Successful Test Fire of SLS-Artemis core stage

Nasa and prime contractor Boeing conducted a successful test fire of the 4 RS-25 LH2/LOX engines which make up the core of the SLS
super heavy booster

The engines fired for full 8 min 20 sec (500 seconds) simulating the time needed for a launch

www.cnet.com...

This followed an earlier attempt which was aborted after 1 min do to anomaly in hydraulics which control the engine gimbel

Looks Space X and Musk got into their heads with all the Starship developments ……...

a reply to: firerescue

The mess politicians have created at nasa is beyond comprehension.
The mission went from a near earth asteroid to going back to the moon.
Orion was built to intercept an asteroid and now it’s supposed to go to the moon but is not capable of landing.
Boeing has done nothing but botch their part of the project.
The fine senator from Alabama has stuck a knife into the neck of the project holding it ransom.

Politicians have interfered with nasa and forced them to procure equipment in military style but without the budget of the military.


The only advantage that space x has is the government can’t interfere with their projects.
Musks promises are a joke but at least they are free to pursue those goals without interference.

a reply to: Bluntone22

SLS - Artemis is symbolic of gubmint military industrial complex, which Eisenhower warned us 60 years ago

SLS was built on the old cost-plus contract system where NASA pays all the development costs plus a profit for the contractor
]
In such a system there is a perverse incentive to not hold costs down , to try to string out the process as long as
possible to keep the gravy flowing

SLS was supposed to ready in 2017, then 2018, then 2020, then 2022

SLs in expected to cost over 1 bil a launch, which means is too expensive to launch

Musk may be a blowhard, even borderline delusional, but cant argue with what he has accomplished

originally posted by: Bluntone22
a reply to: firerescue

The mess politicians have created at nasa is beyond comprehension.
The mission went from a near earth asteroid to going back to the moon.
Orion was built to intercept an asteroid and now it’s supposed to go to the moon but is not capable of landing.
Boeing has done nothing but botch their part of the project.
The fine senator from Alabama has stuck a knife into the neck of the project holding it ransom.

As a 35 year NASA aerospace engineer who worked on all the Moon-Mars architectures from 1990 to 2015, I have to say that it's probably even worse than you think.

The Orion capsule wasn't built to intercept an asteroid; it was built to keep Marshall Space Flight Center fully employed. Orion was part of NASA's Constellation program, begun in 2005 with the supposed intent of keeping NASA in the human space flight business, because the retirement of the Space Shuttle had been announced the previous year.

The idea was to create a transportation infrastructure similar to what the Saturn V had been, with one exception. The Saturn V system used a super heavy launch vehicle, a dedicated lunar landing and ascent stage, a blunt-body crew capsule, and a service module that provided all the support functions for the capsule while it was in space (power, propulsion, communication, attitude control). Theoretically, this system could have been used with small modifications for all human space flight purposes envisioned at the time (Earth orbit, Lunar missions, asteroid missions, Mars missions).

What was different was that one of the lessons supposedly learned from the Shuttle program was that crew should be transported to space on a vehicle that is separate from the cargo vehicle. The Shuttle was both a crew transporter and a cargo transporter, and it was thought that the design compromises that were made to make it a cargo transport made it less safe as a crewed vehicle. So, the Constellation program included a super heavy booster (the Ares V) for cargo and a dedicated crew launcher (the Ares I--sometimes referred to as the "turkey baster" because of its ungainly, top-heavy design). This would have had the desired effect of separating crew from cargo.

At the time, a number of different parties pointed out that if you were willing to transport super heavy payloads to orbit in pieces and assemble them on orbit you could do the entire mission set with slightly modified existing launchers (Delta IV Heavy, and Atlas V). That would allow the program to proceed quicker and less expensively. They also pointed out that there was a law in existence that prohibited NASA from building a new launcher design if an existing, commercial launch vehicle could do the job.

The problem with using commercially available launches was that then there would have been nothing for Marshall Space Flight Center to do, since their speciality was designing and building big new rockets. So the Senator from Huntsville (Shelby) applied obscene amounts of pressure behind the scenes to make sure that NASA wrote the requirements in such a way that two new rockets could be legally justified. The first requirement mandated that on-orbit assembly would not be allowed because it was too risky (even though it had been used quite successfully for the Space Station). That justified Ares V. The second requirement came about because the Orion capsule was deliberately designed to be too heavy for either of the existing launchers to handle. That justified Ares I, and Marshall Space Flight Center was off and running.

Four years later, Obama proposed to cancel the program but he was soon overruled by Congress, and development of the Ares V continued with a smaller budget and a name change to the Space Launch System, or SLS (sometimes referred to as the Senate Launch System, since it was defended by Senator Shelby). With the smaller budget, NASA couldn't afford all the pieces of even a Lunar program, so they cut the Lunar lander and the Ares I. That meant that NASA could still theoretically launch human space flight missions, but it would have to violate its own rule of separating crew and cargo on launches. Oh, well, NASA decided that was no problem.

However, with no Lunar lander under development, Lunar landing missions were out of the question, so the original justification for developing Ares V in the first place evaporated. Oh, well, NASA decided that was no problem.

So they looked around for missions that they could accomplish with the Ares V and Orion capsule. You could go to and from the Space Station, but each trip to and from the Station would probably cost 10 time more than simply buying rides from the Russians and you would have to do that 3 or 4 times a year. You could do trips around the Moon and back, but there was zero scientific or exploration justification of any kind for that kind of mission.

Then some genius (whose name I won't mention) proposed to do an asteroid rendezvous mission. The idea was that even if that wasn't very exciting, at least it represented a new destination. So we started a study inside NASA (which I was part of) to see how you might do that kind of mission. The main problem (as I recall) is that most of the Near Earth Asteroids that you might want to go visit require more energy to get to and back from than a Lunar mission. The Orion capsule was too heavy for that when fully loaded, so you could have a crew of two, max. Another problem is that in order to rendezvous with a specific asteroid, you have to launch at a specific time. If you miss that launch window, it might not come around for many years later. That's unlike a Lunar mission, where you can launch a month later if you miss a particular launch window. It also ended up that there were no asteroids known at the time that you could actually reach. Yet another problem was that most, if not all, asteroids are actually tumbling or rotating. Even if you could find an interesting asteroid and get to it, nobody could figure out how to rendezvous and dock with it, without endangering the crew. You could basically just stand off a hundred meters or so, watch it for a while, and then come home.

Other than that, it was a great idea.

What's special about these Artemis rockets? Better efficiency?

a reply to: Tempter

The engines are the same one used on the Space Shuttles, but Artemis carries four of them not one.

8.8 million pounds of thrust. That is a lot of lifting power. More power means more massive payloads. Heavier stuff into orbit with a single launch. The proximate plan is construction of the Lunar Gateway.

We'll see how that goes.

originally posted by: Phage
a reply to: Tempter

The engines are the same one used on the Space Shuttles, but Artemis carries four of them not one.

8.8 million pounds of thrust. That is a lot of lifting power. More power means more massive payloads. Heavier stuff into orbit with a single launch. The proximate plan is construction of the Lunar Gateway.

We'll see how that goes.

What does 8.8 million pounds of thrust translate too as far as how much it can haul up? Is there like a ratio like 1lb of thrust equals X amount of liftable lbs, if that makes any sense.

originally posted by: 1947boomer

originally posted by: Bluntone22
a reply to: firerescue

The mess politicians have created at nasa is beyond comprehension.
The mission went from a near earth asteroid to going back to the moon.
Orion was built to intercept an asteroid and now it’s supposed to go to the moon but is not capable of landing.
Boeing has done nothing but botch their part of the project.
The fine senator from Alabama has stuck a knife into the neck of the project holding it ransom.

As a 35 year NASA aerospace engineer who worked on all the Moon-Mars architectures from 1990 to 2015, I have to say that it's probably even worse than you think.

The Orion capsule wasn't built to intercept an asteroid; it was built to keep Marshall Space Flight Center fully employed. Orion was part of NASA's Constellation program, begun in 2005 with the supposed intent of keeping NASA in the human space flight business, because the retirement of the Space Shuttle had been announced the previous year.

The idea was to create a transportation infrastructure similar to what the Saturn V had been, with one exception. The Saturn V system used a super heavy launch vehicle, a dedicated lunar landing and ascent stage, a blunt-body crew capsule, and a service module that provided all the support functions for the capsule while it was in space (power, propulsion, communication, attitude control). Theoretically, this system could have been used with small modifications for all human space flight purposes envisioned at the time (Earth orbit, Lunar missions, asteroid missions, Mars missions).

What was different was that one of the lessons supposedly learned from the Shuttle program was that crew should be transported to space on a vehicle that is separate from the cargo vehicle. The Shuttle was both a crew transporter and a cargo transporter, and it was thought that the design compromises that were made to make it a cargo transport made it less safe as a crewed vehicle. So, the Constellation program included a super heavy booster (the Ares V) for cargo and a dedicated crew launcher (the Ares I--sometimes referred to as the "turkey baster" because of its ungainly, top-heavy design). This would have had the desired effect of separating crew from cargo.

At the time, a number of different parties pointed out that if you were willing to transport super heavy payloads to orbit in pieces and assemble them on orbit you could do the entire mission set with slightly modified existing launchers (Delta IV Heavy, and Atlas V). That would allow the program to proceed quicker and less expensively. They also pointed out that there was a law in existence that prohibited NASA from building a new launcher design if an existing, commercial launch vehicle could do the job.

The problem with using commercially available launches was that then there would have been nothing for Marshall Space Flight Center to do, since their speciality was designing and building big new rockets. So the Senator from Huntsville (Shelby) applied obscene amounts of pressure behind the scenes to make sure that NASA wrote the requirements in such a way that two new rockets could be legally justified. The first requirement mandated that on-orbit assembly would not be allowed because it was too risky (even though it had been used quite successfully for the Space Station). That justified Ares V. The second requirement came about because the Orion capsule was deliberately designed to be too heavy for either of the existing launchers to handle. That justified Ares I, and Marshall Space Flight Center was off and running.

Four years later, Obama proposed to cancel the program but he was soon overruled by Congress, and development of the Ares V continued with a smaller budget and a name change to the Space Launch System, or SLS (sometimes referred to as the Senate Launch System, since it was defended by Senator Shelby). With the smaller budget, NASA couldn't afford all the pieces of even a Lunar program, so they cut the Lunar lander and the Ares I. That meant that NASA could still theoretically launch human space flight missions, but it would have to violate its own rule of separating crew and cargo on launches. Oh, well, NASA decided that was no problem.

However, with no Lunar lander under development, Lunar landing missions were out of the question, so the original justification for developing Ares V in the first place evaporated. Oh, well, NASA decided that was no problem.

So they looked around for missions that they could accomplish with the Ares V and Orion capsule. You could go to and from the Space Station, but each trip to and from the Station would probably cost 10 time more than simply buying rides from the Russians and you would have to do that 3 or 4 times a year. You could do trips around the Moon and back, but there was zero scientific or exploration justification of any kind for that kind of mission.

Then some genius (whose name I won't mention) proposed to do an asteroid rendezvous mission. The idea was that even if that wasn't very exciting, at least it represented a new destination. So we started a study inside NASA (which I was part of) to see how you might do that kind of mission. The main problem (as I recall) is that most of the Near Earth Asteroids that you might want to go visit require more energy to get to and back from than a Lunar mission. The Orion capsule was too heavy for that when fully loaded, so you could have a crew of two, max. Another problem is that in order to rendezvous with a specific asteroid, you have to launch at a specific time. If you miss that launch window, it might not come around for many years later. That's unlike a Lunar mission, where you can launch a month later if you miss a particular launch window. It also ended up that there were no asteroids known at the time that you could actually reach. Yet another problem was that most, if not all, asteroids are actually tumbling or rotating. Even if you could find an interesting asteroid and get to it, nobody could figure out how to rendezvous and dock with it, without endangering the crew. You could basically just stand off a hundred meters or so, watch it for a while, and then come home.

Other than that, it was a great idea.

Kudos to OP for this thread.

@1947boomer, thanks for this in-depth and 'behind the scenes' look into the gear production (and accompanying politics) at NASA. Personally I'd enjoy more posts in this vein. I'm always curious when it comes to topics such as decommissioning of the space shuttle, the development of propulsion systems/rockets, and what's in the pipeline (e.g. What is being worked on to propel missions to Mars? Is there any effort to develop a reusable space-plane vehicle like the shuttle but able to lift off/return without immense chemical rockets?)

a reply to: Brotherman

One pound of thrust will "hover" one pound of weight. Since the vehicle itself masses about 6 million pounds that leaves 2.2 million pounds of "excess" thrust. So, with no payload, that constitutes a pretty large level of acceleration.

In order to reach orbit, the vehicle (and payload) must attain a velocity of 17,000 mph as it leaves the atmosphere. Artemis will be able to take 95 tons to orbit. By comparison, the shuttles could lift about 20 tons and the Saturn V could lift 51.

Artemis is a beast.

a reply to: Phage

Actually Phage SATURN V could lift 115 metric tons to LEO, 51 metric tons to lunar trajectory

a reply to: firerescue

Thanks for the differentiation between orbit and lunar injection. But it was 47 metric (51 short) tons to the Moon.

Artemis is still a beast with 15% more thrust in the first stage than Saturn V. Can't come up with numbers for what it can take to LEO because that's not what it's for.

a reply to: Phage

That's pretty cool, thanks for dumbing it down for me shines a new light.

originally posted by: Brotherman
a reply to: Phage

That's pretty cool, thanks for dumbing it down for me shines a new light.

It always amazes me to think that the Saturn V is _still_ (I think?) the most powerful rocket system ever put into mission use, and it was developed 50+ years ago!

The Saturn V was launched 13 times from Kennedy Space Center with no loss of crew or payload. As of 2021, the Saturn V remains the tallest, heaviest, and most powerful (highest total impulse) rocket ever brought to operational status, and holds records for the heaviest payload launched and largest payload capacity to low Earth orbit (LEO) of 310,000 lb (140,000 kg), which included the third stage and unburned propellant needed to send the Apollo command and service module and Lunar Module to the Moon.

We had some pretty damn good engineers back during the Apollo era (despite the legacy of our rocket program being inextricably linked with Project Paperclip and Nazi Germany)

a reply to: SleeperHasAwakened

(despite the legacy of our rocket program being inextricably linked with Project Paperclip and Nazi Germany)

It can be argued that without Von Braun's work man would not have walked on the Moon as soon as they did.

He really was a damned good rocket scientist, even if his work did wreak some havoc on Great Britain. Two edged, etc.

originally posted by: Phage
a reply to: SleeperHasAwakened

(despite the legacy of our rocket program being inextricably linked with Project Paperclip and Nazi Germany)

It can be argued that without Von Braun's work man would not have walked on the Moon as soon as they did.

He really was a damned good rocket scientist, even if his work did wreak some havoc on Great Britain. Two edged, etc.

Couldn't it also be argued that without war the necessity of this technology would have been put on the back burner for a long long time? Prior to this wasn't there only a handful of people more or less that envisioned these machines and purpose?

a reply to: Brotherman

Prior to this wasn't there only a handful of people more or less that envisioned these machines and purpose?

Von Braun was one of them.
So was Goddard.

One got government funding.

originally posted by: Brotherman
a reply to: Phage

That's pretty cool, thanks for dumbing it down for me shines a new light.

It’s not just the lift either.
In order to maintain orbit you must lift the weight of the payload and reach orbital velocity.
The ISS is traveling just under 5 miles a second.
The dumbed down version is only a couple percent of a rockets weight is payload.

a reply to: Bluntone22

Yep.
The vast majority of mass is devoted to fuel. Mass which must also be accelerated and lifted.

Rockets kind of suck actually. But, oh well.

a reply to: Phage

It’s a funny thing that if our planet had just a tiny bit mor gravity we wouldn’t be about to make orbit.

a reply to: Bluntone22

There is no gravity.
The Earth sucks.