Building rockets like oceangoing ships

[glhs837]

Mechanical engineering geekery ahead. Be warned.

So, SpaceX is building as many as six prototypes for it's next generation heavy lifter, spread between two sites, each are building three in a competitive/cooperative/iterative process. MKs 1,3,and 6 are being built in Boca Chica Texas and will launch and land there, while 2,4,6 are being built, for now anyway, in a metal fabrication yard they bought about 6 miles south of Kennedy space Center. MK1, which has a simply 20KM altitude flight profile, will go up and enter a horizontal free fall like a skydiver. Then propulsively right itself and land vertically. The later Marks will expand on this until MKs 5 and 6 potentially return from orbit this way.




Here's the thing, landing legs MATTER. A lot. The existing ones they have used for years now to land Falcons I think 40 something times wont do, so here;s the MK-1s landing legs up close. Six of them equally spaced, nobody is quite sure how they are extending them, but the method of braking them appears to be the eight metal bands passing through linear brakes, four bands on each side of each leg. Very rough build, keeping mind this is the first one, with a high expectation of not surviving it's test series, so fidelity less important than learning at this point. Fly/fail/fix/fly in rapid succession is the plan. So, my mechanically/engineering minded folks take a gander. Nice thing about them building these out in the open air next to a public highway is that we are treated to every step in the process.

https://www.teslarati.com/wp-conten...819-NASASpaceflight-bocachicagal-2-crop-c.jpg

 

[Gilligan]

I often wonder if I would have stayed with rocket engineering had I managed to work for someone as active/busy as Tesla is.

Edit: Meant SpaceX.... LOL..was just reading something about Tesla when I posted that..

 

[glhs837]

I often wonder if I would have stayed with rocket engineering had I managed to work for someone as active/busy as Tesla is.

Well it's SpaceX. not Tesla, but yeah, always hiring. Lots on the plate. Falcon and Falcon Heavy, which have a few years at least before Starship enters service and makes them obsolete. Crew Dragon, they also have a contract to work on both orbital refueling and some aspect of a lunar lander, cant recall if it was descent or ascent stage.

https://www.spacex.com/careers

 

[Gilligan]

I toyed with the idea of accepting offers from Thiokol and Hercules when I decided to get out of gummint job (1987). Glad I didn't...both jobs would have disappeared not too many years after I would have been hired.

 

[glhs837]

Heck, that was the first time Ive looked at it, never saw much point, since the odds of needing an expert in aircraft weapons systems seems pretty low. Everything from spacesuit sewer to lead engineers, welder, fabricators, deburring technicians. NDI techs, propulsion, satellite engineers, quite a lot of open positions.

 

[Gilligan]

Heck, that was the first time Ive looked at it, never saw much point, since the odds of needing an expert in aircraft weapons systems seems pretty low. Everything from spacesuit sewer to lead engineers, welder, fabricators, deburring technicians. NDI techs, propulsion, satellite engineers, quite a lot of open positions.

I was a solid-propellant rocket motor engineer.

 

[glhs837]

I was a solid-propellant rocket motor engineer.

Yep, none of those with these guys. Since re-usability is the watchword, they prefer their rockets liquid fueled. Solids good for a one time use, but SpaceX plans on rapid reuse. The old Falcons, I think they got turnaround down to two months and some change, but the goal with this new one is to be measured in days, if not hours. One reason for the methane and oxygen fuels. no toxicity, "easy" to handle, potentially easy to refine virtually anywhere in the solar system.

 

[PeoplesElbow]

I toyed with the idea of accepting offers from Thiokol and Hercules when I decided to get out of gummint job (1987). Glad I didn't...both jobs would have disappeared not too many years after I would have been hired.

Thiokol definately, what happened to Hercules?

 

[Gilligan]

Thiokol definately, what happened to Hercules?

They no longer operate the plant I was offered a job at. I was also offered a job on the government side in the same GOCO plant but I would have been forever capped because it was the highest level GS position that existed at the facility....nothing like taking a job knowing there was zero promotion possibility. LOL..no tanks.

 

[glhs837]

Seems the bit we care about was sold off to Alliant back around 1995. and then eventually became part of todays Orbital ATK and is now Northrop Grunmans Innovation Systems. So Gill would have a crapton of coffee mugs.

 

[glhs837]

They no longer operate the plant I was offered a job at. I was also offered a job on the government side in the same GOCO plant but I would have been forever capped because it was the highest level GS position that existed at the facility....nothing like taking a job knowing there was zero promotion possibility. LOL..no tanks.

I get it, solid motors, no tanks Good work, Sir.

 

[Gilligan]

I get it, solid motors, no tanks Good work, Sir.

boo.


But speaking of.....when I was offered a job there, TOW missile launch motors were a hot production item.

 

[nutz]

Mechanical engineering geekery ahead. Be warned.

So, SpaceX is building as many as six prototypes for it's next generation heavy lifter, spread between two sites, each are building three in a competitive/cooperative/iterative process. MKs 1,3,and 6 are being built in Boca Chica Texas and will launch and land there, while 2,4,6 are being built, for now anyway, in a metal fabrication yard they bought about 6 miles south of Kennedy space Center. MK1, which has a simply 20KM altitude flight profile, will go up and enter a horizontal free fall like a skydiver. Then propulsively right itself and land vertically. The later Marks will expand on this until MKs 5 and 6 potentially return from orbit this way.




Here's the thing, landing legs MATTER. A lot. The existing ones they have used for years now to land Falcons I think 40 something times wont do, so here;s the MK-1s landing legs up close. Six of them equally spaced, nobody is quite sure how they are extending them, but the method of braking them appears to be the eight metal bands passing through linear brakes, four bands on each side of each leg. Very rough build, keeping mind this is the first one, with a high expectation of not surviving it's test series, so fidelity less important than learning at this point. Fly/fail/fix/fly in rapid succession is the plan. So, my mechanically/engineering minded folks take a gander. Nice thing about them building these out in the open air next to a public highway is that we are treated to every step in the process.

https://www.teslarati.com/wp-conten...819-NASASpaceflight-bocachicagal-2-crop-c.jpg

Mr. Scott would not approve

 

[glhs837]

Mr. Scott would not approve

Hell yes, but Spock might have rigged it to get off the damn planet. I think he did in one episode. Unnecessary fidelity in test articles is just that

 

[Indoyota]

This is cool. But, i'm skeptical on the speed of SpaceX's timeline. If something bad happens, it's going to bring things to a screeching halt.

 

[Ken King]

MKs 1,3,and 6 are being built in Boca Chica Texas and will launch and land there, while 2,4,6 are being built, for now anyway, in a metal fabrication yard they bought about 6 miles south of Kennedy space Center.

Why are they building two 6s and no 5?

 

[glhs837]

This is cool. But, i'm skeptical on the speed of SpaceX's timeline. If something bad happens, it's going to bring things to a screeching halt.

Depends on the bad thing. Crash and burn with no damage to someone else property or injury to folks? Figure out what went wrong, fix that in the next MK, roll it out and launch it. It's risk acceptance done right. These early test articles are to nail down the dynamics, the details that go with "man rating" it follow. This isnt NASA, it's all SpaceX funded. I think they blew up seven or eight Falcons so far figuring out how to land. Only two have resulted in lost payload, since the rest were landing attempts that failed. Thats reason they have six of these, for redundancy during test.

They even put out a "Greatest Hits" video.

Why are they building two 6s and no 5?

Because I'm an ordnanceman who is usually prohibited from performing public maffs.

 

[glhs837]

So, MKs 1 and 2 and done with. Evidently, they had already decided a while back that they were never going to fly them. They kept going for more manufacturing learning. Pressure tested MK 1 with nitrogen, and what they termed a faulty sensor led to a severe over-pressure, blowing the top tank bulkhead and top couple of rings a few hundred feet up. No injuries, lessons learned applied to MK 3 and subsequent. MK 3 starting build in boca, Cocoa appears to be closing up shop, as a new bridge will block overland access to the Cape, so they are moving some functions there while a lot of the team moved to Boca to work MK 3.

https://www.popularmechanics.com/space/rockets/a29871777/starship-mk1-explosion/

New timeline not announced, I think maybe months, expect a flight in maybe Feb/Mar, but thats spitballing.

 

[Indoyota]

Have you noticed the the location of Boca. It's extremely similar to the cape.

 

[GURPS]

Pressure tested MK 1 with nitrogen, and what they termed a faulty sensor led to a severe over-pressure, blowing the top tank bulkhead and top couple of rings a few hundred feet up.

sounds like and old news reel PSA I saw about water heater pressure relief valves .... a water heater ruptures launching it self like a rocket