Starship Booster Prototypes beginning soon

Oldfart1939 · 2020-09-03 09:31:07

The booster stage for Starship has had numerous names. In an interview on 31 August, Elon Musk stated that construction of "Prototype 1" would soon enter the construction phase. So--I suppose that calling this BFR by a more legitimate name would be Starship Booster?"

https://spacenews.com/musk-emphasizes-p … r-testing/

SpaceNut · 2020-09-03 17:58:49

GW has been talking about engine performance for a ssto not being possible but under sizing a first stage could also be a problem for booster.

The overall design of the system is still evolving. While SpaceX previously described Super Heavy as having 31 Raptor engines, Musk said the final number may be less. “We might have fewer than 31 engines on the booster, because we’re trying to simplify the configuration,” he said. “It might be 28 engines. It’s still a lot of engines.”
Musk spent a large chunk of the nearly half-hour interview going into technical details about the Raptor engines that will power Starship, discussing chamber pressures, thrust-to-weight ratios and specific impulse.

The flying silo is a working example just on a smaller scale.

tahanson43206 · 2020-09-03 18:26:31

A version of the flying silo (I believe SN6) had a successful hop today.

(th)

Oldfart1939 · 2020-09-04 09:02:25

The construction of the new High Bay is nearing completion. Some speculation that stacking of Booster Stage rings will begin, as there seems to be lots of rings available. I believe the limiting factor in progress is Raptor engine production and testing?

GW Johnson · 2020-09-06 09:23:50

They are testing something every day out at their McGregor facility, which is 6 miles line-of-sight from my front porch out here on the farm. I can usually tell a Merlin test from a Raptor test, because there is less soot coloring the steam-and-exhaust cloud that the tests create. I see a lot of Raptor tests. And, one of the recent news items told me that they finally got to, and just a bit higher than, their design chamber pressure of 4200 psia for Raptor. THAT is what makes the Isp predictions real. Isp is inherently lower, when you throttle-back to lower thrust and chamber pressure. That's just internal ballistics of chambers and nozzles.

GW

Oldfart1939 · 2020-09-25 15:59:12

According to videos from Boca Chica Maria, the first 3 ring stacks of the booster have been accumulated and are awaiting further stacking in the new yet-to-be-completed high bay structure.

SpaceNut · 2021-05-13 22:28:07

With the progress of starship development for landing the changes required for it have been rolled in and has led to changes in the first stage booster.

The first is the size and fuel mass for the starship to be able to do its task of launch to orbit and beyond.

http://spacelaunchreport.com/bfr.html

Of course the prototype test article is being scrapped and they have moved onto the next

https://www.space.com/spacex-first-supe … ster-photo

now we have the announcement of the first stack ups flight

https://www.teslarati.com/spacex-starsh … t-details/

I think calling the stage the super heavy needs some work in a new name for the stage

https://en.wikipedia.org/wiki/Starship_Super_Heavy

I would think that the first complete rocket will not be fully loaded for either stage of the assembly so what is the level of fuel that we need in each is important to success.

SpaceNut · 2021-07-04 14:05:03

It looks like they are finally building the launch tower and the first of a test vehicle for the booster for starship

louis · 2021-07-04 14:34:38

See the Starship is Go thread - BN3 rolled out for ground testing and BN4 will be the first orbital booster, it seems.

SpaceNut wrote:

It looks like they are finally building the launch tower and the first of a test vehicle for the booster for starship
https://www.nasaspaceflight.com/wp-content/uploads/2021/07/NSF-2021-07-03-05-46-15-672-1920x1071.jpg

SpaceNut · 2021-07-04 15:46:15

louis wrote:

BN3 being rolled out for ground testing.
BN4 scheduled as first orbital rocket.
Do people think getting the Boosters right is more or less difficult than getting the Starships right? I'm assuming more on the basis there are more engines...or is there some inbuilt redundancy?

https://www.space.com/spacex-starship-s … bbf865be49

SpaceNut · 2021-07-14 21:42:25

The only thing that is uncertain might be the position and number of the vents as the Booster will have 33 engines to thermally condition in comparison to Ship’s three sea-level optimized Raptors.

https://www.nasaspaceflight.com/2021/07 … -campaign/

Preparations ahead of a Super Heavy booster test campaign initially involved the potential of a 150-meter hop. However, this since-canceled goal was cited ahead of the vigorous Starship test campaign that eventually resulted in a fully successful test flight with SN15 (Ship 15).
Tagged as a pathfinder, this booster was set to roll out for ground testing. However, an engineering evaluation opted to swap the stacking order of the LOX (Liquid Oxygen) and CH4 (Methane) tankage.

Are they trying to limit leaks on landing?

may need to stop all together as FAA warns SpaceX that massive Starship launch tower in Texas is unapproved

The FAA further emphasized that the "480-foot-tall integration tower is substantially taller than the water tower and lightning towers assessed in the 2014" environmental review.

SpaceNut · 2021-07-21 20:39:07

Testing of engines and fueling has begun in earnest while the waiting game continues.
Super Heavy Booster 3 fires up for the first time

The bulk will be for the boosters, with Super Heavy’s opening 29-engine configuration eventually evolving to a 33-engines on the aft.

E6c7uBIWQAAB0Qb?format=jpg&name=900x900

Oldfart1939 · 2021-07-21 21:33:01

There's an old saying: it's sometimes easier to seek forgiveness than ask for permission.

tahanson43206 · 2021-07-22 06:48:53

For OF1939 re #13

The tried and (reliable) aphorism you've posted seems (at least in my experience) to work best when no one is paying attention.

In this case, having exercised the "ask for forgiveness" option previously, Mr. Musk and company have exhausted any good will they might have enjoyed.

It will be interesting to see how this turns out.

The entire "Nation" is sharing in this risk taking (via the agencies directly involved) ... the rewards for success are substantial.

The impact of failure would be felt locally, of course, but the effects would include a pall on future ventures on shore.

(th)

Calliban · 2021-07-22 10:40:56

Oldfart1939 wrote:

There's an old saying: it's sometimes easier to seek forgiveness than ask for permission.

Not a good philosophy for a first date! ?

I think it is reasonable for the FAA to expect a risk assessment, for something that carries as much stored energy as an A bomb. The bottom line is, there is a burden of proof on Musk to demonstrate that the risk he is imposing on his employees, the public and even himself, are tolerable. Presumably, SpaceX have some sort of safety case? I know they are a 'can do' operation, but a safety case is a legal requirement.

Last edited by Calliban (2021-07-22 10:41:42)

Oldfart1939 · 2021-07-22 12:35:24

This is something of a Red Herring, as far as the total stored energy of an A-Bomb is concerned. There is a property of explosives known as brisance, or shattering power. Methane and LOX do not possess much brisance but a lot of energy to be released. There would be one helluva explosion, but lacking the fast moving shock wave of TNT, a truly brisant reaction. So far we have never seen a SpaceX rocket motor explode on the launch pad on a flyable space vehicle. The only launch pad explosion was traced to a pressure vessel (COPV) overwrap issue.

An explosion at Boca Chica would indeed be spectacular, but not doing a lot of damage to the surrounding area.

Last edited by Oldfart1939 (2021-07-22 12:37:26)

RobertDyck · 2021-07-22 17:02:43

If you want to know what an explosion on the pad of Super Heavy would be like, the closest equivalent is explosion of N1. Super Heavy has 3,400 metric tonnes of LCH4/LOX. N1 had 2,300 tonnes of RP1/LOX. That's including all 3 stages: Block A, B, and V. Actually the 1964 version had 2,383 tonnes, but the video says 2,300. Earth departure stage was Block G with 55.8 tonnes more. But then subtract however much the engines consumed before the explosion. You get the idea.

Click image for YouTube video. It will auto-start at 5:10, so right at the explosion.

Sources: Astronautix index, click on N1 1964 - A, N1 1964 - B, N1 1964 - V, and N1 Block G.
Wikipedia: SpaceX Starship and N1 (rocket) Comparison to Saturn V.

louis · 2021-07-22 19:53:36

Yep, these are reasonable concerns. Space X never goes there in their public statements but it is in my view perfectly valid for the FAA to be concerned about such an event.

RobertDyck wrote:

If you want to know what an explosion on the pad of Super Heavy would be like, the closest equivalent is explosion of N1. Super Heavy has 3,400 metric tonnes of LCH4/LOX. N1 had 2,300 tonnes of RP1/LOX. That's including all 3 stages: Block A, B, and V. Actually the 1964 version had 2,383 tonnes, but the video says 2,300. Earth departure stage was Block G with 55.8 tonnes more. But then subtract however much the engines consumed before the explosion. You get the idea.
Click image for YouTube video. It will auto-start at 5:10, so right at the explosion.
https://i.ytimg.com/vi/gklVhRzkVqA/maxresdefault.jpg
Sources: Astronautix index, click on N1 1964 - A, N1 1964 - B, N1 1964 - V, and N1 Block G.
Wikipedia: SpaceX Starship and N1 (rocket) Comparison to Saturn V.

kbd512 · 2021-07-22 23:48:46

Oldfart1939 is correct:

1. Starship Super Heavy can indeed create a very large and powerful N1 lunar rocket type explosion from vaporizing Methane, but it's nothing whatsoever like the explosive power stored in an atomic weapon or conventional high explosive like TNT / dynamite. All high explosives and atomic weapons produce supersonic blast over-pressure waves. They detonate rather than deflagrate. The term "brisance" that he used is a measure of detonation pressure, and determines how powerful an explosive substance happens to be. TNT is highly brisant, whereas an Oxygen-Methane explosion is not. That doesn't mean you want to be anywhere near either type of explosion, but the destructive potential of a nuclear weapon is greatly in excess of a fuel-air deflagration. FAA is right to be concerned about how close a deflagration of that magnitude occurs to occupied areas.

2. All explosive substances are sub-divided into low and high explosives based upon the rate of expansion of the blast overpressure wave, which is determined by detonation pressure or brisance.

3. Rocket fuels like Kerosene or Methane or Hydrogen, as well as gunpowder, all deflagrate. That means the expanding pressure wave created by the resultant combustion products moves outward from the point of ignition below the speed of sound, because the magnitude of the over-pressure produced by the combustion products is insufficient to create a supersonic blast wave. Pure O2 combusting with pure H2 expands at a rate of 11.75 meters per second.

4. TNT / dynamite and nuclear weapons both detonate. That means the combustion products or atmospheric expansion from the heat released by an uncontrolled nuclear chain reaction produces a blast overpressure wave that moves outward from the point of ignition or uncontrolled chain reaction initiation at velocities faster than the speed of sound. Hydrogen bombs very briefly heat the surrounding atmosphere to up to 300,000,000 degrees Centigrade. A TNT detonation moves outward at a rate of approximately 6,900 meters per second (well above the speed of sound). The atmospheric effects from uncontrolled nuclear chain reactions (atomic weapons) initially move outward at around 15,000 meters per second (the Trinity device, for example), although they very rapidly slow down in Earth's atmosphere. Hydrogen weapons are considerably more powerful and produce atmospheric effects that initially move outwards considerably faster. The actual core of the weapon is blown apart at around 1,000 kilometers per second. The addition of Lithium-6 deuteride (and later Tritium) to the core slowed that outward expansion of the core ever so slightly (not the actual effect / function of the Lithium or Tritium, which was to initiate fusion to convert more of the energy into heat, but what the end result effectively accomplished), allowing far more heat to be released during detonation, which drastically increases the power of the weapon. A very powerful conventional chemical explosive named "Astrolite G" detonates at around 8,600 meters per second, which produces roughly double the explosive force of TNT, so try to imagine how much more powerful a thermonuclear weapon is- such energy releases are measured in TeraJoules.

5. Certain types of low explosives like Hydrogen or gunpowder can be confined within a gun barrel to produce projectile velocities well in excess of the speed of sound, but if you put TNT inside a gun barrel, that highly brisant substance would rupture or shatter the gun barrel, rather than producing a heaving effect upon the projectile being expelled, which is what the aforementioned low explosives do.

Calliban · 2021-07-23 00:08:21

Has SpaceX produced a safety case for Super-Heavy launch? A safety case is a suite of documentation supported by risk assessment, that demonstrates that risks to public and workforce are acceptable. It usually includes operaor actions, safety measures, plant maintenance schedules, etc. In the UK, safety cases are a legal requirement for high consequence industries. I bet something similar is required in the US as well.

kbd512 · 2021-07-23 00:13:03

Calliban,

SpaceX will file their launch permit application with the FAA, and then the FAA will work with SpaceX to devise risk mitigation strategies and range safety protocols with multiple safeguards in place to prevent a situation where loss of control of the vehicle leads to death and destruction. That process includes comprehensive risk assessments.

Calliban · 2021-07-23 03:16:30

kbd512 wrote:

Calliban,
SpaceX will file their launch permit application with the FAA, and then the FAA will work with SpaceX to devise risk mitigation strategies and range safety protocols with multiple safeguards in place to prevent a situation where loss of control of the vehicle leads to death and destruction. That process includes comprehensive risk assessments.

That sounds to me like proper due process. It does take time, but it is essential. Anyone concerned about the cost of safety, should carefully consider how much an accident will cost them (and others).

Is there any reason to believe that SpaceX are being treated unfairly in the execution of this process? Is the burden of proof unusually high, or the process unusually drawn out? I notice that some of the same people that are bemoaning FAA due process here, also consider nuclear power to be too risky. Could it be that they are not in a position to assess the tolerability of risk, or understand the work involved in such a determination?

kbd512 · 2021-07-23 04:49:45

Calliban,

I have not personally seen anything that has the appearance of a prejudiced permitting process. From my personal interactions with them, FAA is not a punitive agency. They exist to promote aviation with appropriate consideration for public safety. Aviation in general, but especially experimental aviation, is an inherently risky and potentially dangerous activity, so it is in the public's best interest to exercise due caution while permitting new aviation-related technology to benefit the general public.

When FAA issues a special certificate of airworthiness for an experimental aircraft, which is what Starship Super Heavy presently is, it comes with certain restrictions, inspections, and evaluation processes to assure compliance with the permitting process.

It would be very unreasonable to think that SpaceX is unfamiliar with this process, because they've been through the complete process several times before. To wit, Falcon 1, Falcon 9, Falcon Heavy, Cargo Dragon, and Crewed Dragon Crew, all had to go through that process. All of those machines are extremely sophisticated, extremely high performance aerospace vehicles that required certificates of airworthiness. Given SpaceX's specific line of business, general understanding, and technical capabilities, there's no acceptable excuse for flying an experimental aircraft without a valid airworthiness certificate issued by the FAA. That would be the equivalent of Lockheed-Martin somehow "forgetting" that their next stealth fighter had to receive FAA approval prior to first flight. They knew it was required and deliberately ignored the rules because someone really wanted to go flying that day. As a result, FAA is probably (rightfully) concerned that SpaceX does what has been agreed upon and permitted by FAA and nothing else.

As previously noted, this new rocket that SpaceX is developing is every bit as powerful as a Saturn V and then some. If Starship fails catastrophically over someone's home, there is a very high probability of injury or death. Generally speaking NASA tests these sorts of machines far, far away from occupied areas for that very reason. No matter how good you think your design is, the possibility of failure is ever-present. Seemingly inconsequential things can and do kill people not involved in experimental aviation, so FAA would not be faithfully executing its duties without careful consideration given to public safety.

As far as risk tolerance is concerned, all risk is relative. There are always trade-offs to be made. What a person considers too risky is generally related to how an undesirable outcome will personally affect them. Ask your average computer engineer what he or she thinks about a new jet design that they worked on, and you'll get a shrug or a "that's not my responsibility". Ask your average pilot at the controls of that shiny new machine and they'll have an entirely different perspective, since the pilot is utterly responsible.

The Apollo Astronauts no doubt held a very different view of how well or poorly engineered their spacecraft was, which is why that feedback loop exists between the Astronaut Office and NASA's engineering divisions. Can you imagine what the Astronaut Office would think of the idea of flying someone to the moon aboard an untested launch vehicle?

Rightly or wrongly, nuclear power has been stigmatized by pop culture and the media as "black magic". In some respects, it is. Nothing else in the universe that we humans know how to use stores that kind of power in such a tiny amount of space. All the general public knows about anything nuclear is that it's powerful beyond their comprehension, intrinsically dangerous, and that they don't understand what constitutes an acceptable risk with nuclear power. As such, most people naturally fear things that are both intrinsically dangerous and wildly powerful. The general public knows what a gallon of gasoline is and how powerful that can be, but has no clue about how powerful a gallon of fissile material is, because there's literally nothing else to compare it to. Handing a metal golf ball to someone and telling them that it represents the total amount of energy they'll use during a human lifetime is like transitioning directly from a Cessna to the Space Shuttle. They both have wings on them and are still subject to basic flight physics, but nothing else is remotely comparable. How do you convince a pilot that the Space Shuttle is "safe" when that beast lands at speeds greatly in excess of what their little prop job could achieve in a dive? Your guess is as good as mine.

RobertDyck · 2021-07-23 09:35:54

watch the video. It states when N1 exploded, fuel and oxygen did not mix well so the explosion was not as powerful as it could have been. The base suffered from broken windows, flying debris, and fire that rained down. The explosion equalled several kilotons of TNT.

I'm all for SpaceX. I want to see Starship fly. SpaceX has proven that an explosion on landing is not catastrophic. After all, Starship has already exploded several times on landing. But that's with residual fuel for landing, not fully fuelled for launch. And that was Starship, not Super Heavy. I don't think we can dismiss concerns by regulatory bodies.

I met the owner of SpaceDev at a symposium. That company built the rocket engine for SpaceShipOne. A different company supplied the engine for SpaceShipTwo. But the owner of SpaceDev said sometimes it's better to ask forgiveness than permission. That was true when FAA had no clue what they were doing. FAA had never been asked to grant permission for an experimental spacecraft before. NASA had done all the work with human spaceflight up to that point. But now, it's different. Rocket engines for Super Heavy are configured similar to N1, and propellant is even heavier. And that doesn't include propellant of Starship stacked on top. True, problems with N1 were caused by lack of testing on a static test stand. Russian engineers had planned a static test stand for every stage of N1, including Block A. One Russian politician at the time did not believe in space, thought it was a waste of money, so took away the money for the Block A test stand, used that money for something not related to space. The result was the only way to test it was to launch N1. That resulted in 4 consecutive failures. The major reason Saturn V succeeded was all stages including S-1C were tested in static test stands before launch. And the F-1 engine had a major problem with pogo, but because the stage was tested before launch, engineers had a chance to analyze it and fix it before launch.

So I'm arguing IN FAVOUR of testing Super Heavy on a static test stand a Boca Chica. SpaceX has demonstrated landing at Boca Chica is safe, they've demonstrated that catastrophic failure on landing will not destroy the town. I would like to see the first orbital launch from Boca Chica, but I don't think we can dismiss concerns by FAA or EPA.

GW Johnson · 2021-07-23 12:21:21

The possibility of an explosion on the pad or during ascent must be adequately addressed in the environmental impact statement. So must the exceedingly-loud noise of either the explosion or the successful ascent. The EPA has to be satisfied with that before the FAA can grant any sort of license to fly. Somewhere down the process, Spacex has not yet satisfied the EPA, an agency renowned for its unforgiving approach to regulation. Musk's tweets probably have made that issue worse by aggravating somebody within EPA.

You don't have to have a full detonation shock wave for a fast-deflagration blast wave to do enormous damage. We have known that since the first airplane gasoline tank exploded in response to being hit with bullets from another plane during WW1. It was a center fuel tank explosion that blew TWA-800 fully apart in mid air a few decades ago. That was jet fuel vapor exploding with air in the tank above the liquid pool, not pure oxygen. With pure oxygen, it just explodes more powerfully, and even a bit faster, but still without a shock wave, just a big subsonic blast. There's movie footage of a V-2 that toppled over and exploded, without even pre-mixing, just the sudden exposure of the alcohol fuel on the ground to liquid oxygen. No shock wave, but extreme violence.

I looked closely at the photos taken from above the ammonium nitrate explosion that took place in West, TX, a few years ago. You can see that the supersonic shock wave was "done" by about 1000 feet from the epicenter. You can see it in the nature of the damage to steel objects. From there on out, the blast was a subsonic blast wave. THAT is what destroyed about half the town.

NASA was restricted by these same risks launching Saturn-5's from Cape Canaveral. There were no persons allowed outside within 3 miles of the pad. It was both the explosion risk and the noise risk that created this 6 mile diameter zone. The zone is bigger for bigger rockets; which is in part why the larger-still Nova rockets were never built. Starship/Superheavy is about 1.5 times the thrust and 2 times the propellant of Saturn 5. It's about like the smaller concepts for Nova.

GW

Last edited by GW Johnson (2021-07-23 12:25:59)

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Starship Booster Prototypes beginning soon

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#9 2021-07-04 14:34:38

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#10 2021-07-04 15:46:15

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#11 2021-07-14 21:42:25

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#12 2021-07-21 20:39:07

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#13 2021-07-21 21:33:01

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#14 2021-07-22 06:48:53

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#15 2021-07-22 10:40:56

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#16 2021-07-22 12:35:24

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#17 2021-07-22 17:02:43

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#18 2021-07-22 19:53:36

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#19 2021-07-22 23:48:46

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#20 2021-07-23 00:08:21

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#21 2021-07-23 00:13:03

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#22 2021-07-23 03:16:30

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