Starhopper Made Some Noise Last Night

1. Baby steps.

   1. This looks like way more than baby steps to me. Contrast with NASA and Russia who have only built small non-flyable prototypes of this engine.

      1. I think it’s both. Yes this is a historic first flight of a full flow staged combustion engine, which is the holy grail of liquid fueled rocket engine combustion cycles. But at the same time, it was only one engine and it was literally only a hop, so it’s also a baby step along the path of a fully reusable TSTO powered by a full flow staged combustion engine.

2. Raptor flies!

   I guess Musk said that we could expect a 200m hop in the next week or so.

   I wish that Blue Origin was as open about their testing as SpaceX. It seems to me that such openness builds some trust, but I don’t whether that’s true or just my wishful thinking. I do believe that such openness keeps space in the public eye and keeps public interest at a higher level than it might otherwise be.

   Also, congrats to SpaceX for landing their 44th booster stage!

   1. And SpaceX has, or soon will have, flown more Flight Proven™ cores than new cores. Which is just staggering ?

3. What I find interesting is the speed with which SpaceX cycles through problems and makes ready for another test. Of course there is risk of not being 100% correct in the root cause and fault fix, but it seems they learn faster by just doing it.

   1. Starhopper in particular is an extremely low-cost vehicle (in aerospace terms anyway), therefore ideal for a high-risk test program.

      There are two (also relatively low-cost) Starship prototypes fairly far along, so if Starhopper goes sideways, one of those can be pressed into service for more hop tests, with the other still available for the higher-performance flights they were designed for.

      1. I’m not sure if having the Starship prototypes already under construction is ideal. If something does go badly wrong with a Starhopper test, the fix might require substantial rework on partially built Starships. A fast cycle from test to test and vehicle to vehicle is great, but it’s better to have the results from the previous iteration before you start bending metal on the next. SpaceX is taking a risk that Starhopper won’t hit any major problems. If it doesn’t their approach speeds up development. But if it does, they’ve wasted a decent amount of money.

         1. But I think that was Patrick Underwood’s point that they are not putting nearly as much time and effort into these like you would normally see in flight test articles, as evidenced by the quick builds. I’m sure there is a risk that they may have to redo something or in worst case have to scrap one, but they are probably more concerned about being ready to go to the next phase of testing but not having hardware ready. This might change as they start getting closer to doing orbital test flights, which as far as I know none of these will be doing unless there have been indications otherwise.

            1. That’s a good point. No matter how much people talk about “test like you fly”, that never actually happens. The real trick is deciding how flight-like the tests and test articles need to be. I guess I’m used to ones that are a whole lot more flight-like than what you’re describing. But that doesn’t mean it should be that way.

               On the other hand, I do know of flight hardware that was tested with some decidedly non-flight-like (and poor quality) ground support equipment, flight software which wasn’t even beta, and clunky prototypes. They ended up fixing “problems” that only existed because of the low fidelity tests and test articles. And the unnecessary fixes actually caused problems in flight. Getting this right isn’t easy. If NASA is erring too far in one direction, I hope SpaceX isn’t going too far in the other direction.

            2. Musk alluded to more billionaires in the wings thinking about buying a flight. I tend to think the high speed of bending metal, not so much already flying. Gives the impression they can very soon open their wallets and jump in .. who will be the first to lay down for another lunar flyby or a lunar landing.

            3. The person with the deep pockets that I like to see step up after a few manned Starship flights is the one who will do Dennis Tito’s Inspiration Mars flyby flight in a Starship.

            4. >ground support equipment, flight software which
               >wasn’t even beta, and clunky prototypes

               I was thinking lots of flight tests gives support equipment and infrastructure (telemetry and instrumentation) with the people that go with it lots of real world experience. Much of this infrastructure doesn’t fly, never featured in photoshoots but they learn what works/what doesn’t work. Doing a flight test every five or six years, a lot hands-on skills can be lost.

         2. Reworking a stainless prototype is very easy compared to aluminum, in that you can cut and weld and cut and weld, by hand.

4. Very nice steady looking engine plume there.

   Quite remarkable progress to be actually flying and with the engine apparently well under control, given it was just February when they fired Raptor for the first time.

   And that first firing was not without serious bugs to clear up either – that first firing showed a green streak in the plume (generally a sign of copper vaporizing from the engine internals) and had a rough shutdown not far this side of explosive. (Mind, in the history of staged-combustion engine developments, that was a remarkably successful first run – the historical average is more like, how far did pieces of the test stand fly.)

   All in all, I’d say this is a serious vindication of SpaceX’s go-fast/break-things/fix-them/go-again developmental approach.

   Put another way, high performance rocket engines are dynamically complex enough that by far the quickest and most accurate engineering simulation is still one-to-one scale analog.

   1. “Quite remarkable progress to be actually flying and with the engine apparently well under control, given it was just February when they fired Raptor for the first time.” The first test stand firing of a complete engine was a few years ago, although that may have been a sub-scale version (I don’t recall). According to Wikipedia the engine has been in development since 2009. It’s not to say they aren’t making good progress, I just wouldn’t characterize it as remarkable… just my opinion. They’ve got a long way to go, and if you ask me, they’ll need a lot of things to break the right way for them to get the complete stack going in a couple of years as Elon has indicated is their aspiration. Integration is often more than half the battle… It’ll be fun to watch, and it’s great they’re letting us watch.

      1. According to Wikipedia, SpaceX first mentioned a LOX/LH2 upper stage engine called “Raptor” in 2009. First mentioned methane at the end of 2012. Began test of representative injectors in 2014. And didn’t really settle on the current Raptor size and begin prototype development until 2015.

         Four years from settling on the size and beginning full scale development to first flight of a large staged-combustion rocket engine is, trust me, remarkable, in the context of the actual history of such. The only thing that’s come close has been long-experienced Russian development teams doing variants of existing designs.

         1. True they apparently changed basics of the design a number of times, but that’s all part of the process, you can’t just discount it. Even ignoring that, compare it to the F-1. Development seems to have begun in 1955, component test firings in 1957, first full engine static test firings in 1959, delivered to NASA in 1963, flight rating test firings in 1964, and full stack orbital flight in 1967 (this is all from Wikipedia) So 5 years from first full engine test fire to flight rating… not really sure you could say the Raptor is flight rated, but say it is, that’s 5 years for the F-1 vs 3 for the Raptor from first full engine test fire to flight rating. The F-1 had 3+ times the thrust, and they apparently spent 2 years solving combustion chamber instabilities. So again i’d Say the Raptor progress was good, but not remarkable… trust me on this 😉

5. Amazing, he wasn’t struck by lightning for implying that there may be a replacement for Shelby Launch System…

   1. Not yet. That we know of.

6. Whatever it takes.

   Go SpaceX.

   Despite the origin of the following phrase, I happily and with great enthusiasm (and absolutely NO credit to its author) state:

   “MAKE AMERICA GREAT, AGAIN”

7. I want to challenge my previous assertion (in the earlier thread) that the cloud was mostly dust in the abort the other day. It was dusty out there at the site, but it wasn’t THAT dusty. So I guess it WAS engine exhaust.

   1. If you hit unprotected concrete with rocket exhaust, you tend to blast concrete dust off the solid surface fairly rapidly. Seen it reported and pictured many times, and in person a few.

      1. It’s also a little scary how much junk starts flying around inside a payload fairing once the engines fire. That’s not something people really knew about until ten or fifteen years ago, when someone put a camera inside and sent the video down. That’s sort of ironic, since those fairings contain spacecraft built in clean rooms.

         1. On the Space Shuttle try as they may every time they opened the cargo doors in flight there was always a nut or bolt or other small FOD that floated out. They apparently instituted a whole bunch of measures to try and mitigate it, but things still got stuck in nooks and crannies until the severe vibration of launch followed by microgravity liberated them.

            1. From what I’ve read, dust and small particles also started coming out of the walls inside the Shuttle’s crew compartment as well. The whole thing makes me wonder about some of the strenuous (and expensive) rules for handling flight hardware.

               It’s all very well and good to say getting dust on a space telescope’s mirror might degrade performance, and that, since you don’t know how much, you should make sure you don’t get any dust on it at all before launch. But, honestly, at some point you have to say dust is going to get there during launch, so why go to such extremes about pre-launch contamination?

               And for dust or sand or whatever, from the SpaceX test’s rocket plume, it makes me wonder about going to lengths to avoid FOD or just building something that isn’t badly hurt by it. Obviously, you don’t want to be careless and just leave things lying around. But how strenuously do you have to police the pad, when you just know firing the rocket will kick up a whole lot of junk?

            2. All the space telescopes I have worked on had mirror covers (either ejectable or hinged) that sealed the interior of the telescope until well after launch. I know that the ridiculous cloud of debris that follows the rocket up was a major source of concern. In some cases the instrument chambers also had sliding doors or covers. Outgassing and transfer of material onto cryogenic surfaces is also a big issue.

               I have no clue what JWST does about this.

            3. There are plenty of space telescopes or flight instruments without baffles, and I have no idea how you’d put a cover over one of those. Also, remove before launch covers are common, although more to reduce chemical contamination of surfaces or detectors than over debris concerns. But maybe mirrors weren’t the best example for me to use.

               There are plenty of exposed surfaces on the outside of a spacecraft, which people go to great lengths to protect before launch. I know of one spacecraft where, during assembly, someone accidentally dropped a small nut, and they never managed to find it. It probably lodged in the bus somewhere. There was a lot of concern about it bouncing around and hitting something during launch. That probably wouldn’t have been significant compared to the normal amount of junk flying around inside the fairing.

            4. Best use for cheaper and greater lift capacity, IMO, is the ability to spend mass to build more robust systems.

            5. OTOH, there won’t be cleannup crews preparing the initial lunar or Martian landing sites. Best to see how it handles flying debris now.

               Starship update in ~2 weeks.

               https://twitter.com/elonmus…

      2. A short digression:

         I wonder how often SpaceX has to refurbish LZ 1 and 2 at the Cape and what the refurbishment entails? . I have the same question re: the landing ships, especially given some of the hot “landings” they’ve seen. Perhaps any damage isn’t as bad as one might expect given that only one Merlin 1d is firing and then only at what, 40% thrust (76,000-ish lbs thrust?).

         Are there any documents available that detail concrete damage secondary to rocket thrust?

         1. That’s not a bad question, and I’m not sure what the right answer is. At best, they would have to repaint the company logo on the pad after each landing. But duration can be as important as temperature, and the pad isn’t exposed for more than a few seconds. I was tempted to write that it shouldn’t be worse than a high-pressure steam cleaning. But since a Merlin burn kerosene, I guess “cleaning” is the wrong word. In any case, and to quote Mr. Musk out of context, it’s “not a flamethrower.”

8. Just think for probably 100th the development cost, a water tank has more flight time than SLS. How high will the water tank fly before SLS completes it’s green run.

9. SpaceX is really the best hope for getting American astronauts to the Moon by the President’s goal. And since it’s the Moon SpaceX will probably be able to do it without NASA money by simply bringing Moon rocks back to sell. Five to ten tons of Moon rocks, even at highly discounted prices, should easily pay for the flight. ?

   1. Do you know if anyone has done a study on the market value of lunar rocks? Specifically price per gram as a function of number of kilograms in the market? If a commercial company is flying the mission, I hope they would be smart enough to look into that sort of thing. There is a certain amount on the market which would maximize profits.

      But I’m afraid scientists probably aren’t a significant part of that market. Modern laboratory techniques don’t need large samples for most purposes. I don’t know if we’re even talking about one carat per investigation. And carats are probably the correct unit, given other, likely customers.

      1. You would think there would be a Moon rock jewelry market.

         1. Yes. I was thinking about how to maximize the profits from that market. Hauling back as much as possible would your the market. Sending back a tiny bit to sell at very high prices would also be suboptimal. There is a point in between which maximizes that. I wonder what that point is.

         2. There probably is, but you will probably need to make it look like something other than dirt to really build it.

         3. It’s an odd market, though, right? Initially the material will be scarce, and so valuable. At some point, though, the scarcity will disappear. What happens to the value then? Could early acquisition inform a higher price?

            Has there ever been a commodity in which everyone knows that current scarcity will swap places with abundance?

            OK, we might be talking about decades. But at some point moon material will become easy to find and cheap to buy.

            1. I think the first samples would retain their value. If they’re sold as souvenirs and collectables, the value would be due to their historical significance. The first lunar samples since Apollo would still have that value, even when moon rocks in general are selling in dime stores.

               A far as similar commodities, maybe uranium. Initially (late 1940s), everyone did think it was very scarce. It gradually became evident that it wasn’t all that uncommon, but still had value as a scarce commodity because the prospecting had been done but not the mining and refining needed to make it available. And quite a few people insisted on sticking with some pretty poor reactor designs, developed around the assumption that uranium was very scarce.

      2. No studies that have been published anywhere. But the base price for lunar regolith would be determined by SpaceX since they would have a transportation monopoly near-term. Nope, scientists wouldn’t be the market, although NASA or some private foundations might buy some samples and donate them to scientists. But the market will be those that want a collectible to remember the flight by. Keep the price low and you will make up in volume the revenue needed.

         Looking at some numbers, let say the mission costs $200 million and you decide to return with 10 metric tons of regolith, about 25% of the return payload possible. That would equal 10 million grams, the current unit of measure, for a price of $20/gram ($20,000/kg)($4/carat). Package it in lots of 5 grams, 10 grams, 25 grams, 50 grams and advertise it. It should sell nicely.

         Think about it. Would you pay $100 to own a piece of the Moon?

         1. I’ve commented on price, supply and how elastic the market is,i other remarks in this discussion. So I will limit myself to your comment on the value of something “collectible to remember the flight by.” That value would probably be quite high for the first human mission to return to the Moon after over fifty years. But what about the twentieth one? Sentimental value does define the worth of memorabilia, but once moon missions are “sustainable” and routine, a lunar rocks won’t have nearly as much value as a collectable reminder of a particular mission.

            1. Exactly, which is why you need to develop other markets for lunar material on Earth. Since the price for lunar material will be about $3/gram as noted above, compared to $45/gram for Gold at current market prices, there are potential jewelry markets, especially if you filter out everything but the glass at the lunar end. Basically you are looking for a sustainable market of around 1-2 billion a year. But to find it you need to invest a couple hundred thousand dollars in doing market research, something space advocates seem to want for free.

      3. Probably not everyone caught what you were referring to about maximizing profits by controlling the amount available on the market. Similar to what De Beers did with diamonds in the twentieth century by systemically releasing diamonds at a rate that maximized profits. And by glamorizing through advertising what was prior to that not considered the most desirable gem. Of course SpaceX probably wouldn’t need to do a lot of advertising to sell Moon rocks.

         De Beers was able to maintain this as long as they had a corner on the market. SpaceX would also likely be a monopoly at least initially for lunar samples at any substantial quantity. If they have a lot of free cargo volume on return flights they could bring back a truckload on each trip greatly reducing the value over time, or keep quantities limited and the price high.

         1. Exactly. A company trying to return moon rocks and sell them for a profit would (or should) pay attention to how many to bring back and what price to charge for them. If sending back half as many allows them to sell them at three times the price, that is a sensible thing for them to do. Or, if selling them for half the price allows them to sell three times as many, well, that would be the sensible thing to do. I was asking if anyone had studied that optimal point on a price-demand curve.

            But it is complicated, as you mention of De Beers’ diamond marketing suggests. That did not end with their near monopoly on diamonds. To this day, people still buy diamond jewelry for certain gifts. Imagine the reaction you would get if you gave someone an engagement ring with a ruby or emerald on it instead of a diamond.

            But that could also change. What about an advertising and marketing campaign which said, “Forget about ‘diamonds are forever.’ Give your partner an engagement ring that is _really_ out of this world!” Done right, it could really drive up the value of moon rocks and do so on a long term basis.

         2. You are thinking about it from the old Paradigm of limited access and rarity, but that won’t be the case when the Starship starts flying. Remember, the down mass of the Starship is about 40 metric tons and the cost per lunar flight will probably be closer to $50 million. Also monthly, even weekly, flights are feasible if the demand exists. So even if a market is established at $3/gram he will make money.

            Incidentally, as a bench mark, Gold is currently going for about $45/gram, so with the Starship the price of Moon rocks will be far less than Gold. And if you are interested Diamonds start at $4,500/gram The new low price for lunar materials opens up a lot of possibilities, especially if he makes 10-12 flights a year. That would be about 400 metric tons of lunar material. And it doesn’t necessarily have to be just Regolith, it will be possible to do processing and refining on the Moon in later missions to isolate components of the Regolith with commercial opportunities.

            That is why for the first mission lunar material will just be sold as collectibles to promote his Starship and reward his supporters. Then it will move on into more serious markets that will sustain the 300-400 metric tons annually from lunar mining activities. Again, that is why Starship is a game changer, not a mere lunar lander.

            1. At the times in the past that I was referring to diamonds were not short in supply, there were apparently stories that when new fields were discovered they could even pick up diamonds off the ground even before they started digging. As new mines opened up either by De Beers or by others who De Beers quickly purchased, there were plenty of diamonds but De Beers only put a relative trickle onto the market.

               You are right this won’t last once a use for regolith is found that makes it worth transporting large quantities back to Earth. But while it’s mainly just for the consumer collectible market, unless Musk feels like bringing it back by the truckload he probably doesn’t have to and can still make a similar profit. Presumably as a nice guy he would donate and give first pick to scientific organizations, or at least sell it to them at his “cost” however that might be calculated, maybe time spent collecting plus extra fuel needed to bring them back.

            2. I don’t think those numbers are correct. At least not initially. I believe a Spaceship would require both multiple tanker flights (five or six) and refueling on the Moon with in situ propellents, in order to return 40 tonnes. I also think that 40 tonnes includes passengers and their luggage. (And rich tourists usually don’t pack light…) SpaceX hasn’t been exactly clear and consistent about the details, but I think I’ve got that right.

               But look at what you could do on an initial flight. Call the mission cost $300 million, for one Spaceship and five tanker flights. If you can sell moon rocks as souvenirs for $1000 per gram, you’d only need to sell 300 kg to cover costs. I think that’s within reach without in situ refueling. Sold as one-gram samples, that would only take 300,000 people willing to buy. I don’t think that would glut the market. I doubt this could go on long, but it might cover or at least subsidize the initial few missions. Perhaps enough to get useful infrastructure on the Moon set up.

   2. If there is a credible plan for a long term transportation service to the Moon I can’t imagine moon rocks would be worth a gigantic amount even at the beginning of that service. Quick google says the cost of meteorites ranges from 50 cents to $5 per gram. Assume 5,000 kilos of rocks at $5/gram and that’s 5,000,000 grams of material at at value of $25M.

      1. Actually, some meteorites sell for as much as $1000 per gram. Those are the very rare ones which are known to come from Mars. The fifty cent per gram ones are common ones like Canyon Diablos (secondary fragments from the Meteor Crater impact, which can be found over a large fraction of the American Southwest.) I think known moon rocks, from a known location on the Moon and reliable provider, would be in the top end of the price range.

         1. Interesting. I guess I was assuming that if the capacity is there to start bringing in literal tons of material that the lunar rocks would be in the same range of value as a common meteorite.

            1. Actually meteorites are quite rare and if you exclude the handful of large ones in museums. I imagine the actual mass of the amounts that have been recovered and on the market will be far less that the material that the Starship could return from the Moon each year. But also remember it’s the mass being taken to the Moon that will build its industrial structure. The initial return mass will only serve to defer the costs of doing so. But it is an indication that NASA funding may no longer be relevant to the exploration and development of the Moon once the Starship is operational and if it hits its numbers.

               Of course NASA will always to free to buy tickets for its astronauts to visit Lunar City, just as other nations and private individuals may do so. And NASA may ship equipment up at what ever the shipping rate is to explore areas of the Moon it is interested in. But SpaceX will be functioning more like Southwest Airlines than the commercial crew program. The question is will NASA be able to handle that? And not just for the Moon but also anywhere in Cislunar space. (Sorry, next week’s lunar flight is booked by a Stanford alumni tour group but we have an opening the following week for your NASA astronauts…??

            2. NASA isn’t going to have a field party bumped by the Stanford alumni tour group. NASA funded (and NSF funded) field work on Earth is selected months in advance, and people start getting ready well in advance. They’ll have their flight to the Moon booked well in advance. Probably while the alumni are still arguing about going to the Moon or one of the Earth orbiting casino.

10. It’s nice to speculate about the value of moon rocks, of course their value is tied to their rarity (and ability to protect against counterfeits, ie earth dirt). But a couple of issues …
    1) Not my area at all, so just asking … Are we sure they’re safe for the general population ?
    2) What about the legalities, more a question when it comes to mining resources ? Should we “stake claims” ??

    1. Well, I think your first question should be reversed. Why wouldn’t moon rocks be safe for the general population? Some of the Apollo samples were given away to foreign heads of state. Thin sections are lent out to college geology courses on a regular basis. For years, the Air and Space Museum in Washington had a Apollo sample on display, where tourists lined up to touch it. (What happened to that, by the way? The last few times I was there, it was either gone or moved. Did all the tourist fingers eventually wear it down to nothing?) Given all the evidence, I think the burden of proof is on anyone claiming moon rocks are unsafe.

       As far as the legalities go, there are none. The real estate may not be bought and sold, but anything you pick up and bring home is your to do with as you like. There used to be a law about all lunar samples being NASA property, on the basis that NASA brought all of them back. But I believe that was modified in the case of samples returned by the Soviet, robotic Luna missions. Also, I’m not sure where you’d want to stake a claim, even if you could. At least, the discussion here has been about ordinary rocks. They’re lying around everywhere on the Moon.

       1. Not sure if there ever was a specific law, it was just recognized that were government property because government employees collected them as part of their job. The meteorites brought back from Antarctica by NASA personnel are also government property for the same reason.

          The Moon rocks given foreign governments, and the 50 states, are a different matter and technically they could enter the market IF they were sold by the respective governments under the laws they have for selling government property. The case involving the Moon rock from Guatemala hinged on the fact that the Guatemala legislature never approved its sale as would be required under their law. If they had then the owner would have been able to keep it.

    2. For 2), the Commercial Space Launch Competitiveness Act of 2015 explicitly allows US citizens and companies to mine space resources, so at least US companies are covered.

11. The next flight is in 2 weeks and the goal is 200 meters. Local hotels in South Padre are offering discounts to folks who want to see the flight and party. There are also reports the Starship will be topped out by then.

    Yes, space IS exciting again!!!

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