Space Launch System

GW Johnson · 2020-02-20 09:26:33

Re post 72 above:

You cannot replace all the AP with RDX or HMX in a solid propellant. You get an explosive, not a propellant, when you do that. You can only replace something like 5% of the 75-85% total solids in a composite with RDX or HMX, and still have a class 1.3 hazard propellant.

Those solids are mostly AP and aluminum, with aluminum never more than 20%. And don't forget to deduct ~3% of the solids for opacifying carbon black and a little bit of yellow iron oxide for the burn rate catalyst.

The more solids in the mix, the thicker the mix "viscosity" (really thixotropic) and the harder it is to cast. Most contractors insist of gravity-driven sleeve casting, which limits them to ~80% solids max. That limits their c* and Isp performance. You have to pressure-cast and pressure-pack to reach 87-88% solids. That's a whole 'nother world in solids manufacture.

GW

edit update 2-21-20: I recently posted an article on solid rockets over at "exrocketman". It has more than you would ever want to know about the topic.

Last edited by GW Johnson (2020-02-21 08:55:13)

Oldfart1939 · 2020-03-12 09:25:18

Oh, oh! More bad news about SLS cost overruns!

https://spacenews.com/sls-cost-growth-e … al-review/

I somehow don't expect this program to last much longer, given the huge amount spent versus how much more is needed to fly this single bird. Senator Shelby has used up an enormous amount of his political capital getting this White Elephant to it's present state. Don't know how much more his colleagues will go along with, before a cancellation/termination.

SpaceNut · 2020-03-12 19:14:45

So they are still trying to pack in extra cash to pay for standing armies of people to do little or no work so as to keep a knowledge base for building more sls vehicles at the extremely slow rate of just 1 launch a year.

That is silly and stupid to design a vehicle with this method of building...

SpaceNut · 2020-03-21 13:16:35

Louis made note of the stopping of work and here is an article in support.
NASA suspends work on Moon rocket due to virus
The space agency is shutting down its Michoud Assembly Facility in New Orleans, where the Space Launch System rocket is being built, and the nearby Stennis Space Center, administrator Jim Bridenstine said late Thursday.

SpaceNut · 2020-03-27 19:21:11

Orion Space craft is ready for final Artemis 1 launch preparation

SpaceNut · 2020-04-06 12:03:46

https://www.nasa.gov/sites/default/file … 2018_0.pdf
Space Launch System Lift Capabilities

after the first couple we should skip the 1b crewed and move onto the model 2 size, make use of the 1b cargo as needed until mars and then switch to the 2 cargo of course with ramperd up production to lower cost not flight rate.

https://ntrs.nasa.gov/archive/nasa/casi … 009204.pdf
COMPOSITE PAYLOAD FAIRING STRUCTURAL ARCHITECTURE ASSESSMENT AND SELECTION

SpaceNut · 2020-04-06 15:12:36

here is the plan finally after 5 months
https://www.nasa.gov/sites/default/file … 0final.pdf

SpaceNut · 2020-05-19 16:18:49

In true form NASA's human spaceflight chief ousted just before big launch

must have been moving to slowly....

SpaceNut · 2020-06-21 20:03:38

https://www.spacedaily.com/reports/NASA … g_999.html

SpaceNut · 2020-06-30 19:44:02

Orion's 'Twin' Completes Structural Testing for Artemis I Mission]

NASA Plans for More SLS Rocket Boosters to Launch Artemis Moon Missions

solid rocket boosters to support as many as six additional flights, for a total of up to nine Artemis missions.
Under this letter contract, with a potential value of $49.5 million, NASA will provide initial funding and authorization to Northrop Grumman to order long-lead items to support building the twin boosters for the next six SLS flights.

SpaceNut · 2020-07-31 18:39:57

The interstage connector for the first NASA Space Launch System (SLS) vehicle was delivered to NASA in mid-July and is in transit to its launch site.

Second SLS Mobile Launcher preps for construction as hardware arrives at KSC

20140002702.Composite-Slide.jpg

NASA, Northrop Grumman plan for 12 additional SLS Solid Rocket Boosters

GW Johnson · 2020-08-01 08:41:53

Spacenut:

How are you managing to post these images? Assume I am almost computer-illiterate when you answer that. Because I am.

GW

SpaceNut · 2020-08-01 09:14:33

this is the page without the url http://newmars.com/forums/help.php#url or img http://newmars.com/forums/help.php#img enclosures which are use in BBCode Format of the line pictue format.

How you get the image address depends a bit on the browser you are using.

The line instruction looks like this one less the =FluxBB bbcode test and the produces FluxBB bbcode test but with no space*
all you need is the address for the image from the website that you want to post. It can not be a created image that is on the computer.

[img *=FluxBB bbcode test]http://newmars.com/forums/img/test.png[ */img] produces FluxBB bbcode test

here is the meter from your website image address with a * to stop the process that would change it into a link
*https://1.bp.blogspot.com/-66L2wAowWmg/XxzkbkaDYBI/AAAAAAAAElo/uN9Mz0Kc0qofCIdfIzrv2IU0zFg8hxXyQCLcBGAsYHQ/s1600/battery%2Btools%2B3.jpg*

SpaceNut · 2020-08-26 20:05:36

Say what Orion Window Panel Complete for Front-Row View on Artemis Moon Mission III mission to put the first woman and next man on the lunar surface, the crew will get a glimpse through the spacecraft's windows.

manufactured by AMRO Fabricating Corp., of South El Monte, California.

https://www.nasa.gov/exploration/system … index.html

Seems like everything is still in prototype mode for all parts and not in steady state yet....

SpaceNut · 2020-09-06 21:18:34

The development baseline cost for SLS is $9.1 billion with initial ground-based systems capability to support the rocket’s first mission has swelled to $2.4 billion but congressional approval was for $7 billion for the project.
Not again Cost for SLS rocket slated for Artemis moon mission explodes

SpaceNut · 2020-10-11 20:07:48

Crucial first fueling test on tap for SLS core stage later this month]

Covered in orange foam insulation, the huge Boeing-built rocket stage has been fastened in the B-2 test stand at NASA’s Stennis Space Center since January, when it arrived by barge from a manufacturing plant at NASA’s Michoud Assembly Facility in New Orleans.
Since January, work to ready the rocket stage for its first test-firing has been suspended several times, first by the coronavirus pandemic, and then by several close calls with hurricanes approaching the Gulf Coast.
The next step in the SLS test campaign at Stennis, known as the “Green Run,” will be to load 733,000 gallons of super-cold liquid hydrogen and liquid oxygen into the core stage.
Numerous sensors will measure how the core stage and its intricate plumbing respond to the loading of cryogenic propellants.
The liquid hydrogen is stored at minus 423 degrees (minus 253 degrees Celsius) in the case of liquid hydrogen, and liquid oxygen is kept at minus 298 degrees Fahrenheit (minus 183 degrees Celsius).
The 212-foot-long (64.6-meter), 27.6-foot-wide (8.4-meter) SLS core stage has the same diameter as the shuttle’s fuel tank. It weighs about 188,000 pounds (85 metric tons) empty, and will weigh around 2.3 million pounds (more than 1,000 metric tons) fully fueled.

Oldfart1939 · 2020-10-11 20:39:43

And all of this testing...only 4 years late!

SpaceNut · 2020-10-12 09:36:21

That was after a decade head start to design the beast from the now modified existing shuttle hardware that seemingly they had forgotten everything from the past when the original parts were built for shuttle use.

About all that was needed from the original ET was structural support for the engines to be mounted inline under it and for the payload to be mounted over it....The 5 segment srb was already in the works and all that remained for the design was the capsule for use on it.

So much time and money was wasted by Nasa and its waffling over the design was not needed to create the machine we are now left with. Some of the bloat in cost can be blamed on the contractors...

SpaceNut · 2020-11-25 16:50:58

NASA 'hard-pressed' to land astronauts on Moon in 2024, cites COVID-19 delays as a factor that has impacted "projects, costs and schedules." September, NASA revealed its $28 billion plan to land the first woman and the next man on the moon by 2024.

SpaceNut · 2020-11-26 21:28:26

SLS continuing engine upgrades, tech development to support launcher evolution

Hopefully its going to make them cost less for the SLS Block 1B vehicle...or lift higher payloads by still fiddling with them...

P1160777.35pct-1170x878.jpg

Aerojet Rocketdyne hydrogen-oxygen engine designs and hardware will be used for the SLS core and upper stages, but both the space agency and the prime contractor for the RS-25 and RL10 engines are investing in upgrades and technology development to make the engines more cost-effective.

RS-25-Additive-Manufacturing.cropped.jpg

Now if the other contractors would do the same to solve how to make what the are working on cheaper as well..
Then we would be able to change The SLS: too expensive for exploration? our topics outcome...

19a5050-002_AR_logo.25pct-1536x1081.jpg

Nice comparison of the SSME 25 and the RL10 for size...

kbd512 · 2020-11-28 03:26:00

SpaceNut,

The nozzle is the part the RS-25 engine that takes the longest to fabricate, is stupidly expensive to fabricate on account of the labor intensive process used, and would benefit the most from additive manufacturing. Ditto for the RL-10 nozzle design. I think I read somewhere that it takes two years to fabricate a RS-25 nozzle using hand-brazed tubing. That's nuts. The Raptor uses a channel wall nozzle for that reason. I think all of our engines should use the Russian channel wall nozzle tech, combined with American additive manufacturing tech, to reduce fabrication costs to the point where we can afford to dump the engines in the ocean after a single flight. It would be better to reuse them, but if new ones can be fabricated in a week and refurbishing "flight proven" engines takes a month or more, then we can afford to routinely remand minor quantities of steel to Davy Jones' locker after 8 minutes of use. Even so, if the power heads could be recovered that would serve as a stockpile of spare parts.

Strangely enough, the limiting factor for both Starship Super Heavy and SLS will turn out to be the time it takes to fabricate or refurbish propellant tanks. We may be able to assemble a set of new or refurbished engines in less than a month, but the standing army will then be twiddling their thumbs waiting on new or refurbished tankage for the next flight. Without sheet steel or ceramic composite robotic propellant tank fabrication, I don't think either concept is practical at this point.

SLS relies upon fabrication and assembly of Aluminum gores or "potato chips", as Tory Bruno calls them, into a propellant tank structure. SpaceX is still trying to hand-fabricate stainless sheet steel. Neither method is economical in the long run, as both are incredibly labor intensive. NASA's robotic welding jig is less subject weld failures, but each gore is brought in and individually welded into the tank structure. In the 21st century, we're still trying to hand-fabricate propellant tanks and spend months machining metal. If production rates are ever to increase and costs to decrease, better fabrication and assembly methods are required.

tahanson43206 · 2020-11-28 08:06:38

For kbd512 re #96

SearchTerm:Nozzle fabrication http://newmars.com/forums/viewtopic.php … 47#p174347

Details of fabrication of RS-25 and RL-10 engines

Recommendation to use additive manufacturing for engines

***

SpaceX is still trying to hand-fabricate stainless sheet steel.

Tesla Automobiles are made using robots. I'd expect SpaceX to implement fully automated Starship assembly as soon as the vehicles are flight proven.

However, taking a leap from the present to what would seem possible ... An entire Starship could be constructed using additive manufacturing.

The 3D printing commands could be written in a few months by an experienced team.

The fabrication could be carried out by multiple print heads operating simultaneously from as many as 36 points of the compass.

That kind of mass production is something to watch for.

Edit#1: And, it turns out it's in use (on a smaller scale)

https://3dprint.com/231703/relativity-s … fuel-tank/

Relativity Space is not alone in wanting to 3D print rockets – there are plenty of companies with the goal of doing just that. What makes Relativity stand out, however, is that it has the means to 3D print entire rockets with almost no intervention from humans. The company’s massive Stargate 3D printer utilizes 18-foot-tall robotic arms equipped with lasers that can melt metal wire. Those robotic arms have the ability to stream about eight inches’ worth of metal onto a large turntable in just a second’s time. Directed by custom software, the robotic arms are capable of producing the entire body of the rocket in one piece.

The key to the potential of this system is the use of a turntable and multiple dispensing robots.

A picture at the web site above shows a tank under "construction" with a turntable and two dispensing robots.

Even at the scale shown in the image, it is clear that four robots could be in operation simultaneously.

Edit#2: https://www.plascore.com/honeycomb/hone … ess-steel/

The web page at the link above shows Stainless Steel Honeycomb Core

Cell sizes are reports as 3/8" - 1/2"

This material could be adapted for rocket walls, to increase strength. I'm not sure how the trades would work out.

One detail that caught my eye is that the "honeycomb is adhesively bonded"

(th)

kbd512 · 2020-11-28 09:48:56

tahanson43206,

Hand-fabrication methods don't always translate to automated assembly. The channel wall nozzle design is a good case in point. 3D printing enables that to occur, but you can't flight qualify a hand-brazed / sintered tube design and then switch to a channel wall nozzle design. A channel wall tends to be more durable than brazed tubing and is certainly less time consuming and therefore less costly to fabricate, but also tends to be heavier. The acoustics will certainly change and you don't want anything important coming loose or otherwise being damaged by that significant design change. That's why we didn't "just switch" to that design for the RS-25, because it's a development program line item that requires re-running through the complete certification process.

For example, if the robotically welded or 3D printed parts are lighter or heavier than hand-welded or CNC machined parts, that starts messing with the vehicle mass and CG. That means you will most likely have to alter component placement within the vehicle, re-evaluate acceptable CG limits, and/or modify the flight control software to account for any imbalance or other changes to flight characteristics, such as landing stability. It's a snowball affect. Any significant alteration of an aerospace vehicle design is not a simple matter of swapping parts.

There are also admonishments to aircraft homebuilders to never substitute Grade 8 automotive bolts for AN-spec aircraft bolts, because simple bolts, even if the Grade 8 is much cheaper to purchase and seems to be "over-designed" for the fastening task "on paper", is in fact a significantly weaker design in terms of tensile strength, shear load capacity, thread contact surface area, ability to resist fatigue cracking from the vibrations produced by a typical aircraft engine, etc. It's almost as if there's a proper use for every material and design, along with a slew of improper uses that have cost lives, hence the admonishments to not randomly substitute components without understanding the relevant design aspects affecting materials and design criteria.

Long story short, switching materials or fabrication methods is not how flight qualification / certification works. You develop / fabricate / test / certify based upon the actual methods and techniques use to construct your flight qualified design. Afterwards, you don't change anything that materially affects the strength or weight of the individual parts, CG limits, or flight characteristics without thoroughly re-testing. Bad things tend to happen if you do.

SpaceNut · 2020-11-29 18:35:57

Barely out of the test phase and we are already handing out more money NASA gives big moon mission to Alabama company

Crews load a Space Launch System Launch Vehicle Stage Adapter aboard a barge in Huntsville, Ala., for delivery to NASA's Stennis Space Center. NASA has asked Huntsville contractor Teledyne Brown Engineering to build two more of the adapters for the next two SLS rockets. How big are these rocket parts? They are roughly 30 feet in diameter by 30 feet tall and consist of 16 Aluminum-Lithium alloy panels, Hess said.

It sure does not look that size....

NASA awarded the contract extension to Teledyne Brown Engineering for two more of what are called Launch Vehicle Stage Adapters (LVSAs) for the Artemis II and Artemis III moon missions. The cone-shaped LVSAs connect the core section of the Space Launch System (SLS) rocket to its cryogenic propulsion stage, an $85 million NASA contract modification to build key parts of two future moon rockets.
President-elect Biden has named his own transition team to prepare for the handover of space policy from Trump’s administration to his own. That team has not spelled out the incoming president’s priorities for space yet, but some analysts believe Biden will continue the moon mission but push its timetable out a few years. That could make the first woman’s walk on the moon in 2028 instead of 2024.

Why another 4 yr delay?

New Space Race Shoots for Moon and Mars on a Budget

SpaceNut · 2020-11-29 20:38:10

Artemis I launch preparations are stacking up
Each booster consists of five segments and will provide 7 million pounds of thrust for the liftoff...

The solid rocket boosters are the first components of the SLS rocket to be stacked and will help support the remaining rocket pieces and the Orion spacecraft. Over the next several weeks, workers will use an overhead crane that can hold up to 325 tons (the weight of about 50 elephants), to lift the remaining segments one by one and place them carefully onto the 380-foot-tall mobile launcher, the structure used to process, assemble, and launch the SLS rocket. The cranes are precise enough to lower an object onto an egg without cracking it.
The first booster segments to be stacked are the bottom sections known as the aft assemblies. These house the system that controls 70% of the steering during initial ascent of the rocket. This section includes the aft motor segment and skirt, and the nozzle that directs the hot gas leaving the motor.
After stacking the other four segments, the final pieces of the boosters are the forward assemblies, which include the nose cone that serves as the aerodynamic leading edge of the boosters. The forward assemblies will attach to the core stage when it arrives next year.

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#76 2020-02-20 09:26:33

Re: Space Launch System

#77 2020-03-12 09:25:18

Re: Space Launch System

#78 2020-03-12 19:14:45

Re: Space Launch System

#79 2020-03-21 13:16:35

Re: Space Launch System

#80 2020-03-27 19:21:11

Re: Space Launch System

#81 2020-04-06 12:03:46

Re: Space Launch System

#82 2020-04-06 15:12:36

Re: Space Launch System

#83 2020-05-19 16:18:49

Re: Space Launch System

#84 2020-06-21 20:03:38

Re: Space Launch System

#85 2020-06-30 19:44:02

Re: Space Launch System

#86 2020-07-31 18:39:57

Re: Space Launch System

#87 2020-08-01 08:41:53

Re: Space Launch System

#88 2020-08-01 09:14:33

Re: Space Launch System

#89 2020-08-26 20:05:36

Re: Space Launch System

#90 2020-09-06 21:18:34

Re: Space Launch System

#91 2020-10-11 20:07:48

Re: Space Launch System

#92 2020-10-11 20:39:43

Re: Space Launch System

#93 2020-10-12 09:36:21

Re: Space Launch System

#94 2020-11-25 16:50:58

Re: Space Launch System

#95 2020-11-26 21:28:26

Re: Space Launch System

#96 2020-11-28 03:26:00

Re: Space Launch System

#97 2020-11-28 08:06:38

Re: Space Launch System

#98 2020-11-28 09:48:56

Re: Space Launch System

#99 2020-11-29 18:35:57

Re: Space Launch System

#100 2020-11-29 20:38:10

Re: Space Launch System

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