Predicting The Future of SLS
Prediction: @NASA_SLS may well be launched – but humans will never fly into space on it.
— NASA Watch (@NASAWatch) July 25, 2017
Prediction: @NASA_SLS may well be launched – but humans will never fly into space on it.
— NASA Watch (@NASAWatch) July 25, 2017
I’ll add to that that if the big commercial rockets (FH, NG, NGL-H, V/ACES etc…) and lunar dragon2 come to fruition by 2022-2025 SLS will get pushed back to block2 in an effort to move the goalposts
(ps. I’m withholding judgement on mini-ITS untill its actually presented and not just a napkin rocket)
Lol! Hey, it’s past napkin stage! It launched a PowerPoint! 😉
That’s been my prediction for years, actually.
I think you’re missing the point of SLS. I also hope it never launches humans (soon ULA and SpaceX will hopefully be doing that)… it’d be a waste. SLS should be used to throw huge payloads into orbit, or to Mars, that ULA or SpaceX can’t. Like a 40mt fully fueled Mars Ascent Vehicle (even the Falcon heavy can’t come close to that). Block 1B SLS with EUS should have the capability of throwing ~2.5 times the payload that Falcon Heavy can to Mars.
Or, buy three FH launches, and save billions.
Seconded. When the cost difference is big, it’s worth it to see if you can just assemble your spacecraft in orbit from smaller launches before sending it out.
You don’t need to do orbital assembly, as such. None of the BEO payloads proposed for SLS are over 40 tonnes. Few are more than 20 tonnes. The only issue is pushing them into their desired trajectory. Therefore you could use distributed launch, without assembly. Put the payload up on FH, send the BEO booster and fuel separately.
For the largest (>40t) payloads, you need “docking” (the ability of the BEO-booster, a modified upper stage, to mate with the payload), in addition to the refuelling.
For <30t payloads, you can launch the BEO-booster already mated to the payload into LEO, at varying degrees of fuelled, and launch additional fuel flights.
LM is pushing for someone, anyone, to pay it to develop ACES into distributed launch. So this isn’t just a matter of “give everything to SpaceX”. I imagine MDA would like to take a crack at it too, given their interest in refuelling satellites. You could COTS the development of the capability, then acquire it as a service contract.
The remaining $25 billion dollars or so over the next ten years could be spent on developing payloads.
I admit though that there are issues as Paul described. It’s far too glib to say that the loads are divided into three [ed: what I mean is that not all loads are divisible].
As to refueling: I know the Soviets were toying with refueling hypergolic on orbit back in the 70’s (60’s?) using compressed gasses. I don’t know the state of the technology for moving hypergolic, or for moving kerosene/ oxygen, on orbit nowadays.
Hypergolic refueling has been “off the shelf” technology for decades. Both Mir and ISS (Russian) modules have been refueled routinely by cargo craft. This has mostly been with Progress vehicles, but the ESA ATV also had this capability.
Again I wasn’t clear. Sorry.
What I meant to talk about isn’t the small, almost trivial quantities used for station keeping and the like.
Mr. Musk talks of ‘tankers’. The Soviets considered a multi-vehicle approach to rounding the moon before Apollo 8 that would have required on-orbit refueling, but abandoned the approach for several reasons, including the difficulty of lifting and then transferring huge amounts of fuel (political issues, too, were part of the picture).
More specifically when speaking of on-orbit refueling I’m thinking about the gargantuan quantities/mass of fuel and oxidizers needed to achieve high ∂v. I don’t know how much fuel would be optimum for, say, a 10 ton vehicle in LEO wanting to head to Jupiter— not even an order of magnitude. I do know that F9 lifts with 275± tons of oxidizer and nearly 150 tones of RP-1. Even a tenth of those values is daunting.
Refueling is a technology that ought to scale well. But I agree that we won’t know for sure until we try.
ULA has written papers proposing to testing cryogenic refueling technologies on their upper stages, but as far as I know hasn’t flown anything yet. They’ve also written papers about full up LEO fuel depots based on their cryogenic upper stage technologies.
3.2km/s to C3=0, 3.3km/s to direct JTO. Using the Oberth sum-squares rule, net delta_v is a twitch under 4.7km/s. Using a LH/LOx insertion stage at 450s Isp, 10 tonnes payload and assuming a 5% mass ratio on the insertion stage, you’re looking at around 20-25 tonnes of propellant.
(Switching to Kerolox, that blows out to 50-55 tonnes of prop, pushing the overall mass above the capacity of single FH launch. But FH could easily handle a refuelling type mission, if you modded the upperstages into tanker and receiver.)
However, if the insertion stage also supplies Jove capture, that’s another 5km/s, pushing propellant mass out to around 120 tonnes.
(Kerolox blows that out to more than 350 tonnes. So no.)
Nobody is answering the real question here. Why does it have to cost billions?
It doesn’t have to cost so much per flight – it all depends on how much you use it. It was the same with the Saturn V and the Shuttle. To do a big rocket takes a lot of infrastructure (a big launch pad, rocket factory, technical workforce, etc.) If that capability costs, say $3B a year to maintain and use like the Shuttle did, then if you launch it once a year, you could say its a $3B mission. If it cost 400M extra for the marginal cost of building an extra rocket per year, then each mission costs $1.7B, three launches come down to $1.26B, etc.
SLS is only as “expensive” as everyone complains about because its not budgeted to be used very much; if it were to be flown two or three times a year, each mission would cost less and while it would still be a big budget item, it would not seem so unusually expensive. Only thing is, to fly more you need a reason which is what the new Administration will hopefully soon offer – a bigger exploration program.
Yes, but where do you find the payloads? People don’t launch a $100 million satellite on a $1 billion rocket. They probably wouldn’t even launch a $500 million satellite on a $1 billion rocket. So, to get the multiple SLS flights per year you suggest, someone would probably have to pay for multiple, ~$1 billion missions per year. That’s just not in the current plans and not in the current budget.
Ya, but if you’re a Congressionally-funded pork hammer everything looks like a pork nail…
SLS/Orion will cost $30+ billion to get to the first flight. That doesn’t change if you fly it more often.
Quite the contrary, it’s likely that the claimed maximum production rate of the current infrastructure is garbage, and hence the cost of increasing production to even 1/yr would be many billions more.
But ignoring that, the cost over the first decade of ops will be another $30+ billion. So you’re looking at an amortised cost of $6b/yr for the first decade of flights (amortising the dev costs over the second decade of ops is not reasonable, given the cost-of-money issue). If you could somehow launch 4 times per year, that’s $1.5b per launch without counting additional costs of increasing production.
[By cancelling Orion, you’d reduce that slightly, but I suspect there’s some cost-shifting between the programs that would still need to be carried if the actual capsule development was killed.]
Given the actual contract values for components, that oft-claimed unit cost doesn’t cover the 4 engines on the core. So no.
Aside:
Lets suppose anyone actually believed that, or even the figures NASA’s Dan Dumbacher testified to Congress ($500-700 per vehicle), that’s still much cheaper than the current USAF estimate for Delta IVH, if operated at 1 flight/yr after the DIVM retirement, at around $1b per launch.
Given that ULA apparently has asked the USAF to allow it to shut down Delta IVH production, why wouldn’t they suggest to the USAF switching that 1 payload per year over to SLS and buying 1 extra SLS flight per year. Since the development and ongoing costs are already paid for, only the marginal cost would need to be covered by the USAF, putting SLS ahead of Delta IVH. If the cost claims are true.
SLS is vertically integrated, uses US-sourced components, has a large payload fairing, and even the smallest version can lift the heaviest national security payloads into the highest orbits. It’s the perfect substitute for Delta IVH. If the cost claims are true.
NASA might want USAF to pay more, but the agency gets to suck up to Congress about how “useful” SLS is. With a minimum of 1 SLS launch per year, even in NASA’s off-years, the public visibility of SLS is increased, which increases PR for NASA’s missions. And NASA gets to see more launches of SLS before flying crew.
The USAF similarly gets to win brownie points with SLS-loving Congress by using their “Big Rocket”, instead of giving the hated SpaceX yet more payloads. (Which has got to be good for vote-trading on funding for other USAF programs.)
And yet, in spite of all these Wins, no-one is suggesting it. Not one person. Not at Boeing, not at OATK, not at ULA, not in the USAF, nor even the SLS-loving members of Congress.
Why, its almost like those “marginal cost” claims aren’t true.
USAF won’t fly anything on SLS because it still hasn’t forgotten how badly it got burned by the space shuttle program. To extract itself out of that mess it had to fund Titan IV, Atlas V, Delta IV, and Delta IV Heavy.
SLS can be flown unmanned. Therefore doesn’t need to be grounded for two years to solve a minor-but-fatal problem before the first RTF. Quite the contrary, having an unmanned RTF flight would make everyone much happier.
Additionally, unlike the Shuttle, I’m not suggesting that SLS would be their only launcher, they’d still have Atlas and F9 for the low mass payloads, and FH for the high-mass.
And I’m not suggesting they kill DIVH before SLS has flown.
The situation would not be synonymous with the ’80s.
The USAF seems to be trying to avoid being solely dependent on FH for larger payloads, especially because it can’t vertically integrate payloads, which means keeping DIVH alive. But if they had an alternative to DIVH, they could let it die without relying excessively on FH.
…If the marginal cost claims were true.
Which is my point. No-one’s even talking about it. Even if it had no chance of actually happening, you’d think SLS-supporters would be throwing it around as an option. Given the high cost of DIVH, when flown once per year, and the supposed low margin cost of adding an extra SLS, it seems fairly obvious. (If the marginal cost claims were true.)
You’re missing my point. Cost isn’t the issue. Control (of the schedule) is the issue.
From what I understand, even before the Challenger disaster, the USAF wasn’t at all happy with the space shuttle. There were other delays and issues with the program which were completely out of their control. Challenger was just the straw that broke the camel’s back and gave the USAF a credible reason to pull out of the program. I seriously doubt USAF would want to be beholden to NASA management again given the entire history of their involvement with the space shuttle.
USAF knows the issues with Delta IV Heavy since they’ve flown it several times already. The issues with SLS are still largely unknown at this point in time and could cause serious schedule delays if NASA screws up the program somehow.
My point is that even if Delta IV Heavy costs more, its schedule is under USAF control.
I understood what you meant, but as I said, SLS isn’t the STS. Operationally, buying an extra vehicle makes it a DoD launch. Once the design is stable, once it has flown, it’s no different from any launch unmanned vehicle.
However, please remember, my argument wasn’t “This is a good idea”.
My argument is, “Given that SLS-supporters throw every possible defence of SLS on the table, no matter how unfunded and unlikely to be funded, why wouldn’t they be crowing about the potential to replace DIVH? If the marginal cost numbers are real.” People like Mike Griffin have already testified to Congress that SLS is competitive with frickin’ Falcon Heavy!
If they really believed that… then this… since they haven’t, they don’t.
The military command structure assumes competence, both above and below your rank.
The military also has plenty of experience with parallel command structures, and it isn’t good experience (e.g. the British and French armies in 1914 and 1939.) When it comes to a heavy lift launch vehicles with a one-per-year flight rate, I suspect the military would rather pay more and have the ability to say “ours” whenever they wanted. If the alternative is getting in touch with a civilian space agency and talking or negotiating over who gets this year’s launch, I don’t think the military would find that attractive.
My premise was adding one flight per year, not capping the launch rate at 1/yr and then divvying that launch up between agencies. The current launch rate will be about 4-5 flights per decade. If the USAF/NRO/etc added enough launches to replace DIVH (approx. 1 per year), and paid only the marginal cost of unit production and ops, that would significantly increase the rate of production of SLS at no additional cost to DoD or NASA as it’s still below the maximum rate claimed for current production infrastructure.
Those extra SLS launches would belong solely to the customer. They would not be USAF/NRO payloads on NASA’s launch.
My point was that the only reason SLS-defenders are not floating this possibility isn’t an anticipation of DoD reluctance, it’s because the numbers thrown around for the marginal cost of SLS, and for the maximum production rate, are garbage. Even the people using those numbers don’t really believe them.
And is no doubt leery of civilian organizations that they depend upon but have zero direct control over.
That’s a little disingenuous at best. Oh, sure, back in the day that kind of calculation would make sense, because back in the day there was nothing to compare costs against.
Times is different, as they say; now we are witnessing a more-or-less comparable rocket without all (most) of the huge trappings you’ve described.
And, without the developmental costs being factored into every launch, a number that always confused figuring the cost of STS as well.
Cost is the issue that everyone is addressing here.
>I also hope it never launches humans
Wasn’t there a time when it was proposed to have big vehicles launch cargo and small vehicles to launch people?
There were many times when this was suggested. But, as far as I know, none of the proposals ever got beyond the viewgraph state. Or, possibly, preliminary design studies.
Ares.
SLS and Orion 2.15 billion dollars wasted down the rat hole. Soon the SpaceX Falcon Heavy flight in the November 2017 the writing in the wall spell doom for it and its more affordable rocket for sure.
Everyone I’d loosing hope
https://spaceflightnow.com/…
Test flights are just that, tests. If something goes wrong, SpaceX will address the issue(s) found and try again.
Musk tried to prepare everyone for a possible FH launch failure last week in a Tweet. Apparently, spaceflight is hard. 😉
If the first, second, or third FH flights fail, then EM-2 might live long enough to fly. Otherwise, mission shrink could doom it. We are so past that way of doing things. Congress…you’re fired.
SLS is a now a rocket in search of a payload. I’m curious to know, if SLS never carries humans, what exactly will it carry? Please forgive my ignorance, but does NASA actually have something in the works that would require such a heavy lift capability or are they going to switch up future promotion of SLS as the rocket that will get your stuff into space with just one, albeit expensive, launch?
No.
It could conceivably shave some transit time off of outer solar system robotic missions. There was a proposal to have the Europa clipper mission plus lander launched on top of an SLS, and it would take a couple years off of the transit time of the hypothetical Ice Giant mission that will be the next Decadal Survey objective.
It’d be expensive, but just about any big outer solar system mission is going to be expensive unless you’re doing a flyby or the bare-bones Enceladus Life Finder mission.
But will they actually do that? . . . I’m not so certain. Probably not.
Actually, the current baseline for Europa Clipper is a SLS (Block 1B). It does not have a lander. In fact, and much to my surprise, I learned that the SLS launch gets _less_ payload to Jupiter. In effect, a direct trajectory (three year cruise) with SLS isn’t quite as capable as an indirect trajectory, with Venus and Earth gravity assists (six year cruise) with an Atlas 551.
The Europa lander, if it were approved and funded, would need _both_ an SLS launch _and_ an indirect trajectory with gravity assists.
For Uranus or Neptune, an SLS would help. Personally, I don’t know who would pay for it, and I think developing aerocapture would help more. But that’s a separate issue.
They have concepts but beyond em-1 (uncrewed Orion lunar test flight on the block 1) and em-2 (crewed Orion lunar test flight on the block 1b) nothing is funded or certain.
The concepts for sls are
ARM(asteroid redirect mission): cancelled, and would not have launched the robotic vehicle just sent astronauts to visit it and the boulder it retrieved in its final orbit around the moon.
DSG(deep space gateway): not yet funded would use excess capacity on sls/orion launches to send up and assemble small sub-10-ton station modules in order to study how space hazards beyond earth orbit would impact future manned deep space vehicles and to provide a platform for commercial and international partnerships to further shore up the case for sls.
DST(deep space transport): essentialy embryonic at this point but basically a 50ton SEP or CHEM-SEP vehicle that could take 4 astronauts to Martian orbit. Launched as a single piece to lunar orbit on block 2 to save mass. It is fueled and stocked at the dsg before shoving of for mars. What they do when they reach mars will depend on what unfunded and unplanned hardware we place there in advance, but the vehicle is completely reusable able to make the journey at least 3 times over its projected 15 year lifespan.
You forgot to mention probe/lander mission to Europa, which someone in Congress has been trying very hard to launch on an SLS.
On the other hand, Musk has talked about FH being able to throw a Dragon V2 to Europa…pie in the sky?
I was talking about missions with payloads that “need” SLS and so far those payloads are Orion, more Orion, and DST because so far the closest the competition gets is 15-20 tons around the moon (Orion is over 30tons)
Europa can be launched on lighter rockets by either extending the transit time or launching orbiter and lander separately.
At some point the technology to refuel very high energy boosters in space will make more sense than building bigger boosters on Earth.
FH, according to the SX website, can deliver about 19 tons to Mars. Or 70 tons to LEO, at which point refueling starts to make sense.
The Europa Clipper mission (which is the only, currently funded Europa mission) does not have a lander. That _multiple_flyby_only_ spacecraft could launch on a lighter vehicle (although calling an Atlas 551 “lighter” feels odd.) But it actually might not save much money. Even compared to the incremental cost of an SLS, the operational costs of three extra years of cruise to Jupiter wouldn’t be cheap. I don’t know much about their operational plans, but I’d guess $200 million, give or take a factor of two. Since an Atlas 551 isn’t exactly cheap, an SLS launch might be cheaper (although calling anything about SLS “cheaper” feels odd.)
There is a concept study for a stand-along Europa lander. At latest report, it has a launch mass of 16.6 tonnes, which is about 270% the mass of any previous planetary mission. At least any successful one (Fobos-Grunt was comparable, but it never made it out of Earth orbit.) The Europa Lander concept not only requires an SLS launch, it requires a long cruise to Jupiter involving an Earth gravity assist.
[Footnote: The European JUICE mission, in development, is primarily a Ganymede orbiter, but it would make two Europa encounters along the way. So it isn’t entirely correct to call Clipper the only funded Europa mission.]
I’m not sure Mr. Musk specially mentioned the Falcon Heavy. The whole part about Europa was pretty vague. Honestly, I do not see how they could land a Dragon on Europa using a Falcon Heavy as the launch vehicle. With the original-described BFR, probably. With a descoped BFR, maybe. But stopping at and landing on Europa takes almost as much delta-v as getting to low Earth orbit.
Ya, he Tweeted something about FH and “a heavily-loaded Dragon to Mars and a lightly-loaded Dragon to Europa.” But, you know, he’s Elon. 😉
Yeah, he never delivers anything at all, does he. Unlike SLS contractors, who always deliver on time. 😉
If Altas V can deliver something to Europa, then FH must be able to as well. (Once it flies) Or is there some law of physics that FH violates that I am unaware of?
The Falcon Heavy doesn’t have a cryogenic (or high specific impulse) upper stage. That really hurts, when it comes to the mass it can send to the jovian system. I suppose you could build or add one. But that’s expensive. It would probably also mean changes to the launch complex. LC-39A used to have facilities for liquid hydrogen, but I’m not sure if they are still in place or easily adapted to this application.
FH has one of the most efficient upper stages ever flown, capable of around 8km/s delta-v with 10+ t of cargo on top. The F9 outperforms some LVs with HydroLox upper stages. Don’t stare yourself blind on high Isp hydrogen stages.
A fully expended FH can put more mass into Earth escape than an Atlas V 551.
A hydrogen upper stage is not a necessity when you already outperform all other existing vehicles. (It won’t match SLS but it will out perform everything else)
Interesting…how does Merlin obtain that performance without staged combustion?
That’s a SpaceX ‘secret sauce’ ;-), but most believe it is a combination is mass fraction (very low empty weight) and high thrust to weight ratio. (which also helps lower the mass). Isp helps… But it merely one of many factors that contribute.
To illustrate… To match an expendable F9 performance to GTO (almost 6t), An atlas V needs 3(!) SRBs. And that’s with a Centaur stage using RL-10, one of the highest Isp engines out there. Yet a two stage RP1 rocket matches it.
Hyper: That explanation goes to a question I’ve wondered about and pestered folks here about for some time: how exactly did SX essentially grab the future, realizing that reusability was obvious, and setting out to do it?
Answer, as I am learning, is that there’s no single answer, but includes:
1. Audacity
2. Fuel densification
3. Mass fraction
4. A very hot engine/ high ISP
5. A shared sense of mission informing an extremely dedicated workforce
6. Knowledge that continued failure meant working at 7-11
7. Fingers crossed by a minimum of 1,000 people.
Of these factors I’d say #1 stands out.
No doubt the F9 has other improvements obvious to rocket scientists but not to passersby like myself. Perhaps some will add to the list.
In summary: they simply built using rocketry’s 91 years’ experience.
(I tried making an ordered list with the <ol> tag but Disqus doesn’t like it apparently).
I think I’d say dissatisfaction, especially at the management level. You could add things like 3D printed engines or new, ground-up engine development. But I’d say the real issue is that older, more established companies (or their management) had a market, were satisfied doing the same thing and getting the same money. If you’re happy with the status quo, there isn’t much incentive to invest in new ideas and innovations. In contrast, SpaceX was founded by someone who was very definitely not satisfied with the status quo. And had enough of his own money to invest in new ideas and innovations. The specific innovations aren’t as important as the interest and resources to pursue them beyond the paper study level.
I’ll disagree with you on emphasis. I think the dominant trait is #5.
They build for Mars. They know that they need to build infrastructure and public confidence along the way. They also know that they need to get paid that $200 every time around the board in this very long Monopoly game. But Mars drives everything.
That is the true break in the paradigm…a physical objective.
Prior to SpaceX the paradigm was letting someone else set the goals and just building to that…with the contracts signed up-front.
SpaceX behaves like a private space agency.
Mars has no oceans to splash down in, so they built a rocket with extra capacity that they could learn how to land.
Interesting…and yet the f9 still has enough structural integrity to swap-ends at super sonic speeds, in atmosphere, with mostly empty tanks, without folding itself in half.
The payload to escape velocity doesn’t matter. Going to Jupiter takes about 3 km/s above escape velocity.
I could probably do without the hydrogen. But the Falcon Heavy second stage is just too big. At burnout, the Atlas second state (a Centaur) has a mass of just 2.3 tonnes. I can’t find the dry mass of a Falcon upper state, but its visibly quire a bit larger than a Centaur. Every kilo of upper stage dry mass is one kilo less payload. The Falcon would do much better for planetary missions if it had an additional, third stage. Shaving mass off the final stage is probably more important than high specific impulse.
Nor is this just scaling by eye. NASA does have a web page to calculate payload mass to various orbits from various launch vehicles. (It’s linked off the Discovery and New Frontiers program library web page.) The Falcon Heavy isn’t on it, but Atlas configurations comparable to a Falcon 9 are. The ones which give the same performance to escape velocity outperform the Falcon at higher C3 (energy above escape energy.)
The typical quoted figure is 3.9t dry mass (and 93t prop). But not sure how many versions ago that was, I think it was post v1.1 stretch, but pre prop-densification but… “illustration is not intended for navigation purposes”.
ON the calculation of payload mass: I wasn’t able to find the site you are describing. I DID LEARN THAT NASA has some very interesting activities for kids; I suppose those won’t be updated anytime soon.
As to the calculations: Did you mean EMTG? That package is powerful, and downloadable, but not much documentation, including suitability for OS X. But perhaps you were thinking of something else?
I hope I don’t get in trouble for this, but… I was thinking about
https://elvperf.ksc.nasa.go…
The reason I might get in trouble is that I don’t think the site was intended for the general public, and a whole bunch of NASAWatch lurkers overloading their server or emailing requests for user support might annoy someone. I almost think they made links obscure to limit traffic.
For reference, the plots are more useful, and for high-energy trajectories, a C3 of 10 km^2/s^2 gets you on the way to Mars, 30 km^2/s^2 on a trajectory to Jupiter which requires a gravity assist along the way, and 80 km^2/s^2 on a direct trajectory to Jupiter.
Another useful NASA web tool is the Ames trajectory search engine,
https://trajbrowser.arc.nas…
Although I don’t always get what I’m looking for without fiddling with the search criteria.
I’m pretty sure Atlas hasn’t sent a lander the mass of a Dragon V2 to Europa. I think that’s what fcrary was referring to. NASA wants (or rather a certain Senator wants NASA to want) to use SLS to sling a lander/orbiter combo out to Europa. I don’t know what the mass of that package is compared to DV2, but DV2 had better be somewhat smaller if the smaller FH were to send it.
That was what I was thinking of. The Europa Lander study has a lander, a sky-crane decent stage, an orbiter purely as a communications relay, a separate propulsive stages to enter Europa orbit and I’m not sure what else. The estimate launch mass is 16.6 tonnes, last time I checked.
And it’s on a bit of a short fuse. The concept involved assumes Europa Clipper will identify a region of fresh ice, or something, somehow, recently in contact with the ocean. So the lander has to get there at the end of, or shortly after, the Clipper mission. Otherwise the Clipper site selection isn’t reliable. No one has said anything about the cost. But I know what Clipper is supposed to cost, I can estimate how much more complicated the lander would be, and multiply in my head. I get a big number.
The point about quickly following Clipper reminded me of Phoenix: $400M to sample a single site.
It’s a bit tangential, but I’ve always wanted to hear from terrestrial geologists about single site, or even small number of site, measurements. No matter how carefully a site is selected from orbit, I worry that a planetary lander’s results may have been very different, if it had landed on the other side of a hill. Terrestrial geology is very diverse, and diverse on small scales. I don’t see why Mars or Europa would be different.
Depending, one supposes, on the approach velocity, which depends again on patience as we wait for the payload to approach.
I wonder if there’s a minimum workable velocity. Ignoring the time issue (already huge, admittedly), how much difference would be made by approach at some minimal velocity?
With enough gravity assists from the Galilean moons, you could work the spacecraft’s orbit down to a Ganymede-Europa Hohmann orbit. That would approach Europa at about 1.2 km/s, and that’s massively better than 5 km/s or so (the Europa Clipper flyby speed and my memory of the Europa Lander concept study report.) There are some other tricks you could play to reduce it further, to the point where Europa’s 2 km/s escape velocity pretty much all that matters.
Unfortunately, that takes time, and time the enemy. All these orbits involve spending time deep in the nasty parts of Jupiter’s radiation belts. The notional orbital tour was not designed to minimize delta-v; it was designed to minimize delta-v while also keeping the radiation dose within acceptable limits. I’m not exactly sure how they balanced the two, but the radiation does push the result well off the minimum delta-v solutions.
Speaking of patience…if SpaceX is going to have deep space aspirations, shouldn’t they leave a Dragon in Earth orbit for a while to test its systems over the long haul…
…oh, ya, right! Lunar colonies! Too bad about Red Dragon. it could have helped with that. 🙁
So the flow of comments wasn’t high enough over the summer so this is thrown out to bait the SLS haters into action?
Prediction: IF (and with this WH who knows) NASA is going to do an expanded exploration program, SLS will accelerate its schedule and you will see more missions annually – including crewed ones. Have at it!
I am not baiting anyone – whoever you are. If you do not like the words that appear on your screen when you visit NASAWatch then do not visit NASAWatch.
in God we Trust..all others bring data. 3B/yr for SLS/Orion can be shifted to Exploration hardware. SLS should not be built.
SLS consumes 2B/yr — with Magic (or propaganda) cut it in half to 1B for 2 launches — 0.5B for 100,000 kg or $5000/kg. Unfortunately, it costs 1-2B/yr to fly 0 times with no missions.
Falcon expendable was 60M/20mT or $3,000/kg. With Crew round up to 100M in a COMMON configuration. 0.5-1B vs 0.1B for a crew launch. Consider reuse: Nolo contendere.
INCREASING flight rate reduces costs as fixed costs are spread out. An example is Vulcan, where it takes 10 flights (not 2) to achieve 100M/flight without reuse. Fly SLS 10 times an its and absurd 1000mT –SLS is too big and too expensive.
Another major issue is solids and certification using common configurations. Solids and crew do not mix well as solids do not shut down, but can be destroyed by the ground ops if they present a danger to any other personnel. The resulting debris field then drives the Launch Abort System mass to am absurdly massive 10mT, about the same weight as the capsule Orion.
Low flight rate prevents and solids prevents common configurations to fly cargo to find that unknown unknown–this means that once certified, SLS will be ‘just like shuttle and EELV’ and will remain essentially the same ol expensive LVs once again for decades. Its past time to make that change.
That’s an outcome that is hard to see. When SLS finally launches, what do you suppose will be the headlines for those sidebars? Something like “SLS Costs Spell Doom?”, for instance. Because the cost of that critter, cool as it is, might as well be an albatross around the neck.
If rockets had necks, that is.
The drive-by press will not take the time to examine SLS. And in some ways that’s a good thing, because they will be able to ignore the stunning development costs.
Historically NASA and partners have been able to justify costs: “Hey! Space is hard!” Now, though, there’s something to compare. It’s dead simple to look at comparisons between SLS and FH.
I will join Keith in the prediction business, though. I predict that the entire SLS story will not end well for NASA.
And I’d guess that those very smart people are looking for a way out, even as we speak.
Above all, I am not an SLS hater. I am just a realist. Unfortunately the basic design of the SLS, like Shuttle, incorporates elements which drive the cost to a level that isn’t practical, and there is no way to increase flight rate, even if the payloads were available, without even more money for more facilities. The handwriting is on the wall, but the many capable and sincere people who are committed to the SLS are not ready to accept the harsh reality. When it is cancelled there will be a lot of bad feeling. There should be a better way to come to a consensus.
Soon there will also be comparisons with the New Glenn, which despite being late to the table is even newer and more capable than the Falcon. The DOD will have a choice of two modern heavy lift launchers which will actually share costs with commercial payloads, something the EELVs claimed but were never able to pull off.
You are lucky that they have tolerated your post and not deleted it. This is a C3PO fanboy club.
“Prediction:IF”
Anybody can make predictions. Here’s mine:
Prediction: Both SLS and C3PO will be cancelled.
Rocket science is hard. If it was easy we would be on Mars by now.
(sigh) another anonymous post from a droid using a fake email address.
“Hey! We don’t allow their kind in here! Your droids will have to wait outside.”
I think I quoted it right. 🙂
C3PO is a droid.
Yet a droid is not allowed inside a C3PO fanboy club!
Will SLS be glitchier at one or two launches per year than FH at four to six? Can an expanded exploration program be funded side by side with a $5 billion a throw launcher? Will the discoveries from an expanded exploration program domino-seed commercial interest in a heavy launcher tech race that quickly renders SLS obsolete? Remember that those launch providers will probably all be NASA partners with access to everything NASA learns from operating SLS, so they will be jumping from the top-most rung of that ladder.
Here’s my prediction. The U.S. government can’t afford to fly the launch cadence necessary for an expanded exploration program flown exclusively on SLS. Cost per pound between Atlas V and F9 is a lot closer than between SLS and FH, and Atlas is struggling. Furthermore, if routine, repeat support missions to any particular destination emerges, they’ll be handed off immediately to a COTS or CC mirror program, not SLS, and funded through Space Act contracts with multiple providers so that the parent program can live on after Congress gets bored with it.
Money is the enabler. $90M a shot enables a heck of a lot more “expanded exploration” than $5B.
What exactly will NASA learn from operating SLS that will benefit NASA partners? There is little new that will be learned here, when the primary mission is to reuse technology from the 70’s.
FH may have 4 to 6 launches/year, but it has a lot of commonality with F9, which will have a higher flight rate.
The only way I see this thing lingering past em-2+epsilon is if NASA announces that block 2 will be designed from the outset as having a nuclear 2nd stage potent enough to cut flight time to Mars. Then it can always be cancelled because of extreme outcry from the clueless, or because of the added cost of developing a NERVA-reboot, or huge reactor/radiators required for the inefficient VASIMR, or molten salt development, or …
As good a prediction as any. One prediction that will come true: at some point NASA will find a way to back away from SLS. The move will start very small.
The frog is in the pan.
Let’s not underestimate the impact of SpaceX schedule creep.
Let’s not underestimate the impact of SLS/Orion schedule creep.
True. I think we can pretty firmly establish that SpaceX can get away with some (more), but SLS/Orion can’t afford any.
Reading the comments on this post and on Keith’s site in general one might think that SLS is an obvious governmental slug.
It’s an easy case to make. I’ve done it many times.
But there’s another side to the issue. There’s a different narrative, one told by Nasa HQ, one that makes sense. One that includes SLS as a logical and important project.
But what is that story? What’s the other side to this equation? Dunno. And if there are people who are familiar with the case FOR SLS, they aren’t posting here, which is too bad.
Logical and important project to what end? To launch large payloads too big to launch on EELVs, of course!
But *what* large payloads need SLS? None are funded!
I think it’s essentially the same logic as the Space Shuttle. NASA originally wanted a real space station (not just a modified Saturn V upper state, which is what Skylab was) and a Mars mission. That required a better (read cheaper) launch vehicle than they had, and launch vehicle development plus a station (let along plus a Mars mission) was way more than the budget could support. So they ended up building the transportation infrastructure first, and then worrying about the station later. By some long, convoluted path, that more-or-less worked. Now they are developing transportation infrastructure for “beyond Earth orbit” and worrying about what BEO will be like later.
It’s not a bad approach, really, to work on infrastructure, and in that sense the policy is easy to defend.
From that policy flowed many implementation questions.
An entire series of questions were asked, and answered, questions that changed with time: develop/ man-rate Atlas or Delta? Do we use STS parts? Stack or side mount? Solids? Clean sheet? New engine?
The 2017 landscape for NASA policy makers has changed. Now we have SLS. Now we have the reusable FH, and the well-defined plans to improve it, including the (possibly needed?) addition of a high-energy third stage.
With similar throw weights the two rockets appear interchangeable, making possible a new question, one only recently even thinkable:
Do we cede the booster business to the private sector?
But these rockets are far from identical. SLS cannot be and will not be the perfect rocket for all “heavy” missions. Nor will FH be able to singly fill that role.
Rockets developed from the two families— SLS and Falcon— are entirely different beasts, even to this untrained observer. Comparing them in terms of throw weight offers an incomplete picture.
Each rocket family has strengths and weaknesses. Having both families available for future projects is a very positive thing for NASA.
Conclusion: the policy to expand infrastructure was a good one then, and remains one now, though modified.
The failures of policy implementation are a different subject.
Throw weight paints an incomplete picture…but it is a simple picture. Cost paints an incomplete picture too, but it is in early critical planning path where most project ideas die.
The first question asked for anything is, “Can it be done with $xxxxxxx?” That is where the first rubber meets the road, and a little inefficiency in a vacume doesn’t get considered until steps three or four.
I know I keep flogging this dead horse, but until people stop doing this…
If SLS was “available” to NASA, at little or no cost to the agency, then yes it might be a positive thing. But as long as SLS is funded by NASA, you have to count the opportunity cost of the missions not flown because of the SLS program. You can’t just look at the technical sheets for each vehicle.
A NASA with Atlas and FH would have some missions limited, but be able to afford many, many more missions. MSL-Curiosity cost about $2.5b, Mars 2020 has a similar budget ($2b, IIRC). Hubble ran about the same. SLS costs you one project on that scale every single year. Even the horribly over-budget JWST, at ~$9b, is just three years of SLS/Orion funding. JW’s primary mission is just 4 years. How long do you think it will take before NASA gets funding for a replacement space telescope in a similar class?
A NASA without SLS can fund 20-50 missions over thirty years that a NASA with SLS can’t. That’s not a “limitation” on missions, that’s an extinction of possibilities.
The Space Launch System was SPECIFICALLY designed to do one thing and one thing only. Retain as many jobs, both NASA and NASA contractors, in as many political districts as possible.