In case you're wondering what a Delta IV Heavy is, it's a regular Delta IV rocket with a bunch of strap-ons. This isn't a new concept, the Soyuz is basically the same thing, as was the Space Shuttle. But usually what strap-ons mean is that you didn't have the technology to build engines big enough to put the payload into space that you wanted to put into space. And the end result is what you expect from trying to scale up technology never built to haul heavy loads to orbit -- the Delta IV Heavy can carry 23,000kg to low-earth orbit. The Saturn V, by comparison, could carry 118,000kg to low-earth orbit.
But of course we can't build Saturn V's anymore. Instead we're reduced to building crappy-ass Soyuz clones with strap-on rockets. And so empires die, not with a whimper, but with a slow sizzle of collapsing capability until the final days when the barbarians walk across the border and the empire collapses without a fight...
-- Badtux the Industrial Penguin
Because a Republican president decided we didn't need no stinking heavy-lift rockets anymore.
ReplyDeleteIf I ever go out that way, I'm considering pouring a vial of piss on Nixon's grave.
well, I don't think that Sat V is the right heavy lift to go forward with: its design was cobbled together from a lot of other ideas (among other things,it wasn't allowed to look like the Vostok) and there were a lot of constraints that had nothing to do with its mission. Just the basic design of it makes it extremely unstable, necessitating vast amounts of extra control and guidance systems, all of which had to be flawless.
ReplyDeleteFrom an engineering POV, there is a lot to be said for strap-on tanks: cheaper, easier to reuse, or swap out if there's a problem, keeps the center of propulsion closer to the front so lower angular momentum.
I'm not saying that Nixon was right to shut down the MMMs, but it's not at all clear that the Sat V was the right way to proceed. OTOH, we have a lot of experience with sidesaddle tanks, thanks to Shuttle.
The fact that they could scale the 1960 era Delta this far is interesting.
ReplyDeleteAs far as Saturn V, that was a brute, multiple engine per frame (5 if memory serves) rather than strap on single engine per frame. Cost and design differences influence that.
It's easier to strap on identical units as construction and test costs are lower. Also the Saturn while powerful was a horrible ride with little items like pogo and the occasional single engine shutdown. It was a marvel but, the shuttle engines were more durable and at about 1/3rd the thrust per engine thrust with adjustable thrust.
I'd also contrast that the loads are actually lighter, lets face it batteries, cameras and computers weight mere fractions of what they did on 1969.
However I agree, we are missing man rated heavy lift and Noxin deserves first blame for that loss.
Eck!
My point isn't that the Saturn V was a great design, but, rather, that we no longer have the technological capability in the American Empire to build a heavy lift rocket anymore -- i.e., that we could not replicate the Saturn V's capabilities even if we wanted to. That ability to successfully complete massive engineering projects of that sort died with the 70's. Even modest projects like the F22/F35 strain the aerospace capabilities of what's left of American industry...
ReplyDelete- Badtux the Industrial Penguin
Well, I think it's a bit eggs and chickens, to be honest.
ReplyDeleteWe don't have the capability, because we don't have the need. If we want the capacity, we can get it: why keep a huge drain on resources around for a maybe event? Even NASA doesn't want it. They want a flying truck, which is a far better solution than a Maserati with a Cat 2500HP engine. Anything we want done now would be better done using multiple Delta IVs. Or using the experience of the current HLVs to make a better one.
Eck, the engine config was 5/3/1: 5 engines in Stage 1, 3 in stage 2, 1 in the the lunar orbiter for earth orbit exit and return. NASA and the AF have extensive experience since the 50's boosting existing rocket's capabilities: see the Nike series for example.
As far as the F22/F35 debacle goes, that's not a manufacturing issue, that's politics. And intra-mural squabbling between the services.
I'm not saying that you're absolutely wrong, Tux. But doing monster manufacturing for the sake of prestige is not a good use of scarce resources, IMNSHO. Show me that we need the capability, and I"ll line up with you.
Well, I suggest that you look at the fate of the Ares V, which was going to launch a Saturn V sized payload to orbit using Shuttle-derived technology. We tried. We couldn't do it.
ReplyDeleteThe fact that the Russians apparently believe there is a market for 40,000kg to orbit might be a Clue(tm). Note that the current Proton-M will put 20,000kg to LEO, so it's not as if their Angara project is happening because they don't have a "heavy" lifter. Angara is a strap-on system of course, but using a more powerful engine (a derivative of the RD-171 used on the Zenit) -- an engine, BTW, which also powers the Atlas V rocket (American industry appears no longer capable of building engines of that scale).
There's two reasons for heavy lifters: 1) Lift a single big load to orbit, or 2) Lift multiple smaller loads to orbit. Many launches now carry 5 or more satellites to orbit. Most of the expense of sending a payload into orbit is the launch, not the booster. A booster capable of hauling 20T to orbit does not cost twice as much as a booster capable of hauling 10T to orbit. Hauling twice as many satellites to orbit, at less than twice the cost, is what's called "cost-effective" in the world I live in. Just sayin' :).
- Badtux the Technology Penguin
We don't need to be screwing up space anyway.
ReplyDeleteWe could contract with the Chinese space agency to build us a heavy lifter.
ReplyDeleteWon't work, Montag. They're still stuck in the 70's, space technology-wise. Their Long March V rocket that's supposed to match the Delta IV Heavy in capability isn't going to fly for another couple of years.
ReplyDelete- Badtux the Flightless Penguin
OK, Tux, I was going to respond in detail here, but I'll just point out that, as you freaking well know, the cost of lifting doesn't rise linearly with payload, but logarithmically. As well as the size and complexity of the LV. So, if you want to switch from launch costs to build costs, I'm not going to argue.
ReplyDeleteEven if you are exactly right, it's not ability that constrains us, but desire. In 1959 we didn't have the capacity to lift 20T either. Somehow we found it.