget
and I think this budget should be directed towards things that can advance us
in the most meaningful ways possible. Measuring the wind speed and density on
Uranus does not really fit the bill there.

Think about SpaceX. What they've done should have been impossible. A private
company operating on a shoestring budget revolutionized space in 15 years?
That doesn't mean Musk is a genius, it means that our current space system is
simply incompetent. There are certainly many reasons for this, including
congress using NASA as a jobs program, but I think a lack of direction is also
a major reason. 'Discovering how life began and evolved on Earth' as a mission
statement is like a philsopher stating his goal is to 'discover the meaning of
existence.' It's a goal that's so impossible and so broad that anything can be
justified in its name.

'Easier' goals are in many ways much harder since you need to remain focused.
And when NASA has focus they, at least in the past, have shown themselves
capable of amazing things. Going from having never even put a man in orbit, to
putting a man on the moon in a decade? Think about that, if you even can. In
today's times that should seem completely unbelievable. And we should be
capable of exponentially more now a days. And that is where we should set our
sights. The point I'm getting at is that if you aim low, that's always where
you're going to hit. Aim high and you might miss, but at least you're pointed
in the right direction.

\---

As one brief aside, those mission statements immediately made me think of
Oumuamua [2] -- that cylindrical weird interstellar object ( _it 's exact
nature is, and will likely remain unknown - the name translates to 'first
scout', as the imagination might imagine_) currently looping around the sun on
its pass through and on its way out of our solar system. Being able to get
ships and ideally humans onto that thing would be groundbreaking and actually
go a long ways towards pushing those mission statements, abstract though they
may be, forward. But our space program and technology is so backwards and
dated that we're instead left watching jaws agape as arguably the single most
relevant tracked celestial object lackadaisically (...as lackadaisical as
30km/s can be) laps us on its way on out of our solar system. It's again
absurd that the primary interest in trying to perform an intercept with this
object has come from the private industry. But hey, at least we'll know the
wind speed in Uranus...

[1] -
[https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/201700...](https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20170006873.pdf)

[2] -
[https://en.wikipedia.org/wiki/%CA%BBOumuamua](https://en.wikipedia.org/wiki/%CA%BBOumuamua)

~~~
mturmon
The instrument you link (I actually do know one of the co-authors on the paper
you reference) isn't a full-up mission focused on the wind speed issue. It's
one instrument that would be part of a larger flagship mission (i.e., many
instruments on one spacecraft). When you put all the instruments together on a
spacecraft, maybe you learn more about the history of Uranus. Isn't "send an
orbiter to Uranus" a goal?

You mention the ambiguity of the animating goals. Part of this is just
linguistic: of course you want to push down these top-level goals to more
granular, 0/1 goals ("was there an ancient lake at this site on Mars?" Answer:
yes). That's what the NAS report does. Now that we know how abundant water was
on ancient Mars, we'd like to return samples to see if there was life. That's
the next couple of missions.

You raise a worthwhile point, I think, about immediately-graspable 0/1 goals,
like "man on moon". I see your point - but I'm really only here to talk about
the unmanned program because my limited expertise covers part of that area.

You like SpaceX. So do I - two good friends left my lab to work there. But
their achievement ("revolutionized space") is not unique. The little Mars
pathfinder had about that much history. There are plenty of other examples
over the same time period, like exoplanet discovery (as you noted), cosmology,
and a host of Earth science stuff.

~~~
TangoTrotFox
You definitely make some good points. I think my issue here is not so much
just the goal orientation, but rather goals that will directly advance other
interests simultaneously. Again getting back to the point that funding since
funding is limited, it seems like it would make the most sense to think of the
big picture with that funding rather than thinking in the short term of what
would be neat to do with their current funding?

So to make this more clear, one reason I think what SpaceX has already
achieved and especially what they plan to achieve is so revolutionary is
because of how it would impact other programs. Like you mention one of NASA's
big goals is a sample return mission. And this is going to be highly complex
and highly expensive. The OSIRIS-REx mission mission is a billion dollar, 7
year mission to get 0.1-2kg of debris from an asteroid that comes within
0.0002AU of Earth with a 6 year period. That's really not reasonable. These
missions would be trivialized with technologies such as the BFR. Such
technology would also enable vastly greater scope and scale of these sort of
missions. A Uranus orbiter will provide some science that might have some
value, but it's not really advancing anything. The chance of revolutionary
discovery is practically 0, and it will be unlikely to have a meaningful
effect on future missions or projects.

Basically it feels quite odd that we're using technology that is comparable in
both price and capability to what we were using the 70s. It's quite peculiar,
and I think this has been the major hold up in us achieving much more in
space. Imagine for a minute that it's 1969. We've just seen live footage of
men walking and driving rovers on the moon. And I tell you that in 50 years
NASA's vision for a flagship mission will be sending a probe to Uranus. And no
man would ever leave low earth orbit again after 1972. Wouldn't you say
something has gone very wrong? And this wrongness continues to persist, and I
think it is because of this _' Well I have $x. What should I spend it all
on?'_ as opposed to aiming for directed evolution and progress.

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searine
Cancel SLS. Cancel Orion.

Mass produce satellites and space station modules instead.

~~~
wil421
These programs for NASA are just as much a job creation program as it is a
mission.

I think with Trump the easiest sell would be more American manufacturing than
a Uranus mission.

~~~
searine
Constellation/SLS was important when there wasn't a commercial launch market
because the programs maintained technical and manufacturing know-how.

Now that there are several competitive and reliable commercial launch
providers who maintain that know-how, we need to stop subsidizing bloated
defense contractors and instead spend that money on buying launches and making
satellites.

~~~
wil421
Why would the US give up all of their launch capabilities to private
companies? From a strategic point of view it’s not a good approach. I’m sure
someone in Washington is making a similar case.

I agree there should be a balence but NASA shouldn’t have to solely rely on
the likes of Space X. Bloated defense contractors are a symptom of the
problem, look at the scope creep of the F35.

Is it the government contractors or unclear/ever changing requirements?

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elsonrodriguez
I don't know that NASA has ever built a heavy launch system in-house without
contractor help.

What's missing is a few more start-ups like SpaceX to totally crowd out the
likes of Boeing from the contractor feeding trough.

~~~
wil421
No they don’t build in house. Like I said it’s as much of a job creation
program as it is a space one.

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slumberlust
Title gore.

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randomerr
Is that the best or worst pun ever?

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viig99
Was thinking the same thing :D

~~~
tzar
The most effective clickbait has readers believing they've caught on to
something.

