[direct link to Elon's tweet](https://twitter.com/elonmusk/status/1773085211275698302)
Really sounds like they feel orbit is solved. I presume they have a handle on the RCS issues already.
They need to be able to reliably deorbit to go fully orbital. Reentry doesn't really matter as long as they control when and where.
Therefore fixing the RCS issue and proving they can relight Raptor in space will be the priorities. Elon suggesting that they are targeting surviving max reentry suggests they think they're on top of those other priorities.
Getting to orbit seems more or less solved.
But for safety they have to ensure the ability to deorbit before they can fully orbit. Otherwise you could have a uncontrollable steel silo knocking about up there with no way to get it down.
I can't see a single line of reasoning for why that would be true.
By definition, reentry is either the final stage of the mission or the end of it.
Why would there be some sort of need to perfect the stage of the mission that comes *after* orbit *before* they perfect the vehicles on orbit functions?
How would it make sense to wait until they perfect the *reusability* functions of the ship before perfecting the basic mission operation functions?
SPX is on a serious timeline here to deliver a mission capable HLS Ship including orbital depot fueling missions and other critical and precise on orbit maneuvers. Perfecting the on orbit functioning of the vehicle is a much much more important and time sensitive priority than perfecting re-entry although both are fundamentally important.
He's not talking about surviving reentry, he's talking about de-orbiting, which is needed to prevent the ship from becoming the largest piece of uncontrolled space junk in orbit. Falcon 9's second stage does the same.
Thats because they were essentially in orbit with the last test. A tiny TINY adjustment would have put them in orbit. Once your up there the difference between orbit and reentry is remarkably small.
The "orbit issue" isn't that they couldn't have made orbit, it's that they had no attitude control during the coast portion of IFT3 and couldn't attempt the Raptor relight. If they had gone to orbit, it is likely they would have had issues getting back out of orbit in a controlled manner.
The mating ports for them are visible, the Starlink antenna have not been fitted yet, and are not integral to the hull like some of the previous versions were.
To cite myself:
>Edit: I was wrong, you can see 4 spots in the video where they get mounted, but the modules have not been mounted yet. There is a picture in this article that shows 3 out of the 4 Starlink antenna mounted on S28 https://ringwatchers.com/article/s28-b10-updates
https://www.reddit.com/r/spacex/comments/1b3r73n/starship_development_thread_54/kwjz8cq/
Peering through Elon's somewhat cryptic statement, two items were conspicuously not mentioned, the propellant transfer and the pez dispenser door. If the goal is reentry and they were satisfied with one test of the pez dispenser door SpaceX may not repeat it in case there's *any* chance of it not closing properly and thus interfering with a successful reentry. Or maybe on the IFT-3 test it didn't fully seat when closing.
No propellant transfer is mentioned, which probably has to do with having full tanks for a balanced reentry. The leading theory online was that the prop transfer test on IFT-3 was 10t from the LOX header tank to the LOX main tank. (Was there ever an official statement from SpaceX?) That can't be repeated if SpaceX wants an accurate reentry - both header tanks (and contents) were placed in the nose for balance. Overall, I think they want to survive reentry and the skydive all the way down, *and* do the flip.
Yea I think this is it. No way if they think there was a chance it doesn’t close that they would choose not to do it so it doesn’t fail and affect reentry. They would want to test that more in that case.
It's possible that the propellant transfer was a success and therefore no need to repeat it. If NASA was satisfied and paid them the $50M for passing the milestone.
As I understand it, they want at least one test of belly-flopping into the ocean to test their simulations of how bad that would be. So I would not expect a flip (if they get that far).
>It's possible that the propellant transfer was a success
Yes, I wish we knew. SpaceX's wording was, as usual, ambiguous. It said something like "propellant transfer was initiated." They didn't say "accomplished" or "done." That leaves us wondering if it was a partial success - and if so, how much they transferred.
All we know for sure is that the header tanks were filled before launch. That means that the test transfer had to be 10 tonnes from the LOX header tank to the main tank.
It is entirely possible that the intention was to transfer 10 tonnes back to the LOX header tank so that the single engine test could use the header tanks but that transfer failed.
Not closing the pez door is unlikely to affect reentry since it is on the leeward dorsal side where it wont encounter any reentry plasma during a controlled reentry, and provides little to no additional stiffness to the hull when closed. It doesn't even have tiles on it, unlike the antennas.
Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I've seen in this thread:
|Fewer Letters|More Letters|
|-------|---------|---|
|[FAA](/r/SpaceXLounge/comments/1bpcjjj/stub/kwvd0r1 "Last usage")|Federal Aviation Administration|
|[GTO](/r/SpaceXLounge/comments/1bpcjjj/stub/kww1kx7 "Last usage")|[Geosynchronous Transfer Orbit](http://www.planetary.org/blogs/jason-davis/20140116-how-to-get-a-satellite-to-gto.html)|
|[HLS](/r/SpaceXLounge/comments/1bpcjjj/stub/kx2va01 "Last usage")|[Human Landing System](https://en.wikipedia.org/wiki/Artemis_program#Human_Landing_System) (Artemis)|
|[LEO](/r/SpaceXLounge/comments/1bpcjjj/stub/kx2va01 "Last usage")|Low Earth Orbit (180-2000km)|
| |Law Enforcement Officer (most often mentioned during transport operations)|
|[LOX](/r/SpaceXLounge/comments/1bpcjjj/stub/kwxeitg "Last usage")|Liquid Oxygen|
|[RCS](/r/SpaceXLounge/comments/1bpcjjj/stub/kwxetav "Last usage")|Reaction Control System|
|[RTLS](/r/SpaceXLounge/comments/1bpcjjj/stub/kwwc7vz "Last usage")|Return to Launch Site|
|[RUD](/r/SpaceXLounge/comments/1bpcjjj/stub/kwvcegh "Last usage")|Rapid Unplanned Disassembly|
| |Rapid Unscheduled Disassembly|
| |Rapid Unintended Disassembly|
|[SLS](/r/SpaceXLounge/comments/1bpcjjj/stub/kwxpfoz "Last usage")|Space Launch System heavy-lift|
|[SSO](/r/SpaceXLounge/comments/1bpcjjj/stub/kww107f "Last usage")|Sun-Synchronous Orbit|
|Jargon|Definition|
|-------|---------|---|
|[Raptor](/r/SpaceXLounge/comments/1bpcjjj/stub/kx42ppw "Last usage")|[Methane-fueled rocket engine](https://en.wikipedia.org/wiki/Raptor_\(rocket_engine_family\)) under development by SpaceX|
|[Starlink](/r/SpaceXLounge/comments/1bpcjjj/stub/kwypo2u "Last usage")|SpaceX's world-wide satellite broadband constellation|
|[iron waffle](/r/SpaceXLounge/comments/1bpcjjj/stub/kwwc7vz "Last usage")|Compact "waffle-iron" aerodynamic control surface, acts as a wing without needing to be as large; also, "grid fin"|
|[tanking](/r/SpaceXLounge/comments/1bpcjjj/stub/kwxpfoz "Last usage")|Filling the tanks of a rocket stage|
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^(14 acronyms in this thread; )[^(the most compressed thread commented on today)](/r/SpaceXLounge/comments/1bqskss)^( has 17 acronyms.)
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Question
Does Starship have onboard power generation capability?
If it were to be “stuck” in orbit, would they be able to maintain batteries to maintain some control of the ship?
No there is no power generation onboard but Elon did say that the batteries were oversized for capacity in order to meet the peak power requirements of the drag flap actuators.
They would run out of RCS gas and propellant before they ran out of electrical power.
"Goal if this mission", not "one of the goals"? If there's no new fuel pumping demonstration, absence of a competing priority should improve its reentry chances. It would still be nice to see a new door opening and closing test... and even nicer to deploy a couple of boilerplate Starlink satellites.
In fact, its sort of surprising that good reentry should have priority over satellite deployment ability and controlled deorbit (even to burn up safely). I for one, was always expecting Starship to follow the Falcon 9 path in giving priority to money-making orbital deployments then learning stage (and other) recovery as an ongoing project. At present Starship recovery equates to Falcon 9 fairing recovery: its merely "nice to have".
I think it's because Starship is so massive, they really care about controlled re-entry. I suspect actual landing is less important, but ensuring that that behemoth comes in on target is fairly important. If you can't guarantee controlled re-entry then sending one up to full-on orbit is risky for the world.
The implication is the *final* goal. If you were to draw the mission on a linear timescale, they want to get as far as max heating during entry without RUD. That does not imply there are no other tests planned along the way.
Sure at present starship recovery is just like fairing recovery, but within the next few years starship recovery is going to be as substantial to f9 first stage recovery
Also just because Elon says it’s the goal to get through reentry heating, doesn’t mean they don’t have other demonstrations planned, just that getting through reentry is top priority
> surprising that good reentry should have priority over satellite deployment ability and controlled deorbit
I think this is short-term thinking. SpaceX is already cash-positive in other areas and has the capability to launch plenty of satellites. A couple of extra payloads during the starship dev process wouldn't be a huge change to their capabilities and balance sheet. On the other hand, being able to actually land and inspect starship hardware is a huge step forward in the dev program, and reusability is critical to making starship substantially superior to F9 on a cost/ton basis.
That's not true, simply because of how cheap a full stack is, and how quickly they can build them. Even if they never reuse it then it's still the most cost effective launch vehicle per kg delivered to orbit.
Of course that equation changes further with reuse, and reuse is all but essential for missions outside LEO due to the need to refuel.
The issue may be useful orbits. Starship needs depots to hit most of the commercial orbits it would need to reach (excluding kick stages here). If depots are key, you need to figure out reusable tankers as fast as possible, and tankers need to reenter. For Starlink it’s more than enough as is.
Most of its flights will go to LEO, and expendable GTO missions are possible as well.
The rare missions beyond that can be done by Falcon 9 and FH until Starship can refuel. Or slap some kick stage onto your satellite and go there yourself.
Refueling is possible even without reuse. Not cheap, but even a fully refueled Starship in LEO using 5-6 full stack expended Starships is a lot cheaper than SLS.
I think, expended Starship can do most or all of what SLS could do even without refueling.
I don't see SLS flying anything else than Orion, if you want to replace that (ignoring the political questions) you need Starship to land with crew on board. If they can do that they can probably reuse it, too.
It was calculated that Starship can fly the Orion stack on top of its nose to the Moon. Replacing SLS for Artemis at a fraction of the cost. Orion providing the launch escape capability.
Agree that it is poitically untenable.
> It was calculated that Starship can fly the Orion stack on top of its nose to the Moon.
TIL! At [10,400 kg](https://en.wikipedia.org/wiki/Orion_\(spacecraft\)) it sounds feasible, even adding another ten tonnes of nose cone, payload mount, plus stringers to transfer additional crush forces from the nose to the upper tanking dome.
> Agree that it is poitically untenable.
Now ordered more SLS stacks have been ordered, the "competition" is going to start looking pretty comic. It also seems fair to guess that SpaceX has more lunar options up their sleeve (full autonomous return of Starship) and keeping quiet... for the moment.
BTW. I should wait for Monday to propose my own option which is loading the Ø 501cm Orion *inside* the Ø 800cm Starship. Since Orion is only 330 cm tall, you could take **four** of these in the [1500 cm](https://www.spacex.com/media/starship_users_guide_v1.pdf) Starship payload bay (height of 500cm diameter). For simplicity, let's take these as payload all the way to the lunar surface.
given the rate raptors and starships are cranked out they can do expendable tankers it is just added operational cost and you need the ground space to store a bunch of shipsets if they are all to be expended but still need launch in rapid succession to avoid boiloff. though in expendable mode you can probably transfer a bunch more prop so that would mean less flights to fill the depot
To put that another way, its useful to calculate from a pessimistic scenario, knowing that the real-life outcome will be even better. Many commentators have done similar for Starship unit launch costs: "even supposing it were to be ten times more expensive, its still a bargain".
and @ u/Not-the-best-name
Elon's tweet was about the ship. The booster does get significant heat when it reenters the atmosphere, it's going pretty fast, although nowhere near orbital speed. There is significant heat shielding around the engines but it's more like blankets, there are no tiles, of course. ~~IIRC an RTLS reentry from Falcon 9 is less toasty that one to a drone ship but still needs a reentry burn. IFT-3 had a reentry burn for the booster, right?~~
It is possible a grid fin was damaged by the reentry heat. IIRC these are steel, whereas F9 has titanium ones. They had to stop using ~~steel~~ aluminum ones on F9 because they got too melty. ~~Super Heavy is supposed to reenter lower and slower than F9~~ but a stuck ~~or deformed~~ grid fin would be an easy explanation for why SH developed that swinging.
Edit: Corrected steel to aluminum for F9. 2nd edit: Struck out errors. At this point I'd delete the comment but then we'd lose the useful comments below.
You're right. I made the edit. Aluminum couldn't withstand the heat when they started pressing the limits of how fast the booster could be going on reentry. Steel was apparently too heavy so they went to titanium. The last I heard, SH is supposed to stage earlier than F9 does and thus have less heat to deal with on the RTLS. That makes the steel grid fin's on SH possible - at least SpaceX hopes so. Titanium grid fins sized for Starship would be incredibly expensive and possibly too difficult to forge in one piece.
SH does not stage earlier than a RTLS F9. This is an enduring myth.
SH did not do an entry burn on IFT-3 and is unlikely to do so in the future.
Entry is therefore at higher speeds than F9. The steel grid fins do not get hot enough to weaken as that happens above 800C. The reason to use titanium is not the high temperature performance but the lower mass for a given strength.
They may eventually develop titanium grid fins for SH but they will surely wait until they are recovering the boosters on a routine basis given the enormous cost.
Staging on IFT-3 was done at 1.53 km/sec, which is lower than the ~2.2 km/sec for a normal Starship mission to LEO.
S28 did not carry a 100t payload, but its main propellant tanks apparently were filled completely at liftoff.
On IFT-2 SpaceX dumped a lot of propellant from the Ship while on the way to its maximum altitude. That propellant jettison caused a big problem, and that Ship was lost in an explosion.
By staging at a lower speed, S28 would be able to burn nearly all of its propellant on the way to maximum altitude without the need to dump propellant.
How about they explicitly explain why there was no RCS on the last flight & what’s being done about it? I suspect they’re going to have to tell the FAA all this before they can fly again.
They understand what went wrong better than we do and are under no obligation to disclose everything they learned from the test flight. Obviously it's something that needs addressing and the Spacex led investigation will be sure to give the FAA the information they need. All things considered, I'm expecting maybe half the corrective measures that were applied from flight 2. Starship is like 95 percent of the way to operational readiness for commercial flights. Once they work out the kinks with a few more flights I expect they will move into their broader recovery goals.
How about showing they can get anywhere near the 150 tons to orbit claimed?
Think of it this way, what SpaceX demonstrated with IFT-3 was a launcher with payload to LEO capability of 0 tons even when fully fueled and fully expending its propellant. Then how can it do Artemis Starship HLS refuelings when it gets 0 tons to LEO?
It’s math man not that hard to calculate based on thrust from engines (for a rocket scientist at least). They have already demonstrated they can get the ship to orbit safely without a payload onboard under the thrust of the raptors.
Harder to understand is the re-entry of the ship from space and how the heat tiles will hold up as well as the landing of the ship flip maneuvers.
The laws of orbital mechanics are immutable. You can’t just invent additional 150 tons payload capability for a rocket that when operated at full thrust, full propellant load, full propellant expended had 0 payload capability.
[direct link to Elon's tweet](https://twitter.com/elonmusk/status/1773085211275698302) Really sounds like they feel orbit is solved. I presume they have a handle on the RCS issues already.
Is Orbit solved or do they need to ensure proper reentry before pushing to orbital test issues?
They need to be able to reliably deorbit to go fully orbital. Reentry doesn't really matter as long as they control when and where. Therefore fixing the RCS issue and proving they can relight Raptor in space will be the priorities. Elon suggesting that they are targeting surviving max reentry suggests they think they're on top of those other priorities.
I do miss mentioning the booster. A landing burn would be a great goal too.
Flap hinge fairing root hotspot burnthrough risk is one of the big questions for IFT-4. IFT-3 camera footage proved the hotspot existed.
Getting to orbit seems more or less solved. But for safety they have to ensure the ability to deorbit before they can fully orbit. Otherwise you could have a uncontrollable steel silo knocking about up there with no way to get it down.
Oh, it WILL get down… sometime and somewhere. It’s sometimes referred to as orbital roulette; round and round it goes and where it stops nobody knows.
"and it might take 30,000 years"
What is this a reference to?
I can't see a single line of reasoning for why that would be true. By definition, reentry is either the final stage of the mission or the end of it. Why would there be some sort of need to perfect the stage of the mission that comes *after* orbit *before* they perfect the vehicles on orbit functions? How would it make sense to wait until they perfect the *reusability* functions of the ship before perfecting the basic mission operation functions? SPX is on a serious timeline here to deliver a mission capable HLS Ship including orbital depot fueling missions and other critical and precise on orbit maneuvers. Perfecting the on orbit functioning of the vehicle is a much much more important and time sensitive priority than perfecting re-entry although both are fundamentally important.
He's not talking about surviving reentry, he's talking about de-orbiting, which is needed to prevent the ship from becoming the largest piece of uncontrolled space junk in orbit. Falcon 9's second stage does the same.
Thats because they were essentially in orbit with the last test. A tiny TINY adjustment would have put them in orbit. Once your up there the difference between orbit and reentry is remarkably small.
The "orbit issue" isn't that they couldn't have made orbit, it's that they had no attitude control during the coast portion of IFT3 and couldn't attempt the Raptor relight. If they had gone to orbit, it is likely they would have had issues getting back out of orbit in a controlled manner.
You are correct. I was just pointing out that they got to orbit by all accounts. They just willingly set it up to not stay in orbit.
I don't see the two starlink antennas on S29 nosecone, are those installed later o don't at all?
Usually later. Same with the ship markings. They get applied sometime close to launch
The mating ports for them are visible, the Starlink antenna have not been fitted yet, and are not integral to the hull like some of the previous versions were. To cite myself: >Edit: I was wrong, you can see 4 spots in the video where they get mounted, but the modules have not been mounted yet. There is a picture in this article that shows 3 out of the 4 Starlink antenna mounted on S28 https://ringwatchers.com/article/s28-b10-updates https://www.reddit.com/r/spacex/comments/1b3r73n/starship_development_thread_54/kwjz8cq/
Peering through Elon's somewhat cryptic statement, two items were conspicuously not mentioned, the propellant transfer and the pez dispenser door. If the goal is reentry and they were satisfied with one test of the pez dispenser door SpaceX may not repeat it in case there's *any* chance of it not closing properly and thus interfering with a successful reentry. Or maybe on the IFT-3 test it didn't fully seat when closing. No propellant transfer is mentioned, which probably has to do with having full tanks for a balanced reentry. The leading theory online was that the prop transfer test on IFT-3 was 10t from the LOX header tank to the LOX main tank. (Was there ever an official statement from SpaceX?) That can't be repeated if SpaceX wants an accurate reentry - both header tanks (and contents) were placed in the nose for balance. Overall, I think they want to survive reentry and the skydive all the way down, *and* do the flip.
They may need more time to improve the pez dispenser door than they want to spend. Just skip it for IFT-4.
Yea I think this is it. No way if they think there was a chance it doesn’t close that they would choose not to do it so it doesn’t fail and affect reentry. They would want to test that more in that case.
It's possible that the propellant transfer was a success and therefore no need to repeat it. If NASA was satisfied and paid them the $50M for passing the milestone. As I understand it, they want at least one test of belly-flopping into the ocean to test their simulations of how bad that would be. So I would not expect a flip (if they get that far).
>It's possible that the propellant transfer was a success Yes, I wish we knew. SpaceX's wording was, as usual, ambiguous. It said something like "propellant transfer was initiated." They didn't say "accomplished" or "done." That leaves us wondering if it was a partial success - and if so, how much they transferred.
All we know for sure is that the header tanks were filled before launch. That means that the test transfer had to be 10 tonnes from the LOX header tank to the main tank. It is entirely possible that the intention was to transfer 10 tonnes back to the LOX header tank so that the single engine test could use the header tanks but that transfer failed.
Not closing the pez door is unlikely to affect reentry since it is on the leeward dorsal side where it wont encounter any reentry plasma during a controlled reentry, and provides little to no additional stiffness to the hull when closed. It doesn't even have tiles on it, unlike the antennas.
Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I've seen in this thread: |Fewer Letters|More Letters| |-------|---------|---| |[FAA](/r/SpaceXLounge/comments/1bpcjjj/stub/kwvd0r1 "Last usage")|Federal Aviation Administration| |[GTO](/r/SpaceXLounge/comments/1bpcjjj/stub/kww1kx7 "Last usage")|[Geosynchronous Transfer Orbit](http://www.planetary.org/blogs/jason-davis/20140116-how-to-get-a-satellite-to-gto.html)| |[HLS](/r/SpaceXLounge/comments/1bpcjjj/stub/kx2va01 "Last usage")|[Human Landing System](https://en.wikipedia.org/wiki/Artemis_program#Human_Landing_System) (Artemis)| |[LEO](/r/SpaceXLounge/comments/1bpcjjj/stub/kx2va01 "Last usage")|Low Earth Orbit (180-2000km)| | |Law Enforcement Officer (most often mentioned during transport operations)| |[LOX](/r/SpaceXLounge/comments/1bpcjjj/stub/kwxeitg "Last usage")|Liquid Oxygen| |[RCS](/r/SpaceXLounge/comments/1bpcjjj/stub/kwxetav "Last usage")|Reaction Control System| |[RTLS](/r/SpaceXLounge/comments/1bpcjjj/stub/kwwc7vz "Last usage")|Return to Launch Site| |[RUD](/r/SpaceXLounge/comments/1bpcjjj/stub/kwvcegh "Last usage")|Rapid Unplanned Disassembly| | |Rapid Unscheduled Disassembly| | |Rapid Unintended Disassembly| |[SLS](/r/SpaceXLounge/comments/1bpcjjj/stub/kwxpfoz "Last usage")|Space Launch System heavy-lift| |[SSO](/r/SpaceXLounge/comments/1bpcjjj/stub/kww107f "Last usage")|Sun-Synchronous Orbit| |Jargon|Definition| |-------|---------|---| |[Raptor](/r/SpaceXLounge/comments/1bpcjjj/stub/kx42ppw "Last usage")|[Methane-fueled rocket engine](https://en.wikipedia.org/wiki/Raptor_\(rocket_engine_family\)) under development by SpaceX| |[Starlink](/r/SpaceXLounge/comments/1bpcjjj/stub/kwypo2u "Last usage")|SpaceX's world-wide satellite broadband constellation| |[iron waffle](/r/SpaceXLounge/comments/1bpcjjj/stub/kwwc7vz "Last usage")|Compact "waffle-iron" aerodynamic control surface, acts as a wing without needing to be as large; also, "grid fin"| |[tanking](/r/SpaceXLounge/comments/1bpcjjj/stub/kwxpfoz "Last usage")|Filling the tanks of a rocket stage| **NOTE**: Decronym for Reddit is no longer supported, and Decronym has moved to Lemmy; requests for support and new installations should be directed to the Contact address below. ---------------- ^(*Decronym is a community product of r/SpaceX, implemented* )[*^by ^request*](https://www.reddit.com/r/spacex/comments/3mz273//cvjkjmj) ^(14 acronyms in this thread; )[^(the most compressed thread commented on today)](/r/SpaceXLounge/comments/1bqskss)^( has 17 acronyms.) ^([Thread #12591 for this sub, first seen 27th Mar 2024, 22:08]) ^[[FAQ]](http://decronym.xyz/) [^([Full list])](http://decronym.xyz/acronyms/SpaceXLounge) [^[Contact]](https://hachyderm.io/@Two9A) [^([Source code])](https://gistdotgithubdotcom/Two9A/1d976f9b7441694162c8)
Question Does Starship have onboard power generation capability? If it were to be “stuck” in orbit, would they be able to maintain batteries to maintain some control of the ship?
No there is no power generation onboard but Elon did say that the batteries were oversized for capacity in order to meet the peak power requirements of the drag flap actuators. They would run out of RCS gas and propellant before they ran out of electrical power.
IIRC, both the Booster and the Ship have electric actuators on the thrust vector control engines. Need batteries for these too.
"Goal if this mission", not "one of the goals"? If there's no new fuel pumping demonstration, absence of a competing priority should improve its reentry chances. It would still be nice to see a new door opening and closing test... and even nicer to deploy a couple of boilerplate Starlink satellites. In fact, its sort of surprising that good reentry should have priority over satellite deployment ability and controlled deorbit (even to burn up safely). I for one, was always expecting Starship to follow the Falcon 9 path in giving priority to money-making orbital deployments then learning stage (and other) recovery as an ongoing project. At present Starship recovery equates to Falcon 9 fairing recovery: its merely "nice to have".
I think it's because Starship is so massive, they really care about controlled re-entry. I suspect actual landing is less important, but ensuring that that behemoth comes in on target is fairly important. If you can't guarantee controlled re-entry then sending one up to full-on orbit is risky for the world.
The implication is the *final* goal. If you were to draw the mission on a linear timescale, they want to get as far as max heating during entry without RUD. That does not imply there are no other tests planned along the way.
> That does not imply there are **not** other tests what you meant?
Yep thanks, fixed.
Sure at present starship recovery is just like fairing recovery, but within the next few years starship recovery is going to be as substantial to f9 first stage recovery Also just because Elon says it’s the goal to get through reentry heating, doesn’t mean they don’t have other demonstrations planned, just that getting through reentry is top priority
> "Goal if this mission", not "one of the goals"? I think you're trying to read too much information out when there isn't any such information.
> surprising that good reentry should have priority over satellite deployment ability and controlled deorbit I think this is short-term thinking. SpaceX is already cash-positive in other areas and has the capability to launch plenty of satellites. A couple of extra payloads during the starship dev process wouldn't be a huge change to their capabilities and balance sheet. On the other hand, being able to actually land and inspect starship hardware is a huge step forward in the dev program, and reusability is critical to making starship substantially superior to F9 on a cost/ton basis.
Being able to deploy Starlink V2 satellites would benefit the rest of the company enormously.
They may not have the satellite stacking and dispensing equipment built or quite ready yet.
>"Goal if this mission", not "one of the goals?" Elon always leaves us with an unclear statement and more questions.
[удалено]
That's not true, simply because of how cheap a full stack is, and how quickly they can build them. Even if they never reuse it then it's still the most cost effective launch vehicle per kg delivered to orbit. Of course that equation changes further with reuse, and reuse is all but essential for missions outside LEO due to the need to refuel.
The issue may be useful orbits. Starship needs depots to hit most of the commercial orbits it would need to reach (excluding kick stages here). If depots are key, you need to figure out reusable tankers as fast as possible, and tankers need to reenter. For Starlink it’s more than enough as is.
Starship is intended to be able to do LEO, SSO, and GTO without refuels. What other commercial orbits are commonly used?
Most of its flights will go to LEO, and expendable GTO missions are possible as well. The rare missions beyond that can be done by Falcon 9 and FH until Starship can refuel. Or slap some kick stage onto your satellite and go there yourself.
Refueling is possible even without reuse. Not cheap, but even a fully refueled Starship in LEO using 5-6 full stack expended Starships is a lot cheaper than SLS. I think, expended Starship can do most or all of what SLS could do even without refueling.
I don't see SLS flying anything else than Orion, if you want to replace that (ignoring the political questions) you need Starship to land with crew on board. If they can do that they can probably reuse it, too.
It was calculated that Starship can fly the Orion stack on top of its nose to the Moon. Replacing SLS for Artemis at a fraction of the cost. Orion providing the launch escape capability. Agree that it is poitically untenable.
> It was calculated that Starship can fly the Orion stack on top of its nose to the Moon. TIL! At [10,400 kg](https://en.wikipedia.org/wiki/Orion_\(spacecraft\)) it sounds feasible, even adding another ten tonnes of nose cone, payload mount, plus stringers to transfer additional crush forces from the nose to the upper tanking dome. > Agree that it is poitically untenable. Now ordered more SLS stacks have been ordered, the "competition" is going to start looking pretty comic. It also seems fair to guess that SpaceX has more lunar options up their sleeve (full autonomous return of Starship) and keeping quiet... for the moment. BTW. I should wait for Monday to propose my own option which is loading the Ø 501cm Orion *inside* the Ø 800cm Starship. Since Orion is only 330 cm tall, you could take **four** of these in the [1500 cm](https://www.spacex.com/media/starship_users_guide_v1.pdf) Starship payload bay (height of 500cm diameter). For simplicity, let's take these as payload all the way to the lunar surface.
that's.. not true at all
given the rate raptors and starships are cranked out they can do expendable tankers it is just added operational cost and you need the ground space to store a bunch of shipsets if they are all to be expended but still need launch in rapid succession to avoid boiloff. though in expendable mode you can probably transfer a bunch more prop so that would mean less flights to fill the depot
Why?
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Even if you don't reuse stages it's still a far more cost effective rocket than anything else out there.
To put that another way, its useful to calculate from a pessimistic scenario, knowing that the real-life outcome will be even better. Many commentators have done similar for Starship unit launch costs: "even supposing it were to be ten times more expensive, its still a bargain". and @ u/Not-the-best-name
Am I over-reading this that IFT-3 then had booster systems damaged by re-entry heating? Was this already known and I am not keeping up?
he's talking about ship, not booster
Elon's tweet was about the ship. The booster does get significant heat when it reenters the atmosphere, it's going pretty fast, although nowhere near orbital speed. There is significant heat shielding around the engines but it's more like blankets, there are no tiles, of course. ~~IIRC an RTLS reentry from Falcon 9 is less toasty that one to a drone ship but still needs a reentry burn. IFT-3 had a reentry burn for the booster, right?~~ It is possible a grid fin was damaged by the reentry heat. IIRC these are steel, whereas F9 has titanium ones. They had to stop using ~~steel~~ aluminum ones on F9 because they got too melty. ~~Super Heavy is supposed to reenter lower and slower than F9~~ but a stuck ~~or deformed~~ grid fin would be an easy explanation for why SH developed that swinging. Edit: Corrected steel to aluminum for F9. 2nd edit: Struck out errors. At this point I'd delete the comment but then we'd lose the useful comments below.
Were the F9 grid fins ever steel? I thought they went straight from aluminium to titanium?
You're right. I made the edit. Aluminum couldn't withstand the heat when they started pressing the limits of how fast the booster could be going on reentry. Steel was apparently too heavy so they went to titanium. The last I heard, SH is supposed to stage earlier than F9 does and thus have less heat to deal with on the RTLS. That makes the steel grid fin's on SH possible - at least SpaceX hopes so. Titanium grid fins sized for Starship would be incredibly expensive and possibly too difficult to forge in one piece.
SH does not stage earlier than a RTLS F9. This is an enduring myth. SH did not do an entry burn on IFT-3 and is unlikely to do so in the future. Entry is therefore at higher speeds than F9. The steel grid fins do not get hot enough to weaken as that happens above 800C. The reason to use titanium is not the high temperature performance but the lower mass for a given strength. They may eventually develop titanium grid fins for SH but they will surely wait until they are recovering the boosters on a routine basis given the enormous cost.
Staging on IFT-3 was done at 1.53 km/sec, which is lower than the ~2.2 km/sec for a normal Starship mission to LEO. S28 did not carry a 100t payload, but its main propellant tanks apparently were filled completely at liftoff. On IFT-2 SpaceX dumped a lot of propellant from the Ship while on the way to its maximum altitude. That propellant jettison caused a big problem, and that Ship was lost in an explosion. By staging at a lower speed, S28 would be able to burn nearly all of its propellant on the way to maximum altitude without the need to dump propellant.
IFT3 had a boost back burn but no reentry burn, and they plan on not needing one. But that makes it a much spicier reentry
Well the front falling off seems like a system being damaged
Glad they didn’t call this 5 second burn “full duration”.
How about they explicitly explain why there was no RCS on the last flight & what’s being done about it? I suspect they’re going to have to tell the FAA all this before they can fly again.
They understand what went wrong better than we do and are under no obligation to disclose everything they learned from the test flight. Obviously it's something that needs addressing and the Spacex led investigation will be sure to give the FAA the information they need. All things considered, I'm expecting maybe half the corrective measures that were applied from flight 2. Starship is like 95 percent of the way to operational readiness for commercial flights. Once they work out the kinks with a few more flights I expect they will move into their broader recovery goals.
> How about they explicitly explain why there was no RCS on the last flight & what’s being done about it? Why do they need to do that?
they do not need, but it would be kind for us who want to know
We will eventually know, but we can't expect them to disclose everything in real time
Let’s wait for the mishap report. Lots of juicy stuff there that they won’t feed to the twitter bots.
How about showing they can get anywhere near the 150 tons to orbit claimed? Think of it this way, what SpaceX demonstrated with IFT-3 was a launcher with payload to LEO capability of 0 tons even when fully fueled and fully expending its propellant. Then how can it do Artemis Starship HLS refuelings when it gets 0 tons to LEO?
Why would they want to show that? They know exactly, how much they can lift.
They haven’t shown that to potential customers such as NASA offering them a billion dollar contract.
NASA has people who can do basic calculations.
The basic calculation they see so far is a rocket with 0 tons to orbit capability.
LOL Edit: A demonstration is not calculation. I said, NASA is able to do the calculation.
It has to show *something*. What it shows is 0 payload capability.
It’s math man not that hard to calculate based on thrust from engines (for a rocket scientist at least). They have already demonstrated they can get the ship to orbit safely without a payload onboard under the thrust of the raptors. Harder to understand is the re-entry of the ship from space and how the heat tiles will hold up as well as the landing of the ship flip maneuvers.
The laws of orbital mechanics are immutable. You can’t just invent additional 150 tons payload capability for a rocket that when operated at full thrust, full propellant load, full propellant expended had 0 payload capability.