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NASA Delays First Flight of New SLS Rocket Until 2019 (arstechnica.com)
schwit1 writes: Despite spending almost $19 billion and more than thirteen years of development, NASA today admitted that it will have to delay the first test flight of the SLS rocket from late 2018 to sometime in 2019. "We agree with the GAO that maintaining a November 2018 launch readiness date is not in the best interest of the program, and we are in the process of establishing a new target in 2019," wrote William Gerstenmaier, chief of NASA's human spaceflight program. "Caution should be used in referencing the report on the specific technical issues, but the overall conclusions are valid." The competition between the big government SLS/Orion program and private commercial space is downright embarrassing to the government. While SLS continues to be delayed, even after more than a decade of work and billions of wasted dollars, SpaceX is gearing up for the first flight of Falcon Heavy this year. And they will be doing it despite the fact that Congress took money from the commercial private space effort, delaying its progress, in order to throw more money at SLS/Orion.
This rocket was built on top of SLS Linux. Cool stuff!
SLS has always been a make-work program to preserve legacy jobs at Space Shuttle contractors. If NASA (or anyone else) has set out to design the best possible heavy-lifter with today's technology, they wouldn't use strap-on SRBs, and probably wouldn't bother with H2/LOX in the first stage either. (Just look at the two private companies that are developing heavies -- SpaceX and Blue Origin.)
I have a running bet with some friends on how many times the SLS will fly (if ever). My money's on two flights before it gets the axe.
XML is like violence. If it doesn't solve your problem, you're not using enough of it. --AC
It's not worth rushing it
SpaceX is notorious for delays.
The big and crucial difference between the two organizations is that SpaceX has been incrementing up to FH while simultaneously doing something commercially useful, as opposed to NASA's One Big Project approach (which it had to do for a variety of reasons.
"I don't know, therefore Aliens" Wafflebox1
Out of curiosity, which era of history or presidential legacy are you comparing those 8 years to? I'm kinda old and I don't recall any president in my lifetime not fucking up the economy. Clinton balanced the budget, but left GWB with a huge cleanup bill which Clinton should have been spending money on the whole time, Reagan, Bush and Bush all spent money like a whore who found a rich customer's credit card on the floor after he left.
You seem to think the grass used to be greener... it was always brown and we were convinced by our leaders it just needs more water. The only real difference is Obama was Internet era and we saw what he was doing. Before that it was much easier to keep you from seeing the yard.
If NASA (or anyone else) has set out to design the best possible heavy-lifter with today's technology, they wouldn't use strap-on SRBs, and probably wouldn't bother with H2/LOX in the first stage either.
Hi, I'm only a rocket engineer graduated from Kerbin university, but what's the rationale ?
SRBs are a pain-in-the-ass to "refuel"... it takes weeks of meticulous work. Liquid H2 is a "pernicious molecule" according to Elon Musk. It's so tiny it's hard to contain; it's colorless and odorless, and burns with an invisible flame. Yes, it gives you a higher ISP than RP-1, but not so much higher as to make it worth the trouble. (H2 is mostly used in upper-stages, where the higher performance has a better pay-off.)
Note: IANA rocket scientist, the above is just what I've gathered over the years as an armchair space enthusiast.
XML is like violence. If it doesn't solve your problem, you're not using enough of it. --AC
Did anyone seriously think they would kick the thing off on time? This is a govt. project.
Solids have horrible failure modes for a manned space flight platform. Not to mention they are inefficient like heck. The only reason to use solids is because you're indirectly funding ICBM tech. I'm not sure I agree with the LOX/H2 thing though. It kind of depends on the vehicle and engine design. But it is true hydrocarbons are a lot more dense and hence result in less vehicle manufacturing costs.
...I WONT be going to Mars? I thought that was the plan.
And yet Ariane 5 has both solid rocket boosters and a H2/LOX fist stage.
"It's such a fine line between stupid and clever" -- David St. Hubbins, Spinal Tap
Kerolox is for hipsters, real men fly ClF5 + Pentaborane
True. I hadn't thought of that. But I'd note that Ariane-5 was developed in the mid-90s, and was based on the Ariane-4, which also had SRBs. I wonder if they would make the same design choices today?
Also, I wouldn't classify Ariane-5 as heavy lift... it's in the same ballpark as Falcon 9. Not that that makes a huge difference in fuel choice. But it's interesting that both SpaceX and Blue Origin are not using LH2/LOX for their heavy-lift boosters.
XML is like violence. If it doesn't solve your problem, you're not using enough of it. --AC
True. I hadn't thought of that. But I'd note that Ariane-5 was developed in the mid-90s, and was based on the Ariane-4, which also had SRBs. I wonder if they would make the same design choices today?
Perhaps not but sometimes the best path forward is to not try to relive the past. Perfect can be the enemy of good. Something can be very useful without being optimal. The computer you are typing this on has a lot of historical cruft in it but removing that cruft is generally more expensive than simply building around it. If it is economically not viable in the face of some new technology then eventually it will get replaced (see SpaceX) but if it is "good enough" compared with the available alternatives then there is no point in reinventing the wheel. SRBs may not be perfect but they demonstrably have been economically useful.
I'm not arguing for or against SRBs but merely pointing out that if the expensive work of development has already been done then it makes sense to keep using them until something truly better comes along to replace them in the market. Whatever replaces them has to provide a substantial cost/performance savings or there is little point.
Ariane 6 is due for first flight in 2020 and uses SRBs... :)
Did anyone seriously think they would kick the thing off on time? This is a govt. project.
You say that as if private enterprise projects never miss a deadline...
SLS has always been a make-work program to preserve legacy jobs at Space Shuttle contractors.
Perhaps in part but it also serves a few other purposes. Probably the most important one is that it gives NASA a path to getting heavy lift capabilities in the event that the private enterprises working on the problem fail. It's a hedge of a sort, albeit an expensive one. Let's say hypothetically that SpaceX cannot get their Falcon Heavy to work for some reason. If NASA put all their eggs in that basket they could reasonably end up with no heavy launch vehicle. With SLS in the works NASA won't find themselves without options no matter what the private sector does.
Remember that as recently as a few years ago it wasn't at all clear that private companies like SpaceX would be as successful as they have been so far. It was uncharted territory and when you go into uncharted territory it's sensible to have a backup plan in place just in case things go wrong. Things are looking better by the day for private launch companies but there is still time for things to go tits up before SLS is operational.
I have a running bet with some friends on how many times the SLS will fly (if ever). My money's on two flights before it gets the axe.
I think it will depend heavily on how successful companies like SpaceX and Blue Origin turn out to be. You may very well be right but I would regard that as a best possible scenario. If SLS ends up seeing a lot of use it means that SpaceX and the rest failed.
Ariane 6 is going to have the same configuration.
The most probable cause is that both SpaceX and Blue Origin aren't experienced enough to use either solid fuel boosters or hydrogen fuel. My speculation is that they have employed a lot of ex-USSR aerospace engineers who aren't accustomed to either and both companies simply don't have a technological base that is required for liquid hydrogen - it is after all notoriusly diffcult, one only has to read about the Energia launcher development to see why.
"It's such a fine line between stupid and clever" -- David St. Hubbins, Spinal Tap
Not so much missile tech dev and more about wealth redistribution and international politics. Emphasis on missile tech rolled off during Apollo as NASA turned almost exclusively to flag waving politics. After that it was made nearly irrelevant in the flag waving campaign (ISS is counter flag waving as it embraces those we previously tried to one-up). It then transferred to wealth redistribution via internal politics of Congress.
The Republican states which receive that pork (Fl and Tx) do a excellent job of turning their share of the spoils into pure waste (manned space post ISS). The Democrate states (mostly CA and Va) actually attempt and mostly succeed turning their take into useful product.
Yes, some of us are fagots. Others are not and we accept them both as equally as we can. That's freedom...
That's not the reason you don't use it for a first stage. The disadvantages of hydrolox (which are numerous) are offset by its incredible specific impulse. But for a first stage, specific impulse doesn't matter that much, while thrust matters a lot. Thrust is in large part proportional to fuel density, as a turbopump sweeps out a fixed volume per rotation, so the denser the fuel, the more mass (and generally all else being equal, energy) it pumps per rotation.
Another aspect is that first stages are big, meaning that cost is more important than specific impulse. By contrast, when dealing with an upper stage, a small increase in mass has a huge increase in first stage size, and since first stages are so large and expensive, that's a big cost. So you generally want a higher ISP upper stage. With the caveat that "storability" requirements for engines that need to restart can shift the balance; because hydrogen is so deeply cryogenic it's difficult to store for protracted lengths of time. Also, the longer you plan to have a stage in usage without maintenance, the more you tend to favour simple propellants over high performing ones, particularly when you're dealing with small, light engines. So for example if you have an interplanetary probe you'll tend to favour a self-pressurizing hypergolic system so that you only have to rely on a couple valves working, even though self-pressurizing propellant tanks are heavier and hypergolics tend to be lower specific impulse. Engines that are smaller still are often monoprops for an even greater degree of simplicity.
"He's a liar whose lawyer is lying about his lying lawyer's lies."
Just remembered that Delta-IV also uses LH2/LOX first stage, and also can have SRBs attached. But I think you're right that SpaceX opted against LH2 because of the added level of difficulty and expense. More to the point, I suspect that they figured out early in the process that reusability was within reach without LH2... and they turned out to be right. But if the numbers had gone the other way, I think they would have spent the time and money to master LH2.
Luckily, they didn't have to; fuel 'densification' was more than enough to get the job done.
As for SRBs, I suspect both companies avoided them for the reasons you give, but chiefly for the sake of reusability. SRBs just don't work well with a fly-refuel-fly-again scheme. And if you can do the job without them, why bother?
XML is like violence. If it doesn't solve your problem, you're not using enough of it. --AC
Solids really aren't that bad when reusability isn't a concern. They're very high thrust, which is exactly what you want out of a booster, and they're structurally very simple. Their low impulse and high structural mass are not particularly important aspects for boosters. Reuse of solids however gains you very little, because there's so much work in refurbishing them.
"He's a liar whose lawyer is lying about his lying lawyer's lies."
SpaceX and Blue Origin would not use solids, not because there's something wrong with solids per se, but because they're not "fuel and go", which makes them expensive to reuse - and SpaceX and Blue Origin are all about reuse.
A lack of experience with hydrolox surely factors into the picture for SpaceX and Blue Origin; they'd get significantly higher payload fractions by using a hydrolox upper stage. But they're willing to accept lower payloads in order to simplify their manufacture and ground infrastructure, and in particular because the need their propellants to be storable, and storing LH for long periods is a PITA. Storing methalox is quite difficult, but nothing compared to hydrolox.
"He's a liar whose lawyer is lying about his lying lawyer's lies."
The worst thing about LH2 is that once you get it cold enough to be liquid, it changes phase with the relative spins of the two atoms, and the heat generated by that warms it up just enough to become a gas again. It takes days to properly chill LH2.
#naabhaprzrag, #sverubfr-000, #agi-fcbafberq, negvpyr[pynff*=' negvpyr-ary-'] { qvfcynl: abar !vzcbegnag; }
Remember Challenger? When solids fail the possibility of vehicle loss is quite high.
Only issue is it has corrosion and toxicity issues that make NERVA seem clean in comparison.
The government exists for defense and the things the private sector can't/won't do. Now that there are multiple private rocket companies NASA should be refocused to things like breakthrough propulsion (EM Drive, Warp Drive, even Orion-style nuclear, etc), life support/reclamation (as opposed to the current wasteful system of "crack water and dump the shit overboard"), and other supporting technologies to colonization of space. The government, including NASA, is always going to be slower than the private sector in production, it only really shines when there is no incentive for private corporations to do a thing.
FWIW SpaceX uses TEA-TEB for the LOX/Kerosene rocket ignition. A teensy amount of it but still.
This is why you set goals and let the scientists & engineers figure it out. When Apollo was built we didn't have Congress constantly dictating to NASA how it should be built, where it should be built or making design decisions. Fast forward to the 21st Century, we have endless committees getting nowhere with a constant tug of war on where components should be built and by whom.We've laid off the core of NASA who knew how to make the shuttle work and yes, regrettably we've had to spend tax dollars on busy work to keep ATK and others from going out of business.
In the meantime, ISS manned missions will be handled by the Russians who are our sometimes on again/off again friends. Now, because of these relationship issues, do any of us believe that the costs of doing business with the Russians won't significantly increase over the next few years? The ISS will be shuttered before it's end of life in 2024, another multi-billion dollar boondoggle that now the US can't fully support yet we provided most of the funding for. Bravo!
After billions spent on Orion/SLS, we still have no way to get our astronauts into LEO much less beyond. Didn't we win the race to the moon?
Harrison's Postulate - "For every action there is an equal and opposite criticism"
Neither one ever balanced the budget. Their was one _projected_ balanced budget, it went pop with the first dotcom bubble.
That budget was only balanced if you believe that the SS trust fund is a valid source of revenue for the general fund.
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
What happened to the space suits we have been using?
Did someone accidentally burn down the warehouse containing every existing suit, and every copy of the blueprints for them?
All we really need (from a ground-launch perspective) is just enough to get into orbit. Any flights beyond there could be launched from orbit.
Do you really want to spend weeks traveling to mars in a cramped rocket nose-cone, or would you rather ride in a large roomy ship that was built without the constraints of having to fit on top of a single rocket?
Thank you for fleshing that out, and putting it much better than I would have. The main purpose of the booster/first stage is to get the second stage up into the super-thin air going super-fast, and let your vacuum-optimized LH2/LOX engine(s) operate in ideal conditions.
LH2 is a huge PITA to work with (more demanding than LOX or liquid methane), and is not even necessary if you have a high-performing booster that can run on RP-1 -- which is an easy-to-handle liquid at both ambient pressure and temperature.
And thank you for illuminating a nagging, old question... why do hydrolox boosters so often have SRBs attached? Now I know.... it's the thrust coefficient.
XML is like violence. If it doesn't solve your problem, you're not using enough of it. --AC
Remember Challenger? When solids fail the possibility of vehicle loss is quite high.
Or when "o-rings" fail. If the booster had been one piece, it wouldn't have failed.
It must have been something you assimilated. . . .
discussion of that at NASAwatch, http://nasawatch.com/archives/...
mfwright@batnet.com
be able to tell us what he really thinks. I wonder if 30 years from now he will say, "None of you understood the situation and some of the [insert scenerio here] that I was facing and all the [insert list of dirty laundry here]."
mfwright@batnet.com
As if liquid boosters can't fail catastrophically? Check out SpaceX's last failure. Liquids are hardly immune to catastrophic failure.
And actually more to the point, you've got it backwards. The SRB failure on Challenger was slow, more like a blowtorch. The explosion was when it compromised the external tank (which, obviously, stored liquids).
Solid propellants aren't like explosives. More to the point, you have to keep them under pressure to get the sort of burn rate that is desired for a rocket.
"He's a liar whose lawyer is lying about his lying lawyer's lies."
Yeah, but they tend to hit them more often then they miss. Most govt. projects miss their deadlines.
And make no mistake, the orange trout with the mullet and the comb-over... is every bit a politician.
Clinton balanced the budget...
The Dot-com Bubble balanced the budget.
That SpaceX failure happened during the hold down phase. In any decent manned booster you only put people on the rocket after the wet dress rehearsal and the hold down test. Plus, solids can't be throttled.
Blue has experience with hydrolox, and will use it in the optional third stage for New Glenn. However, they'll only fly that when they need really big payloads or high energy orbits.
Storing liquid methane and oxygen really isn't that difficult. Look at what we do with shipping and storing liquefied natural gas, which is just impure methane...we transport and store it on scales vastly larger than needed for Musk's grandest Mars plans, and LOX is only slightly colder.
My only nitpick would be that NASA has been getting along without heavy lift capability since the Saturn-V was retired.
That's true but I'm not convinced it is a relevant issue. We gave up our heavy lift capability because the powers-that-be many decades ago decided the shuttle was the way to go and they couldn't get funding for both given the politics of the day. In hindsight that was a mistake but at the time the best path forward wasn't so clear. So you have to ask the question whether lacking heavy life capability was good policy or an error in planning? I would argue that we've been "getting along" without heavy lift because there wasn't any heavy lift to be had. The government was the only organization until recently in a position to fund development of such a beast and for various reasons congress decided other items (like the shuttle) should take priority. I see it more as an error in planning rather than a lack of any need.
It's kind of a chicken-vs-egg question. You cannot utilize heavy lift capabilities that don't exist and it's hard to justify building heavy lift rockets until you can prove there is demand for them. Nobody is going to design something to go into space that requires a launch vehicle that doesn't (and won't) exist.
Think how much money probably could have been saved in construction of the ISS if we had heavy launch capability? It likely could have cut the number of launches or improved the capabilities significantly.
That is why I still give at least equal weight to the "pork-barrel" theory for SLS.
Oh have no doubt that pork is a piece of the puzzle but I just think it is a smaller piece in regards to SLS than many think it is. Nothing government funded gets done without some amount of pork. The problem as I see it is that in the best case scenario SpaceX and Blue Origin come out with wildly successful launch vehicles. Then congress will see that and ask NASA why they needed to spend billions on a redundant launch vehicle which makes NASA look worse than they deserve. It's hard to sell the idea that we needed to spend billions just in case SpaceX fails.
That's not true. The third stage of the ill fated Minuteman IV was both solid and throttle-able. It used valves on the sides to control the chamber pressure and thus burn rate. It was an overly complicated advancement of the shaped charge ports used to cutoff the third stage on the Minuteman I, II, & III. They couldn't get it to work right before the whole project was scrapped, but it works in theory.
There were also several plans to use a variable width nozzle choke to control chamber pressure and allow for thrust vectoring solids. Basically all those projects ended whenever someone asked "Why not just use a liquid engine?"
So you can do it, it's just difficult and expensive and why bother?
That is so laughably false.
The ISP is still going to be crap.