Twenty years ago, the Galileo spacecraft flew through a plume on Europa

Galileo's closest approach to Europa brought it within 206km of the Moon's surface.

Read the whole story

 

[gulthaw]

While this is all very cool, I need to engage in a point of pedantry:

When you say "Moon" (capital 'M'), it is generally a given that it's a proper name, and therefore referring to Earth's moon.

Europa, on the other hand, is a moon (lower-case 'm').

This is especially confusing given that the capitalization is inconsistent, and there are frequent references to "the Moon."

While it's fairly easy to determine the meaning you're going for, it's a bit of a grate on the metaphorical ears and a distraction, to have to keep making the mental switch from "Moon" to "moon."

Edit: Muphry's Law.

It would be so much simpler if we call all agree to call Earth's moon Luna. We'd never have to capitalize Moon (except at the beginning of a sentence). Alas, that staple of sci-fi doesn't seem to have caught on.

I'm all in for that although for the life of me I don't know what sci-fi you're referring to :/

But then again, I've read a lot in spanish (that being one of my native languages) and in spanish "the Moon" is called "la Luna" (la Lluna in catalan, pronounced as yuna - the same y as "you" - for those curious )


I'd love to see an Europa Report kind of mission

 

[wouterr]

Can someone explain how these geysers exist? If there are kilometers of ice above the ocean, could there be a geyser in a place where a big meteorite strucked the ice? Or is that not possible? Would love more info on this.

 

[Richard Malcolm]

How can a person that supports so much legislation that ignores science be such a space science supporter? Mr. Culberson would be an interesting person to sit and have a drink with.

Because a big chunk of the money being spent building the probe is going through his district. As far as Culberson is concerned, this is not about science, its about government largess in his district.

Now, I don't think that's entirely fair. The more you read on Culberson (including some stuff Eric Berger has written), it's hard to shake the impression that Culberson is genuinely interested in Europa for its own sake, and has made some effort to gain at least some surface impression of the science involved. I think he's a genuine Europa enthusiast here. He spends far more time on this subject than any parochial interests in his CCD requires.

Now, it's true that he likely has other, vested, interests - though the truth is, his congressional district will get only very modest (EDIT: if *any* - as Eric has pointed out in the comments here) amounts of the funding going to build the Europa probe, or the SLS launcher it will go up on. The vast majority of those vehicles will be designed and built elsewhere.

In short, however much he might like pork, it's not really fair to paint him as just another Richard Shelby or Mo Brooks.

 

[Richard Malcolm]

How can a person that supports so much legislation that ignores science be such a space science supporter? Mr. Culberson would be an interesting person to sit and have a drink with.

One word... jobs.

He's from Texas - with NASA based in Houston, Texas, I am sure any major project like this would be good for his constituents.

On the climate denial... same - jobs. Texas is a major oil and gas producer, he's looking to protect jobs.

The NASA center in Houston (JSC) does not do planetary science, they do human spaceflight.

The Europa probes are being built at JPL in California.

Edit: ninja'ed by Eric, almost word for word lol

If SLS dies so does Orion. They are all bedfellows. The (intentionally designed) Europa mission requires the SLS. See the SLS is necessary. The more likely the SLS is funded the more likely Orion remains funded.

NASA in their budget request asked to look at using commercial launch providers for the Europa mission. Culbertson in committee killed that and put language in the budget will obligates NASA to use the SLS and the SLS only for the Europa mission.

That is true, and I wish he had not. It really ought to be NASA's call on what launcher it uses. SLS is ludicrously expensive, with a launcher that will likely cost MORE than the $2+ billion cost of the probe itself. (And yes, SLS should be cancelled outright, today.)

But that said, there are legitimate reasons to want to use SLS, if one is unwilling to knock the mass down to something Falcon Heavy could fly on a direct trajectory to Jupiter. Because in that case, SLS Block 1 *will* get it there much faster (with all the advantages that entails), and without the need for the thermal shielding needed for the Venus gravity assist. And that may well be part of Culberson's reasoning.

 

[blackhawk887]

How can a person that supports so much legislation that ignores science be such a space science supporter? Mr. Culberson would be an interesting person to sit and have a drink with.

One word... jobs.

He's from Texas - with NASA based in Houston, Texas, I am sure any major project like this would be good for his constituents.

On the climate denial... same - jobs. Texas is a major oil and gas producer, he's looking to protect jobs.

The NASA center in Houston (JSC) does not do planetary science, they do human spaceflight.

The Europa probes are being built at JPL in California.

Edit: ninja'ed by Eric, almost word for word lol

If SLS dies so does Orion. They are all bedfellows. The (intentionally designed) Europa mission requires the SLS. See the SLS is necessary. The more likely the SLS is funded the more likely Orion remains funded.

NASA in their budget request asked to look at using commercial launch providers for the Europa mission. Culbertson in committee killed that and put language in the budget will obligates NASA to use the SLS and the SLS only for the Europa mission.

That is true, and I wish he had not. It really ought to be NASA's call on what launcher it uses. SLS is ludicrously expensive, with a launcher that will likely cost MORE than the $ billion cost of the probe itself.

But that said, there are legitimate reasons to want to use SLS, if one is unwilling to knock the mass down to something Falcon Heavy could fly on a direct trajectory to Jupiter. Because in that case, SLS Block 1 *will* get it there much faster (with all the advantages that entails), and without the need for the thermal shielding needed for the Venus gravity assist.

Ahem. Venus gravity assists are no longer on the table as I understand it. It's either Earth Gravity Aassist (more than 1 AU at all times) with a deep-space maneuver (on DIVH or FH) or just a direct insertion (on SLS or FH). The flight time is ~5 years for the former and 2.5-3 years for the latter.

The VEEGA trajectory (Venus-Earth-Earth gravity assist) was only required with Atlas V 551, and even then the mass limit is under 4500 kg, compared to 6000 kg direct on SLS. Flight time with VEEGA is over 7 years.

FH can likely do 4500 kg direct and over 5000 kg with a kick stage. But when Culberson met with JPL they were using outdated figures (provided by ULA, of all people) which would show FH to about the same performance as DIVH, only about 1700 kg direct sans kick stage and >3000 kg direct with a kick stage.

 

[Statistical]

How can a person that supports so much legislation that ignores science be such a space science supporter? Mr. Culberson would be an interesting person to sit and have a drink with.

One word... jobs.

He's from Texas - with NASA based in Houston, Texas, I am sure any major project like this would be good for his constituents.

On the climate denial... same - jobs. Texas is a major oil and gas producer, he's looking to protect jobs.

The NASA center in Houston (JSC) does not do planetary science, they do human spaceflight.

The Europa probes are being built at JPL in California.

Edit: ninja'ed by Eric, almost word for word lol

If SLS dies so does Orion. They are all bedfellows. The (intentionally designed) Europa mission requires the SLS. See the SLS is necessary. The more likely the SLS is funded the more likely Orion remains funded.

NASA in their budget request asked to look at using commercial launch providers for the Europa mission. Culbertson in committee killed that and put language in the budget will obligates NASA to use the SLS and the SLS only for the Europa mission.

That is true, and I wish he had not. It really ought to be NASA's call on what launcher it uses. SLS is ludicrously expensive, with a launcher that will likely cost MORE than the $2+ billion cost of the probe itself.

But that said, there are legitimate reasons to want to use SLS, if one is unwilling to knock the mass down to something Falcon Heavy could fly on a direct trajectory to Jupiter. Because in that case, SLS Block 1 *will* get it there much faster (with all the advantages that entails), and without the need for the thermal shielding needed for the Venus gravity assist.

If there is sufficient scientific merit to the SLS then there is no language required to mandate it. NASA would use it because it is the best tool for the job. On the other hand if the SLS isn't the best tool for the job the cons outweigh the pros then you pull some pork politics bullshit and force NASA to use it.

So that doesn't excuse his 'reasoning'.

 

[blackhawk887]

How can a person that supports so much legislation that ignores science be such a space science supporter? Mr. Culberson would be an interesting person to sit and have a drink with.

One word... jobs.

He's from Texas - with NASA based in Houston, Texas, I am sure any major project like this would be good for his constituents.

On the climate denial... same - jobs. Texas is a major oil and gas producer, he's looking to protect jobs.

The NASA center in Houston (JSC) does not do planetary science, they do human spaceflight.

The Europa probes are being built at JPL in California.

Edit: ninja'ed by Eric, almost word for word lol

If SLS dies so does Orion. They are all bedfellows. The (intentionally designed) Europa mission requires the SLS. See the SLS is necessary. The more likely the SLS is funded the more likely Orion remains funded.

NASA in their budget request asked to look at using commercial launch providers for the Europa mission. Culbertson in committee killed that and put language in the budget will obligates NASA to use the SLS and the SLS only for the Europa mission.

That is true, and I wish he had not. It really ought to be NASA's call on what launcher it uses. SLS is ludicrously expensive, with a launcher that will likely cost MORE than the $2+ billion cost of the probe itself.

But that said, there are legitimate reasons to want to use SLS, if one is unwilling to knock the mass down to something Falcon Heavy could fly on a direct trajectory to Jupiter. Because in that case, SLS Block 1 *will* get it there much faster (with all the advantages that entails), and without the need for the thermal shielding needed for the Venus gravity assist.

If there is sufficient scientific merit to the SLS then there is no language required to mandate it. NASA would use it because it is the best tool for the job. On the other hand if the SLS isn't the best tool for the job the cons outweigh the pros then you pull some pork politics bullshit and force NASA to use it.

So that doesn't excuse his 'reasoning'.

NASA is going to do what the President tells them to do. I would not entirely assume that's based solely on scientific merit...

 

[Router66]

Can someone explain how these geysers exist? If there are kilometers of ice above the ocean, could there be a geyser in a place where a big meteorite strucked the ice? Or is that not possible? Would love more info on this.

Nobody really knows. They may be an analogous to Earth's volcanoes, fizzing lakes, or something related to cryo tectonics. If they are on the same spot when Clipper gets there, it means they are a long term feature, which in turn implies some kind of convection with the ocean. I think. If they aren't there... well, it's anybody's guess I suppose.

What's important at this point is that they may let us take a look at what's bellow the surface ice sheet.

 

[JohnDeL]

Data from space probes is often still being gone over years (and decades) after the fact by space scientists and often results in "new" discoveries.

This is true. My dissertation in 1998 made use of data from the Viking probes in 1975.

And that is why NASA keeps all of its data on-line and available for anyone to use! (Warning: the interface is a pain in the butt and the data is sometimes reformatted to fit newer interfaces.)

I'd love to see an Europa Report kind of mission

Unfortunately, Jupiter's rather intense radiation field means that will never happen. Europa probably has an interior icy brine water "mantle" which is shielded from Jupiter's radiation by Europa's icy crust.

 

[Torbjörn Larsson OM]

The cool is strong in this one.

They confirm the position of a repetitive vent with another method.

That new method was developed on a similar probe circling the *next* gas giant over, diving into similar vents.

That said, and while finding out habitability or even life on Europa would be interesting, Enceladus is still a better target. The vents are persistent and sourced by serpentinization, coupled to how life emerged on Earth, while the ocean age is also old enough to have sourced life. There is no guarantee that the Clipper mission will see something without a lander in the vent region. And Culberson shoot himself in the foot there, the lander is now a separate mission [ https://en.wikipedia.org/wiki/Europa_Cl ... er_history ], and Culberson is leaving the voting position.

Perhaps interesting note: Earth ejecta has reached Europa much more often than Enceladus (where it is average one crust piece hitting over 4 billion years). They have just published on a multicellular (a nematode) surviving ejecta accelerations (400,000 g) without really noticing.

Flash frozen worm cryo sleepers may thaw out in the right conditions...

Can someone explain how these geysers exist? If there are kilometers of ice above the ocean, could there be a geyser in a place where a big meteorite strucked the ice? Or is that not possible? Would love more info on this.

I haven't seen the NASA discussion, but the way the article notes the recent impactor it may have been a strong candidate mechanism discussed. Else there are other fissures all over Europa ice surface, and signs of recent turnover showing near surface water activity, so no worries about existence as such.

 

[uhuznaa]

Can someone explain how these geysers exist? If there are kilometers of ice above the ocean, could there be a geyser in a place where a big meteorite strucked the ice? Or is that not possible? Would love more info on this.

Nobody really knows. They may be an analogous to Earth's volcanoes, fizzing lakes, or something related to cryo tectonics. If they are on the same spot when Clipper gets there, it means they are a long term feature, which in turn implies some kind of convection with the ocean. I think. If they aren't there... well, it's anybody's guess I suppose.

What's important at this point is that they may let us take a look at what's bellow the surface ice sheet.

Europa is criss-crossed by these orange lines you see in the article photo which are thought to be cracks (or former cracks) in the ice through which water came through. Europa is constantly massaged by tidal effects which can cause these cracks in the ice shell and squeeze out water from the ocean below the ice. Landing near one of these cracks and drilling into the ice probably would give you a good sample of what came out of there over time.

 

[Reso1]

You can't claim it is bad that Congress interferes in NASA and forces them to build a pork launcher to nowhere and then make justifications when the same Congress mandates it is usage.

Yes, we can. You aren't seeing the big picture.

SLS is a pork project because it is an expensive political project for which similar capabilities and results could be more efficiently purchased off the shelf from commercial providers. NASA has no reason to even be in LEO at all anymore. This is classic waste or corruption which occurs all across government spending.

Nothing about the Europa missions is the same as that. There is no one going to sell an off the shelf probe for it. It is a novel mission to unexplored worlds pushing the boundaries of human knowledge. This is exactly why NASA exists at all. Sending probes to Europa or Enceladeus to scan the water for organic material will probably be the most import things NASA does THIS CENTURY, just like Apollo was last century.

A Congressman being savvy enough to recognize that such a large project requires political maneuvering to reach completion is not something anyone who cares about NASA's core mission should be complaining about.

 

[solomonrex]

ALL THESE WORLDS ARE YOURS EXCEPT MURICA. ATTEMPT NO IMMIGRATION THERE.

 

[Quasius]

While this is all very cool, I need to engage in a point of pedantry:

When you say "Moon" (capital 'M'), it is generally a given that it's a proper name, and therefore referring to Earth's moon.

Europa, on the other hand, is a moon (lower-case 'm').

This is especially confusing given that the capitalization is inconsistent, and there are frequent references to "the Moon."

While it's fairly easy to determine the meaning you're going for, it's a bit of a grate on the metaphorical ears and a distraction, to have to keep making the mental switch from "Moon" to "moon."

Edit: Muphry's Law.

It would be so much simpler if we call all agree to call Earth's moon Luna. We'd never have to capitalize Moon (except at the beginning of a sentence). Alas, that staple of sci-fi doesn't seem to have caught on.

I was going to say the same. Seriously, it's well past time. +1

PS: But we would then have to prepare for Moon-gate. I you think about how the subject of Pluto losing it's planet status was overblown, just wait until someone suggest changing from calling it the Moon to Luna.

You'd have the Bronies on your side at least.

 

[Pluvia Arenae]

You can't claim it is bad that Congress interferes in NASA and forces them to build a pork launcher to nowhere and then make justifications when the same Congress mandates it is usage.

Yes, we can. You aren't seeing the big picture.

SLS is a pork project because it is an expensive political project for which similar capabilities and results could be more efficiently purchased off the shelf from commercial providers. NASA has no reason to even be in LEO at all anymore. This is classic waste or corruption which occurs all across government spending.

Nothing about the Europa missions is the same as that. There is no one going to sell an off the shelf probe for it. It is a novel mission to unexplored worlds pushing the boundaries of human knowledge. This is exactly why NASA exists at all. Sending probes to Europa or Enceladeus to scan the water for organic material will probably be the most import things NASA does THIS CENTURY, just like Apollo was last century.

A Congressman being savvy enough to recognize that such a large project requires political maneuvering to reach completion is not something anyone who cares about NASA's core mission should be complaining about.

Shouldn't the big picture extend beyond the artificially limited options of "wastefully expensive SLS-based Europa mission as soon as possible" or "no Europa mission"? We're only limited to those options if we assume that this specific Europa mission has to get pushed through Congress in the near term.

But it seems to me that anyone concerned more with maximizing the scientific returns from NASA's solar system exploration budget should be fully willing to either (1) delay the exploration of Europa until after SLS's cancellation, in order to avoid this absurd artificial dichotomy, or (2) propose a much smaller, cheaper mission with just the most basic instruments, that can be launched on that faster trajectory by current launchers.

Is there some reason these other options are not reasonable?

Pushing this one specific mission regardless of the opportunity cost of wasting a billion dollars of NASA's science budget on one SLS launch.... That's not a big picture view. It's actually a rather narrow my-project-at-all-costs view.

 

[alastairmayer]

While this is all very cool, I need to engage in a point of pedantry:

When you say "Moon" (capital 'M'), it is generally a given that it's a proper name, and therefore referring to Earth's moon.

Europa, on the other hand, is a moon (lower-case 'm').

This is especially confusing given that the capitalization is inconsistent, and there are frequent references to "the Moon."

While it's fairly easy to determine the meaning you're going for, it's a bit of a grate on the metaphorical ears and a distraction, to have to keep making the mental switch from "Moon" to "moon."

Edit: Muphry's Law.

It would be so much simpler if we call all agree to call Earth's moon Luna. We'd never have to capitalize Moon (except at the beginning of a sentence). Alas, that staple of sci-fi doesn't seem to have caught on.

So what should Spanish speakers call the Moon since Luna is literally just "Moon"? El Mún?

They can call it Selene.

(Or whatever they want; it's their language.)

 

[alastairmayer]

How can a person that supports so much legislation that ignores science be such a space science supporter? Mr. Culberson would be an interesting person to sit and have a drink with.

Because a big chunk of the money being spent building the probe is going through his district. As far as Culberson is concerned, this is not about science, its about government largess in his district.

Sorry Chudan, I live in Culberson's district, this project does nothing for Texas Seventh Congressional District. He just really believes in the Europa mission.

It bums me out that people have gotten so comfortable with the whole "he's a Republican and therefore we must find anything we can to undermine what we'd celebrate coming from someone else" thing.

It's possible to have distinct beliefs and interests even if they don't fit neatly into an overarching philosophy. He might not be 100% on board with scientific findings broadly, but that doesn't mean he isn't genuinely curious about and in favor of certain kinds of discovery.

I'm not in favor of torture, but I'm not all-in on hippie humanism either -- color me a cynical hypocrite too, I guess.

Sorry Culbertson is not a good guy in this case. He has forced NASA to use the SLS even though NASA's wanted to look at commercial launchers. Worse he has expanded the politicization of space (pork) from rockets and HSF into probes an area which has largely remained below the radar for Congressional meddling.

I mean when Congress meddles with NASA and forces them to build the SLS that is generally considered bad. Culbertson meddles with NASA and forces them to use the SLS for two missions and somehow that is a good thing? Walk me through that.

If the SLS gets axed prior to 2024 then what? Oh crap these two probes were designed to only work with the SLS guess that is $5B to $7B down the drain. Worse you know that won't happen because the cost of these probes will be justification to keep the SLS alive. "We can't axe the SLS because all these missions depend on it. It is utterly vital for exploration of space" (be honest if it works for this mission missions it won't end here.

If the Europa mission is ready to go in 2024 and SLS has already been axed, I'm sure they'll find a way to launch it via BFR.

 

[Richard Malcolm]

How can a person that supports so much legislation that ignores science be such a space science supporter? Mr. Culberson would be an interesting person to sit and have a drink with.

One word... jobs.

He's from Texas - with NASA based in Houston, Texas, I am sure any major project like this would be good for his constituents.

On the climate denial... same - jobs. Texas is a major oil and gas producer, he's looking to protect jobs.

The NASA center in Houston (JSC) does not do planetary science, they do human spaceflight.

The Europa probes are being built at JPL in California.

Edit: ninja'ed by Eric, almost word for word lol

If SLS dies so does Orion. They are all bedfellows. The (intentionally designed) Europa mission requires the SLS. See the SLS is necessary. The more likely the SLS is funded the more likely Orion remains funded.

NASA in their budget request asked to look at using commercial launch providers for the Europa mission. Culbertson in committee killed that and put language in the budget will obligates NASA to use the SLS and the SLS only for the Europa mission.

That is true, and I wish he had not. It really ought to be NASA's call on what launcher it uses. SLS is ludicrously expensive, with a launcher that will likely cost MORE than the $2+ billion cost of the probe itself.

But that said, there are legitimate reasons to want to use SLS, if one is unwilling to knock the mass down to something Falcon Heavy could fly on a direct trajectory to Jupiter. Because in that case, SLS Block 1 *will* get it there much faster (with all the advantages that entails), and without the need for the thermal shielding needed for the Venus gravity assist.

If there is sufficient scientific merit to the SLS then there is no language required to mandate it. NASA would use it because it is the best tool for the job. On the other hand if the SLS isn't the best tool for the job the cons outweigh the pros then you pull some pork politics bullshit and force NASA to use it.

So that doesn't excuse his 'reasoning'.

I don't disagree with any of that. It should be NASA's call.

What I am saying is that there are advantages to direct trajectory. If it were me, however, I would simply strip the probe down until its mass was light enough that it could fly on the most appropriate and cost effective commercial launcher and still reach Jupiter on a direct approach. Which is likely the Falcon Heavy.

 

[Richard Malcolm]

How can a person that supports so much legislation that ignores science be such a space science supporter? Mr. Culberson would be an interesting person to sit and have a drink with.

One word... jobs.

He's from Texas - with NASA based in Houston, Texas, I am sure any major project like this would be good for his constituents.

On the climate denial... same - jobs. Texas is a major oil and gas producer, he's looking to protect jobs.

The NASA center in Houston (JSC) does not do planetary science, they do human spaceflight.

The Europa probes are being built at JPL in California.

Edit: ninja'ed by Eric, almost word for word lol

If SLS dies so does Orion. They are all bedfellows. The (intentionally designed) Europa mission requires the SLS. See the SLS is necessary. The more likely the SLS is funded the more likely Orion remains funded.

NASA in their budget request asked to look at using commercial launch providers for the Europa mission. Culbertson in committee killed that and put language in the budget will obligates NASA to use the SLS and the SLS only for the Europa mission.

That is true, and I wish he had not. It really ought to be NASA's call on what launcher it uses. SLS is ludicrously expensive, with a launcher that will likely cost MORE than the $ billion cost of the probe itself.

But that said, there are legitimate reasons to want to use SLS, if one is unwilling to knock the mass down to something Falcon Heavy could fly on a direct trajectory to Jupiter. Because in that case, SLS Block 1 *will* get it there much faster (with all the advantages that entails), and without the need for the thermal shielding needed for the Venus gravity assist.

Ahem. Venus gravity assists are no longer on the table as I understand it. It's either Earth Gravity Aassist (more than 1 AU at all times) with a deep-space maneuver (on DIVH or FH) or just a direct insertion (on SLS or FH). The flight time is ~5 years for the former and 2.5-3 years for the latter.

The VEEGA trajectory (Venus-Earth-Earth gravity assist) was only required with Atlas V 551, and even then the mass limit is under 4500 kg, compared to 6000 kg direct on SLS. Flight time with VEEGA is over 7 years.

FH can likely do 4500 kg direct and over 5000 kg with a kick stage. But when Culberson met with JPL they were using outdated figures (provided by ULA, of all people) which would show FH to about the same performance as DIVH, only about 1700 kg direct sans kick stage and >3000 kg direct with a kick stage.

Is that actually true about Venus having been dropped from consideration? The last I checked...the preferred gravity assist profile used a Venus assist. I am happy to stand corrected.

As for Falcon Heavy: I suspected they were using older performance data on the FH. That said, I still assume that even an expendable Block 5 Falcon Heavy with a kick stage could not do a direct trajectory to Jupiter in the Clipper's current configuration. It's just that my solution would be to trim the probe down, even if that means the loss of some capabilities, to reach that point. Not insist on the hideously expensive and delayed mega-pork launcher which may or may not be available when the probe is ready in 2022.

 

[alastairmayer]

“All these worlds are yours except Europa. Attempt no landing there.”

I am getting so tired of this stupid meme which gets brought up a half-dozen times whenever somebody mentions Europa.

You do realize that it's fiction, right? We never had a base on the Moon, we didn't discover a monolith, we never sent a manned expedition to Jupiter, and Jupiter did not ignite into a small star in 2010. We would have noticed.

 

[blackhawk887]

...
Pushing this one specific mission regardless of the opportunity cost of wasting a billion dollars of NASA's science budget on one SLS launch.... That's not a big picture view. It's actually a rather narrow my-project-at-all-costs view.

That's not at all how NASA's budget works. There isn't going to be an extra billion for science if it goes on a cheaper launcher. That money will still be spent on SLS, unless SLS is cancelled outright.

Remember that SLS exists purely, 100%, to keep Boeing, ATK, and Aerojet rolling in the pork. That's it. Any science launches are purely incidental.

Even if SLS is cancelled now, most of that money will still be spent on SLS contractors. I'd prefer that SLS be cut now. But that's not going to happen anytime soon, so the next best thing would be to use it for useful launches.

 

[alastairmayer]

I thought Culbertson was backing it out of his undying love for science so of course there would right?

He can't fund it himself; he needs support of other Senators and Reps.

Oh come on. Really so litterally every NASA mission has only two options
a) require the SLS
b) never get funding

How is the Mars 2020 rover getting funding? JWST? WFIRST? He is the head of the committee. The entire committee would vote against it unless it was turned into SLS pork. Really. Even though only one member of the committee is a major SLS proponent. Really you believe that? Even if you do believe that what a friggin horrible future for NASA. instead of pork being constrained mostly to launchers and HSF it will permeate every aspect. All of NASA will become a worthless over budget make work program to support the SLS.

It is NASA. Once it gets out of committee the overwhelming majority of Congress is going to vote in favor of NASA's budget because a) it is a drop in the bucket and b) there are no political points to gain by cutting NASA's budget.

Since he's trying to advance the timelines for both Europa missions, and fund them at hundreds of millions of dollars over the levels that NASA requested, yes.

Also JPL told him that commercial vehicles will add 3 to 5 years to the flight time. That probably isn't true now, and certainly won't be in 2024, but JPL is planning the mission.

Mars robotic missions don't plausibly gain anything from SLS. There's no reason to even bring it up.

Of course Mars robitic missions could gain from the SLS. You could build a bloated even larger rover and get it their quicker. Your claim is that this mission doesn't benefit from the SLS either yet here we are.

The extra funding is only needed to accelerate the timeline (which almost certainly will be missed JWST cough cough. It is a nothing burger. Name me one congress critter which would vote against the Omnibus spending bill (and likely kiss their career goodbye) over this complete nothng in terms of federal spending.

Once again lets just step back. Is Congressional meddling in the mission of NASA good or bad? I state it is bad and it is always bad. Congress should fund NASA and largely be hands off not dictating timelines and launch vehicles.

"Should", sure. But that's never going to happen. NASA's money comes from Congress, so they're going to want a say in how it is spent.

If you don't want that, you don't get to have a NASA. Sucks, but that's what we've got.

 

[blackhawk887]

Is that actually true about Venus having been dropped from consideration? The last I checked...the preferred gravity assist profile used a Venus assist. I am happy to stand corrected.

As for Falcon Heavy: I suspected they were using older performance data on the FH. That said, I still assume that even an expendable Block 5 Falcon Heavy with a kick stage could not do a direct trajectory to Jupiter in the Clipper's current configuration. It's just that my solution would be to trim the probe down, even if that means the loss of some capabilities, to reach that point. Not insist on the hideously expensive and delayed mega-pork launcher which may or may not be available when the probe is ready in 2022.

Last I saw, Clipper had 45% margin on payload with SLS, so shifting to FH would simply eat into that margin. They wouldn't necessarily even have to trim any science off the probe.

FH should have at least a dozen launches by then, so the margin needed for potential underperformance should be smaller than SLS which will have at most one launch.

 

[Mandella]

“All these worlds are yours except Europa. Attempt no landing there.”

I am getting so tired of this stupid meme which gets brought up a half-dozen times whenever somebody mentions Europa.

You do realize that it's fiction, right? We never had a base on the Moon, we didn't discover a monolith, we never sent a manned expedition to Jupiter, and Jupiter did not ignite into a small star in 2010. We would have noticed.

**gasp**


Blasphemer!!!!!!

Next you'll be saying the Earth is flat.

 

[alastairmayer]

“All these worlds are yours except Europa. Attempt no landing there.”

I am getting so tired of this stupid meme which gets brought up a half-dozen times whenever somebody mentions Europa.

You do realize that it's fiction, right? We never had a base on the Moon, we didn't discover a monolith, we never sent a manned expedition to Jupiter, and Jupiter did not ignite into a small star in 2010. We would have noticed.

**gasp**


Blasphemer!!!!!!

Next you'll be saying the Earth is flat.

No. Just terribly, terribly disappointed that none of those things actually happened. Hell, I would have settled for the moonbase.

 

[Pluvia Arenae]

...
Pushing this one specific mission regardless of the opportunity cost of wasting a billion dollars of NASA's science budget on one SLS launch.... That's not a big picture view. It's actually a rather narrow my-project-at-all-costs view.

That's not at all how NASA's budget works. There isn't going to be an extra billion for science if it goes on a cheaper launcher. That money will still be spent on SLS, unless SLS is cancelled outright.

Remember that SLS exists purely, 100%, to keep Boeing, ATK, and Aerojet rolling in the pork. That's it. Any science launches are purely incidental.

Even if SLS is cancelled now, most of that money will still be spent on SLS contractors. I'd prefer that SLS be cut now. But that's not going to happen anytime soon, so the next best thing would be to use it for useful launches.

I'm aware that the SLS development budget is legislatively dedicated to SLS. But are you saying that the launch cost for a science mission launched on SLS would not come from that mission's budget? That wouldn't be the case if it were on a commercial launcher, right?

For example, if it launched on an expendable FH, that $150mil would come out of the Europa Clipper budget, right?

 

[wyrmhole]

...
Pushing this one specific mission regardless of the opportunity cost of wasting a billion dollars of NASA's science budget on one SLS launch.... That's not a big picture view. It's actually a rather narrow my-project-at-all-costs view.

That's not at all how NASA's budget works. There isn't going to be an extra billion for science if it goes on a cheaper launcher. That money will still be spent on SLS, unless SLS is cancelled outright.

Remember that SLS exists purely, 100%, to keep Boeing, ATK, and Aerojet rolling in the pork. That's it. Any science launches are purely incidental.

Even if SLS is cancelled now, most of that money will still be spent on SLS contractors. I'd prefer that SLS be cut now. But that's not going to happen anytime soon, so the next best thing would be to use it for useful launches.

I'm aware that the SLS development budget is legislatively dedicated to SLS. But are you saying that the launch cost for a science mission launched on SLS would not come from that mission's budget? That wouldn't be the case if it were on a commercial launcher, right?

For example, if it launched on an expendable FH, that $150mil would come out of the Europa Clipper budget, right?

If SLS gets canceled, yet Clipper survives and switches to FH, expect its budget to be reduced by the ~$1bil difference in launch costs. Congress is not going to just let that money float.

That's why this ends up being so frustrating and counterintuitive when you look at it from an idealistic engineering/science approach. Because the budget for these missions isn't fixed and depends on an entity very much not primarily focused on the science and engineering. Not only is the extra money to launch SLS not going to stick around to be spent on useful things just because you switch to a cheaper launch vehicle, in the current regime where SLS is driving NASA's budget the non-launch parts of the budget are a lot bigger than they would likely be otherwise exactly because it then helps justify using the pork launcher. Without the ties to the pork launcher, it's not clear it would have any budget at all.

 

[qwi]

If it is plumes of water, and if life lives in water, I wonder if any Europan life might have been carried along for the ride, and I wonder if there is any way to detect that...

The scientists behind the Europa missions are very, very much interested in this question, and quite possibly answering it.

Just to add to this with some references (I'll try and use as many Open Access as possible, apologies for any paywalls) and a note of caution...

Entrained micro- or nano-biota would probably be best directly detected by a dust detector, such as the SUrface Dust Analyser (SUDA) instrument on the Europa clipper (http://adsabs.harvard.edu/abs/2014EPSC....9..229K), which may be able to detect the associated long-chain organics, amines etc. - although proving these species weren't just present as dissolved organics in the emitted water plumes (e.g. https://www.sciencedirect.com/science/a ... via%3Dihub) would be a different matter. JUICE sadly doesn't have a dust instrument. Sigh.

Modelling indicates that macroscopic grains up to about 10 microns in size (roughly bacterial) may be lofted to the tops of any plumes (100-200 km, https://www.sciencedirect.com/science/a ... via%3Dihub) although the likelihood of sampling such a particle would probably be low.

Some notes of caution though - although the latest results are exciting, they are far from definitive and even the previous "positive" plume detections (http://science.sciencemag.org/content/343/6167/171.full, http://iopscience.iop.org/article/10.38 ... /2/121/pdf, http://iopscience.iop.org/article/10.38 ... aa67f8/pdf) are not always consistent with non-detections (e.g. as mentioned by Sparks 2016, concerning their nearly temporally-coincident observations with those of Roth 2014, plus the non detection of an endogenic hotspot by ALMA (https://arxiv.org/abs/1708.07922). Explanations for the near-Pwyll hotspot seem to be reverting to the original "variations of thermal inertia" explanation (e.g. https://ui.adsabs.harvard.edu/#abs/2017 ... R/abstract, https://arxiv.org/abs/1708.07922, http://science.sciencemag.org/content/284/5419/1514), although surface alteration by plume activity (e.g. deposition of a fluffy layer) may actually produce this. However, given the likely spreading of such plume deposition over the surface, one might expect this to be clearly visible (c.f. Io plume deposition or Enceladus's highly reflective surface). The plumes modelled by Jia are not coincident with the Pwyll "hotspot".

If near surface water is responsible for a hotspot and plume emission, it is estimated to lie within 1.8-2 km of the surface (http://iopscience.iop.org/article/10.38 ... aa67f8/pdf), which, if the surface ice is "floating" on a subsurface ocean, implies a crust thickness of no more than 18-20 km (water will rise through the crust to a distance proportional to the ratio of the densities of ice/brine). With a thicker crust (25-40 km, such as proposed by e.g. https://www.nature.com/articles/34862) a mechanism needs to exist to bring the water closer, such as gas exsolvation (https://www.sciencedirect.com/science/a ... via%3Dihub), localised crustal thinning, or diapir-induced melting of a lens of water above a (solid) plume of warm ice - caused by e.g. changes in salinity (https://agupubs.onlinelibrary.wiley.com ... 99JE001062).

If the latter method is occurring, then it may be that the process is not particularly suited to the sampling of extant life in plumes, although that wouldn't rule out the presence of life itself.

 

[Mandella]

“All these worlds are yours except Europa. Attempt no landing there.”

I am getting so tired of this stupid meme which gets brought up a half-dozen times whenever somebody mentions Europa.

You do realize that it's fiction, right? We never had a base on the Moon, we didn't discover a monolith, we never sent a manned expedition to Jupiter, and Jupiter did not ignite into a small star in 2010. We would have noticed.

**gasp**


Blasphemer!!!!!!

Next you'll be saying the Earth is flat.

No. Just terribly, terribly disappointed that none of those things actually happened. Hell, I would have settled for the moonbase.

Hell, I would have been happy with Moonbase Alpha...

 

[CRandyHill]

Methinks if the president killed the SLS tomorrow, it would be the greatest act of liberation NASA ever received. Their budget would shrink, but their capabilities would rise. There is still lots of support for planetary exploration, manned and unmanned. There will even be more if flagship missions cost $2B less (each SLS flight is going to cost at least that with R&D and annual operations costs included).

And the SLS is the greatest obstacle to manned exploration of Mars there is. That effort will require orbiting many millions of pounds of equipment, supplies, interplanetary craft and fuel. Costing more than $10B per million pounds before even paying for all that equipment renders any NASA SLS based manned exploration program no where near affordable.

The Falcon Heavy can put 1 million pounds of cargo in orbit for around $600M. That brings a Mars program actually within reach. If BO or BFR improve on those costs further, even private industry could pay for Mars missions.

 

[wyrmhole]

Methinks if the president killed the SLS tomorrow, it would be the greatest act of liberation NASA ever received.

It would, but like Pres. Obama found when he killed Constellation: It Don't Work That Way.

And you might think okay but this Congress seems like they'll never stand up to this President they look the other way and justify his actions for him and that's really only true as long as they're able to work towards their agenda of greed and graft. Canceling SLS would be the opposite of that and there'd be pushback which would result in caving like always. Not that this would really happen anyway. Trump doesn't care about NASA and definitely not about pork, he would just like to take credit for SLS launching, or FH launching, or whatever, without having to do anything. I'm sure Shelby has already figured out how this works and gotten his membership at Mar-a-lago.

Still, one can dream.

 

[Pluvia Arenae]

...
Pushing this one specific mission regardless of the opportunity cost of wasting a billion dollars of NASA's science budget on one SLS launch.... That's not a big picture view. It's actually a rather narrow my-project-at-all-costs view.

That's not at all how NASA's budget works. There isn't going to be an extra billion for science if it goes on a cheaper launcher. That money will still be spent on SLS, unless SLS is cancelled outright.

Remember that SLS exists purely, 100%, to keep Boeing, ATK, and Aerojet rolling in the pork. That's it. Any science launches are purely incidental.

Even if SLS is cancelled now, most of that money will still be spent on SLS contractors. I'd prefer that SLS be cut now. But that's not going to happen anytime soon, so the next best thing would be to use it for useful launches.

I'm aware that the SLS development budget is legislatively dedicated to SLS. But are you saying that the launch cost for a science mission launched on SLS would not come from that mission's budget? That wouldn't be the case if it were on a commercial launcher, right?

For example, if it launched on an expendable FH, that $150mil would come out of the Europa Clipper budget, right?

If SLS gets canceled, yet Clipper survives and switches to FH, expect its budget to be reduced by the ~$1bil difference in launch costs. Congress is not going to just let that money float.

If that is really what would happen, then the long-term responsible thing to do (for anyone with influence over the designs of missions, as Culberson seems to have) is to systematically cap the scope of each mission such that its size and trajectory allows it to launch on at least 2 existing launch vehicles, explain it as a financially prudent risk-mitigation measure, and wait for Congress to redirect the launch funds to some nebulous aspect of SLS development. (Don't roll your eyes, yet. Let me explain.)

Since Congress is averse to actually shrinking NASA's total budget, and Shelby won't let them shrink the SLS budget, taking a mission off of the SLS manifest represents another chunk of money they have to artificially funnel to MSFC and the SLS contractors with no clear purpose. That means the percentage of NASA's budget dedicated to a rocket to nowhere becomes larger.

The faster that happens, the sooner it gets cancelled.

Putting even one artificially inflated mission on SLS, in a hyper-focused attempt to guarantee that single mission, has the side-effect of putting SLS on life-support and dragging out its death, thereby extending the amount of time that NASA spends with a massive chunk of its nominal budget being completely useless. It means screwing over NASA in the long term, just to save that one mission. This short-sighted approach is exactly what Shelby wants. He set a trap, and people are falling right into it.

Yes, this might cause some missions (at this point, just Clipper, I think) to not get funded until after SLS's eventual cancellation allows NASA to reboot without so much of its budget being hijacked. Yes, that sucks for the scientists who really, really want to study Europa. But to anyone trying to optimize NASA's overall scientific returns, it is a reasonable sacrifice towards the goal of restoring NASA's useful (non-SLS) budget.

As important as Europa research may be, saving this one mission is not worth the cost of keeping all of NASA enslaved to Shelby and MSFC.

 

[maehara]

How can a person that supports so much legislation that ignores science be such a space science supporter? Mr. Culberson would be an interesting person to sit and have a drink with.

Previous answers have pointed to jobs as a reason, but I think that's very much secondary. I listened to an intervew that Culberson gave to the Planetary Society's podcast around a year ago, and it was very clear to me that he was a person who was looking to get his own name into the history books as the person who (funded the mission that) first found life on another world. It's about his legacy, and little more.

 

[Pluvia Arenae]

How can a person that supports so much legislation that ignores science be such a space science supporter? Mr. Culberson would be an interesting person to sit and have a drink with.

Previous answers have pointed to jobs as a reason, but I think that's very much secondary. I listened to an intervew that Culberson gave to the Planetary Society's podcast around a year ago, and it was very clear to me that he was a person who was looking to get his own name into the history books as the person who (funded the mission that) first found life on another world. It's about his legacy, and little more.

Which is why he's willing to play Shelby's game and keep NASA shackled to SLS in order to get his personal pet project funded. He doesn't care about scientific discovery overall. He cares about this one mission. And that strongly suggests that it's about legacy.

 

[andygates]

I just have to say, "cryotectonics" is the coolest damn word.

Oh, and: If Clipper is specced for launch on SLS, presumably another launcher could do the mission but slower? (IIRC the "clipper" is as in "fast ship")... Could Falcon Heavy do the job ?

 

[blackhawk887]

If that is really what would happen, then the long-term responsible thing to do (for anyone with influence over the designs of missions, as Culberson seems to have) is to systematically cap the scope of each mission such that its size and trajectory allows it to launch on at least 2 existing launch vehicles, explain it as a financially prudent risk-mitigation measure

The folks at JPL aren't stupid, they are doing exactly that. DIVH and FH are the backup LVs.

And Shelby isn't the only one behind SLS. Boeing, ATK, and Aerojet have a lot of lobbying power with Congress, as does Lockheed whose Orion is pretty much dependent on SLS. SLS will be canceled eventually, but probably not before it flies a couple times. By the time it's obvious to enough people that it's a dinosaur, enough hardware will be built that stopping those flights won't save much money.

Bureaucratic inertia and lots of lobbying by financially interested parties will most likely get SLS in the air.

Since Congress is averse to actually shrinking NASA's total budget, and Shelby won't let them shrink the SLS budget, taking a mission off of the SLS manifest represents another chunk of money they have to artificially funnel to MSFC and the SLS contractors with no clear purpose. That means the percentage of NASA's budget dedicated to a rocket to nowhere becomes larger.

The faster that happens, the sooner it gets cancelled.

Putting even one artificially inflated mission on SLS, in a hyper-focused attempt to guarantee that single mission, has the side-effect of putting SLS on life-support and dragging out its death, thereby extending the amount of time that NASA spends with a massive chunk of its nominal budget being completely useless. It means screwing over NASA in the long term, just to save that one mission. This short-sighted approach is exactly what Shelby wants. He set a trap, and people are falling right into it.

Yes, this might cause some missions (at this point, just Clipper, I think) to not get funded until after SLS's eventual cancellation allows NASA to reboot without so much of its budget being hijacked. Yes, that sucks for the scientists who really, really want to study Europa. But to anyone trying to optimize NASA's overall scientific returns, it is a reasonable sacrifice towards the goal of restoring NASA's useful (non-SLS) budget.

NASA's nominal budget isn't going to get cut, but that money also isn't going to go to planetary science. MSFC isn't going to get closed. Boeing, Lockheed, ATK, and Aerojet are still going to get paid.

At best, those monies will be redirected into R&D on new propulsion and vehicles for HSF. Which would be a lot better than SLS, but it's going to be a while before that happens.

 

[Skyfire77]

“All these worlds are yours except Europa. Attempt no landing there.”

I am getting so tired of this stupid meme which gets brought up a half-dozen times whenever somebody mentions Europa.

You do realize that it's fiction, right? We never had a base on the Moon, we didn't discover a monolith, we never sent a manned expedition to Jupiter, and Jupiter did not ignite into a small star in 2010. We would have noticed.

**gasp**


Blasphemer!!!!!!

Next you'll be saying the Earth is flat.

No. Just terribly, terribly disappointed that none of those things actually happened. Hell, I would have settled for the moonbase.

Hell, I would have been happy with Moonbase Alpha...

I'd take Alpha Beta Base at this point.

 

[Pluvia Arenae]

If that is really what would happen, then the long-term responsible thing to do (for anyone with influence over the designs of missions, as Culberson seems to have) is to systematically cap the scope of each mission such that its size and trajectory allows it to launch on at least 2 existing launch vehicles, explain it as a financially prudent risk-mitigation measure

The folks at JPL aren't stupid, they are doing exactly that. DIVH and FH are the backup LVs.

And Shelby isn't the only one behind SLS. Boeing, ATK, and Aerojet have a lot of lobbying power with Congress, as does Lockheed whose Orion is pretty much dependent on SLS. SLS will be canceled eventually, but probably not before it flies a couple times. By the time it's obvious to enough people that it's a dinosaur, enough hardware will be built that stopping those flights won't save much money.

Bureaucratic inertia and lots of lobbying by financially interested parties will most likely get SLS in the air.

Since Congress is averse to actually shrinking NASA's total budget, and Shelby won't let them shrink the SLS budget, taking a mission off of the SLS manifest represents another chunk of money they have to artificially funnel to MSFC and the SLS contractors with no clear purpose. That means the percentage of NASA's budget dedicated to a rocket to nowhere becomes larger.

The faster that happens, the sooner it gets cancelled.

Putting even one artificially inflated mission on SLS, in a hyper-focused attempt to guarantee that single mission, has the side-effect of putting SLS on life-support and dragging out its death, thereby extending the amount of time that NASA spends with a massive chunk of its nominal budget being completely useless. It means screwing over NASA in the long term, just to save that one mission. This short-sighted approach is exactly what Shelby wants. He set a trap, and people are falling right into it.

Yes, this might cause some missions (at this point, just Clipper, I think) to not get funded until after SLS's eventual cancellation allows NASA to reboot without so much of its budget being hijacked. Yes, that sucks for the scientists who really, really want to study Europa. But to anyone trying to optimize NASA's overall scientific returns, it is a reasonable sacrifice towards the goal of restoring NASA's useful (non-SLS) budget.

NASA's nominal budget isn't going to get cut, but that money also isn't going to go to planetary science. MSFC isn't going to get closed. Boeing, Lockheed, ATK, and Aerojet are still going to get paid.

At best, those monies will be redirected into R&D on new propulsion and vehicles for HSF. Which would be a lot better than SLS, but it's going to be a while before that happens.

Regarding those last two sentences: If true, that's fine. My point was that people with influence over mission design and concern for NASA's usefulness as a scientific organization, instead of as a jobs program, should be taking missions off of the SLS manifest to hasten its demise, not adding to its manifest and thereby prolonging the waste resulting from its existence. Culberson is doing the latter, which harms NASA just for the sake of his pet project.

 

[wyrmhole]

If that is really what would happen, then the long-term responsible thing to do (for anyone with influence over the designs of missions, as Culberson seems to have) is to systematically cap the scope of each mission such that its size and trajectory allows it to launch on at least 2 existing launch vehicles, explain it as a financially prudent risk-mitigation measure

The folks at JPL aren't stupid, they are doing exactly that. DIVH and FH are the backup LVs.

And Shelby isn't the only one behind SLS. Boeing, ATK, and Aerojet have a lot of lobbying power with Congress, as does Lockheed whose Orion is pretty much dependent on SLS. SLS will be canceled eventually, but probably not before it flies a couple times. By the time it's obvious to enough people that it's a dinosaur, enough hardware will be built that stopping those flights won't save much money.

Bureaucratic inertia and lots of lobbying by financially interested parties will most likely get SLS in the air.

Since Congress is averse to actually shrinking NASA's total budget, and Shelby won't let them shrink the SLS budget, taking a mission off of the SLS manifest represents another chunk of money they have to artificially funnel to MSFC and the SLS contractors with no clear purpose. That means the percentage of NASA's budget dedicated to a rocket to nowhere becomes larger.

The faster that happens, the sooner it gets cancelled.

Putting even one artificially inflated mission on SLS, in a hyper-focused attempt to guarantee that single mission, has the side-effect of putting SLS on life-support and dragging out its death, thereby extending the amount of time that NASA spends with a massive chunk of its nominal budget being completely useless. It means screwing over NASA in the long term, just to save that one mission. This short-sighted approach is exactly what Shelby wants. He set a trap, and people are falling right into it.

Yes, this might cause some missions (at this point, just Clipper, I think) to not get funded until after SLS's eventual cancellation allows NASA to reboot without so much of its budget being hijacked. Yes, that sucks for the scientists who really, really want to study Europa. But to anyone trying to optimize NASA's overall scientific returns, it is a reasonable sacrifice towards the goal of restoring NASA's useful (non-SLS) budget.

NASA's nominal budget isn't going to get cut, but that money also isn't going to go to planetary science. MSFC isn't going to get closed. Boeing, Lockheed, ATK, and Aerojet are still going to get paid.

At best, those monies will be redirected into R&D on new propulsion and vehicles for HSF. Which would be a lot better than SLS, but it's going to be a while before that happens.

Regarding those last two sentences: If true, that's fine. My point was that people with influence over mission design and concern for NASA's usefulness as a scientific organization, instead of as a jobs program, should be taking missions off of the SLS manifest to hasten its demise, not adding to its manifest and thereby prolonging the waste resulting from its existence. Culberson is doing the latter, which harms NASA just for the sake of his pet project.

Yep, that's exactly what he's doing.

But personally I don't see it affecting how long NASA is saddled with SLS very much if at all. SLS is going to crumble under its own weight and +/- one probe nominally slated to use it won't change when that happens. After all look at the missions for the rocket. As far as science missions there's Europa Clipper and... nothing.

The rest is all SLS+Orion to lunar orbit with various pieces of the Lunar Gateway which only exists as a concept to give SLS+Orion a place to go. But so far the only thing being paid for are studies, and don't be surprised if it never goes past that because actually building a space station around the moon will be really expensive regardless of the rocket used to fly it so it's a hard sell.

Similarly, I don't think you need to worry about lots of planetary probes being build around using SLS because a mission big enough to 'need' SLS is really expensive regardless of SLS. There just aren't that many Flagship-class missions to create a big demand for SLS on its own.

That's what the gateway is for.

They can either work up the support to fund the gateway, or SLS is going to wither away.

 

[blackhawk887]

At best, those monies will be redirected into R&D on new propulsion and vehicles for HSF. Which would be a lot better than SLS, but it's going to be a while before that happens.

Regarding those last two sentences: If true, that's fine. My point was that people with influence over mission design and concern for NASA's usefulness as a scientific organization, instead of as a jobs program, should be taking missions off of the SLS manifest to hasten its demise, not adding to its manifest and thereby prolonging the waste resulting from its existence.

Ideally, sure.

But pragmatically, the first couple SLS missions are going to fly, eventually. Clipper or no. They can either fly pointless unfinished Orion lunar flybys/gateways to nowhere, or they can fly science missions.