NASA Announces Next Heavy-Lift Vehicle to Replace the Space Shuttle

[quagmire]

NASA has announced a new heavy-lift vehicle to replace the retired Space Shuttle fleet. This new vehicle called, Space Launch System or SLS will rival the old Saturn V rockets by producing up to 20% more thrust( depending on configuration) than the Saturn V.

The first stage of the rocket will use 3-5 Space Shuttle Main Engines and SRB's. The upper stage will use J-2X engines which are updated engines used on the second stage of the Saturn V.

More here:

http://www.nasa.gov/exploration/systems/sls/slsannouncement.html

 

[MacNut]

I was reading this last night. If this rocket will be 400 feet will it fit into the assembly building?

http://www.nasa.gov/multimedia/videogallery/index.html?media_id=111389911

 

[quagmire]

I was reading this last night. If this rocket will be 400 feet will it fit into the assembly building?

It will fit. The LUT's for the Saturn V were 400 ft tall.

The question would be will the service tower for the SLS fit in the VAB?

 

[MacNut]

So looking at the renderings, is the whole tower mounted to the crawler. And what becomes of pads 39a and b.

 

[quagmire]

So looking at the renderings, is the whole tower mounted to the crawler. And what becomes of pads 39a and b.

Yeah, the towers are going to be attached to the Mobile Launcher Platform like it was for the Saturn V.

Pads 39A and 39B are being reconfigured back to a clean pad design like it was for the Apollo Program.

This is what 39B currently looks like.

 

[MacNut]

So what is different about this plan from Constellation. They were both heavy lift rockets.

 

[quagmire]

So what is different about this plan from Constellation. They were both heavy lift rockets.

Constellation had two rockets the Ares-I and Ares V. The Ares I would send the crew to space while the Ares V would launch cargo and/or the lunar module to go to the moon, etc.

The SLS seems to be more flexible than Constellation. I would also argue safer. With Ares-I, it didn't look like it had any engine out capability. If any of the engines failed, it was coming back down to Earth. Where the SLS much like the Saturn V looks like it will have an engine out capability to reach orbit if any of the engines failed.

 

[fat jez]

Not sure I'd be wanting to be lifted into space by the SRBs given that once they're lit, there's no throttle. That and the SRB was the cause of losing Challenger. Although I suppose they'd go back to having a LES, so if something did go wrong, the crew would have a fighting chance of survival

 

[MacNut]

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Do you really want a throttle considering you will need all the power you can get to get you into orbit. The SRB is not what brought Challenger down, it was a lack of oversight and carelessness.

 

[quagmire]

Not sure I'd be wanting to be lifted into space by the SRBs given that once they're lit, there's no throttle. That and the SRB was the cause of losing Challenger. Although I suppose they'd go back to having a LES, so if something did go wrong, the crew would have a fighting chance of survival

Even if the SRB's could be throttled, Challenger was doomed anyway. No one knew of the leak until they reexamined the footage.

What doomed Challenger is the fact the O-Rings were not designed to handle the cold temps. Engineers told managers this, but they launched anyway.

Do you really want a throttle considering you will need all the power you can get to get you into orbit. The SRB is not what brought Challenger down, it was a lack of oversight and carelessness.

When launching the Shuttle, they do throttle the SSME's back for a bit when going through the area of maximum dynamic pressure to relieve stress on the vehicle.

 

[fat jez]

Even if the SRB's could be throttled, Challenger was doomed anyway. No one knew of the leak until they reexamined the footage.

I was making two points in one paragraph, so in the context of Challenger, ignore the throttling comment. In actual fact, they had known of previous flights with damage to the o-rings, but as there had seldom been much damage to the secondary o-rings, it wasn't deemed that serious. Michael Mullane discusses some of these issues in his book, Riding Rockets.

When launching the Shuttle, they do throttle the SSME's back for a bit when going through the area of maximum dynamic pressure to relieve stress on the vehicle.

Yes, this was my point regarding the lack of throttle on an SRB. They have to contrive a throttling effect by how they load/burn the solid fuel such that at the area of maximum dynamic pressure (Max Q), they throttle back the SSMEs and the power output of the SRBs diminishes.

 

[quagmire]

Yes, this was my point regarding the lack of throttle on an SRB. They have to contrive a throttling effect by how they load/burn the solid fuel such that at the area of maximum dynamic pressure (Max Q), they throttle back the SSMEs and the power output of the SRBs diminishes.

Even with the Saturn V, they had to throttle down as well for Max Q. So I am not seeing the issue with the SRB's not being able to be throttled.

Fun Fact: They throttle the SSME's back down to 70% output, but that only reduces the total thrust by 5%. I never realized how much thrust the SRB's contributed to the total thrust.

 

[(marc)]

When launching the Shuttle, they do throttle the SSME's back for a bit when going through the area of maximum dynamic pressure to relieve stress on the vehicle.

I think I heard that sentence a thousand times in various shuttle launch videos

 

[iJohnHenry]

I think I heard that sentence a thousand times in various shuttle launch videos

Bah. Chemical rockets for Space have had their day. 100 years, tops.

 

[rezenclowd3]

Bah. Chemical rockets for Space have had their day. 100 years, tops.

Maybe next will be "green" rockets, powered by Prius motors and batteries ;-)

 

[iJohnHenry]

I think the moon gun, featured in Jules Vern's From The Earth To The Moon might be an answer.

Now where did we put that Canadian engineer that was working on a super-sonic gun for Iraqi government??

Oh, never mind. I think he was assassinated already by the Mossad.

The g-force would probably kill everyone anyway.

 

[velocityg4]

Bah. Chemical rockets for Space have had their day. 100 years, tops.

Too bad there are no replacements yet. Even ION/Plasma engines have to get thrust by propelling a chemical. There is no method I have heard of to convert electricity directly into thrust in space.

I do find the SLS interesting though. Hopefully it isn't vaporware. It would be nice if more work was put into a space elevator though. That could make deep space travel much more affordable, realistic and possibly profitable.

That is what will truly push space travel. When people can make more money from going to destinations in space than it costs to go there.

 

[iJohnHenry]

Even ION/Plasma engines have to get thrust by propelling a chemical.

Yes, ION engines are very frugal, and provide constant acceleration, but at extremely low levels. And they have to get into space first to even be effective.

All this spells time, and as the May fly of the Universe, we have little of that.

 

[anotonin]

I hope this goes well. Now on to recruiting younger people to fly this thing. The younger they are, the longer time they can manned this station.

 

[taedouni]

You cannot have an active control system to throttle solid propellant chemical rockets. Once lit it will continue to burn until completely burned. The purpose for the SRB is that the payload needs a lot of thrust in order to achieve high altitudes. Solid Propellant rockets deliver a low specific impulse which mean that they are very inefficient when it comes to fuel but they are CHEAP and it they take up less space. (Compare the External tank vs the two SRBs for the Space Shuttle System).

 

[Sackvillenb]

Ah, back to the old classic rocket design. Rather ironic, perhaps. But at least nasa will still have a space program of some sort! While we as humans have many, many problems here on the earth's surface, our exploration and technological use of space is a crucial component to our evolution as a civilization and species.

 

[quagmire]

Rocketdyne and partners want to bring back the Saturn V's F-1 engine to use as the SLS's booster instead of the 5 segment SRB's. I personally hope NASA will award them the contract as the F-1's are awesome.

http://www.spaceflightnow.com/news/n1204/18dynetics/

 

[Rodimus Prime]

So basicly they cancel the consolation project then turn around and bring back a new version of it?

This is not so much NASA fault as Washington fault for forcing NASA to keep redesigning late threw a process to something new as the political winds change.

My big question is what states is this new project going to be based in.

 

[MacNut]

So basicly they cancel the consolation project then turn around and bring back a new version of it?

This is not so much NASA fault as Washington fault for forcing NASA to keep redesigning late threw a process to something new as the political winds change.

My big question is what states is this new project going to be based in.

Ya the article says for trips to the moon and mars, I thought that whole thing was scrapped.

Why not move on to the F-1a?

 

[Rodimus Prime]

Ya the article says for trips to the moon and mars, I thought that whole thing was scrapped.

Why not move on to the F-1a?

It is sad they are doing this now because NASA has been bleeding its best people left and right. They are moving on to safer and higher paying jobs. Those people are leaving in rather large numbers for greener pastures. They will never be back all because they cancelled so much.
Also I want to know where these projects are to be going on.