Exoscientist

The “Angry Astronaut” gives a review of potential buyers of ULA and concludes Blue Origin would be the best match: He suggests keeping Tory Bruno to remain as head of ULA after the takeover. I agree Blue Origin would be a good match. A key reason is Blue Origin is committed to reusability for their launch vehicles. But “Angry” notes their slow approach won’t work when SpaceX is advancing so rapidly. He feels Tory Bruno would promote a faster approach. I like Tory, but quite frankly he was only giving lip service to reusability at ULA. With the leadership at Blue Origin giving the directive that reusability has to be primary at ULA it might work. Bob Clark

The first solution to the riddle comes from the assumption that from its economy of volume that SuperHeavy/Starship will be THE be-all, end-all for ALL of spaceflight. In point of fact, for EVERY form of transport going back to the horse-drawn era, the transport has always come in different sizes. The point is well illustrated by the example of the jumbo jets. See the highlighted sentence in the article: The largest jumbo jets actually make up a *tiny* proportion, less than 1%, of total air traffic. The same is true of car traffic. The amount of traffic carried by Greyhound buses is a tiny proportion of the traffic carried by passenger cars. Sure, the bus companies and the jumbo jet airliners would love if the majority of passengers were on their vehicles, but THATS NOT WHAT THE CUSTOMERS WANT. The airline companies know this of course. The same airline companies that operate the jumbo jets also operate the smaller aircraft. If those airline companies were to only offer the jumbo jets they would rapidly go out of business. ArianeSpace found a similar phenomenon with the Ariane 5. It was designed to carry separate satellites to orbit. But what they frequently found is that when one satellite was ready to go, ArianeSpace had to wait around for another satellite ready to go for it to be worth launching the Ariane 5. And in point of fact most satellite companies wanted their OWN DEDICATED LAUNCHER. That is the primary reason why ArianeSpace wanted to move to the Ariane 6, so customers could affordably have their own dedicated launchers. The Falcon Heavy gives further evidence of this. The per kilogram cost of the FH is less than the F9. If per kilogram cost was the key thing, then the Falcon Heavy would packed with separate satellites and would be launching as often as the F9. But in point of fact, FH launches have been few and far between, and have only been used when there are satellites that can’t be launched on the smaller launchers, including the F9. As before, the satellite companies want their own dedicated launchers. SpaceX might claim their per kilogram cost will make them preferred but the example of the bus companies and the airlines make that argument extremely dubious. Their own Falcon Heavy also argues against it. Also, I don’t agree their per kilogram cost will in fact be that much cheaper than the other New Space companies. For those other companies know SpaceX was able to cut development cost by 90% by the commercial space approach, i.e., getting private financing rather than government financing. Then consider: when pricing their launch vehicles the largest proportion of that price is not coming from the production cost, but in fact due to the amount added on to recoup the development cost over time. SpaceX has spent $10 billion developing the SuperHeavy/Starship with more billions yet to be spent on the development. This is in the range of 100 times higher than the development cost for the companies with smaller launchers. Then the amount to be added on to the price due to development cost, which again makes up the largest bulk of the customer price, will be radically smaller. Note that SpaceX won’t be superior in price reduction due to reusability either since all the New Space companies also are focusing on reusability. Robert Clark

Brain Teaser: Why does Falcon Heavy disprove the SpaceX justification for building the SuperHeavy/Starship? MAJOR hint: Why did Arianespace want to move away from the Ariane 5 to the Ariane 6? After writing that, it occurred to me there are two different answers to my riddle. Hint for 2nd answer: how many Merlin’s flew on actual operational missions on Falcon 9’s before the Falcon Heavy flew? How many times did the Raptor before the SuperHeavy/Starship? Bob Clark

In addition to the three alarming facts about the launch I discussed previously there was another fact just as alarming, the lean the rocket initiated soon after launch. It was assumed this was commanded by launch control. But Elon revealed this was done by the rocket itself to compensate for the 3 shut down engines: Elon Musk pushes for orbital goal following data gathering objectives during Starship debut written by Chris Bergin May 3, 2023 … “Those engines did not explode, but they were just, the system didn’t think they were healthy enough to bring them to a full thrust,” added Musk during a post-flight Twitter spaces call, adding that is why the vehicle appeared to lean away from the Tower during ascent. It was assumed the lean could have been related to pad avoidance, but Musk quickly noted that it is undesirable due to the “blowing torch” of the Raptor 2 engines on the OLM ring. “If you move sideways sooner, you are moving that big, cutting torch across the launch ring. So, you can think of this thing like the world’s biggest cutting torch, basically. Depending on how close the engines are, they erode that steel at a roughly — I think half an inch to an inch per second of high strength steel is eroded by the cutting torch.” “(The lean was actually) related to the engines out, and we do not normally expect to lean. It should be aspirationally going straight up.”https://www.nasaspaceflight.com/2023/05/musk-orbital-goal-starship-debut/ This is extremely concerning because if this really was a fully automated compensation maneuver then if the shut down engines were on the other side the lean would have been towards the launch tower! The result would have been a catastrophic explosion. Bob Clark

The Angry Astronaut gives an insightful analysis of the environmental lawsuit against the FAA and suggests it could delay another launch from Boca Chica for another two years. The reason is the extent of the spread of concrete debris is beyond the 700 acres implied in the FAA environmental assessment. This means a more detailed environmental impact report must be written. This takes longer, thus suggesting the longer time for another launch license to be granted: Bob Clark

Launch and landing is by same vehicle. SpaceX is still talking about rapid reuse out of Boca Chica, so same issues arise. Bob Clark

I’m suggesting they are being lax to appease SpaceX since SpaceX is currently the only provider of military launches, the only provider for launches to the ISS, and the only provider for a lunar lander for the Artemis missions. So there need to be reviewers independent of both SpaceX and the FAA. Something just occurred to me. If SpaceX previously said the Starship launchpad would be located 20 miles off-shore because of the noise from sonic booms, wouldn’t the same issue apply to the residents of South Padre Island and Port Isabel only 5 to 6 miles away? ELON MUSK: NOISY STARSHIP SPACEPORTS WILL BE 20 MILES OFFSHORE. https://futurism.com/the-byte/elon-musk-starship-spaceports-offshore Bob Clark

Three quite alarming facts were revealed in Elon’s twitter Spaces discussion: Elon Musk - Spaceship update after explosion - Spaces Twitter. https://www.youtube.com/watch?v=pe4B2eIeXfs First, the Raptors likely were not damaged by the concrete thrown up. If so, then 8 Raptors failed on their own during the flight. Second, thrust vector control, TVC, failed at some point during the flight. Third, the FTS took far too long to destroy the vehicle at 40 seconds. These three facts together could have led to catastrophic results to the public. If that many Raptors had failed and without TVC closer to the ground, the FTS would not have been able to destroy it before it was over densely populated area if headed in that direction. The multiple failures of Raptors during tests, and not just shutting down or being shut down, but actually leaking fuel and catching fire, led to my arguing SpaceX should be required by the FAA to construct a separate all-up test stand for full thrust, full flight duration testing. Had this been done then both the launch pad damage and the likely Raptor failures would have been picked up. I also argued there should be an independent review aside from the FAA by space safety experts on the safety of the launch. If so, the inadequacy of the FTS likely also would have been picked up. I say it’s likely it would have been seen beforehand because assuming the FTS did activate there seems to be only one reason why it did not destroy the vehicle immediately: the strength of the explosives used were not sufficient to penetrate beyond the tank wall strength. This SHOULD have been seen beforehand. Tank wall thickness depends on the width of the tanks and the material used. Because of its size, the closest analog to the SuperHeavy stage was the Saturn V’s S-1C first stage. It’s max wall thickness was in the range of ~6.5 mm while for the SuperHeavy it’s in the range of ~8mm, about 25% thicker. BUT it’s also important to remember the specialty high strength stainless steel used on the SuperHeavy is much stronger than the standard aerospace grade aluminum used on the S-1C. Given the greater thickness and greater material strength, these two facts together give a tank wall tensile strength for the SuperHeavy about 3 times higher than that of the S-1C.The amount of explosives used should have been adjusted accordingly. Bob Clark

Well put. Bob Clark

Good point. Has anyone done a frame by frame analysis to see if the flame front expanded at supersonic speed or not? Robert Clark

Thanks. That’s very relevant because of the ground water issue at Boca Chica. Another relevant question is how much total weight had to be supported, bridge plus cars? Robert Clark

This article link was posted on Reddit that suggest the pilings were dug 30m, 100 feet, deep: https://www.teslarati.com/spacex-orbital-starship-launch-pad-texas/amp/ But the article writer may have taken the 30m, 100 feet, underground idea from the length of the pilings visible above ground before they were put in place. Perhaps we can estimate how far below ground they would go by their length as measured lying down horizontally before placement and by the length visible above ground when they are put in place, as partially dug in below ground. Bob Clark

Here’s a short clip of it:

!!! I wanted a separate static test stand for all 33 engine engines constructed because I had no confidence all 33 Raptors would burn for the full flight duration. The idea of damage to the pad from the demolished concrete from the thrust was not even on my radar. But if the full test stand had been constructed, this is another major flaw that would have been picked up beforehand. Bob Clark

Is that an accurate representation of how the separation was supposed to work? Bob Clark

There seems to be universal agreement that not having flame diverters was a mistake. As the “Angry Astronaut” puts it, the launch should be considered a success but major improvements need to be made,

By separation mechanism I mean one of the methods used before on staged rockets that mechanically separates the stages, not simply using centrifugal force. Robert Clark

What they’re discussing at SpaceX right now, “Ok, whose bright idea was it not to have a stage separation mechanism?” This article discusses the decision not to have a stage separation mechanism: https://www.teslarati.com/spacex-starship-new-simplicity-extremes/ An unfortunate decision because if the stages did separate there might not have been any need to send the destruct signal. Plus you would have gotten far more data by seeing what the Starship upper stage could do. Bob Clark

Think that’s an April Fools joke. Bob Clark

Avi Loeb has received a $1.5 million private grant to conduct his search for the interstellar meteorite fragments beneath the ocean’s surface: https://avi-loeb.medium.com/a-gift-from-a-silver-star-af2993e0169a Bob Clark

I agree with you number of launches is the more important parameter. Likely prices will decrease and as you said if it decreases by half, that means 2,000 Falcon 9 equivalent launches. But that means an even larger market for other launch companies to get into and even greater necessity for them to get into reusables. Robert Clark

Global Space Launch Services Market is projected to reach at a market value of US$ 47.6 Billion by 2030: Visiongain Research Inc October 05, 2021 09:33 ET | Source: Visiongain Ltd https://www.globenewswire.com/news-release/2021/10/05/2308874/0/en/Global-Space-Launch-Services-Market-is-projected-to-reach-at-a-market-value-of-US-47-6-Billion-by-2030-Visiongain-Research-Inc.html Several independent market research surveys have put the space launch market at about the ~$40 billion range by ~2030. That amounts to about 1,000 reusable Falcon 9’s. That’s a large market for other launch companies to also take part in. BUT they have to use reusables to stay competitive with SpaceX. Otherwise, they’ll also go the way of ULA having to ask for buyers to avoid bankruptcy. In that regard ULA and Arianspace should upgrade their coming launchers, Vulcan Centaur for ULA and Ariane 6 for Arianespace, to add an additional engine to their first stages. As it is now, neither can lift off without using solid side boosters. But the space shuttle showed solid side boosters do not save costs on reuse, while SpaceX showed all-liquid rockets do. Robert Clark

I had estimated that the Vulcan Centaur given three BE-4's could get ~27 tons to LEO. But that was using a weight-optimized Vulcan dry mass estimate. However, I tried the SilverbirdAstronautics.com estimator on the Vulcan with the usual two BE-4's in the two side booster configuration and it gave results well above what was given on the ULA page on the Vulcan Centaur. So I think my dry mass estimate was too optimistic, i.e., too low. What I used was 25,000 kg for the Vulcan booster dry mass given three engines. The basis for that estimate is the weight-optimized Falcon 9 booster, using aluminum-lithium for the tanks, gets about a ~25 to 1 mass ratio. Then since methalox is at about 80% density of kerolox it should get about 20 to 1 mass ratio. This would give the Vulcan booster a dry mass of 25,000 kg. But that dry mass results in a badly overestimated V/C with two side boosters payload compared to that stated by ULA. So here's a another stab at a dry mass estimate. Make a comparison to the Atlas V booster mass ratio. This is hardly weight-optimized using just standard aluminum for the tanks as does the Vulcan stage. The Atlas V booster has a mass ratio of only 15 to 1. Then the Vulcan with methalox at only 80% the density of keralox might get ~12 to 1 mass ratio. So the Vulcan dry mass might be as high as 45,000 kg. This results in a much closer Silverbirdastronautics.com payload estimate to the ULA numbers. Bob Clark

Not like I know him. I asked via his twitter account: Bob Clark