Posts by Flocke Kroes 4560 publicly visible posts • joined 19 Oct 2007
Fluke: probably, but it has shown that skydiver + flip + vertical landing is possible.
The blatantly obvious reasons for not flying SN15 again is because the design of the ship and engines have both evolved drastically since then and the landing although a nice optimisation is not on the critical path to earning money. The focus now is on getting to orbit.
4x RS-25 engines produce 8 or 9 MN of thrust depending on the version. That is enough to lift most of the core stage or one and a bit solid rocket boosters. Without lighting the solids, SLS would be pinned to the mobile lunch tower without any hold down clamps, stage 2, or payload and would stay there while it burned through all its propellant. A more interesting test would be to light the SRBs (14.6MN each) with some hold down clamps and see if anything survives. Either that, or try it with 16 raptors.
Raptors are tested individually at SpaceX's McGregor site. Failure to light today probably says about as much as the launch table at Boca Chica (which supplies the high pressure gasses to spin up the turbopumps) as the engines - which are an old design. Perhaps they could do engine tests on the launch table but as that would damage the site and as the factory can turn out new rockets faster than the environmental impact assessment allows launches, the obvious step after booster 7 / ship 24 is to scrap booster 8 / ship 25 (already done) and launch booster 9 / ship 26 (already built).
Artemis 2 is still scheduled for November 2024 (big sack of salt) and Artemis 3 for December 2025 (large truck of salt). Should be on booster 40 at least by then, with some of those boosters flying more than once.
N1's biggest problem was the test stands for their engines. There weren't any, partly because of lack of budget but mostly because the engines were single use and a test would have have been to destruction even for a faultless engine.
The other option would be to go for a smaller number of large engines. As the engine gets bigger, combustion instability becomes of more difficult problem to solve until you end up the the development schedule of a BE-4.
Comparing apples and oranges. If the cost of a launch is $4B even the US government can only afford ½ a launch per year and the consequences of failure would be dire. On the other hand if your factory can crank out 12 full stacks per year and your launch licence only gives you 5 then half your rockets will be scrapped without even attempting a launch - yes this has already happened several times. SpaceX are doing a massively better job of minimising manufacturing cost and time because they feed back manufacturing problems into the design. Old space put years of work into creating the perfect design which turns out to be optimised for cost plus billable hours because of difficulties discovered during manufacturing. The US government has painfully worked out that a design even that expensive to build and operate is cheaper than a cost plus design change.
Well before Musk, links to Twitter worked without a login or javascript. One of the pre-Musk changes to make the site completely non-functional without javascript. As I will not visit untrusted sites with javascript enabled I stopped following even the occasional link to Twitter well before the buy out. The current fashion is some sort of embed, perhaps an iframe with content loaded from Twitter if javascript is enabled. My FOMO has not been anywhere near sufficient to investigate.
Perhaps not requiring a log in is because Musk thought is was a good idea by itself. I could more easily believe it was a means to reduce the load on the log in servers after Musk turned off one of the data centers.
If a 'real' crypto currency is actually transferred between users, Twitter has to buy the coins so stops having the money then there are transaction fees and there is the possibility that the user may find a way to sell those coins without involving Twitter. Musk just bought a huge pile of GPUs for AI. He could use them for crypto mining instead and collect the transaction fees but that costs electricity.
The next step up would be to never transfer ownership of the coins and just keep track of transactions. No wasted electricity or external transaction fees but still the money went as soon as the coins were bought and at some point Musk has to find greater fool to sell to and cash out. Twitcoins are the obvious solution: he can mint new ones as needed for free. He can directly control the exchange rate so he can cause they appearance of high interest rates. He keeps the capital so he can use some of that to pay out to people who actually test the ability to sell. The exchange rate can fluctuate by the second so other people always buy a little high and sell a little low unless they catch on, then the price can plummet and he keeps all the money.
Remember - some people do not have the source code for software they depend on. Although I would expect that by now they would have had to buy themselves into another lock in relationship with a different vendor.
About all I remember of VMS is that every time the team dealing with it got a new hire someone would have to deal with a machine clogged up by a full disk because VMS defaults to creating new versions of files instead of overwriting.
Musk was fired from paypal. Peter Thiel (spit) made it profitable. Musk got his first fortune by selling out of paypal after Thiel (vommit) did all the real work.
McDonnell Douglas died before SpaceX was born. They had some excellent money men with no clue how to run an engineering company. They sold out to Boeing and became their management team, sending Boeing in the same direction that they had taken McDonnell Douglas. Long before SpaceX reached orbit, Boeing got caught cheating on government tenders. The "solution" was to merge Boeing's and Lockheed Martin's rocket businesses into a single company: United Launch Alliance. The US government got completely screwed with monopoly launch pricing. They went out of their way to fund competitors (and they still do). Musk was in the right place at the right time. Space is hard as demonstrated by Rocketplane Kistler and Blue Origin. SpaceX succeeded because they had far more money the Kistler and more than Blue got in its early years. ULA and SpaceX measured success very differently: by ULA standards ULA were the obvious winners because they charged far more for doing far less. ULA still have lucrative US government contracts because the US government wants to assure access to space by having two independent suppliers. They know the end is near and are looking for a buyer because they know they cannot survive in a competitive market. Boeing is the lead contractor for SLS. The are very happy with that business: cost plus, $4B/launch and protected by politicians from both sides of the country. With Musk busy with Twitter for the last 6 months SpaceX has made excellent progress on Starship.
Tesla looks amazing when you look at the share price but if you look deeper their business is a tiny fraction of what that price would suggest. Musk has demonstrated exceptional ability at being found not guilty of securities fraud and when found guilty, of convincing the jury to award damages of $0. The law suits are piling up (at the glacial pace of the legal system). Even Musk has spotted the problem and has responded by hiring a hard core legal team team of streetfighters. Tesla is on its way to becoming a litigation company while the old motor industry are finally pulling their fingers out of their arses and setting up to build electric vehicles in quantity. When they do, they will stop paying Tesla for EV credits. Tesla is already reaping the rewards of lousy fit and finish, actively hostile customer support, broken FSD, and becoming the status symbol equivalent of a MAGA hat.
Boring company looks good on Musk's tunnelling rate figures. When you actually start comparing prices, Musk quotes for narrower tunnels and does not include lighting, ventilation or fire suppression in the costing. Digging the hole is only one part of the problem. Site surveys and permitting are sufficiently expensive to smother the cost benefits of a reusable tunnelling machine that makes fragile bricks.
Demanding to pay $44B for Twitter without doing due diligence demonstrates his business ability. Twitter was marginally profitable until he gave it $13B of debt. Any of his talk about making Twitter profitable can be thrown in the bin where it belongs because of the litigation building up from non-payment of bills. By all means, give him all your money in return for a promise of the highest interest rates in the world. Watch us laugh at you when you find you cannot withdraw your cash.
The short answer in no, but at least they have a system to limit the damage. There are about a hundred of those job titles, all overlapping so that no-one can do anything with the cooperation of at least three others. As more than three people cannot agree on anything of importance nothing gets done. That is a big improvement on anything our politicians want to do.
I see "we want but we won't pay" as a big step forward. In the past the government would provide tax payer's money to telcos to build infrastructure. The telcos would say thank you then do nothing so that there would still be a reason for another hand out a few years later.
Musk wants Twitter->x.com to become a payment processor where people leave their money with him because he promises the highest interest rates in the world. At the same time he is avoiding promises Twitter made to staff he has fired, staff he offered redundancy payments to, the owners of the offices Twitter rents, various software suppliers, hosting companies, ...
SpaceX are going for B2B and government contracts with Starlink. There have been tests with US military aircraft. SpaceX offer a specially priced service (exorbitant) for cruise ships and civil aviation.
If your product is bad you sell it to other businesses. If it is FUBAR you get the government to mandate it. Other companies not going for the mass market says more about their limitations than SpaceX not advertising their commercial and government services to the general public.
You used to be able to steal a car by reaching under the wheel arch, unplugging a connector and plugging in your CAN bus device. At this rate, next decade you will need a hammer for one of the windows _and_ a screw driver to get to a CAN bus connector.
Doesn't have to be a sale. The important bit is that the company can still operate but is protected from their creditors: every contractor and supplier that delivered but has not been paid will not get paid until VO 'returns to profitability'. VO could barely sell one launch a year at a price lower than the cost of building and launching a rocket. Add in aircraft maintenance costs and those creditors will be kept waiting until after the sun becomes a red giant.
NASA has so many applicants that they can massively over-specify the requirements for crew. I have many concerns about the Artemis missions but the a failure caused by a member of the crew is ridiculously unlikely, especially in comparison to SLS/Orion. (The most valuable contribution that SLS/Orion makes is huge delays that will provide time to retire many of the Starship HLS risks.)
Focusing on one thing and interpreting everything else only as it affects that one thing puts you far down the path of fanaticism.
If you had done some minimal research you would have found that Canada is a member of ESA and that ESA contributes the service module required for each SLS/Orion launch. The NASA's Office of the Inspector general costed the service module at $1B included in the $4B cost of an SLS Orion launch (excluding R&D and ground support infrastructure). On top of that, the international agreements makes Artemis and LOP-G very difficult for the US government to de-fund or cancel.
If you had complained about the cost, cadence or inflexibility I would have been right there with you but ESA have contributed a fair share for one seat on this flight.
VO was spun out of VG in 2017. VG goes back to 2004. Back then VG's air dropped orbital launch concept was called Launcher One. The plan was to partner with SpaceX. VG would repurpose an aircraft as an orbital launch platform and SpaceX would provide the rocket. It was a courageous decision on many levels: air launch provides some large technological hurdles for only a modest payback. SpaceX had some experimental engines but had not got to orbit. With hindsight it became clear that the biggest problem was SpaceX saying "your rocket will be ready real soon now" while working exclusively on their ground launched vehicle - Falcon 1. Perhaps VG->VO should have spotted they were getting thoroughly screwed over earlier.
VG/VO did some pioneering work with composites. They discovered many of the problems and some of the solutions that Rocket Lab later put to good use. They developed a hybrid rocket engine and discovered that a hybrid combines the biggest problems of solid rockets with some of the problems with liquid rockets while providing a significant barrier to scaling beyond a small rocket. VG/VG spent a large amount of money on what later were shown to be dead ends. Perhaps spending a bit more would have broken through some dead ends. Certainly pivoting earlier would have given them a better chance.
When it became clear that their past R&D spend had given them a debt burden that would make them uncompetitive against any launch start up but Pythom they made the correct financial decision: cash out and unload the mummified corpse of the company onto some idiot investor. What better choice could they have made than the UK government? Perhaps they would have gotten away with it too, if it weren't for you meddling kids! a defective fuel filter.
The launch failure made the news but Virgin Orbit had two successful launches before that. Compare them to their nearest rival:
Virgin Orbit Launcher One: $12M to put 300kg in 500km SSO. Dev cost $700M. Nearly 1 launch per year.
Rocket Lab Electron: $7.5M to put 200kg in 500km SSO. Dev cost $100M. ~8 launches per year.
Just on those numbers, VO's predicament was clearly dire. In real life, SpaceX does two or three transporter missions per year each taking over 100 small satellites to SSO. The price of a whole Falcon 9 launch is about $60M. Divide that by 100 payloads and you get $600k each - a tenth of the cost on an Electron rocket. Rocket Lab make sense for the odd customers that are not going to SSO or want Rocket Lab's Photon space craft or time on their communications network.
VO's unique selling point is that their aircraft can in theory take of in weather that would scrub a rocket launch then fly Launcher One to somewhere with better weather. In real life, most customers can wait a few days for nice weather. Launcher One would have been an excellent product a decade ago. It has been blatantly obvious for years (to rocket enthusiasts) that Launcher One was too little, too late. Launch investors have difficulty with the blatantly obvious and it has been clear for a long time that Branson has been cashing out at the expense of people who had more money than sense.
My criticism of VO is not intended to be smug. What I would like is investors to put their money into something that can compete with Falcon 9 at least, and preferably against the likely potential of Starship instead of projects that divert rocket engineers from products with a future.
So we switch from boffin to brainbox, egghead or whatever. The IOP can run another study and find that over 90% of the population think replacement word is heavily gendered too. The problem is not the word but people's perception. The place to start is to find the cause of people's perception. My first guesses would be Sheldon Cooper, Brian Cox and Spock. Even when writers decide to make a scientist female we get Susan Calvin, Bennett Halverson, and Temperance Brennan more often than Jane Foster, Jemma Simmons or even Dr Harleen Quinzel.
Boeing have got paydays for passing milestones and hope to get more when the actually transport (and return) astronauts. Presumably the expected cost of continuing is less than the payments they have yet to receive ($?M for this test flight + $90M * 4 astronauts * 6 flights). To make the economics less simple, Starliner is intended to carry 5: 4 NASA + 1 tourist and Boeing get to sell the tourist seat for whatever rich tourists will pay.
There is also a theoretical possibility of more flights. The commercial crew program promised SpaceX and Boeing 6 flights each. The plan was to divide up flights beyond those 12 between SpaceX and Boeing. NASA have so far allocated flights up to 2030: 14 to SpaceX and 0 to Boeing. Boeing could theoretically get some pure tourist flights to the ISS and to Blue Origin's Orbital Reef (because Jeff would rather not buy launches from Elon).
In real life, there is a limited supply of Atlas V rockets to launch Starliner and no more will be built. There are enough reserved for this test flight and the six operational flights. After that, Boeing has to find a new man rated rocket. The obvious choice would be Vulcan. Someone would have to come up with the money to man-rate Vulcan. Boeing could do that by putting up their prices - just like SpaceX did for launches after their first 6 (to include the cost of delays provided by congress reducing the funding for the commercial crew program). The silly choice would be SLS: put another $200M onto the per seat cost and add a year of delay to Artemis for each launch to the ISS and that is before factoring in the cost of another mobile launch platform equipped to supply Starliner.
In the background to such decisions: NASA have clearly decided they can man rate Starship HLS for a trip from Lunar orbit to the Moon and back. What happens _when_ they decide to man rate it for launches from and landings on Earth? Their choices are either to go with the flow or watch Jared Isaacman's Polaris III orbital party on youtube.
To get best advantage from the Earth's spin you want to go east. That is less important for polar and sun synchronous orbits where the best choices are northeast or southeast. Only Israel launches west, and only because dropping spent rocket stages to their east would be problematic.
Virgin Orbit could fly a long way west from Cornwall so the rocket could then launch east but as they have some flexibility in selecting the takeoff site it would be easier to just pick a suitable start point.
Imagine throwing a tennis ball at a bowling ball. The tennis ball is going to keep most of its speed and transfer only small amount to the bowling ball. If you throw a tennis ball at another tennis ball then the high energy tennis ball will transfer about half its energy to the other ball. The same thing happens with high energy neutrons: hitting a heavy atom makes very little difference but hitting hydrogen slows the neutron down. Slow it down enough and it will hang around long enough in you computer to cause problems.
One third of the atoms in water are hydrogen. For mineral oils the proportion is slightly over one third so they should be worse. Silicone oils are a really bad choice at about 60% hydrogen. There are some fluorocarbons that are used for cooling and contain no hydrogen - just carbon, fluorine and oxygen. The older choices were a global warming problem but that is fixed in the newer ones.
I tried some numbers:
A Starship payload is >100t. A PTFE (first material I could think of that can probably handle the temperature range) cable that mass long enough to go half way around the moon would have a diameter of less than 3.3mm. The actual payload that a Starship can land on the Moon (and still return to NRHO) is currently a matter of wild speculation. 150t is a reasonable guess, so that would leave 50t for the deployment system. Space is nothing like that easy, but those numbers show a cable running half way around the Moon is not obviously insane - unless you launch it with SLS.
One of the ingredients is dust swept from the temple floor. Is there anything in the bible about spilling some arsenic powder during prayers? It is not it the ten commandments (Exodus 34) - I checked all the way from the requirement to cut down trees to the forbidden goat recipe.
Each month of delay is salary for the entire workforce plus the cost of maintaining idle manufacturing and launch infrastructure. RocketLab charge $7.5M for 200kg to SSO. A startup without RocketLab's reliability record is not going to sell at that price. It would not take many months to exceed the launch cost of one small satellite in a ride share.
In real life, small rockets are a tiny niche. The most common launches are for constellations where you need to put a pile of satellites on a big rocket to divide the price down. The next step down are the ride shares to sun synchronous orbit (SSO). SpaceX launch two or three per year carrying over 100 satellites at a price selected to take launches away from every small rocket provider. There are national launches eg China will only launch on a Chinese rocket, India will only launch on an Indian rocket. All of NASA and DoD will go on US rockets. The bigger satellites going to GTO will take a Falcon 9 (or the DoD will pay through the nose to keep ULA in business). There are the occasional oddities that can ride share with Starlink. That pretty much leaves a dozen or so small satellites per year going to an unusual orbit that cannot take a ride share to SSO.
Launch companies with a hope of staying in business are developing a medium sized reusable constellation launcher. Even that has a big risk: Starship's target launch price is what you would currently pay for a RocketLab Electron (we are years from Starship launch cost going under its target price). 1000x the payload mass for the same price is going to remove the mass constraint that contributes much of the cost of a satellite. When a 'small' satellite has a mass 1000kg to eliminate the cost of mass optimisation small launch vehicles will only be used for a couple of national prestige launches per year.
I am not going to take launch license issues that seriously until I see a business plan that will compete in the foreseeable future. These days it is rare to find one that can compete in the current market. I think Virgin Orbit (not to be confused with Virgin Galactic) is on a path through bankruptcy intended separate the assets and IP from existing debt.
If the UK (or the EU) wanted a competitive launch industry it would have to fund a pile of small launch payloads to be launched on UK (EU) rockets just like NASA and the DoD do in the US.
For a start, anything that counts seconds will diverge from UTC. Everything with its own time keeping would need to be modified to count lunar seconds instead. The meter is defined by the distance travelled by light in a second so you get a lunar meter as well. The kilogram is safe but a whole pile of derived units get lunar versions: velocity, momentum, force, energy, power, current, voltage, angular velocity, angular momentum... You get a new temperature scale or have to use different thermodynamic constants near the moon.
Life is actually easier if you keep the second in common and just accept that the conversion from Earth time to Moon time is not simply add a constant.
Contactless is supposed to have a range of a few cm. Enthusiasts with a Pringles tube have got that up to 30cm. RF engineers have reached 60cm - the width of a door. I asked my bank for a card without contactless so I could walk through shop doorways without given them my ID. If the EU has banned authorisationless payments the please lets rejoin the EU.
Someone else's laptop displayed a white screen at power on and did nothing else. As it was Windows and the screen was not mostly blue I was out of my depth - I have been a complete penguin for decades. I decided to try asking the BIOS if there was a hard disk. Power up + DEL, F1, F2, F10 and F12 did not get me to the BIOS so I tried asking a search engine. The first site that led me to had a chat window that offered help. It was completely useless. I could understand a human might offer Windows specific advice on the first and perhaps second response but after the fourth it was clear that whatever was answering (very promptly) had no idea that it was possible for a computer to fail in a way that you could not get to a log in prompt and wasn't going to hear any combination of words to that effect. I would have expected a competent human to offer "Try attaching an external monitor". Even a fairly thick AI might go for HYTTIOAOA.
[I found elsewhere that the BIOS access key for a Sony Viao was to power up with the ASSIST key - which didn't work either. With no way to select an alternative boot device I was stuck and recommended trying someone with the appropriate parts to swap out.]
How to spot a ChatGPT controlled car repairer facing a flat battery: it is the one changing each wheel in turn until it discovers which one is flat.
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