Third time is almost the charm for SpaceX's Starship SpaceX has launched its third Starship Super-Heavy rocket on a test flight that went almost entirely to plan. The 110-minute test window opened at 0700 CT on March 14, and, after a delay to clear boats from the range, the 33 Raptor engines of the Super Heavy booster were lit, and the Starship stack left the pad at 0825 CT. …
> Once it started hitting the atmosphere its disassembling accelerated very rapidly.
Not really.
At first it managed to maintain intended attitude (tiles-protected belly first) well into the altitude where plasma builds up.
You could see the fin on one side moving to maintain that attitude (which seemed to work pretty well at first).
Then Starship rolled out of control, the fin basically folded up and stopped moving(would have been interesting to see what happened on the other fin at that moment)
The craft then rotated the tiles sideways, exposing unprotected skin to the plasma, then reoriented to an engine-first reentry.
Then transmission stopped.
Overall absolutely fascinating.
A big Thumbs Up to the SpaceX team.
It did appear to be tumbling before the re-entry, and there didn't seem to be much RCS thruster activity, which I would have kind of expected to happen to get into re-entry orientation. There also seemed to be quite a lot of something venting out of the rear end long after the burn ended. However it did indeed seem to find the right orientation once it got into the upper atmosphere and its aero surfaces started to work. Fantastic to watch the plasma building up under it live like that! I'm really looking forward to the analysis of the flight, so we can find out exactly what went on, but clearly another huge step forward from the previous flight.
I heard it said that they are using the "waste" fuel that needs venting to keep the pressure at safe levels as the thrusters and that exhaust may freeze on the nozzles, especially on the shaded side and bits of ice breaking off might have been the "debris" we were seeing. I'm no rocket engineer or physicist, but it sounds plausible to me. Happy to be corrected :-)
"I heard it said that they are using the "waste" fuel that needs venting to keep the pressure at safe levels as the thrusters and that exhaust may freeze on the nozzles, especially on the shaded side and bits of ice breaking off might have been the "debris" we were seeing."
Outside of the atmosphere, there is little chance of ice forming from venting cryogenic propellants. It happens on the launch pad a lot since those are in humid locations. LOx isn't going to form a solid. Methane? I'd have to look that up. If either or both are being used for thrusters, they should be widely separated so they don't become a fire hazard or you'd really get some thrusting.
A bunch of the heat tiles are still coming off. They don't seem to have worked out how to fasten them in a way that accommodates movement of the outer skin of the rocket. A hole in those tile's coverage may explain some flaming seen on the video just before the whole things went pear shaped.
> At first it managed to maintain intended attitude (tiles-protected belly first) well into the altitude where plasma builds up.
Not in the stream I saw. There appeared to be continuous rotation before and throughout the door testing that did not appear to be deliberate or controlled.
Throughout reentry, the tiles rotated in and out of alignment at around 1 RPM. The fins went to maximum deflection a number of times suggesting that they were attempting to stop the spin.
Combine the loss of the booster, rather shaky door demonstration, odd failure to show anything around propellant transfer and complete absence of re-ignition test, and it looks like SpaceX have a lot of work to do. Musk's absence during the proceedings suggest he does not have great confidence at this stage... the clock continues to tick.
"I believe controlling the attitude with just flaps and wings isn't going to work in the thin atmosphere. Reaction thrusters will be needed to quickly correct any attitude errors or they risk the Ship breaking up due to thermal stress."
This makes talk about IFT 2 dumping propellants as part of the flight plan very odd. Why wouldn't they use residual propellant in the thrusters? For that you want them to be gaseous, not liquid, so it's far easier to tap the components off since there's no need to have liquid at the port. If there is, it's not a problem to turn it into a gas before it hits the RCS valves. They could also use hypergolics to simplify things. Or, they can be very complicated and use a bit of both.
Same here, that was stunning! They very kindly explained why we were able to see it too. Basically 'cos Starship is frikken big!
And me! Was just watching Scott Manley's review here-
https://www.youtube.com/watch?v=8htMpR7mnaM
and was fascinating actually seeing the plasma effects on re-entry. Seemed like it almost got it's Starlink+ dispenser working which they'll need to complete Starlink. Depending on how much we can trust SpaceX's figures, even without re-use it's AFAIK the cheapest way to lift a 100t payload into orbit. More work needed to actually deploy something big, but it's progress.
"And me! Was just watching Scott Manley's review here-
https://www.youtube.com/watch?v=8htMpR7mnaM"
He also pointed out something I'd not noticed in the live stream. There was still some pressure in the cargo hold as seen by the wisps of vapour, which then proceeded to rush towards the hatch when it opened. I wonder if that could be an issue, eg causing a "thrust" and possible rotation? I suppose it depends on how much remaining pressure there was. Although it was interesting to see a real life demonstration of a pressure loss in space. It didn't look as violent as Hollywood shows us :-)
"I suppose it depends on how much remaining pressure there was. Although it was interesting to see a real life demonstration of a pressure loss in space. It didn't look as violent as Hollywood shows us :-)"
It can depend on many things. Was that pressure there due to something leaking/venting or was it due to the rocket being sealed up well and residual? Since there wasn't a need to maintain pressure, it would have been prudent to make sure it wasn't pressure tight. If it wasn't pressure tight, but tight enough that whatever was leaking into that space gave it a little pressure, you won't get a giant decompression blast. To see whispy vapor like that at that stage of flight is a concern.
"even without re-use it's AFAIK the cheapest way to lift a 100t payload into orbit."
It has to not explode first and THEN they can work on getting the price per kg down to something identifiable. At $2bn/year in dev costs, will there ever be any ROI? The cheapest price quotation also assumes the entire payload capacity is used. Stick another sports car inside sans battery pack and the cost per kg will be at the top end. For grins, let's say they load a whole stack of Starlink satellites in the payload and the rocket goes boom. What's the price tag, including lost opportunity, on 100t of those birds?
"Seemed like it almost got it's Starlink+ dispenser working which they'll need to complete Starlink."
It took them over 4 minutes to get the door to open, a bit. It then looked like when they commanded it to close, it fell out of the tracks to keep it aligned. There was no dispenser installed on this flight, only a door so that's a non-starter. No in-space engine relight. The Booster exploded 1/2 km up. The Starship couldn't align itself for proper reentry and melted/disintegrated going at nearly its top speed when signal was lost. From the propellant gauge readouts, it's hard to see how there's enough capability for the system to carry a payload, much less 100t to LEO.
Yep, if there was no intention to reuse it, it would be able to put 1,000 metric tons into orbit.The estimated expendable payload to LEO is 250-300t
" Yep, if there was no intention to reuse it, it would be able to put 1,000 metric tons into orbit.
The estimated expendable payload to LEO is 250-300t"
If you look at the propellant gauges with no payload, how the heck is it going to be able to take 250t to LEO. It can't even make orbital velocity stripped bare.
"The estimated expendable payload to LEO is 250-300t"
Elon just let slip that the current iteration of Starship used for IFT3 might be able to put 40-50mt into LEO. Starship v3 might be able to put 200mt into orbit but it still remains to be seen if the whole system is reliable at all, much less reliable enough to entrust 200mt of expensive space hardware to it's payload bay.
Given what the fuel gauges were reading on IFT3 after the launch of an empty test article, I'm very skeptical of any amount of payload.
Yep, if there was no intention to reuse it, it would be able to put 1,000 metric tons into orbit.
That's as much as ISS weighs.
The ISS weighs ~450tonnes.
StarShip is planned for 100-150t reusable or 250-300t expendable, not 1000t.
You might be getting confused with the internal volume of 1000m3, which is comparable to the ISS. You could fit out a StarShip as a research station and get something akin to the ISS in orbit in one launch.
You might be getting confused with the internal volume of 1000m3, which is comparable to the ISS. You could fit out a StarShip as a research station and get something akin to the ISS in orbit in one launch.
It'll be interesting to see what options they end up with to handle mass/volume and reusability. So the bigger the volume, the bigger the hole needed and bigger challenges to protect that during re-entry. Or maybe they'll have fairings that can jetison and still protect the re-entry vehicle.
"Or maybe they'll have fairings that can jetison and still protect the re-entry vehicle."
Not an option - the fins* and header tanks need that fairing to still be there.
They'll end up with a massive door, or a pair, and that's not an impossible task - the shuttle had such bay doors.
* I like Tim Dodd's use of the term elonerons, cf_ ailerons
Not an option - the fins* and header tanks need that fairing to still be there.They'll end up with a massive door, or a pair, and that's not an impossible task - the shuttle had such bay doors.
Yep, it'll be an interesting challenge, ie doors vs repositioning control surfaces and tanks to enable a stubby Starship. It gets us closer to doing fun stuff though. I'm assuming for space stations, the challenge is more volume than mass, so sections need to be large enough to be habitable. But being able to lift large sections makes larger space stations possible, then the potential to create staging posts maybe in geo orbits for building and servicing lunar or Mars bases.. Where I guess mass will play a bigger part for shielding.
"It'll be interesting to see what options they end up with to handle mass/volume and reusability. So the bigger the volume, the bigger the hole needed and bigger challenges to protect that during re-entry. Or maybe they'll have fairings that can jetison and still protect the re-entry vehicle."
The booster isn't going orbital so that can come back, but if you fit an expendable faring on the Starship, it's not coming back (in one piece). It would also be a whole new vehicle. The Pez dispenser is an interesting concept and could work due to the configuration of the Starlink satellites, but maybe not for commercially available satellite busses. I don't see a market for 100t of Cubesats all going up on the same launch. One has to keep in mind that Starlink is an in-house project, not a paying customer (for the F9 as well). Some serious doubt has been cast on that system ever being profitable and could end up just leaving a whole load of orbital debris if it goes belly up. Maybe the concept includes a government buyout to prevent that along the lines of "too big to fail".
'SpaceX had said: "This new flight path enables us to attempt new techniques like in-space engine burns while maximizing public safety."'
Clearly maximal public safety would be achieved by not chucking five thousand tons of metal and explosive propellant into the sky and letting it fall back to earth.
-A.
Unless I'm missing something, following that line of reasoning, the implication is that we should not have a space program, because of public safety.
I invite you to consider the impact on public safety caused by e.g. not having modern weather forecasts, as a direct consequence of that.
So you'll be calling for banning all cars.
Clearly "maximising public safety" is one of a number of things they are trying to optimise, they evacuated a very large area of the indian ocean, and the gulf of mexico of all air and sea traffic, and a significant area around the launch site of all people.
> So you'll be calling for banning all cars.
As a fairly extensive car driver*, that would be deeply hypocritical.
No. I'm just saying that claiming to be "maximising public safety" whilst launching really enormous experimental rockets into (near-)orbit is much like the oft expressed platitude "we take your privacy seriously" while hoovering up your personal data and storing it on internet-connected servers. It's OK, we use a password.
-A.
Also motorcyclist, cyclist and pedestrian, from time to time.
"So you'll be calling for banning all cars."
If somebody was going to take their hot rod with bald tyres out on a rainy day to see how fast it will go on the motorway.......
Usually, the belief is that one will use their car to travel to and from with expectation that nothing bad is going to happen. At worst, there might be a concern that the wheezing old wreck might need to be abandoned at the side of the road and there should be tools onboard to remove the number plates and scrape off all of the VIN numbers.
>It's the language I object to. Clearly they are not maximising public safety and claiming so is disingenuous.
No, it's not. "Maximising" in no way implies the absence of any constraints, such as "being a rocket company", on the variable you are maximising. In fact, I can't think of any case where you maximise something without constraints. The language is perfectly accurate (whether they are actually maximising, of course, is harder to figure out).
Also, I reiterate that having a space program is good for public safety, because of weather forecasts if nothing else, and that has a hard requirement of launching rockets.
"Clearly they are not maximising public safety and claiming so is disingenuous."
When the head of the company is putting out statements that "maybe it might work" but we're not afraid to iterate rapidly and blow things up, there's need of concern. A fuel/air explosion with that much propellant is on a nuclear scale. Sure, no radiation, but all of those adjacent nature preserves would be swept of their endangered species.
"I choose not to live that way."
But you do choose to keep sharp pointy things off the floor so when you get up and trundle to the loo, there's little chance of a foot injury and a trip to the doctor for a Tetanus shot.
Maximizing safety in a rocket program would include things like a high confidence in the rocket performing the mission. SpaceX isn't doing that. Their approach is much closer to "let's light the fuse and see what it does".
It went up, and it came down. Success!
That reminds me of Brian Hanrahan's famous phrase ''I counted them all out and I counted them all back'' when reporting during the Falklands conflict
I care not one way or the other, but if this is really your idea of fun can I suggest you shut down your computer for a while, step outside and sample real life? You never know, you may find it interesting (and the graphics are pretty good).
On your logic every bomb ever made was a dud. Sadly, that isn't true.
Whatever you think of Musk, SpaceX proved this sort of tedious nonsense to be baseless the day they successfully landed a booster on a barge. why it continues is beyond me.
I had a brain fart and thought it was happening 1am local time! But since I'm not at work today, I was browsing a bit of Youtube just after lunch and the Live stream appeared in the suggestions. Boy am I glad I was wasting time on Youtube today :-)
I'm not 100% sure, but I think they did actually succeed in all of their primary goals too. And from what I gather, they have the kit and the plans for a number more test flights this year too. Looking forward to seeing both bits make successful "soft" landings and I REALLY hope we get to see an actual catch attempt this year!
"The aim is for another half dozen flights - and they have the hardware to be able to do that."
They don't have general permission for more than 5 flights per year from Boca Chica and even that's subject to reduction. I am waiting to see what the reports from the ecological assays look like. There are a bunch of endangered animals in the area that even a perfect flight will kill/maim or scare off of nests/dens. There may be a ban put in place to during certain periods even if flights are allowed to continue. If there is a big accident that destroys a lot of the infrastructure, that might bring the curtain down on the location since a lot of what's there right now was never properly permitted.
How many tons of kerosene or methane are used in each launch? What about the environmental impact of chilling that huge amount of oxygen, the carbon impact, etc? And we suffer huge fuel prices as Musk soaffs it on space.
How many to refuel the "Starship" to go & return from the Moon? 12 I have read. Utterly unbelievable waste of energy.
How many to refuel the "Starship" to go & return from the Moon? 12 I have read. Utterly unbelievable waste of energy.
Please define 'waste of energy'. How about we ban all motor racing, NASCAR and F1, surely the gas/petrol used in those is a 'waste'; no - unless you can convince me of the benefit to humanity of allowing it. Come to think of, all those private cars burning fuel, when surely everyone should use public transport or just walk - tell me do you advocate the banning of cars?
And don't get me started on all the aircraft flights that happen each day, how much waste of energy must that entail - need to get across the Atlantic, why just use a sailing ship, yes it'll take two weeks but the saving in energy......?
"Please define 'waste of energy'. How about we ban all motor racing, NASCAR and F1, surely the gas/petrol used in those is a 'waste'; no - unless you can convince me of the benefit to humanity of allowing it."
Well there are some benefits, though how much they actually benefit us is questionable.
Certainly there are some efficiency gains which have been passed down from sports like F1, as well as such innovations as ABS, and materials engineering research enabling much larger carbon fibre structures.
If we didn't have ABS then there is a good chance the people would simply have to drive a little more carefully, but since risk homeostasis exists... we can't have both :(
> How many to refuel the "Starship" to go & return from the Moon? 12 I have read. Utterly unbelievable waste of energy.
You would hope that a Register reader would have at least a basic grasp on numbers - the strange way that 12 times "what sounds a lot to me" is utterly dwarfed by "a big number I can not understand" times "not enough to worry about, surely".
Like - how many gas and diesel cares were on the road today? And how much did each of those waste idling? And then the same tomorrow, tomorrow ...
How many light bulbs were left on in empty rooms (even if they were all efficient LED)? While we are at it, what about the environmental impact of LED house lights failing needlessly & being replaced because they are driven too hard (deliberately)?
The costs of one-off / very low count projects like Artemis are trivial compared to the combined costs of all the wastage from people like you - and like me.
"think of all of the wasted energy from having headlights on during the day to prevent"
The solution looking for a problem effect. Sounds great when presented to a political body that will pass a law about it with no further thought, but doesn't make sense just below the surface. There's also the problem of traveling into the sun and a car coming in the other direction masking it's presence by having lights on instead of being a dark spot up ahead.
My "daytime" driving lights draw 21W each. Sometime in the next week I'm going to see about removing that load. I put a new head unit in the car and with the ignition and those lights on, I ran the battery pretty flat. I didn't notice that the the lights were on during the day while I fiddled with getting software loaded and updated. Now I know to back the key off another click when I'm working on updates although that turns off the ECU so I can't do that when debugging Torque Pro. Live and learn. I just found out that the V6 version of my car has a bigger battery fitted so I'm upgrading to that size since what they put in the 4cyl version is anemic and I've added more gadgets. I always thought the space allocated for the battery was larger than what was there.
Exactly zero tons of kerosene... I don't think that they are still using generators.
Booster takes 750t of methane, Ship takes about a third of that (250t) so overall a thousand tons.
Methane has an energy density of ~50MJ/kg, so a launch uses ~50TJ of energy, that's ~14GWh.
Not a huge amount of energy in the grand scheme of things, the US consumes ~4EWh of electricity each year, and plenty of gas usage that isn't electrical.
"...a launch uses ~50TJ of energy, that's ~14GWh."
To put that in perspective, it's approximately equivalent to one big power station running for a couple of hours.
Compare that with, say, Bitcoin mining which is, er, currently using about 100 TWh annually - six or seven starship launches per month - in the equivalent of an electronic horse race to produce exactly nothing.
~160 seconds to do all but a few tens of tons of propellant...
If that's ~65 tons burnt then it's 32TJ, or 200GW, *way* more than the UK grid ever pulls....
Those raptors are seriously powerful ~ 650kg/s mass flow, of which ~140kg/s is Methane, so that's ~7GW each... two and half times the largest power station in the UK (https://electricityproduction.uk/plant/)
And there are 33 of them... which would add up 231 GW - so that matches the initial estimate closely enough.
I haven’t run the numbers on Starship specifically. But actually launcher waste far less fuel than people think. A Falcon9 uses a total of 150 tonnes of fuel and oxygen combined. For comparison, a 747 jet maximum fuel load is 200 tonnes. And that’s all fuel, therefore much more CO2 for the 747 (if that’s your concern). Plus, amongst launchers, Falcon9 Merlin engines run on (space-grade) kerosene, really rather similar to standard jet fuel. As opposed to, say, Ariane second stage, which is hydrazine - horribly toxic.
To give a real feel for this, a current satellite on its way, Eutelsat 36D, was recently flown to Florida from Toulouse aboard a purpose built Airbus Beluga, for launch on the Falcon9. The (return) flight of that transport aircraft will have burnt more fuel than the launch. And particularly if you add in the flights for all support personnel.
I suspect you've just remembered the amount of RP-1:
Badly written sentence in the first google hit splitting the masses.
"Both stages of SpaceX’s workhorse Falcon 9 rocket guzzle about 312,200kg of LOX and 186,006kg of RP-1 throughout a flight."
That's about 37% RP-1, so 146t of 393t - that's close enough to 150t
"As opposed to, say, Ariane second stage, which is hydrazine - horribly toxic."
Yes, but they use that MMH outside of the atmosphere and it's an extremely reliable fuel in that situation. Look at how many issues there have been relighting and keeping lit those Raptor engines. The ascent stage in the Apollo lander used Aerozine/N2O4 for reliability. It was really hard to have that combination not work. If it didn't, there would have been no way for the moon walkers to get back to the capsule for the trip home. Being green or saving a few bucks was not even a factor.
Scott Manley video for reference.
They had a lawn chair variant and a concept where "the pilot would stand and steer the whole thing by leaning to the side to adjust the centre of mass"
"How many to refuel the "Starship" to go & return from the Moon? 12 I have read. "
At least 12 if everything goes to plan. If there is any waiting time, it could take several more to compensate for "boil off". There's still some question about whether they will be using an orbital tanker or using the lunar lander directly to receive propellant transfers (which still needs to be worked out).
Complaining about the environmental impact of the space industry (which is actually critical to our modern lifestyles ec.) makes people feel good but it's about as relevant as complaining that windmills kill bids.
If we go by the "move big stuff around using fuel" metric, as spectacular as a rocket launch looks like, it's trivial and unless it scales to 100s of Starship launches a day, it will remain trivial.
Consider for instance that cruise ships burn 150 to 250 tons of fuel a day and that were are well over 300 active at this time... and other than as floating petrie dishes, they're not exactly useful.
The difference, of course, is that musk's rockets don't claim to be environmentally friendly.
Complaining that windmills kill birds is rather more relevant, as it compounds with the unreliability and low productivity of wind turbines, as well as with other issues (chief being the enormous amounts of land that has to be cleared for them and the fact that wind requires dispatchable, conventionally fuelled backups for when it isn't blowing).
They are an inefficient, ineffectual waste of funds that should have been put into building out nuclear AND they kill birds.
"They are an inefficient, ineffectual waste of funds that should have been put into building out nuclear AND they kill birds."
Fewer birds than other buildings.
They are very efficient, and a very effective energy generation mechanism - forty something percent of UK electrical generation last year.
> chief being the enormous amounts of land that has to be cleared for them
Wind farms do not take vast swathes of land - first, being giant lollipops, the big part is suspended well above the ground (this is sort of important to how they work), leaving space beneath for grazing, cropping, chasing your beloved through the spring meadow flowers.
Second, the vast majority of UK wind farms are (being) built out to sea.
Yes, they are taking seriously any concerns about the effects on sea life (e.g. marine vegetation growth on the bases leading to increased biodiversity and then to sea mammals gaining new feeding grounds).
"Wind farms do not take vast swathes of land -"
Where I am they are using vast swathes of land, but that land isn't being cleared other than for the bases and access roads. I happen to be near an area with very good wind resources. There's lots of solar farms as well since the land isn't much good for many other things. To keep the solar farms cleared, I've seen an enterprising farmer bringing in a load of sheep and a couple of dogs to knock back the massive plant growth due to having some shade here in the desert. Whenever I see them, I never have the time to stop for a chat. I'd like to find out if they rent the sheep out or if it's an even trade. I'd also like to know if the sheep will eat some of the more problematic plants that plague my garden.
While I sort of agree with you, I would dispute that "enormous amounts of land that has to be cleared for them". Here in the UK, where most land is at a premium, there are many on farmland and the farmer simply ploughs around them and their access roads/tracks. The "wasted" land is minimal. Others are up on moorland which isn't used for much other than maybe some sheep grazing, and the sheep really don't seem to care about for the slight disruption and minimal loss of grazing.
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...the space industry (which is actually critical to our modern lifestyles ...
The space industry is actually one of the least critical industries to "modern lifestyles".
Most ancient industries are more critical: Wood, steel, copper, textiles, printing**, ceramics, water, coal, concrete, ditch digging, quarrying, baking, roads ...
All the satellites could be turned off at the end of the year, and there really wouldn't be much lost. Try stopping any one of the above.
The applications of satellites mostly fall in the convenience category.
** Just thought I'd include something new fangled that was invented in the last 500 years
Fuel efficient?
AtlasV takes 305 tons of propellant (first and second stage, no boosters) for a 12 tons to LEO
Soyuz takes 4*40+96+22 = ~280 tons of propellant for ~7 tons to LEO
Falcon9 takes 400 + 92 tons for ~22 tons to LEO, or 18.5 tons when the booster is recovered.
Those are mass factors of 25, 40, and 22 (26 with recovery).
Starship is 3400t+1200t, with a payload capacity of 150t (250t if expended)
That's a ratio of 18.5 (better than any of the above) when expended, and 31 when fully reused (middle of the pack, but without disposing of all the engineering every time).
"Starship is 3400t+1200t, with a payload capacity of 150t (250t if expended)"
Based on if the entire capability is used. The reason there aren't competing heavy lifters is there isn't a market for them. On the contrary, advances in electronics, metallurgy and composites is bringing down the size and weight of satellites for a given set of capabilities. For the odd government agency launch (spy sats) that need a heavy lifter, that's where the strapon boosters come into play. They're cheap and cheerful while not adding tons of mass to the base vehicle.
There isn't a market for them - partly because they don't exist.
If Starship is genuinely reusable... then the cost of launch becomes primarily fuel cost, which is going to be cheaper than engine cost.
The efficiency is clearly based on how many payloads you want to put in a specific orbit, but shared launches are becoming far more common than they used to be.
Got to get SLS and Orion ready as well.
The starship bit is actually progressing fairly well, even if a little slower than some might have hoped.
They've demonstrated launch and hot staging of the full stack, along with reuse of the launch facilities.
They've demonstrated the flip and boostback burn as well as aerodynamic control of the booster.
They've demonstrated a full burn of the ship, and some degree of control on reentry.
They've also demonstrated subsonic control, flip, relight and landing of the ship (though not yesterday).
That's a pretty long list of successful operations so far.
The payload doors looked like they had some movement, but it's not clear how successful that was yet.
Quite a bit of material being liberated on the way in which I don't believe was all ice. Towards the end there was visible tile damage on the observed vane leading edge and on the body tiles. If this was indicative of the rest of the ablative surfaces then its a testament that the craft lasted as long as it did within the plasma cloud.
Perhaps the failed in orbit engine burn was intended as significantly more than a test.
Onwards and upwards towards the next test.
One minor point - the tiles are not ablative as they want something that doesn't need to be swapped between flights (especially as there are some 18,000 tiles).
Does look like there's still some work to do on attachment and strength though - but much better than early flights.
Again, in the interests of accuracy over pedantry-
https://dictionary.cambridge.org/dictionary/english/ablative
'the form of a noun, pronoun, or adjective that in some languages, for example Latin, shows by whom or what something is done, or where something comes from:'
I also stated 'ablative surfaces' as opposed to 'tiles'
It's my understanding that the tiles used in this system are not meant to melt or evaporate but meant to exploit their extremely low thermal conductivity property to protect against the frictional heat generated.
'the form of a noun, pronoun, or adjective that in some languages, for example Latin, shows by whom or what something is done, or where something comes from:'
You've managed to quote one of two definitions for "ablative". In referring to grammar, "the ablative" is indeed the form of the noun/adjective that shows by whom or what something is done.
It also has a secondary use: of or relating to "ablation", which is the process of ablating (surgical removal or loss of a part).
An "ablative heat shield" is a sacrificial heat shield which burns away (hopefully not completely!), and this use is common/standard in spaceflight. Everyone - including NASA since the 1950s - has used this meaning in reference to spaceflight. It means exactly what John Robson says, and if you think it really doesn't mean that, then you should - in the interests of accuracy - write to both SpaceX and NASA and tell them they've been getting wrong for decades!
The Dragon capsule uses an ablative heat shield, as does Soyuz, because it's extremely simple and reliable. The Shuttle didn't - too heavy, and they didn't want to have to replace the heatshield after use (but then the tiles kept falling off anyway and needed a huge amount of maintenance). The StarShip tiles are not ablative, because they want to turn it around rapidly.
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'You've managed to quote one of two definitions for "ablative". In referring to grammar, "the ablative" is indeed the form of the noun/adjective that shows by whom or what something is done.'
Yes, and I have used it in the sense that it is the surfaces where the frictional heat is carried away. This doesn't have to be via attrition of material it can equally be done via emission of radiation which is the method employed by the Complex Matrix Composites system.
I was clarifying to John Robson that I was not referring to tiles, I was crystal clear in referring to 'surfaces' but I am sure he doesn't need your help with understanding that.
I don't doubt the historical use of the terms but as you have already confirmed my accuracy i don't think it's necessary for me to contact SpaceX and NASA though I am sure they would appreciate you speaking on their behalf. I'm also sure they would appreciate your potted history as well, I however was already up on it.
From: https://www.nasa.gov/humans-in-space/after-15-years-1000-tests-orions-heat-shield-ready-to-take-the-heat/
"The Apollo crew module’s heat shield relied on a material called Avcoat to beat the heat. It’s an ablator, meaning it burns off in a controlled fashion during re-entry, transferring heat away from the spacecraft. "
"Following the Artemis I mission, the Ames team will also harvest samples of the charred Avcoat tiles to analyze how the material ablated."
Ablated - i.e. shed bits to carry away some of the energy of reentry
The shuttle however had a Thermal Protection System, consisting of High/Low Temperature Reusable Surface Insulation tiles - note the lack of the word ablative, because it wasn't an ablative system.
Space Explored has a useful paragraph:
"An ablative heat shield, as SpaceX uses on Dragon’s primary heat shield, works by heating part of the material itself into gas and burning away, thus moving the heat buildup away from the capsule. By comparison, a thermal soak heat shield – as was used on the Space Shuttle – is designed to absorb the heat and radiate it, without the material burning away."
Let's ignore active cooling etc, since AFAIK noone uses it yet.
" If this was indicative of the rest of the ablative surfaces then its a testament that the craft lasted as long as it did within the plasma cloud."
The engines and aft end were used a lot in the descent, but the craft didn't slow down very much for all of that.
The visible plasma is an indicator of temperature, not heat. When there was sufficient heat load to really do damage, that was the end of the signal. I am wondering if the control surfaces were adequate to get the craft lined up properly to enter the atmosphere. Perhaps if it were coming in at the correct AOA, the flappy paddles would have been able to keep it passively stable when they weren't good enough to get it into correct alignment beforehand.
Considering that SpaceX is the only company using mainly re-usable spacecraft and the Starship prototypes are intended to be fully re-usable, that's an interestingly wrong observation from you. If you want to attack Musk over something credible, I'll probably join in with you, but picking on the one thing SpaceX is doing right that no other launcher is yet doing is so far off the target, the proverbial barn door must be on a different planet to you!
And you should apologise for so brutally ruining a perfectly good verse.
Note of course that Elon intends Starship to land on the bloody launch tower, whilst every other operator intentionally throws away every launch vehicle after one use.
And yes I know it was meant as a joke... meant is doing alot of heavy lifting in that sentence though.
I don't understand. This is basically a direct descent/ascent to the Moon from Earth orbit. This is contrary to the Apollo and Soviet systems of Lunar Orbit Rendezvous, the former proven to work. The reason Lunar Orbit Rendezvous was chosen: immensely more fuel efficient, this cheaper.
The 33 engines on the first stage suffered failures very similar to the N1. So nothing new.
Apparently nothing learnt either. I feel so saddened that this huge White Elephant is destroying the Earth's resources, wasting precious talent, doing it in a manner that befits a Tintin story.
It's a staged descent from LEO, and an ascent only to LLO.
The 33 engines on the first stage acheived a full duration burn - in what way is that a failure "similar to the N1"?
And suggesting that starship is "destroying the Earth's resources" is somewhat hyperbolic don't you think?
Yes, there is some material scrappage going on at the moment, but the intent is explicitly not to waste resources, they're aiming to reuse the thing - repeatedly.
And when they use in in an interplanetary setting they intend to refuel it from local resources...
"The reason Lunar Orbit Rendezvous was chosen: immensely more fuel efficient, this cheaper."
And it's not actually cheaper if you consider the possibility of complete reuse of the vehicle by not dropping stages all over the earth moon system.
We got back ~5.5t of the saturn 5 stack, throwing away 200t (and fuel).
If instead you launch using starships then you get back *all* of the spacecraft, just using fuel.
Ok, you use more fuel - but you also have more mass to the lunar surface...
HLS is looking at ~100t payload to the surface, the uncrewed version of Apollo was looking at 5t - so that's twenty times more payload.
Assume 12 launches needed then that's 4,800t each, and 1200 extra in "payload" fuel to refuel the lander in orbit - that's 58kt
Apollo used about 2.5kt of fuel, multiply that by twenty to get the same delivered mass is 50kt, slightly less, but you just threw away twenty full stacks of SaturnV.
I'm actually surprised how close it is - the basic "bigger rocket is more efficient" comes quite close to wiping out the "six stages" efficiency of the apollo scheme.
And the reusability plays a larger role than you might think in the total cost. Fuel for the SpaceX stack is about a million dollars, but they have 39 raptors, which SpaceX are aiming to bring the cost down to a quarter of a million dollars - if the *smash* that goal and bring it down to $100k then they'll still have $4m of engines alone on each stack... ignoring everything else which makes up the rocket. Being twenty percent less fuel efficient is clearly cheaper than throwing away the engines.
The Monn is an awful place to live or work:
1. Lack of gravity (so need to stay fit, keep bone density, etc).
2. Lack of oxygen and water. (The water on the moon held in hydrated crystals in rocks, one does not squeeze a rock and get out water, readily.)
3. Too cold or hot.
4. Too much radiation, increasing likelihood of cancer.
5. The regolith, the Moon dust, woe woe. Due to lack of wind, the only weathering (such as onemay call it/ is either high-speed impact or solar radiation. The former, over the last 3+ billion years, has created a form of "sharp sand": this is microscopically sharp quartz. Quartz is second only to diamond in hardness. As it is atomically sharp, by Van der Walls forces (electrostatic polarity) it is "sticky" and does not brush off. Moreover the Solar wind that constantly impacts the day-side of the Moon (which changes every 28ish days) causes this nightmare of a type of dust to become charged, so repels, so raises to a height of about 10-20 odd metres. This causes the dust to eventually cover anything up to that height in a fine layer of effectively irremovable "gunk". Hence noi mrrors on the Moon!! The Apollo Lunar suits had major issues with Moon dust in the wrist joints. The Lunar Vehicle had to have sealed baring and drum brakes. The Lunokhod rovers, similarly. Anyone heard of Asbestosis and the affects of microscopically sharp, small particles on the lungs?
6. Energy. In the light of the above, on must have an abundant source of reliable energy. This cannot be solar,as the solar panels will degrade seriously over time. So nuclear is out only current option. But we all "hate nuclear" as that is not "green", "good" or "nice". The only suitable reactors are liquid-metal (high density, very efficient), but these we hate as the only things we might use such reactors of suitably small size is nuclear ballisticissile submarines. Even there we don't use them (safety and noise). So due to he lack of research, these are too risky and or expensive. So we have no long term, ample power.
So: one will not be bulldozing this stuff onto a base to provide shielding. One will not be romping about in buggies. One will be strenously avoiding it.
So why go? Basically so some rich tourists can "have a look". Fair enough. But let's be realistic: the Moon is much more cheaply left to robotic exploration. Much cheaper, much safer, muchore science return per unit cash spent.
"Hence noi mrrors on the Moon!!"
Except the mirrors which the apollo program took there, and are still in use to this day?
"So why go?"
Because people can still do things robots can't, and because developing the technology for this enables other missions as well.
One could argue the world would be a better place if Columbus had sailed back and noone had returned from Europe to the American continent, but going to the moon is a stepping stone, or a pathfinder.
Of course if you do set up a permanent moon base then you don't need to keep earth levels of bone density, just not needed - and in all likelihood early bases would be subterranean (sublunarian?), even if that's only partly underground, and partly with rocks and dust overlaid.
"The Monn is an awful place to live or work:"
So was your office in the jurassic period... in fact it probably wasn't a great place to work a hundred years ago.
"Of course if you do set up a permanent moon base then you don't need to keep earth levels of bone density, just not needed"
Assuming one would move to luna permanently. If people are meant to rotate to an from Earth, health issues due to lack of gravity will put limits on the time. Even if people don't need bone density to hold up to lunar G, there are other health issues that could radically limit a person's lifetime if they are a seen in lunar G. Bearing children on the moon is really scary.
Would you consider the ISS a permanent base in LEO?
Because they contend with even less (effective) gravity...
No idea why bearing children would be particularly scary, I mean it's not something that I'd advise until we have some better understanding of the long term effects on growth overall...
"No idea why bearing children would be particularly scary, I mean it's not something that I'd advise until we have some better understanding of the long term effects on growth overall..."
Scary mainly since there is zero data and the first time a woman gets pregnant in less than 1G or takes a fetus to full time in less than 1G it might have some very bad outcomes. How many times will there be attempts to reproduce in space if the early outcomes are poor? Of all of the medical issues that aren't elective, this is one with lots of societal and ethical baggage.
There is always no data to start with...
That's why I wouldn't advise it until we have some better understanding of the long term effects of low gravtiy on growth...
Early data (https://www.cell.com/iscience/fulltext/S2589-0042%2823%2902254-X) suggests that mammalian embryos can develop in microgravity, which is likely far more challenging than merely low gravity
"1. Lack of gravity (so need to stay fit, keep bone density, etc)."
The human body's reaction to fractional G still needs to be determined. Zero G (or micro G) is problematic as has been shown. Is 1/6 enough? We don't know and won't until somebody has remained on/in the moon long enough to get good data. Radiation is a factor, but it's a good idea to plan to live/work under the lunar surface eventually rather than build infrastructure on the surface. I'd rather see missions aimed at investigating what looks like cave or lava tube entrances over fiddling about at the south pole looking for ice. We know there is ice there. Access to water is important but not if people are reduced to goo.
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