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#26 2017-07-15 11:30:43

Oldfart1939
Member
Registered: 2016-11-26
Posts: 1,780

Re: Space Launch System

SLS is so far behind schedule and over budget that it should be cancelled!
Here's a link to a Space.com article about "How NASA Could Reach Mars faster with Public-Private Partnerships."
https://www.space.com/37491-nasa-to-mar … ships.html

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#27 2017-07-15 13:26:14

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 16,726

Re: Space Launch System

Congress is the reason that we have the problems with the past constellation and now with SLS as they are not setting the cost within the required law that forced nasa down this rabbit hole to begin with.
So have these companies talk to Congress again will no get the results that is desired. Now do we want to put this to the National Space Council is the question as will they have the control of funding that is required or on the directives to start work....

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#28 2017-09-24 18:36:26

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 16,726

Re: Space Launch System

SLS EM-1 & -2 launch dates realign; EM-3 gains notional mission outline

Following a series of issues over the last year with the Core Stage for the first flight of the Space Launch System rocket, the launch dates for both the EM-1 and EM-2 flights are beginning to align, with EM-1 now targeting No Earlier Than 15 December 2019 and EM-2 following on 1 June 2022.  Additionally, the EM-3 flight has gained its first notional mission outline, detailing a flight to Near-Rectilinear Halo Orbit to deploy the Hab module for the new Deep Space Gateway.

To much time between changing venues of what is being accomplished.....

Screen-Shot-2017-09-22-at-12.15.01-350x205.png

EM-3: mission scenario for flight for Deep Space Gateway construction flight:

According to the preliminary mission outline, the EM-3 flight would be a crewed mission to Near-Rectilinear Halo Orbit (NRHO) around the Moon.

NRHOs are best understood as bridge orbits between the L1 and L2 (Lagrangian 1 and 2) points in the Earth-Moon system that carry highly stable, highly elliptic trajectories with periapsis points close to the surface of the the moon.

Placing the DSG in a NRHO will create a DSG orbital trajectory that takes the outpost close to the lunar surface to permit low-energy transfer opportunities for scientific excursions in cislunar space and to the lunar surface itself.

For EM-3 specifically, the mission carries a total duration of 16-26 days with baseline objectives to “demonstrate spacecraft systems performance beyond LEO for crewed flight” and to launch the DSG habitat module to NRHO and mate the Hab to the already-launched Power and Propulsion Element (PPE).

Screen-Shot-2017-09-22-at-12.07.30-350x232.png

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#29 2018-12-25 08:51:29

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 16,726

Re: Space Launch System

still mixing designs of the past with modern artwork with renewed interest in heatshield types

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#30 2018-12-28 12:37:55

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 16,726

Re: Space Launch System

As I indicated in the ares 1 topic I could have thought that we have a more collective topic for the sls but it seems quite spread out...

Ares I (CLV) - Upper stage status evolved into the SLS upper stage

Automated Transfer Vehicle (ATV) - ESA ISS cargo carrier this has eveloved into the srvice module for Orion

Orion (CEV / SM) - status mating has been done for EM1 test flight

Ares V (CaLV) - status this was the base line once forced to reuse existing labor and construction components to make the SLS

Current status of a moon lander is dormant and are critical for a lunar landing to celebrate the 50 anniversary of Apollo 11:
Northrop Grumman Lunar Lander Challenge

Altair - Lunar Lander (LSAM) - status

The system still is lacking the ability to land on the moon and while Nasa has chosen to go with a mini space station for moon observation is seen as a distraction. It is also seen the same for going to mars as well.

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#31 2018-12-28 15:54:27

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 16,726

Re: Space Launch System

We started talking about shuttle derived ships way back in 2004 long before getting to the rehashed vehicle that congress said that they wanted. We looked at many a frankenstien rocket and using other engines as well.

Launch Vehicle Engine Selection Using Probabilistic Techniques of course with the engines come the fuel and oxidizer set so we need to chose wisely as that goes to the next issue of the tanks to put it in for the stage that we are designing..

The Advanced Cryogenic Evolved Stage (ACES)- A Low-Cost, Low-Risk Approach to Space Exploration Launch where by we are looking at what is it expected to do and is it for a payload to still go with it.

Of course this is why we are in a 2 rocket sls first version for getting to the moon...
Ares V: Supporting Space Exploration from LEO to Beyond

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#32 2019-02-27 21:38:15

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 16,726

Re: Space Launch System

As Nasa gets closer to being able to launch the Big Dumb Rocket from the past they are going to need this largest hydrogen cryogenic sphere ever built for NASA

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#33 2019-02-27 21:51:17

kbd512
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Registered: 2015-01-02
Posts: 3,010

Re: Space Launch System

Big dumb rockets using existing hardware were supposed to be cheap, but then the government got involved.

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#34 2019-02-27 22:04:42

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 16,726

Re: Space Launch System

As well as the congress and there areas that would have lost jobs....so much for government welfare program...
oh wait thats working for it but just were over paid for doing so little

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#35 2019-03-27 18:20:17

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 16,726

Re: Space Launch System

Well the Senate launch system is coming up smelling and the administation is about to put its foot down.
US to speed up astronaut return to Moon: target 2024 not 2028 as there is a race to the moon.

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#36 2019-04-03 16:53:13

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 16,726

Re: Space Launch System

Now that Nasa has a new date for going to the moon but now it seems that we have now got one for mars as well. NASA Administrator Jim Bridenstine told a Congressional committee on Tuesday that President Trump’s accelerated timeline to put humans back on the Moon is within the space agency’s capabilities, and that a revved-up lunar mission will improve the odds of American astronauts reaching Mars by 2033. NASA wants to land astronauts on Mars by 2033

Time to step it up Nasa.

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#37 2019-04-07 17:07:22

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 16,726

Re: Space Launch System

I think that the final engine testing has been done and now its time to fly this rocket.
This Week at NASA: Accelerating a Human Return to the Moon and More

Now its time for NASA Administrator Jim Bridenstine to get further control of all projects and get them producing on schedule without the delays and cost overruns.

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#38 2019-04-09 11:58:33

knightdepaix
Member
Registered: 2014-07-07
Posts: 212

Re: Space Launch System

About solid or liquid fuel, can solid and/or liquid carbon allotropes and/or carbon oxide(s) react with liquid oxygen to generate enough thrust as rocket propellants?

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#39 2019-04-09 12:04:41

elderflower
Member
Registered: 2016-06-19
Posts: 1,149

Re: Space Launch System

Carbon monoxide would be a useable choice for a cryogenic engine. 2CO +O2>2CO2.
Solid carbon might work in a hybrid engine C+O2>CO2 and 2C +O2> 2CO.

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#40 2019-04-09 16:27:22

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 3,717
Website

Re: Space Launch System

The problem with carbon at "ordinary" combustor conditions is that it is a solid of a certain particle size governed by the chain length.  Particle size greater than atomic scale means reaction rates slower than an atomic-scale gas.  A typical fine powdery soot at airbreathing combustor conditions reacts something like 10 to 100 times slower than gaseous forms like CO or methane. Getting solid carbon broken down into an atomic scale gas effectively means preheating it to well over 5000 F,  something usually considered quite impractical.  Ugly little fact of life,  but there it is.  --  GW

Last edited by GW Johnson (2019-04-09 16:28:20)


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#41 2019-04-23 21:24:51

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 16,726

Re: Space Launch System

The ever changing view of nasa and its rocket plan to go beyond LEO to the moon and mars with a rocket that is to costly to use.. So plan B is in need of work....

NASA Launch Services Program outlines the alternative launcher review for EM-1

21ebca59-47b8-477e-b098-4e831c432541-1170x780.jpg

The issue for Orion is lunar injection delta-Vs and the trans-lunar injection (TLI) requirements and whether we can use a direct launch...

Gateway-Delta-V-Comparison.jpg

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#42 2019-04-23 21:29:12

kbd512
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Registered: 2015-01-02
Posts: 3,010

Re: Space Launch System

Plan A hasn't even been put on a pad after what will be more years in development than the Saturn V program ever existed, from first contract to final flight.

Plan B has already successfully flown twice, one BEO mission and one GEO mission.

Plan A really should use a rocket that's already flown if the goal is to return to the moon in the next 5 years, but what do I know.

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#43 2019-05-02 16:01:39

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 16,726

Re: Space Launch System

SLS Forward Join Set for Horizontal Assembly to Liquid Hydrogen Tank

Can you say building in slow motion....

sls-forward-join-set-horizontal-assembly-liquid-hydrogen-tank-hg.jpg

core stage assembly plan, technicians and engineers will mate the forward join with the liquid hydrogen tank horizontally rather than vertically. This revised approach of mating the two critical components allows technicians and engineers to finalize the outfitting and testing of the engine section concurrently.
The forward join consists of three parts: the forward skirt, liquid oxygen tank and intertank. It makes up 66 feet of the 212-foot-tall core stage.

The core stage includes the liquid hydrogen tank and liquid oxygen tank that together hold 733,000 gallons of propellant to power the stage's four RS-25 engines needed to launch SLS and NASA's Orion spacecraft beyond Earth's orbit forward to the Moon.

NASA is charged to get American astronauts to the Moon by 2024.

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#44 2019-07-05 20:55:38

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 16,726

Re: Space Launch System

Its odd that Nasa would build without the proper tools to make things in a timely manner but they did. Michigan company helping NASA speed up SLS development

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#45 2019-07-06 07:00:09

tahanson43206
Member
Registered: 2018-04-27
Posts: 1,332

Re: Space Launch System

For SpaceNut re #43 and #44

Thanks for the follow up in #44, showing how NASA is converting from vertical assembly to horizontal.  Since vertical assembly was used in Apollo, and in most launches by NASA since, it must have been a major change for engineers and management to decide to adopt horizontal assembly.

I asked Mr. Google if Russians assemble their rockets horizontally, and found that my impression appears to be correct.

https://g2gcommunities.org/news/space-s … -assembly/

This web site article explores the differences between the Russian and American procedures in some detail.

In Russia however they have always constructed their rockets horizontally and lifted them before launch

The article lists pros and cons of both methods.   

Edit: After thinking about the article for a while, it occurs to me that there is a third alternative which the Americans may pursue.

That is to assemble some components horizontally, and then to raise the combined structure to vertical for final assembly.

This is something which might be interesting to keep an eye on.

However, it appears that SpaceX has gone with horizontal assembly:
https://www.space.com/spacex-falcon-hea … video.html

(th)

Last edited by tahanson43206 (2019-07-06 07:07:06)

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#46 2019-07-06 10:03:51

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 16,726

Re: Space Launch System

Well it is easier to build a low heighth building in a huricane zone than to be a robust tall building that will not....
Lifting a rocket even as big as BFR will be problematic even for the sls but from all of the other indications is that its possible without an incidences.

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#47 2019-10-12 09:11:50

Oldfart1939
Member
Registered: 2016-11-26
Posts: 1,780

Re: Space Launch System

In an announcement on SpaceNews this morning, the acting associate administrator for human spaceflight, Ken Bowersox, strongly hinted that the first SLS test flight will slip to mid 2021.

Note: earlier typo said 2022.

Last edited by Oldfart1939 (2019-10-12 10:25:05)

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#48 2019-11-29 23:22:27

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 16,726

Re: Space Launch System

The name of the new race to the moon still has not set in as Artemis II rocket propellant tanks prepped for next phase of manufacturing

artemis-rocket-propellant-tanks-transported-hg.jpg

Teams at Michoud completed welding on each of the giant tanks earlier this fall. The liquid oxygen tank has completed proof testing and is being readied for non-destructive evaluation, while the liquid hydrogen tank is being prepared for proof testing.

The tests validate weld strength and ensure structural soundness of the structures. Testing methods of the two propellant tanks differ due to the size and load differences the two pieces of hardware will experience during flight.

The liquid oxygen tank and liquid hydrogen tank hold a combined 733,000 gallons of propellant super cooled to minus 423 degrees Fahrenheit to power the four RS-25 engines at the bottom of the rocket. Crews are working in tandem on flight hardware for Artemis I and Artemis II. The core stage for Artemis I is in the final stages of production at the facility.

https://www.nasa.gov/sites/default/file … 112017.pdf

The mass of 1 gallon of water is 3.7854 kilograms, which is 210.3 moles of H2O. From the stoichiometry, there is a 1 to 1 (2 to 2) ratio of water to hydrogen produced, and so 210.3 moles of H2 will be produced. 210.3 moles of H2 weighs 420.6 grams, or just under one pound (see the Related Questions links to find out how to calculate the volume of that much H2 produced).

733,000 gallons x 3.7854 kilograms = 2775 mT of fuel in the first stage

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