notex said:

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Well, first of all, oh crap.

Second, there are advantages and disadvantages to both materials. Carbon fiber is lighter and stronger and doesn't flex. It's also an order of magnitude more expensive and much more difficult to produce in quantity as SpaceX is doing with the steel starships.

The rough scale of thousands of starships launching per year, turn around times of several hours etc., is basically why they switched I think.

60 times cheaper, and pretty great with temperature gradients; the 'old' stuff won over carbon fiber basically.

https://everydayastronaut.com/stainless-steel-starship/

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Now you might be thinking, "If the entire system is reusable the cost of the rocket doesn't really matter as much, does it?" Well, of course that's true to some degree, but forget the physical benefits of stainless steel, if something is 60 times cheaper, it can really quickly affect your bottom dollar. And SpaceX is, after all, a private company looking to make a profit at the end of the day. Sure, they could spend 10 years developing the most advanced carbon composite fuselage ever that costs insane amounts to produce, but let's look at where that'd get them in 20 years. Now they lost a lot of time of potentially profiting off the development of a fully reusable vehicle, and THEN they'll have a rocket that's even more expensive to build!

We're once again seeing SpaceX not fall into the trap of the sunk cost fallacy. I talked about this quite a bit in a video titled "Why does SpaceX keep changing the BFR" after we saw its third big change in design at the Dear Moon announcement in 2018. But the fact is, this all checks out. It might be easy to think this is a disappointment, a letdown or a compromise, but quite frankly it IS a compromise.

Engineering is always a compromise. And that's not a bad thing.

There's trade offs to absolutely every single decision whether it be time and money, or whether it be a flight profile where it might make sense to throttle down at a certain point, to trade offs in strength and weight of certain materials. There are ALWAYS trade offs!

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But to your other point, the flip at the end is indeed impressive, and I hope it reliably works well in the future. However, an upper stage surviving re-entry is always to me more impressive from a sheer engineering perspective (the only human built things to have pulled it off are capsules, I think, and some film parachuted down). That huge mass has incredible forces on it to pull it off, and it must both be controlled, and not suffer any single point of failure during several critical minutes. Aerobatics are pretty visually, but not anywhere near as demanding. Again, just my opinion.

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Do you consider the shuttle to be an "upper stage"? It went as fast Gemini and Mercury upper stages, and was a lot heavier than either of them (and starship). I think those factors are what are most important to the ass-painery of reentry.

notex said:

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Well, first of all, oh crap.

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I second the 'oh crap'

LOL, I guess the shuttle should count (as should the Russian one) by the standards I laid out. I'm not a pro at this either but I've sort of blacked out the whole shuttle era mentally as it was...a bit absurd, imho. Sorry, rant over.

Frankly, it's a nice distraction from politics at this point, to follow.

notex said:

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LOL, I guess the shuttle should count (as should the Russian one) by the standards I laid out. I'm not a pro at this either but I've sort of blacked out the whole shuttle era mentally as it was...a bit absurd, imho. Sorry, rant over.

Frankly, it's a nice distraction from politics at this point, to follow.

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I agree on the absurdity of the shuttle program. Watching how fast Space X is advancing, I wonder how much father along we'd be if the shuttle didn't monopolize US space travel for all that time. Companies like Space X would have been able to innovate and compete for business like in other industries for decades.

I used to say on here that when NASA spent all that money on the shuttle that they were advancing the space industry at the expense of everything else. That perhaps if we kept that tax money in the hands of the private sector that we'd be behind where we are now in space, but further ahead in medicines, computers, food, etc. However, now it seems clear that the shuttle program set us behind in space too. While we clearly would not have been to the moon in 1969 if it wasn't for government spending an assload on Apollo, somewhere after that the curve dipped below zero and slowed down progress. I'll have to think more about that.

notex said:

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LOL, I guess the shuttle should count (as should the Russian one) by the standards I laid out. I'm not a pro at this either but I've sort of blacked out the whole shuttle era mentally as it was...a bit absurd, imho. Sorry, rant over.

Frankly, it's a nice distraction from politics at this point, to follow.

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The Space Shuttle Orbiter was often referred to as the "upper stage." In some of the early missions, there was a radio call-out "go for second stage" after SRB separation.

The shuttles looked absolutely badass, and I loved them as a kid (still do to an extent). But looking back on them somewhat objectively, they were a misstep in space exploration.

aTmAg said:

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notex said:

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LOL, I guess the shuttle should count (as should the Russian one) by the standards I laid out. I'm not a pro at this either but I've sort of blacked out the whole shuttle era mentally as it was...a bit absurd, imho. Sorry, rant over.

Frankly, it's a nice distraction from politics at this point, to follow.

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I agree on the absurdity of the shuttle program. Watching how fast Space X is advancing, I wonder how much father along we'd be if the shuttle didn't monopolize US space travel for all that time. Companies like Space X would have been able to innovate and compete for business like in other industries for decades.

I used to say on here that when NASA spent all that money on the shuttle that they were advancing the space industry at the expense of everything else. That perhaps if we kept that tax money in the hands of the private sector that we'd be behind where we are now in space, but further ahead in medicines, computers, food, etc. However, now it seems clear that the shuttle program set us behind in space too. While we clearly would not have been to the moon in 1969 if it wasn't for government spending an assload on Apollo, somewhere after that the curve dipped below zero and slowed down progress. I'll have to think more about that.

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A few things here:

1.) NASA never had a monopoly on space flight, but very few people were willing to risk their own money on space prior to the 2000s. There's some notable people who tried private space ventures - like Constenoga - but they were under funded, ill conceived, and imploded after things exploded. It was really the X-prize that got private space moving and commitment of people like Musk to spend lots of money out of their own pocket. None of which had anything to do with the Shuttle program.

2.) The irony is that NASA's original vision for the Shuttle was a blunt body vehicle that didn't look too terribly different from Starship. It's been known for a long time that big empty rockets that are "fluffy" on re-entry are a great way to manage heating. NASA always planned to land horizontally, but with much stubbier wings than the Shuttle got. It was NASA getting forced into bed with the USAF that gave us the Shuttle we know.

Isn't that why the payload bay ended up so grotesquely large? IIRC the DOD said they'd launch satellites on it if they made it that big but then never did

Yes. The US Air Force at the time was considering secret missions where shuttles could take off quickly and capture enemy satellites. They had plans in place for shuttles to have missions lasting less than a few hours. They were to takeoff, intercept a satellite, and land after just a few orbits. The size of the payload bay was partially due to Air Force requirements.

At that time, they believed shuttles would have very quick turnaround times and would more or less be similar to souped up airplanes. As they got further into the development they realized that refurbishing shuttles after reentry was going to be a huge task, the USAF more or less walked away and they now had a craft not fully designed around the types of missions they would actually be asked to do.

TriAg2010 said:

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aTmAg said:

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notex said:

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LOL, I guess the shuttle should count (as should the Russian one) by the standards I laid out. I'm not a pro at this either but I've sort of blacked out the whole shuttle era mentally as it was...a bit absurd, imho. Sorry, rant over.

Frankly, it's a nice distraction from politics at this point, to follow.

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I agree on the absurdity of the shuttle program. Watching how fast Space X is advancing, I wonder how much father along we'd be if the shuttle didn't monopolize US space travel for all that time. Companies like Space X would have been able to innovate and compete for business like in other industries for decades.

I used to say on here that when NASA spent all that money on the shuttle that they were advancing the space industry at the expense of everything else. That perhaps if we kept that tax money in the hands of the private sector that we'd be behind where we are now in space, but further ahead in medicines, computers, food, etc. However, now it seems clear that the shuttle program set us behind in space too. While we clearly would not have been to the moon in 1969 if it wasn't for government spending an assload on Apollo, somewhere after that the curve dipped below zero and slowed down progress. I'll have to think more about that.

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A few things here:

1.) NASA never had a monopoly on space flight, but very few people were willing to risk their own money on space prior to the 2000s. There's some notable people who tried private space ventures - like Constenoga - but they were under funded, ill conceived, and imploded after things exploded. It was really the X-prize that got private space moving and commitment of people like Musk to spend lots of money out of their own pocket. None of which had anything to do with the Shuttle program.

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Prior to the Challenger disaster, most American payloads were required to be flown on the shuttle. That was because it was thought that the shuttle would be cheap if it flew a lot. And the X prize was not a big motivator, since it was only $10M. For comparison, Falcon 1 cost $90M to develop and SpaceShipOne, that won the prize, cost $25M to develop. For them, the real prize was profits via paying customers (including governments). Several companies were willing to risk their own money on space prior, but NASA refused to do business with them, since they were pushing the shuttle. The American Rocket Co. in the 70s and Space Industries of Houston in the 80s were a couple of them.

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2.) The irony is that NASA's original vision for the Shuttle was a blunt body vehicle that didn't look too terribly different from Starship. It's been known for a long time that big empty rockets that are "fluffy" on re-entry are a great way to manage heating. NASA always planned to land horizontally, but with much stubbier wings than the Shuttle got. It was NASA getting forced into bed with the USAF that gave us the Shuttle we know.

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When you say NASA was forced into bed with the USAF, that makes it sound like the USAF pounded NASA's door demanding a role in the shuttle. That's not the case. The shuttle was about to lose funding, so NASA approached the USAF and the intel agencies to find more customers, not the other way around. To the USAF and intel guys, the shuttle was worthless unless it was bigger. So to keep these new customers NASA made it larger. That's not USAF's fault, it's NASA's fault. What should have happened was for NASA to drop the whole idea once once the USAF and intel agencies asked for it to be larger. The USAF would continue to use their rockets and NASA would find something more worthy to spend taxpayer money on. Instead, NASA maintained that it would be cheap despite the larger size. Then kept launching it for decades despite the exorbitant costs.

You left out the fact that the airforce forced NASA to use the two SRB system that ultimately led to the shuttle being a death trap, thinking it would be a faster system, and that the segmented theikol boosters are DOD kickbacks...

Nasa didn't HAVE to give in to the USAF...they could have just stopped existing, or not had a manned program....

The SRBs existed then and on SLS today because the Air Force needs to keep the industrial base intact for the previous and next generation of minutemen missiles.

Ag_of_08 said:

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You left out the fact that the airforce forced NASA to use the two SRB system that ultimately led to the shuttle being a death trap, thinking it would be a faster system, and that the segmented theikol boosters are DOD kickbacks...

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I've read otherwise and it doesn't really pass the smell test for many reasons. First of all, it's not like the USAF said "we DEMAND SRBs!!!" The USAF and intel agencies required launching large satellites. That plus the promise of reusability is what forced SRBs. Unless NASA was going to land rockets like Space-X is now, then there is pretty much no other option other than SRBs for that. You can reuse stuff that you jettison at 28 miles, but you can't for things that are at near orbital speed at 70 miles. If Harley Davidson approached me about a custom motorcycle and I tell them I need to be able to transport my entire family of 5, it'd be THEIR fault if they lie to me and tell me their motorcycle will be able to hold 5, not my fault for telling them I need to carry that many. They should tell me "sorry a motorcycle is not for you then" and move on to the next potential customer.

Furthermore, even if we pretend the USAF demanded they use SRBs, it wouldn't have been their fault that the Challenger blew up. There is nothing inherently unsafe about SRBs. In fact that were quite safe after challenger. If they weren't, they wouldn't be used on SLS. I think NASA deserves more blame for that than Thiokol and certainly more blame than the USAF. And there were many other near disasters that didn't happen due to luck. And Columbia where the luck ran out.

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Nasa didn't HAVE to give in to the USAF...they could have just stopped existing, or not had a manned program....

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If it's a waste of money and effort to have a manned program then they shouldn't have a manned program. That is what a responsible agency would do. Their good science like Voyager, rovers on Mars, etc. have no astronauts. But instead they grasp for huge budgets like every other governemnt agency no matter how wasteful it is. They shouldn't be excused for it.

lb3 said:

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The SRBs existed then and on SLS today because the Air Force needs to keep the industrial base intact for the previous and next generation of minutemen missiles.

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It would be cheaper just to pay Thiokol money. It's not like Thiokol is staying afloat by providing NASA 100 SRBs.

Sorry for getting this sidetracked, but a couple points. First, a funny graphic;

They do have it upright/vertical again, as of yesterday.

Second, here is a nice video describing the mission NASA agreed to USAF to essentially lay out the shuttle's final configuration. I wouldn't blame one organization or the other, it was really congress that drove the two to combine on the shuttle's unfortunate configuration; politics.



http://www.jamesoberg.com/sts-3A_B-DRM.PDF

https://thehighfrontier.blog/2015/10/19/blue-shuttle-how-the-air-force-influenced-the-sts-design-process/

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What emerged was an integrated plan for a fleet of Space Stations in Earth and Lunar orbits serviced by nuclear powered shuttles. Heavy boosters of the Saturn V class would still be needed to loft the largest payloads, but for regular service flights to and from orbit NASA proposed a reusable Shuttle, with George Mueller instrumental in guiding the initial studies for this craft, outlining the early policy for the system prior to leaving NASA. Clearly a reusable craft that could be readily serviced and rapidly returned to flight would offer significant economic advantages over the expendable boosters used up to that time.

A number of ideas were studied in the early phases with Lockheed, McDonnell Douglas, General Dynamics and North American Rockwell developing initial designs for configurations that could meet NASA's requirements. Lifting Bodies were one obvious direction, with the work being done at NASA's Flight Research Centre at Edwards AFB in the Mojave validating their early promise. Some designs proposed piggy-back systems with a large reusable booster stage and a smaller orbiter. Others looked at large expendable booster stages that could loft a re-usable spaceplane. Single Stage to Orbit (SSTO) configurations were also examined as was a Trireme of three craft of which one would continue to Orbit, while the others returned to base.

***et's Design
Eventually the two stage fully reusable piggy-back configuration emerged as the most promising and the contractors were invited to concentrate on this. As with previous crewed vehicles, NASA's Manned Spaceflight Centre worked on their own concept under the guidance of legendary designer Max ***et. Having earned his stripes as part of the original Space Task Group that designed the Mercury and later Gemini and Apollo capsules, ***et had demonstrated an innate ability to envision reliable craft by placing simplicity at the forefront. He now turned his attention to the proposed Shuttle and what emerged was a blunt bodied, straight winged Orbiter carried on a huge winged booster craft. The stack would launch vertically with initial thrust coming from the booster stage which would carry the orbiter to hypersonic velocities before releasing it to fly the rest of the way into orbit.
...
Justifying the Shuttle
By 1969, with the dust barely settled on the Sea of Tranquility, NASA's Acting Administrator Tom Paine was working hard to push his Integrated Post Apollo plan, but things weren't looking good. Although he found an ally in Vice President Spiro Agnew, it was clear that there was neither the appetite nor the funding for a large space exploration initiative from Nixon's Administration. Public opinion had turned away from space, concentrating instead on the Vietnam War and social problems within the United States.

Through the Agnew-chaired Space Task Group, three options were presented to Nixon, but even these were subject to the harsh economic realities of the time. As the 1970's dawned and inflation began to bite, the Bureau of Budget under Robert Mayo took a long hard look at NASA and demanded significant cuts.

For Paine, this meant that rather than looking towards an expanded programme, he was faced with cutting Apollo flights, ending production of the Saturn V and fighting for the very continuation of piloted spaceflight.
From this bleak picture the Shuttle emerged as the main point of focus. Grand plans for Space Stations and planetary missions could wait, but a Shuttle would keep America in the game, providing a way to achieve these goals in the future while retaining orbital access and an economical launch platform in the near-term. Accordingly, focus switched to making the Space Transportation System a larger, more capable 'space truck' able to meet the majority of the Nation's launch requirements at a fraction of the cost of expendable boosters.

As the Shuttle grimly hung on in the face of fierce Congressional opposition, narrowly avoiding cancellation in a tied vote, NASA's attention turned to ensuring the Air Force launch manifest could be brought to the Shuttle. If this could be done, managers were confident that the numbers would stack up in their favour and justify the Shuttle's continued development. But the deal would not come without costs to NASA as the Air Force had very specific requirements for any launch system that would replace their expendable boosters.

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Sigh, anyway, that last piece goes on and I think is accurate in it's history, but ultimately...the shuttle program became pretty costly/inefficient and essentially 'sucked all of the oxygen in the room' from any other US program from the early 70's through the mid 90's. Just my two cents, of course, but I think we 'could have done better.'

Maybe SN9 to the pad Thursday. Dunno yet.

I wonder if they can change the flap out that quickly

bthotugigem05 said:

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I wonder if they can change the flap out that quickly

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I'm gonna guess no but we will find out shortly. Maybe it's just a cryo test first while they complete SN10.

PJYoung said:

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bthotugigem05 said:

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I wonder if they can change the flap out that quickly

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I'm gonna guess no but we will find out shortly. Maybe it's just a cryo test first while they complete SN10.

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I'm sure they can. Another flap already spotted in route on a truck.

I think they will have at least a week or two of pad testing before any kind of lift off.

Static fire is the real indicator on readiness.

bthotugigem05 said:

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I wonder if they can change the flap out that quickly

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One of the flaps on SN8 looks like it could have the frame bent and buff out the rest...

scottimus said:

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PJYoung said:

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bthotugigem05 said:

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I wonder if they can change the flap out that quickly

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I'm gonna guess no but we will find out shortly. Maybe it's just a cryo test first while they complete SN10.

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I'm sure they can. Another flap already spotted in route on a truck.

I think they will have at least a week or two of pad testing before any kind of lift off.

Static fire is the real indicator on readiness.

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Looks like we are gonna have to wait until after Christmas

PJYoung said:

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The sequence at 13:15 with the engine gimbal to belly flop is mind blowing.

NASAg03 said:

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PJYoung said:

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The sequence at 13:15 with the engine gimbal to belly flop is mind blowing.

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Even assuming a successful landing of course, can you imagine being a passenger during a Starship landing?

I do think they cancelled the rollout for SN9 today/tomorrow...but it sounds like SN9 has been repaired.



I don't think it will even roll to the pad now until the 28th, but perhaps it won't even be 9, but 10?

It would be neat to see SN9 and SN10 both sitting on the launchpad, possibly in the next week or two. Apparently 10 is getting the lower fins installed this week still.

https://muskette.com/are-we-about-to-see-two-starships-on-the-launchpad/

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On the day of SN9's fall, we saw another flap being delivered to the production site, but there's growing speculation that could've been meant for SN10 or possibly another in-progress prototype.

Currently, SN10's tank section is fully outfitted in the Mid Bay and only lacks aerosurfaces for completion. On the evening of Dec. 15, Mary from NSF spotted a canard being installed on SN10's nosecone. By all intents and purposes, it's nearly ready for a rollout of its own.

That brings us back to the original question: is SpaceX planning to have both SN9 and SN10 on the pad at the same time? Will SN9's pushed-back timeline and the rapid advent of SN10 make it more feasible that they share a pad? The layout of the launch pad area gives each pad considerable distance from the other in the event of a launch, so there's minimal risk that one would be damaged by the other during a test flight.

It could still be that only SN9 makes it out to the pad first after these delays/repairs are over. Or, at this point, maybe SN10 cuts in line. One thing is for sure, it makes very little sense to have another near-fully assembled prototype loitering at the production site for another month and it should be an exciting end to an otherwise dreary year no matter what happens!

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NROL launch in a few minutes, complete with a RTLS

bthotugigem05 said:

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NROL launch in a few minutes, complete with a RTLS

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T-7 mins

will25u said:

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bthotugigem05 said:

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NROL launch in a few minutes, complete with a RTLS

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T-7 mins

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Hold at T-00:01:53.

Maybe some stuff happening Monday!

I watched this booster launch from the Kennedy Space Center press complex for CRS-20 in March!