Gee, Gerst, surely you didn’t just figure this out?
Although payloads are yet to be announced, Mr. Gerstenmaier confirmed the flight rate has to be once a year as a minimum requirement, in response to a question from Bejmuk – who had assumed SLS would only launch once every two or three years.
Mr. Gerstenmaier noted that ”repetitive cadence is necessary” as the reason SLS will launch every year.
And yet, there are no plans, or budget, to do that.
Here’s what I wrote in the book (and I wrote this at least a year ago):
It should be noted that NASA currently plans only two flights for the SLS — one in 2017 to demonstrate the 70-ton capability, and one with a crew in 2021, to . . . somewhere. They have said that, when operational, it may only fly every couple of years. What are the implications of that, in terms of both cost and safety?
Cost wise, it means that each flight will cost several billion dollars, at least for those first two flights. If, once in operation, it has a two- or three-billion-dollar annual budget (a reasonable guess based on Shuttle history), and it only flies every couple of years, that means that each subsequent flight will cost anywhere from four to six billion dollars.
From a safety standpoint, it means that its operating tempo will be far too slow, and its flights far too infrequent, to safely and reliably operate the system. The launch crews will be sitting around for months with little to do, and by the time the next launch occurs they’ll have forgotten how to do it, if they haven’t left from sheer boredom to seek another job.
As a last-ditch effort to try to preserve the Shuttle in 2010, some suggested that it be maintained until we had a replacement, but to fly it only once per year to save money.[11] The worst part of such a proposal would have been the degree to which the system would have been even less safe, given that it was designed for a launch rate of at least four flights per year. It was unsafe to fly it too often (as NASA learned in the 80s as it ramped up the flight rate before Challenger), and it would be equally so to fly it too rarely. NASA’s nominal plans for SLS compound this folly, which is magnified by the fact that both internal NASA studies and independent industry ones have demonstrated that there is no need for such a vehicle to explore beyond earth orbit (existing launchers could do that job just fine, with orbital mating and operations), and it is eating up all the funding for systems, such as landers and orbital propellant storage facilities, that are necessary. All of this is just more indication that actually accomplishing things in space is the lowest priority for Congress (and unfortunately, the space agency itself, otherwise, the administrator would be more honest with the appropriators on the Hill).
Emphasis added.
The SLS requirements document states that the SLS will be production limited to one every other year. They are required to be able to launch three in any given year — because some reference missions require that many launches — but they can only build them one per two years.
Wishful thinking aside, NASA can’t sustain a one-per-year SLS flight rate with the industrial capacity (meaning: money) they’ve got.
Better that he figured it out late than never. I think that if the government wants to fund heavy lift capacity all it has to do is come up with missions that actually require it. Be it launching more ISS modules or doing a new space station or whatever. Still this is kind of besides the point. Once they mandated dual launches per flight they should have reconsidered whether a multiple launch architecture was viable for manned inner solar system exploration using existing systems or expansions of them. The EELVs have detailed rocket capacity expansion plans using modular architectures with the same propulsion and booster blocks and SpaceX also is developing increases in rocket capacity and reusability. So why bother to use a custom built rocket which can’t be used for anything else?
Note that when I say ‘government’ I am neither talking about NASA nor the President which did not want this abortion at all. The problem is in the Senate and its misguided pork barrel policies.
“Better that he figured it out late than never.” Yeah. Gerstenmaier is probably the smartest and most level-headed person at HQ. Speculation on my part, but I believe he’s had enough of pork-politics direction and decided he must do what he can to put the Senate on notice that their pork project won’t work in the real world given the planned budget marks. At least Gerst’s conscience will be clean when he’s either forced out or decides he’s had enough of the insanity and resigns.
e.g. an Atlas V or Delta IV Heavy launch would put nearly 30 tons in LEO. N1 had three times the capacity and Saturn V had four times the capacity. Since most of the payload will be fuel you can use a fuel depot in orbit to launch all that mass in multiple flights. The fact is in the long term we will not want to use Earth generated fuel to propel chemical rockets in space at all. Not when you can get the fuel into space from a cheaper lower gravity well. Hence all the old NASA proposals for LUNOX and the ilk. Putting the propellant depots in space separates the problems nicely. With a fuel depot in orbit you could start creating a space based economic market based on generating cheap propellant for inner space propulsion.
To address the problem of launching too infrequently, why can’t launches be simulated with enough fidelity to give everyone the practice they need? (In addition to computer simulations, I’m imagining doing things in real life such as rolling launch vehicles out to the pad, and, separately, test-firing engines, and so forth.) That’s not enough? Sorry if this a FAQ.
They could then save money by just pretending to launch their pretend rockets, while launching the real payloads on a Falcon Heavy :).
Give the current KSC, MSFC, and JSC orgs and personnel a year or more of downtime, filled with sims, flight techniques meetings, in-flight anomaly reviews, math model updates based on data from the preceding flight, etc., and there will be a million changes to hardware, software, procedures, and flight rules for each successive SLS launch…meaning each launch will have some first-flight-type risks.
Quote from the NasaSpaceFlight.com coverage:
“However, because the HLV was designed for Beyond Earth Orbit (BEO) missions, it would be so overpowered, its payload would have include a large amount of BALLAST.”
So what kind of “Ballast” will the SLS launch during a crewed mission, and exactly what payloads have we been developing to be launched on the SLS with whose money?
Maybe they can launch batches of lead bricks to be used someday for radiation protection, even though we now know that water is better shielding.
Launching the SLS once a year just to maintain the practice of the ground crew IS as bad as launching the shuttle once a year. That is not often enough.
In support of “Godzilla”, there is no immediate need for an HLV, even though I expect that SpaceX will field one before 2020. The Raptor engine program is under way. But the SpaceX HLV will be reusable, and thus affordable, for the high mass, high launch rate missions such as building space logistics bases with propellant depots, docking position trusses, heavy mission equipment and good radiation shielding for crews outside of the magnetosphere. Frequent HLV launches will be a requirement – these thus need to be reusable to be affordable. For construction of the logistics bases, and to launch efficient Mars landers or ferries, we will need an HLV that can launch modules and integral reentry vehicles up to 15 meters across.
The SLS, since it is expendable, is far too expensive to support such missions, cannot physically be launched often enough and it is not wide enough to launch such wide payloads.
Frequent HLV launches will be a requirement – these thus need to be reusable to be affordable.
Heavy lift and reusability are incompatible. Building a theoretically reusable vehicle that it sits in the hangar most of the time rather than being used, because there are very few payloads that large, makes no sense. That was the mistake NASA made with the Space Shuttle.
For construction of the logistics bases, and to launch efficient Mars landers or ferries, we will need an HLV that can launch modules and integral reentry vehicles up to 15 meters across.
Nonsense. Your viewgraphs may require Galactica-class reentry ships. Mars doesn’t.
Even if 15-meter vehicles turn out to be desirable, for some reason, that doesn’t mean we need superheavy lift. You have the bizarre, fixed idea that it’s impossible to assemble vehicles in space and everything must be launched in one piece. Does the International Space Station exist in your world, John? Do you know how it got into orbit?
Max Hunter said that people who think large construction projects like logistic bases require heavy lift have no knowledge of history. The United States built a *lot* of bases during World War II, in remote locations and often under enemy fire, with nothing larger than the DC-3.
In the post-war era, building the US research base at the South Pole required *hundreds* of aircraft flights, and construction in an extremely hostile environment. But the NSF didn’t delay the project for decades while they lobbied Congress for a $100-billion appropriation to develop a million-ton aircraft that could deliver a prefabricated base in one piece. They didn’t insist on 15m-diameter airplane fuselages, because the design looked so cool. They used the transports that were available and affordable.
When humans build the first base on Mars, it will be done the same way. Not as some Von Braunian cost-be-damned megaproject.
Heavy lift and reusability are incompatible.
They are not incompatible. It is just that presently there are not enough launch payloads to justify the development of a vehicle like that.
He makes a good point though. Fairing size is just as much a limiting factor as how much weight a rocket can lift.
I think the lack of payloads is a red herring, because they could easily just launch a locomotive engine, which can range in weight anywhere from 100 to 250 tons. If the locomotive they choose is a bit too heavy for the SLS, they could just remove its traction wheels because the wheels would be useless in space. You might argue that a locomotive would be useless in space, but since it would be the vital element that justified launching the monster rocket with a sufficient flight rate to maintain the SLS program’s funding, it would of course be just as important as the core stage and boosters.
“Heavy lift and reusability are incompatible. Building a theoretically reusable vehicle that it sits in the hangar most of the time rather than being used, because there are very few payloads that large, makes no sense.”
Then why is SpaceX developing HLV capability?. The reason some can say that there are no payloads for HLV’s is that we are still living in the low-mass space mission era. Even the Space Station, after over a decade of flights, is only about 500 tons. To do serious space exploration and development, you need thousands of tons of vehicles and equipment in space and on planetary surfaces. Those who say there are no payloads seem to have little imagination. This article of mine 9 years ago gives a reasonable list of HLV payload types: http://www.space.com/adastra/adastra_mega-modules_051007.html
Understand that I do not advocate the US government spending ANY money developing an HLV, SLS or any other design. That should no longer be NASA’s job. When we need HLV’s, private ones will be available for NASA to use.
The space station is made of modules which are designed to be plugged together tinker-toy fashion in orbit with no stresses on the structure. Imagine sending the shuttle into orbit in 25 ton chunks and then reassembling it in orbit so that it can re-enter! How many people would it take in orbit to do that? The shuttle is also just about the worst example of a reusable vehicle, except all the others which are totally expendable!.
I do not use viewgraphs. I use numbers! The Mars ferries I have in mind are not giant Battlestar type vehicles. They only mass 30 tons empty. But to land on Mars efficiently (you have heard of the Mars EDL problem?), they have to be very WIDE to present as large an area as possible to the entry stream, slowing down more as they enter and saving propellant. Such a wide, capsule shaped ferry can land 25 tons of cargo on Mars and use only 15 tons of propellant.
The analogy to an Antarctic base is actually a good one. It did take an awful lot of plane flights to ferry all of the equipment to Antarctica in various locations. However, all of those airplanes could be reused. If we could not re-use an airplane, would a base at the South Pole even be possible?
Most of the equipment for such large logistics bases can be shipped to LEO in non-HLV boosters. It is only the large, bulky things which would take a very large number of people to re-assemble that need the HLV to get them to LEO. If you cannot get the item to LEO, you can’t use it on the Moon or Mars.
Then why is SpaceX developing HLV capability?
Sigh. That’s a religious argument. You may believe that SpaceX is infallible, but I don’t belong to your church. I don’t take anything on faith just because Elon says so.
Besides, you’re misquoting your own deity. Elon has said that SpaceX *won’t* build the superheavy lifter unless he gets government funding for it. He knows it’s a sucker bet.
To do serious space exploration and development, you need thousands of tons of vehicles and equipment in space and on planetary surfaces.
No, it will take *millions* of tons — but that tonnage will be divided over many, many vehicles and bases. One vehicle does not need to be large enough to do everything — just large enough to accomplish a useful mission.
How many people would it take in orbit to do that?
So what?
I explained this to you before, John. Having large numbers of people living and working in orbit is a feature, not a bug.
Having a large, robust infrastructure in Earth orbit will make it *easier* to send humans to Mars — not harder. I don’t know why you find that so hard to understand.
More importantly, having humans living and working in space, in large numbers, is *not* just a means to an end. It is a goal in itself — to many of us, a far more important goal than simply sending a handful of NASA astronauts on a sprint to Mars.
Such a wide, capsule shaped ferry can land 25 tons of cargo on Mars and use only 15 tons of propellant.
For how many tens (or hundreds) of billions of dollars? You say you use numbers, but you never do even the most basic financial calculations. You may think the Federal government has an infinite pot of money and should make all of it available to NASA, but that isn’t going to happen no matter what you think.
I should also point out that SpaceX thinks it can land on Mars with the Dragon capsule — which is *not* 15 meters in diameter. Is SpaceX infallible, except when they disagree with you?
The shuttle is also just about the worst example of a reusable vehicle, except all the others which are totally expendable!
Now, you’re being dishonest. “All the others” are not “totally expendable.” The X-15 was not totally expendable. SpaceShip One was not totally expendable. I know you know better, because we’ve had this conversation before.
And yes, I know you’re going to say those vehicles don’t count because they weren’t single-stage to Mars or Alpha Centauri — but one again, going into space is *not* just about sending a tiny handful of government employees on a cool trip to some faraway place.
“More importantly, having humans living and working in space, in large numbers, is *not* just a means to an end. It is a goal in itself ”
I have stated this quite a few times myself. Having large numbers of humans in space, but not just for the one or two week stay, but long enough that seperate cargo runs are needed. Once you start running the numbers on how much cargo will be needed, and the cargo launch vehicle runs needed, you start to see that is is a feature. that is why I never really pushed and advocated for the CATS, or cheap reusable lift. Cargo companies would invest in that on their own as competition heated up for cargo runs. For me it was always ACCESS. We are finally seeing that now as each President has nibbled away at the NASA only model and pushed for more commercial.
To George Turner:
I missed seeing your great locomotive parody. I was trying myself to think of the most useless thing they could use for ballast, and actually, there are uses for “locomotives” in space, but not right away. First, a large, reusable rocket stage designed to propel payloads to L1 or Mars could be considered a “prime mover” which many equate with a locomotive. See http://en.wikipedia.org/wiki/Prime_mover_(locomotive)
Secondly, those driver wheels could be of use after all. My design for a materials transport system in a space factory uses single rail cars with roller coaster car bogies (so the car does have friction and contact with the rail surfaces and cannot float away). Such bogies have small wheels on several sides of each rail. In space, the slowest part of any operation is docking, since you do not want to mash the docking ports with large vehicles. Therefor you have a large docking area, serviced by multiple rail lines, where delivery of the goods is much faster since the rail cars can speed up and slow down rapidly without damaging the equipment. The single car “trains” would deliver the supplies directly to where the construction robots need them. Images of such a factory can be seen at:
http://www.behance.net/gallery/Space-Stuff/7964775
My mind inadvertently combined Rand’s two favorite things, the SLS and high speed rail. 🙂
The need for heavy lift really comes into play when you start looking at radiation shielding for routinely getting through the Van Allen belt and on into space, as all your vehicles become much heavier. It would also allow the vehicles to be much more robust, and probably cheaper (if the heavy lift is cheaper per pound, which the SLS is not) because you lose the incentive to spend a fortune trying to shave off a few pounds.
I think one of the better approaches to re-usable heavy lift is to make it scalable so that even if your heavy-lift missions are fairly infrequent, your overall flight rate with the same hardware remains high. The Falcon 9H uses three first stages, and you could imagine a derivative vehicle that could fly with one, three, five, or nine core first stages, depending on the payload requirement. Then your nine-core heavy-lift vehicle isn’t sitting idle in a hanger for months, the hardware stays busy flying lighter missions with fewer cores.
“From a safety standpoint, it means that its operating tempo will be far too slow, and its flights far too infrequent, to safely and reliably operate the system.”
Which is it Rand? Your entire book suggested “Safety is Not an Option” and that is why we are not exploring the Cosmos but you use the safety logic when disssing the SLS. You are confused and biased beyond belief. Please try and come up with a consistent argument.
Your entire book suggested “Safety is Not an Option”
Apparently you can’t even read the very cover of a book.
I’m sorry you’re so confused. I can explain it to you, but I can’t understand it for you.