anticarrot wrote:Unfortunately Saturn V and SLS are also very silly rockets. The former was built to win a race (very well built as it happens, but it's still a silly optimisation metric)
I've also read that it's still (even accounting for inflation) the cheapest-per-pound launch system that humanity has ever had (that might have just been for the heavy-lift market, I understand that structural design lets larger rockets dedicate a larger mass fraction to fuel, so I'd still buy into it).
Certainly cheaper than the shuttle.
anticarrot wrote:There are many ways to give NASA more capability, but almost none of them require the LC-39 launch complex that those 20,000 jobs revolve around.
A rebuild might be nice, but it's just about the best location in America for launches (certainly Jarvis Island, and maybe some of the others beat it, but they aren't part of the continental US), it's already granted access to a launch window, it already has pads suitable for very large payloads, it has a delivery road suitable for very large loads, and it has an assembly complex suitable for very large loads.
All in all, the LC-39 site is a keeper. It might be nice to tear most things down and rebuild with better facility designs, but that's it.
Mikk wrote:(talking about SpaceX)Considering how safety concious (despite driving perhaps the most competitive launch price for a new rocket family yet (that I've been able to find anyway)) that particular rocket manufacturer is, betting on catastrophic failure on their next flight doesn't seem like the good choice.
I don't know, with their previous history it's possible that they'll have some sort of launch failure. What
I wouldn't count on is a failure to learn from any failures that they might (or might not) have. They've shown pretty well that they aren't stupid.
Mikk wrote:As for the usefulness of resurrecting Saturn technology? Well, those things weren't engineered to be cheap either.
And yet the shuttle still managed to be more expensive. Good job NASA!
Mikk wrote:Whether we believe them or not, SpaceX is claiming to be on the crusade to develop cheap, safe, marinized and reusable (Merlin 1C or 1D (I forget which) have been claimed to be useful for up to 20 launch test burns) launch vehicles, and re-entry cargo return vehicles. NASA certainly seems to be buying their sales pitch.
They're probably pretty serious. There's potentially a good amount of money to be made in space launches, especially if what I've read about the cost actually being dominated by launcher costs is true.
Mikk wrote:Orion crew capsule is probably going to beat the DragonRider to the first manned flights tho. We'll have to wait and see how well the ideas for Dragon-derived robotic missions other than cargo-ferry will work out as well.
If they can launch the Orion capsule then it won't be such a big deal, since the "big" market for manned Dragons will presumably only come with the commercial space travel market, which is still a little ways off.
anticarrot wrote:A launch vehicle should be designed to put stuff into orbit as cheaply and reliably as possibly. The SLS was required to use components from the shuttle; a launch system characterised by it's expense and unreliability. There is a reason it is nicknamed the Senate Launch System.
Not entirely a reasonable complaint. One of the bigger problems with the shuttle was the requirement that it support use for polar orbits. If not for the extra weight required to support that it might have been very successful, and even less accident-prone. I've heard that was the only reason why it needed those ceramic tiles, too.
anticarrot wrote:If you want to put large payloads in orbit, then you need some kind of reliable, low-cost heavy lift rocket.
This is an error. Large and heavy are not the same thing. Size pre deployment and post deployment can also very by an order of magnitude. But beyond that... What payload are you thinking of that cannot be broken down into 50 or 30 ton pieces? And that's a question even NASA can't answer.
Probably volatiles for the forever-desired Mars mission. It's cheaper to launch them in as large a mass as you can, since that allows you to use the least possible container mass. You can divide it up into more containers, but then you're only increasing the mass that you have to transport into orbit.
anticarrot wrote:Here's a challenge. Sit down and do the maths and work out how much useful payload your choice of upper stage can softland on the moon from lunar orbit. It'll be far in excess of NASA's severely self-censored dreams. We don't need custom hardware for every single application. One patch of vacuum is completely identical to another patch as far as a rocket engine is concerned.
Actually, I wouldn't want to use an upper stage for a moon landing unless I'd had a hover-test demonstration. Balancing on top of the rocket like that is potentially a very touchy operation, so you want to be certain that the rocket itself can handle it.
Beyond that, yeah, that's a stupid complaint. If it can't be launched by your current rockets then redesign it to be assembled in orbit at the ISS from multiple pieces. You
were intending these to be in-space replenish so that we wouldn't have to keep launching them, right NASA? Oh? Well, never mind.
anticarrot wrote:Neither a spaceplane nor a DC-Y could fulfill this role.
The DC-Y wouldn't need to launch a lunar lander. The DC-Y could BE a lunar lander (with 30 tons of cargo) via direct-return, aerobreaking and an orbital fuel depot. That would take about 40 launches (mostly for fuel) which wouldn't be a particular problem for DC-I if it functioned as advertised.
I'd personally want to strip extra bits off, and ONLY use it as a moon lander/launcher, but that's just pedantry (I think that's how it's spelled...).
anticarrot wrote: It's hard to build space stations or interplanetary exploration vehicles 9 tonnes at a time.
Explain please, with examples. Because we build
EVERYTHING ELSE HUMANKIND HAS EVER USED out of pieces smaller than 9 tonnes. Sorry, but this claim really don't hold water, and it's immensely frustrating to see it repeated over and over again.
In essence, if you can launch the whole thing at once then it's as easy as it can be. If you just have to fill it's tanks after it's up, that's just about as good. The more work you have to do in space to make it usable, the worse. Thus, heavy-launch rockets are better for the "exciting" jobs because you can do more work with less effort.
Once we get space-based construction going this won't be important any more, but we don't actually have that stuff yet.