what the new NASA Space launch system says to other rockets

[comicbstudeo]

http://en.wikipedia.org/wiki/Space_Launch_System

Edited April 10, 2014 by comicbstudeo

[Jouni]

The reason, I guess, is that engines are expensive, but fuel is cheap. To get the most out of the engines, you want to add more fuel as long as it still increases the payload capacity, resulting in rockets with TWR < 1.2 at liftoff.

KSP-style rockets with initial TWR > 1.5 would be really inefficient.

[problemecium]

^ Exactly what he just said. I'll put eight Mainsails (or whatever arrangement with the new engines) on a ship, but only to then add 70,000 units of fuel. My experimentation has shown that delta-V is maximized when the ship is barely able to make it off the pad and could only lift a few more tons - that way the acceleration is low enough that I can blast full throttle the whole way up (meaning maximum efficiency) without going past terminal velocity.

[sal_vager]

Rockets are actually less efficient while still below about 100m/s, so getting up to speed is a must (that's what SRB's are for)

I'd describe the NASA SLS as the upper limit of chemical rocket technology, I doubt there will ever be a larger rocket or one more powerful before some other technology completely replaces the need for such craft.

As for the KSP version, I describe it as beefy

[comicbstudeo]

updated title to get across what i was trying to say

[EtherDragon]

So, a Skipper, Mainsail, and SLS walk into a bar...

The Skipper goes, "I lifted an Apollo style orbiter and CM into orbit."

The Mainsail goes, "Yea? Well I lifted a Jool interplanetary ship into orbit."

They both turn to the SLS, "I just did a powered descent and landed a planet - on your planet."

Everyone looks at the Class-E parked outside. Both the Skipper and Mainsail whistle, and say, "That rocks!"

[problemecium]

And then the BFE-5000 walks in and goes "So what'd I miss?"

[Lazro]

Everybody in the room stares at him a second, the they run as he destroys the entire universe with a single breath.

[LethalDose]

http://en.wikipedia.org/wiki/Space_Launch_System

http://i.imgur.com/TRg0zMT.png

That's pretty darn funny

[Guest]

That smoke though...

[NovaSilisko]

I'd describe the NASA SLS as the upper limit of chemical rocket technology, I doubt there will ever be a larger rocket or one more powerful before some other technology completely replaces the need for such craft.

SpaceX would like a word with you! ;p They've got interesting things planned, but it's unlikely they'll fly before SLS.

Edited April 11, 2014 by NovaSilisko

[Rakaydos]

SpaceX would like a word with you! ;p They've got interesting things planned, but it's unlikely they'll fly before SLS.

I thought SpaceX's stuff wasnt as big (at least for the block 2) but could be launched for a 10th the price?

[MaverickSawyer]

No, for years, there's been rumblings of a Falcon X or even a Falcon XX being on the drawing boards...

[nadreck]

SpaceX would like a word with you! ;p They've got interesting things planned, but it's unlikely they'll fly before SLS.

I seriously doubt the SLS will ever fly, especially the Block II. One launch (not development costs) will be more than the Falcon X and Raptor Engine development program cost. But even if they don't cut the funding the SLS project has 2 to 3 times the delays as SpaceX programs do (and they run about 100% over time planned).

Raptor engine ( http://en.wikipedia.org/wiki/Raptor_(rocket_engine)) is a full flow staged combustion engine using Lox/LNG and will be more throttleable as well as having an impressive ISP (partway between Lox/JP1 and Lox/H2).

[Walker]

But even if they don't cut the funding the SLS project has 2 to 3 times the delays as SpaceX programs do (and they run about 100% over time planned).

I'm just a lurker but that got me thinking - what delays does SLS project have? They're still on track with december 2017 lunch, AFAIK they concluded PDR and are preparing for 2015's CDR. On the other hand Falcon's Heavy first launch may slip from 2014 to 2015.

[Streetwind]

Bro, do you even lift?

I'd describe the NASA SLS as the upper limit of chemical rocket technology (...)

SpaceX would like a word with you! ;p They've got interesting things planned, but it's unlikely they'll fly before SLS.

To be honest, bragging rights are earned by successful flights. As such, the SLS is a long ways off of being the pinnacle of rockets, or even of having the right to ask anyone if "they even lift". Because the SLS doesn't lift either, much like any ominous SpaceX plans. The rocket with the right to ask that question is the Saturn V. Or, if we're talking about rockets that fly today, it's the Delta IV Heavy.

The next contender to trump the Delta IV is SpaceX's Falcon Heavy. The maiden flight is scheduled for "Spring 2014". That means with the usual delays asssociated with launching rockets, we'll probably see it in July or August. Then it will be determined if it flies, and gets to flaunt its 55tons to LEO in everyone's faces, or if it falls and needs a rework.

[maccollo]

The next contender to trump the Delta IV is SpaceX's Falcon Heavy. The maiden flight is scheduled for "Spring 2014". That means with the usual delays asssociated with launching rockets, we'll probably see it in July or August. Then it will be determined if it flies, and gets to flaunt its 55tons to LEO in everyone's faces, or if it falls and needs a rework.

It was supposed to fly back in 2013, then 2014 and now it's been pushed back to 2015 as far as I cant tell. Every year it's getting delayed another year.

[Streetwind]

It's still in the launch manifest on the official SpaceX website. In fact, only the (repeatedly delayed) CRS-3 mission and one unspecific Orbcomm launch are still listed before it. Every other 2014 mission is listed after the Falcon Heavy demonstration flight. And there's 11 of them. So until I hear any news otherwise (I stalk their twitter), I'm giving them the benefit of doubt.

There is a Falcon Heavy launch for late 2015 as part of their US military EELV certification program planned, too. maybe you were thinking of that one?

[maccollo]

In a March interview this year, musk said the following about Falcon Heavy.

We need to find three additional cores that we could produce, send them through testing and then fly without disrupting our launch manifest.

I'm hopeful we'll have Falcon Heavy cores produced approximately around the end of the year.

That basically means it's delayed until early 2015. The problem appears to be that they can't keep up with demand for falcon 9 flights, so they have to take the cores they would otherwise use for the first Falcon Heavy to fly more falcon 9.

[Streetwind]

Ah. Well, that's too bad, but at least it's a reason that makes sense and not some mysterious delay for administrative reasons.

[Javster]

A plane would say "do you even generate lift?"

[comicbstudeo]

you mean like

[costermonger]

you mean like

http://i.imgur.com/DH7NYI3.png

Haha, the Mriya just wasn't quite ridiculous enough and somebody had to photoshop four more engines onto the thing?

[tntristan12]

Having just discovered the "do you even lift" meme myself, I approve of this message!

[rdfox]

There's no reason that SLS would be the pinnacle of chemical rocket technology, except for there being very little call for lifting locomotives and (maritime) ships into LEO. It might be less efficient than building a "bespoke" single-core rocket to do so, but there's no reason that clustering cores can't provide what is, in essence, unlimited lifting capability (albeit with some nasty infrastructure costs and ugly engineering to create the payload bus).

In 1968, NASA was looking at possible post-lunar Saturn derivative boosters. One of the wilder ones was a proposal from Marshall Space Flight Center (i.e., Huntsville) to build a Saturn-derived booster capable of putting 500 tons into LEO in a single throw. How? Take four(!) Saturn INT-21s (Saturn Vs without third stages--essentially, the configuration flown to launch Skylab) and bolt them together side by side in a cluster. The idea was that this could launch a manned Mars mission in a single throw...