Author Topic: SLS capability touted for Europa Lander capability, Enceladus sample return  (Read 119653 times)

Offline ugordan

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I'd certainly go with someone like Bob Pappalardo before going to Carolyn Porco. The latter shares that same "gee, wouldn't it be nice to have such a huge rocket" angle the SLS guys naturally have, without going down and thinking about what it all entails.
« Last Edit: 01/08/2012 12:01 am by ugordan »

Offline Peter NASA

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Yeah Chris, don't listen to launch vehicle people, talk to Planetary Scientists. Oh, but don't go to certain ones, go to the ones who hate large rockets.

Jeez, you guys are transparent.

Offline ugordan

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Ooh, I'm real sorry someone's proposing at looking at the other side of the medal here, other than looking at a "Planetary Scientist" (in capitals) who will just tow the party line.

What exactly are Porco's credentials when it comes to designing missions, anyway?

Offline Blackstar

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Engineering capability assessment only I'd say.

Not even that. It's rocket guys developing a list of cool things that their rocket could do, without actually looking at the feasibility of the missions. A true engineering capability assessment would require an end-to-end evaluation. And it would necessarily ask the question what is the most cost effective rocket to do this?

Put another way, this report simply said "here are some things that this rocket could theoretically do." But that doesn't make them legit.

Of course this doesn't suggest the decadal survey will approve such a mission.

Just that's it's possible.

Maybe because it will be possible the next survey will have to study the possibility of doing such missions.

The decadal survey that ended last year did hear presentations on Enceladus sample return. Nothing on a Europa lander, however. Enceladus sample return is possible, but there are a number of major challenges. One major challenge is that any vehicle flying through the plumes to gather material would move so fast that the material would be destroyed during collection. So you would have to slow the vehicle down in some way. Yeah, people postulate that you could use a vehicle with a lot of delta-v to do that (thereby requiring a large rocket at Earth), but that seems pretty dubious. But there's another major challenge--such a mission would take 18-20 years to return the samples. Do you really want to launch a mission that doesn't provide its primary science return until two decades later?

Europa landers were not considered by the decadal survey because that's too big a step. That's like NASA in 1958 establishing its first goal as landing a spacecraft on Mars. Well, the first step is to fly by Mars, then orbit, then land, right? We have flown by Europa. The next obvious step is to orbit it with better instruments (although, if that is too expensive, you would do flybys and accept lower science return). One of the big problems with landing on Europa (besides the horrible radiation) is that the best imagery of the surface has something like 12 meter per pixel resolution, and only for a small part of the surface. You need much better than that in order to put a lander down. And Europa's surface is very craggy. No way you do a lander mission before you do a higher-resolution imager.

The possibility of that kind of money being spent on planetary probes is small and this might be something the article is missing?

It's missing that and a lot of other context. Simply put, Europa is not the top priority planetary science mission at NASA. (Note: it could be, assuming that the Mars program falters, but that's a really complicated issue.) And the Europa program is currently desperately trying to find a mission that costs less than the $4.7 billion that the decadal survey estimated for their previous spacecraft proposal. So right now all their emphasis is on making their mission cheaper, not more expensive. If somebody mentioned launching an expensive lander mission on an SLS during an Outer Planets Assessment Group meeting (OPAG--the primary US group on outer planets science), they would be laughed out of the room. That's my objection: the article implies that this is legitimate, whereas the people who are actual experts in the subject know that in the current political, economic, science, and technology environments it is totally not legitimate.

Offline M_Puckett

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Gee,

Somebody emailed a link to this article to Ms. Porco yesterday,  I wonder who did that? :)

I am needling her to register and participate on the forum.  I will also send he a link to this thread to further encourage her.

Chris, consider her buzzed.
« Last Edit: 01/08/2012 12:12 am by M_Puckett »

Offline Blackstar

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Yeah Chris, don't listen to launch vehicle people, talk to Planetary Scientists. Oh, but don't go to certain ones, go to the ones who hate large rockets.

Jeez, you guys are transparent.

Sigh.

What he should do is go and talk to an expert on Europa spacecraft design and ask them what they think. The way it usually works is that you start with the mission, design a spacecraft, and then figure out what rocket you need, adjusting the parameters based upon your budget (meaning trying to find the cheapest spacecraft and rocket that will perform the mission). You don't start with a rocket and then figure out what you can put on it.

Pappalardo is in charge of JPL's Europa program. He is the authority.

Go and read the planetary science decadal survey released in March 2011. Read what it says about launch vehicle costs KILLING the planetary science program. The entire planetary science community is very worried about launch costs eating their lunch. They want cheaper rockets.
« Last Edit: 01/08/2012 12:24 am by Blackstar »

Offline Chris Bergin

To all, it's getting a bit roudy, let's not. Everyone can post, I'm absolutely willing to answer for my article, and thus this is all useful. Remember, I'm just a monkey with a typewriter, I'm learning, I'm open to learning, I'll hold my ground when I think it's required, but people just need to work out I'm approachable - as this nearly turned into a drive-by ;D

Right then...


"Carolyn Porco: Planetary scientist, leader of the Cassini imaging team, director of CICLOPS, & author-to-be" retweeted the article, saying "Looks like these guys (@nasaspaceflight) read my NYT OpEd http://nyti.ms/tEYjJF abt using SLS (aka AresV) 4 deep space http://bit.ly/zaQkUc" - so maybe that would be a good starting point to give her a buzz?

I'd start by reading the NRC's "Launching Science" report, cited earlier. Then look at the planetary decadal survey. Then look at the decadal survey mission studies.

And I wouldn't go to Porco. Go to somebody currently involved in Europa mission studies. JPL public affairs can give you names, but you can stumble across an obvious one if you ask the question of who is in charge of JPL's Europa program...

And don't start it from the SLS angle, because it's just not legit. That's not what the planetary science program is doing and not how they look at it--they need real rockets, missions that can be done using current technology, and missions that don't cost more than (say) $3 billion. Most importantly, they are not the top priority mission in the decadal survey. In addition, they are trying to reduce the cost of their mission, not make it even bigger.  Start with "what are you currently doing, and what would a future Europa exploration campaign look like?"

And you might take a look here:

http://www.lpi.usra.edu/opag/Oct2011/lander_forum_presentations/

Copy! Downloaded the presentations and will give them a good read. Copy on the approach. I suppose I could "include" the SLS angle, by asking what they think of the suggestion in the Con Ops. But yeah, I wouldn't head into that wearing a SLS hat for a SLS article. I'd be interested in a Europa mission (how's, when's, etc.) even if SLS hadn't been mentioned....so that would be the primary interest/main angle. We are - after all - trying to broaden out with coverage of the deep space missions.

I'll try JPL PAO and see if they can arrange something.

Gee,

Somebody emailed a link to this article to Ms. Porco yesterday,  I wonder who did that? :)

I am needling her to register and participate on the forum.  I will also send he a link to this thread to further encourage her.

Chris, consider her buzzed.

Nicely done, thanks :)
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Offline Blackstar

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Copy! Downloaded the presentations and will give them a good read. Copy on the approach. I suppose I could "include" the SLS angle, by asking what they think of the suggestion in the Con Ops. But yeah, I wouldn't head into that wearing a SLS hat for a SLS article. I'd be interested in a Europa mission (how's, when's, etc.) even if SLS hadn't been mentioned....so that would be the primary interest/main angle. We are - after all - trying to broaden out with coverage of the deep space missions.

I'll try JPL PAO and see if they can arrange something.

You should also go here:

http://www.lpi.usra.edu/opag/Oct2011/presentations/

Here is the context:

-in 2008-2011 JPL was working on the Europa Jupiter System Mission.
-EJSM was not an _approved_ NASA mission, meaning that JPL had money to study it, but not money to design and build it.
-in March 2011 the planetary science decadal survey came out. It had an independent cost estimate for EJSM of $4.7 billion, which was too big for the planetary program to afford. EJSM was ranked second in priority as a flagship class mission, and the decadal survey said that the mission should be de-scoped by JPL to make it cheaper.
-in summer 2011 JPL started studying ways to make an EJSM-type mission cheaper. This soon split into two separate studies: a flyby, and an orbiter. You can find briefings on both of those at the link above.
-in late summer 2011, NASA also asked JPL to look at the possibility of Europa landers.
-all three studies--flyby missions, orbiter missions, and lander missions--are due to be finished around March 2012.

Everybody who is involved in planetary science understands that lander missions are the hardest and the least technologically mature. You can see that in the presentations. JPL has built Jupiter orbiters. It has not built missions that land on outer planet moons. And Europa is hell. JPL has been studying Europa orbiter missions for over a decade now. Those studies have the most technological maturity.

JPL is trying to find the lowest-cost mission it can do that still meets a "science floor," meaning the lowest amount of science that is acceptable. My guess is that they are trying to design a mission that could come in at around $2.5-$3 billion. That means that they will want the cheapest Atlas V they can get, and the smallest spacecraft they can get.

Offline Jason Sole

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http://www.nasaspaceflight.com/2012/01/sls-capability-europa-lander-capability-enceladus-sample-return/

More roadmap fun! :)

Had just read this before I saw the posts crying about poor planetary science. Excellent read.

Offline Andy USA

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Off topic trolling is not allowed on here. Do not respond to them. Thread cleaned up.
« Last Edit: 01/08/2012 02:20 am by Andy USA »

Offline TomH

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Here's the thing that the article completely missed--there is no mission role for this.

...a number of people posting in this thread, seem to think that these Europa and Enceladus missions are legitimate. They're not. They're not planned, they're not approved, they're not even being studied for SLS. The legitimate list of missions that NASA can consider is contained in the planetary science decadal survey...

...a bunch of rocket vehicle guys were producing a study of what their cool rocket could do, and so they asked around about challenging missions to the planets, and somebody mentioned a Europa lander and an Enceladus sample return, so the rocket guys--let me repeat that for emphasis--THE ROCKET GUYS--inserted that into their document...

They want the cheapest rocket they can get to perform the basic mission.


I fully accept what is on the decadal survey, but as its title states, it is a 10 year survey. SLS will barely be in Block I by the end of that time and we will be well into future decades before we go through Block IA and reach Block II. I would ask whether it is prudent or imprudent to examine how versatile a new launcher may be and in what ways its components can be mass produced efficiently and cost effectively and to how many possible future missions it can economically be applied. Saturn V was designed for Apollo and at the end of that program, the LV was discarded in favor of STS, which while in theory was supposed to be economic and have a multi-purpose role, proved too complex, with too much maintenance, and with too little payload to vehicle mass ratio. I know the studies were done, but perhaps more attention should have been paid to Saturn's potential to perform missions beyond Apollo and Skylab. The politically correct doctrine has been to define a mission and then design an LV specifically for that purpose. That may make for optimum mission performance, yet it may also make a good target for a budget cutting congressional appropriator. EELVs have shown their versatility to perform a variety of missions and it simply seems prudent to find a balance between LV mission specificity vs. a multi-purpose LV.  An LV that is overly mission specific can incur prohibitive cost due to a limited production run. A launch system that is too broadly designed may not perform well enough at any of them to be cost effective. The mission creep of the F-22 and F-35 programs is also instructive in terms of cost inflation when too much versatility is demanded after the original design is chosen.

In too many professions, elitists become insular, sequestering themselves in an ivory tower, out of touch with the common citizen. I am not a rocket scientist, nor a planetary scientist. I am, however, trained in science with a very broad education in many fields. I am smart, know a lot more about space exploration than the average Joe on the street, am an avid supporter of NASA and space exploration while nevertheless having concerns about federal budgets, have contact with the public, and I vote. From my point of view, knowing the full range of versatility of this LV is much more important than the fact that the current decadal survey does not include missions described in this thread.

In the early 1800's William Gladstone, then British Chancellor of the Exchequer, was on a budget balancing crusade. Unhappy with funding for scientific research in the nascent field of electricity, he challenged Michael Faraday to justify any manner in which his esoteric research could ever benefit the citizenry. In the early stages of designing electric motors, Faraday stated to the future prime minister that he was not certain of the manner in which the research would manifest itself, yet said, "I'm sure you'll soon be able to tax it." Imagining the world without electricity today it seems not too different than imagining ourselves in the stone age. Physicists investigating the new field of quantum mechanics in the 1920s had no idea that they would make possible the microelectronic circuits and CT scanners we take for granted today. Yet without their study, we would be without these advances.

Personally, I believe the AJAX vehicle proposed on this site would have been a better choice than SLS. Nevertheless, Nelson, Hutchison, Shelby, Hatch, et al. have made the choice. I would posit that it is very prudent to excruciatingly examine the full range of this LV's potential, both now and in the future. This is why I have inquired about it eventually having multiple KeroLox boosters, as well as the possibility of one of those KeroLox boosters serving as a core itself with EELV sized SRBs. Perhaps this would offer great cost savings; on the other hand it might incur the kind of cost inflation fifth generation fighter programs have done. We need to know with much precision how versatile this LV could ever possibly be. I think it unlikely we would get another chance at a HLV prior to mid-century. We have seen several STS replacement proposals crash and this is likely our last chance to get it right for a long time. I am not advocating starting down the long road of modifications that Ares had. I am advocating scrutiny of the myriad ways this LV could avail itself for many decades into the future so that it does not go the way of Saturn. We must know exactly what this LV can do and exactly what it cannot do.

Faraday, Edison, Westinghouse, Einstein, Jobs and so many others moved science and technology in ways that revolutionized civilization. Scientific research is vital to the survival of our civilization. As research becomes more expensive and finances more scarce, we must be ever more circumspect in our choice of the projects we fund. In order to exercise financial wisdom, we must first have knowledge; a portion of that is knowing all of the things SLS will and will not be able to do. We search for new knowledge in all areas of science and then find synergy in them. Will the LHC confirm the Higgs boson? Will someone determine a correct formula for the theory of everything? What could we learn from a monolithic 10m space telescope launched on SLS? What are the ways large payload SLS missions might benefit us?

It will take both the aerospace professional as well as the avid amateur space fan like me as I try to share that passion with my students to keep the space program alive. I see our camaraderie on sites like this one as a way to engender excitement anew among the public. Like Faraday, we have no idea of the full fruit our current research will yield in decades to come. What we can be sure of is that it will be world changing if we allow ourselves and inspire our children to dream.
« Last Edit: 01/08/2012 03:53 am by TomH »

Online Steven Pietrobon

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This all reminds me of the Voyager Mars and Venus missions proposed in the 1960's (not to be confused with the latter Voyager outer planets missions). The first mission was to launch two orbiter/lander missions to Mars in 1973 on a Saturn V. Instead, two Titan-IIIE launchers were used, one for each orbiter/lander, now renamed Viking. Read about the first Voyager missions on the Beyond Apollo blog. According to Beyond Apollo, Voyager was not funded by Congress partly because it was tied to a future crewed Mars mission.

As shown by Viking, I don't think a very large HLV like SLS is necessary for outer planet exploration. Smaller vehicles can be used. I don't think reducing mission times is a big advantage. In a trade between using a smaller launch vehicle or increasing capability with mission time, I think the former will nearly always win. Also, going for a big initial mission first time can be costly, especially when there has been no time to learn about the actual environment the mission is going to. I think its better to start small, and gradually work you're way up from there. There may be a time when the capabilities of an SLS sized vehicle would be desirable, but that's far in the future from what I can see.
Akin's Laws of Spacecraft Design #1:  Engineering is done with numbers.  Analysis without numbers is only an opinion.

Offline CitabriaFlyer

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Blackstar's comments about SLS in the context of the current decadal survey are well taken.  However, SLS will probably be coming into its own with the Block 2 version in the late 20s.  Scientific objectives, public opinion, economics  and international relations may all be quite different by then. 

Not really my intention to open up the whole "if you build the rocket the payloads will come" argument that has raged on this site.  I am not qualified to debate the issue though I would hope to see that happen.  Imagine if the government said we will subsidize 12 Block2's a year and different agencies (NASA directorates, private sector, other governmental agencies) competed for the boosters and the best idea (however you define that) wins.

Another thought is that someone mentioned the best use of SLS for planetary exploration was to support massive fuel depots.  I like this idea.  Then  the science directorate need only pay for an EELV class booster, but fly out to the EML dump (subsidized by a larger pool of payers), top off and then fly a higher energy trajectory to the destination.  This way you tend not to design a >5billion dollar payload that takes advantage of the SLS capacity.  If SLS blows up you are out the expensive payload.  If SLS blows up on the way to a depot you are only out the prop.

Finally, Chris did the correct thing in pointing out that the SLS guys are interested in talking about their rocket's capabilities.  That is just journalism.  Report the facts.  The great thing about this forum is that then the facts can be analyzed.  More fun to analyze things rather than Chris to tell me the problems with SLS for planetary exploration.

Finally, what makes the decadal survey  set in stone?  If one of the President's daugters thinks it would be cool to fly to Enceladus on SLS we might just be doing it.  Seriously, if the senate designs a rocket for political purposes don't you think they would designate a destination for political purposes?  If Sen Shelby can garner support to launch an SLS to Saturn who cares about the scientific practicality?  Even the people who read the decadal survey are going to think that is cool.

Offline ugordan

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If Sen Shelby can garner support to launch an SLS to Saturn who cares about the scientific practicality?  Even the people who read the decadal survey are going to think that is cool.

Not if that same senator makes the planetary community have to pay for his pet project instead of the community spending their allocated pool of money on priorities they themselves picked. This is what's great about the planetary program. It's not primarily driven by politics and I for one would like it to remain that way.

The community as it stands now can hardly afford some modest Atlas V variants. If these folks think they can offer a much better ride for the same amount of money an Atlas (let alone a Delta IV) costs, then I'm all for it. The planetary community isn't looking for bigger (because they can't afford it), it's looking for cheaper. If bigger turns out cheaper as well, of course they won't complain. I just don't see that happening, however.

Offline Jim

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It would seem that an advanced SLS liquid booster would make an interesting launch platform on its own. It would be more powerful than Ares I. If multiple options were considered in the original design phase, it seems that this rocket (as a single core) could possibly add up to 8 solids (Aerojet is currently upgrading its 67' SRB) as needed, cluster in CCB configurations of 3 to 7 cores, all in addition to serving as a tandem booster on SLS. It would in some sense be filling the role of Atlas V Phase II and more. Would not such a vehicle be able to fill some of the mission roles described in this thread?When it's time for the advanced booster design competition, I would think including such options in their proposals would give ULA (and possibly others) an added edge over ATK with their advanced solids.

ULA only exists to produce EELV's and not advance boosters for other vehicles.  Boeing and/or LM would probably want to do that themselves.
« Last Edit: 01/08/2012 01:18 pm by Jim »

Offline Warren Platts


Quote from: Blackstar
The way it usually works is that you start with the mission, design a spacecraft, and then figure out what rocket you need, adjusting the parameters based upon your budget (meaning trying to find the cheapest spacecraft and rocket that will perform the mission). You don't start with a rocket and then figure out what you can put on it.

This is not true: read Prof. Porco's Op-Ed article. There are all kinds of missions that would be enabled by heavier mass probes that require beefy rockets to get into space. The mission is always constrained by the rockets that are available. Who wouldn't want a 25-tonne orbiter around a place like Jupiter or Saturn? But with present rockets, it's just impossible, so naturally 25-tonne probes don't make it onto the Decadal Survey. You start with the biggest probe you think you can get away with (and that depends on the rockets that are available) and then scale back expectations from there.


Quote from: Blackstar
They want the cheapest rocket they can get to perform the basic mission.

There are creative ways to leverage SLS that would at once enable lower launch costs and heavier, much more functional probes. E.g., check out Zegler et al's papers on a depot-based space architecture. According to Zelger, by rendezvousing at an L2 depot, a space probe could load up on propellant there, and then proceed to the outer Solar System via a gravity assist around the Earth.

If planetary scientists don't discuss these sorts of plans in the decadal survey, that's not because such missions aren't "legit", whatever that means, that's simply a result of such architectures not being an option.

I agree that following the old Apollo template where everything goes up in one BFR would be hugely expensive, and therefore not very useful. However, if SLS's primary job was humping propellant to a series of prop depots in LEO and the Lagrange points, they could maybe get the flight rate up to 6 per year and thus launch 720+ tonnes of propellant to LEO per year at a cost of $3B or less. That would be a pretty good deal.

By enabling cost effective, heavier probes, the cost for the mission hardware can actually go down. Small does not automatically equate to cheaper--unless of course small means amputated functionality. In fact, it's usually the opposite that is the case: the drive for smaller probes isn't to save money, it's because they are so mass-starved; it's the push to shave off every last unnecessary ounce that is a major cost driver.

An affordable depot-based architecture fueled by SLS launches allows one to trade extra mass for lower probe construction costs, or trade extra mass for faster transit times and still be affordable.
"When once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return."--Leonardo Da Vinci

Offline TomH

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ULA only exists to produce EELV's and not advance boosters for other vehicles.  Boeing and/or LM would probably want to do that themselves.

Thanks for pointing that out, as well as for doing so in a tactful manner. I appreciate the correction.

Online oldAtlas_Eguy

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Philosophy of LV design:

A – CxP – design a single or a set of LV’s to fit a mission

Advantages:
1) The LV’s are designed to simplify the mission complexity

Disadvantages:
1) If support for the mission erodes the LV will not get built
2) Changes to the mission hardware drive changes to the LV design causing ever increasing costs during DDT&E for the LV

Method of creating LV design requirements:
A primary or set of primary missions are defined with iterations made until an optimal set of LV requirements are derived. Meaning mission hardware design process is in advance of LV design.

B – SLS – design a general purpose LV with a set of capabilities that missions are then designed to

Advantages:
1) Political support is for the LV alone not for any specific mission
2) Design changes are minimized keeping DDT&E costs hopefully under control

Disadvantages:
1) No missions until design stabilizes
2) No funding for missions until LV program is well under way and near to completion because design of a mission around an LV not yet existing is very risky for a mission program
3) For some missions high complexity and additional hardware as well as increased total mission costs occur, non-optimal LV fit to missions

Method of creating LV design requirements:
A politically levied set of nice to have capabilities expressed in top level requirements are made that fit within the allowed budget. Meaning LV design process is in advance of mission hardware design.

Apollo/Saturn V was an example of the first and Shuttle an example of the second.

Here we have DRM’s being tailored to a specific LV design. Politically more support for the LV will come from different specific mission supporters that would fly on SLS than ever would occur in the first case. So these DRM’s will be important to be wide ranging showing how varied SLS use can be, as this one is compared to the HSF DRM’s. It’s not so much whether this DRM will be executed but that it shows how SLS can be used for a variety of advanced missions. Both manned and unmanned.
« Last Edit: 01/08/2012 07:53 pm by oldAtlas_Eguy »

Offline Jim

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Apollo/Saturn V was an example of the first and Shuttle an example of the second.


Actually wrong on both.  The Saturn V was designed for the LOR mission.
The shuttle was designed around reconsats, space station modules and future LH2 stages.

Offline Blackstar

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Quote from: Blackstar
The way it usually works is that you start with the mission, design a spacecraft, and then figure out what rocket you need, adjusting the parameters based upon your budget (meaning trying to find the cheapest spacecraft and rocket that will perform the mission). You don't start with a rocket and then figure out what you can put on it.

This is not true: read Prof. Porco's Op-Ed article. There are all kinds of missions that would be enabled by heavier mass probes that require beefy rockets to get into space.

You do not understand this at all.

There might be "all kinds" of theoretical missions that could use big boosters. There is no money to build them. You start with an idea of how much the mission should cost and then try to fit within that budget, trading off capability to get there.

Do yourself a favor: stop reading op-eds and go and read the decadal survey. You don't have to read the whole thing, just read the executive summary. That is the document that guides planetary science priorities. You'll learn a lot.

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