Exoscientist

For my cost estimates I was taking cost reductions by a factor of 10 in both scenarios by reusability. If for Superheavy/Starship you take it to be a reduction by a factor 100 in cost by reusability then the same would be true for Starship/mini-Starship and costs would be ca. $1 million per launch, still much lower than a supposed $18 million for 18 launches with reusability of the full Superheavy/Starship. There really is no logical reason to use the multiple launch approach with 18 SuperHeavy/Starship launches to accomplish a single mission compared to a single launch approach of a rocket at only 1/3rd the size. It would be like the Apollo engineers running the numbers on the Saturn V and realizing it could do a Moon mission in a single launch, decided to do it instead with 50 launches of the Saturn V for that one single Moon mission. The argument of the greater payload of the multiple launch approach doesn’t hold water either. SpaceX said their multiple launch, multiple refueling approach can get 100 tons cargo to the lunar surface. The Starship/mini-Starship using an existing Falcon 9 upper stage or Centaur V upper stage as the lander can get 20+ tons cargo to the lunar surface. Then the equivalent of 50 launches of this launcher can actually get 1,000 tons to the lunar surface. Bob Clark

The renewed discussions on the possibility SLS might be cancelled have renewed discussion of replacement architectures for returning us to the Moon. I mentioned in the thread: that because of the low production cost of the Starship, SpaceX should investigate a smaller system with the Starship as the 1st stage and a "mini-starship" as an upper stage. A key cost fact is SpaceX amply demonstrated with the Falcon 9 that the first stage is much easier to reuse than the upper stage. Then I estimated a $11.7 million cost for such a Starship/mini-Starship launcher as partially reusable. I calculated the expendable version might have an LEO payload of 120 tons. Then based on the Falcon 9, if the Starship as 1st stage landed downrange this launcher might still get 80% payload of the expendable version. That would mean still 100 ton payload as partially reusable at a $11.7 million cost. That's a cost per kilo of ~$120 per kilo. That's nearly two orders of magntitude cheaper that the going rate just a few years ago, before SpaceX, of $10,000 per kilo. And even with the partially reusable Falcon 9, the price per kilo is still $3,000 per kilo. Quite importantly, because it doesn't need orbital TPS, orbital refueling, tank stretch or upgraded Raptors, this is a capability we have now. I argue that this is better than the current approach. For instance the fully reusable Superheavy/Starship V2 will have payload at 100+ tons, and still need all of orbit capable TPS, orbital refueling, tank stretch and upgraded raptors. And it will need all of these to get a ca. $10 million reusable launch cost. But the SS/mini-SS will reach the same payload capability, at only be 1/3rd the size of the SH/SS, without the difficult technical advances. The advantage of this approach extends also to lunar missions. SpaceX wants a multiple refueling approach of SH/SS for lunar missions. This will be in the range of 18 total flights with refuleings, the orbital depot, and the Starship HLS itself. In contrast the SS/mini-SS can do it in a single launch. And the current plan needing 18 launches will actually be 18*4 = 72 times bigger than using a single Starship. Taking into account the size also of the mini-Starship the current SH/SS lunar plan will be about 50 times the size of just a single SS/mini-SS. A comparison of the relatively sizes of the two approaches for getting to the Moon: Compared to: Bob Clark

The conclusion you could get a Saturn V-class launcher, i.e., 100+ ton payload to LEO, using the Starship as a 1st stage and a “mini-Starship” as an upper stage is based on this estimate Elon once made for an expendable Starship dry mass. But that is for an upper stage use where it did not have enough engines for liftoff from ground. Assume for 1st stage use it needs 9 engines. Increase the dry mass now to 50 tons for the greater engine mass. For the mini-Starship, an upper stage commonly is 1/3rd to 1/4th the size of the lower stage, so call it 420 tons propellant mass. As an upper stage it doesn’t need high engine thrust so assume same mass ratio of ~30 to 1 as for Elon’s expendable Starship estimate, giving it a dry mass of 14 tons. Take Starship exhaust velocity as ground launched as comparable to that of the Superheavy, 3,500 m/s. And take the upper stage’s vacuum exhaust velocity as 3,800 m/s. Then we could get ~120 tons to LEO: 3,500Ln(1 + 1,200/(50 + 434 + 120)) + 3,800Ln(1 + 420/(14 + 120)) = 9,200 m/s. In that last post I cited Zubrin’s comment that Elon’s says the Starship production cost could be brought down to ~$10 million. But that undoubtedly is for high production rates. But the current production cost for Superheavy/Starship is estimated to be ~$90 million, with about 30%, $27 million, for Starship: STARSHIP COST ANALYSIS OVERVIEW Note: This is Payload's current estimate and not based on access to any internal Space data or proprietary information. Current Estimated Starship & Booster Full Stack Cost (S in thousands) 39 Raptor Engines 39,000 Labor. 35,000 Structure, plumbing, tiles, parts 13,000 Avionics 3.000 Total 90,000 *Payload costs estimates are based on a post-R&D 1-2 year forward-looking model. This is an educated best estimate and not based on Space internal data. Further cost reductions are expected in the long-run. $90M cost: Payload estimates it costs $90M to manufacture a fully integrated Starship based on a post-R&D/test production phase near-term model. The go-forward cost does not factor in the near $5B SpaceX has spent on R&D to date. ~70% of costs accrue to Super Heavy and ~30% to Starship upper stage. Future Starship (upper stage) cost reductions: As Starfactory comes online and Raptor production is refined, Space aims to reduce costs even further. A focus on Starship's upper stage: When SpaceX achieves full reusability, production of Starship second stage vehicles will be an order of magnitude higher than booster production. • The company plans to eventually build multiple second stage Starships per week and reduce Raptor engine's production cost to $250K a pop. If successful, the long-term cost to mass produce second-stage Starships could drop to $10M to $15M a vehicle. However, for purposes of this report, we will analyze costs as they are today. Raptor 2 engines ($39M) Payload estimates each Raptor 2 engine costs ~$1M to build. The 39 engines-which include three additional upper-stage engines that will be added in the future-are by far the biggest Starship cost, adding $39M to total cost. SIM per Raptor 2 engine is half as expensive as its $2M+ Raptor 1 predecessor. 20 SpaceX hopes to eventually bring the cost per engine down to ~$250K. Payload Research 18. Elon Musk on X 19. Space 20.Elon Musk on X 21. Elon Musk on X https://docsend.com/view/fi9wuazzeex57iig Say, for a mini-Starship upper stage its cost would be a 3rd of the $27 million production cost of the Starship, so $9 million. So the full vehicle production cost at $36 million. So a Saturn V-class launcher capable of 100+ tons to LEO at ca. $36 million. Note also SpaceX demonstrated with the Falcon 9 landing just the first stage, i.e., partial reusability, much easier than full reusability. Then this Starship now as first stage could be reused cutting its cost to, say, $2.7 million per launch, for the total partial reuse cost of $11.7 million per launch. This is a Saturn V-class vehicle capable of single launch Mars or Moon missions we could launch now. No thermal tile problems, or needing to master orbital refueling, or stretching tanks, or increasing Raptor thrust. We have this capability now. Bob Clark

How are you getting twitter links to embed? Bob Clark

Nice calculation. I’d like to get some feedback on these estimates I made after I heard Robert Zubrin say Elon told him the Starship, i.e., the upper stage only, could be made for ~$10 million production cost: https://twitter.com/spacewatchgl/status/1855925836932841756 I was surprised that Elon estimates a Starship only cost of ~$10 million. At a ~$10 million Starship cost, SpaceX should investigate it as 1st stage of a smaller system, with a mini-Starship as the 2nd stage at perhaps only ~$2 million additional cost, due to its proportionally smaller size. Get ~100 ton to LEO Saturn V-class launcher at only ~$12 million cost(!) As the first stage now, Starship loses only a proportionally small payload by reusing if you land it down range. Then close to a 100 ton partially reusable launcher for only ~$3 million(!) Say, payload reduced to 80 tons with partial reusability. Then price per kilo only $3 million/80,000kg = $37.5 per kilo(!) Bob Clark

I haven’t seen the discussion on the best payload bay doors to use. Is there some reason why the SpaceX “clamshell” version is non-optimal: https://i.sstatic.net/D3MYv.png Bob Clark

I don’t agree with that. Note that SpaceX also wants to use his idea of using ISRU on Mars to generate the propellant for the return trip. Zubrin is just using standard spaceflight engineering practice that for high delta- v missions like to the Moon or Mars you use progressively smaller additional stages. Instead of using additional stages, SpaceX wants to use that same single large size Starship to go all the way to the Moon or Mars. This requires multiple refuelings. Plus, because of its large amount of propellant the ISRU requirements on Mars become large also. Zubrin estimates 10 football fields worth of solar cells for the power to run the ISRU. Bob Clark

The glowing base on the booster during reentry prior to the landing burn has been described as reentry heating. But closer examination suggests fire in the engine compartment: https://youtube.com/clip/UgkxfnFwF67GBwv4ItsloQPyL-XOTQSYz723?si=iOlffJRajEGCMDE8 This may have been due to the leaks that have been a recurring problem for the Raptor. Bob Clark

Commercial Starship Super Heavy booster came within one second of aborting first “catch” landing. Jeff Foust October 25, 2024 https://spacenews.com/starship-super-heavy-booster-came-within-one-second-of-aborting-first-catch-landing/ This illuminates why I argue it’s likely SpaceX will ultimately decide to go with landing legs and landing on a landing pad anyway. Landing legs can be optimally designed to be lightweight to add only a small amount to the dry mass. Then it won’t be worth risking a launch tower worth hundreds of millions of dollars for such a small loss in payload. The loss of revenue from missed launches of the operational Starship over the months when the tower is being rebuilt can amount to billions in lost revenue. Also it’s mentioned there wasn’t the expected amount of pressure in the Raptor. This could have been due to a fuel leak. Fuel leaks and the resulting fires have been a recurring problem with the Raptor: What Happened to Starship SN11? | SpaceX Starship SN11 Test Flight & Explosion Cause Analysis. https://youtube.com/clip/UgkxziHi2GsiVoF9v_DAa1YYQuU6fDskrWQU?si=qx0I7p_ussOY9bhT Then the giant plume of flame seen shooting up the side of the booster may in fact have been due to a fuel leak. Additionally, its mentioned one of the chine covers blew off exposing valves that are sources of single-point failure if they had been damaged. Notably the landing video shows the cover blew off before the engine restart began. It was speculated it was due to atmospheric forces, but it may have been due to a fire within the engine compartment releasing pressurized gas. Bob Clark

Could you give the time according to the launch time? It only went 1 hour 6 minutes from launch to Starship splashdown. Bob Clark

There was a notable fuel leak and flame on the outside of the booster during the landing burn. Perhaps this leak also extended into the engine bay? Bob Clark

The estimated cost of the Artemis landing missions will be in the range of $8 billion per mission. This is an unsustainable cost. However, there is an approach to returning to the Moon that would only be ca. $100 million(!) per mission, comparable to the cost NASA is spending just getting to the ISS. This is to use the Starship in expendable mode. According to SpaceX it would have a payload capacity of ca. 250 tons to LEO. Moreover, it could be done literally tomorrow. Just strip off the reusability systems to get the full 250 ton to LEO capability and put an existing smaller stage such as the Falcon 9 upper stage atop it to act as a 3rd stage/lander. However, NASA and SpaceX are too wedded to their SLS and multiple Starship refueling approach. But recall the beginning of the U.S. space program in the late 50’s when our rockets kept failing, while the Soviet Union’s kept succeeding, made famous in the book and movie the Right Stuff. We weren’t able to finally succeed until we gave it over to the military to manage. In view of the strategic importance of returning to the Moon, the DoD might want to pay for this low cost, independent approach to returning to the Moon that has the distinct advantage of allowing a sustainable lunar presence and at high flight cadence. Should the DoD be involved in returning us to the Moon? https://exoscientist.blogspot.com/2024/10/should-dod-be-involved-in-returning-us.html Bob Clark

What would be even better is a test fire with three burns each at the full length of an actual reusability burn and at the actual wait times in flight between restarts. Scott Manley does not believe Raptor reusability has been proven: https://youtube.com/clip/UgkxY0chim5r54_TVXenspfEUN1b7VqiuxNC?si=MpWfWi2GyEUZU-23 Bob Clark

Robert Zubrin has argued numerous times that the multiple refueling approach is a poor approach to lunar or Mars missions: If you give it a small 3rd/lander stage you can do the missions with no refueling flights required at all Robert Clark It’s an unwritten rule at the FAA if a company does not want to reveal proprietary formation, then the FAA won’t reveal it either. SpaceX has yet to admit a Raptor exploded during the last landing burn, nor that the booster exploded shortly after ocean touchdown. If SpaceX won’t reveal it, the FAA won’t either. Robert Clark

Expendable, Starship can do 250 tons to LEO: Elon has made news by stating Starship can make unscrewed flights to Mars in 2 years and crewed flights in 4 years. But just stripping off the reusability systems the Starship would have a 200 to 250 ton payload capability and could do single launch flights to Mars now. Bob Clark

Contrary to the criticism that the FAA is singling out SpaceX, they are actually protecting SpaceX.  From the FAA: SpaceX's current license authorizing the Starship Flight 4 launch also allows for multiple flights of the same vehicle configuration and mission profile. SpaceX chose to modify both for its proposed Starship Flight 5 launch, which triggered a more in-depth review," agency officials wrote. "In addition, SpaceX submitted new information in mid-August detailing how the environmental impact of Flight 5 will cover a larger area than previously reviewed," they added. "This requires the FAA to consult with other agencies." Note mention of a change in “mission profile”. The change to a landing on land compared to an ocean landing is a quite significant change in mission profile. For a landing on land you have to give extra scrutiny to the possibility of an explosion. Angry Astronaut discusses this in his video: FAA releases vital information about SpaceX Starship! https://youtube.com/clip/UgkxzdNH9SHX1vbzntoM31LLNxOr_FO3oUS8?si=tgQ9IDcsQY8k6Ejx The FAA has two sometimes opposing interests. One, they want to preserve public safety, but they also don’t want to reveal proprietary information from a company. Note though proprietary information can be information beneficial to a company. But it can also be information detrimental to the company. It’s fairly evident a Raptor exploded during the landing burn. But SpaceX does not want to discuss this publicly. Also most people are aware of the fact the Super Heavy exploded after ocean touch down. SpaceX also has not wanted to discuss this publicly. But the possibility of an explosion during a landing catch has to be given serious consideration by the FAA. However, because SpaceX has not wanted to discuss publicly the fact the booster exploded after touchdown the FAA can’t reveal this either. Bob Clark

A great influence in developing funding and support for space among the public is psychological: Scenario 1.): Public: When can we have continually inhabited stations on the Moon? Answer: maybe we can send the first landing mission in 2029. But it’ll cost perhaps $8 billion per mission amortized over total program cost like Apollo did, in current dollars, and wind up being cancelled like Apollo was. Public: When can we send manned missions to Mars? Answer: maybe by the 2030’s. Scenario 2.): Public: When can we have a continually inhabited stations on the Moon? Answer: we can launch a manned mission tomorrow. They’ll cost in the range of $100 million per flight, comparable to flights to the ISS. So we can have continually inhabited stations on the Moon tomorrow. Public: When can we send manned missions to Mars? Answer: we can launch manned missions tomorrow. They’ll cost in the range of $100 million per flight, comparable to flights to the ISS. So we can launch them, in fact several of them, every two year launch window. Robert Clark

AUGUST 26, 2024 China proposes magnetic launch system for sending resources back to Earth by Matt Williams, Universe Today https://phys.org/news/2024-08-china-magnetic-resources-earth.html The problem is even if publicly it is described as merely a transport method from the Moon to the Earth, any other country has to regard it as potentially an indefensible weapon because due to the long distance from the Moon to the Earth even a deviation in pointing of a fraction of a degree could result in its landing point instead of being over the ocean winds up being over a city. By the way, I like the mention in this article of the Robert Heinlein novel, The Moon Is A Harsh Mistress, which first described the idea of projectiles being shot from the Moon to the Earth as a weapon. Bob Clark

Is China planning to weaponize the Moon? https://youtu.be/eElDqTNe4oE?si=hv8Y3tgo9gBDfbF_ China wants to build a 1 megawatt nuclear reactor on the Moon, 10 times the size the U.S. is planning on. Why? Evidence suggests it’s for their electromagnetic launcher they want to use for sending resources from the Moon to Earth. This is analogous to the SpinLaunch™ being constructed on Earth for reducing the cost to LEO. But on the Moon with no atmosphere and much reduced gravity it can send the payload all the way to lunar orbit and even all the way to Earth. Being just electrically powered the launches will be at just the cost of generating the electricity. But it needs to be kept in mind it could send anything, anywhere on the surface of Earth. When you realize the Chinese space program is just an off-shoot of their military the possibility arises it could be used as a weapon. “Mr. President, we must not ALLOW a spin launch gap!” (With apologies to “Dr. Strangelove”.) Bob Clark

The capabilities of the expendable Superheavy/Starship are spectacular, 200 to 250 tons to LEO now. What’s even more astonishing is the cost is only in the $100 million range. This means we can send a manned-capable Mars mission not in the 2030’s but literally in just a few days with the IFT-5 stripped of its reusability systems to get that max payload with an F9 upper stage strapped atop it, and for costs for what we spend to send astronauts just to the ISS. The dream of manned flights to Mars is already here. All that is required is to recognize it. Bob Clark

Robert Zubrin has noted that the SuperHeavy/Starship can do Moon and Mars missions with no refueling flights nor SLS required if given a smaller 3rd stage that would actually serve as the lander, a mini-Starship if you will: Dr. Robert Zubrin - Mars Direct 2.0 - ISDC 2019. https://youtu.be/9xN1rqhRSTE?si=8unKEkYOxl4gQT0i Then it is important to keep in mind SpaceX has an existing stage that can serve for the purpose in the fully man-rated Falcon 9 upper stage. But you need the higher payload capacity of the expendable SH/SS at ca. 200 to 250 tons to be able to do it in a single launch. This is quite remarkable when you consider Elon has said the launch of the SH/SS only costs ca. $100 million. Then the implication is if the upcoming IFT-5 in a few more days were stripped of reusability systems so that it’s payload capacity was 200 to 250 tons, then that launch itself with a Falcon 9 upper stage as a Earth departure stage/lander could do a demonstration mission for single launch missions to the Moon or to Mars. We could have Moon or Mars flights now at costs we are spending for flights to the ISS. Robert Clark

Ok I’ll take all look at the original reporting. Bob Clark

Actually, they can’t know that because the astronauts are not actually in the capsule. They are on the ISS hearing the sounds through speakers on the capsule. Then the speakers can be picking up sounds actually in the capsule. Bob Clark

Not likely. Probably the same as what happened on the first Chinese manned spaceflight in 2003: Who or What Is Knocking On His Spacecraft? | NASA’s Unexplained Files. https://youtu.be/ioJsRQ53IEM?si=xc4Arfx6ZadjG7lg It’s believed to be differential expansion due to thermal differences. Bob Clark

The sh*t just got real: according to OIG, Artemis IV, the first landing mission, can’t happen until 2029 because that’s how long it’ll take to get the needed ML-2 ready: https://youtu.be/-i0EH1ibCVg?si=NllGFepDET88aIBv But China plans to land men on the Moon BEFORE 2030: China plans to put astronauts on the moon before 2030 News By Sharmila Kuthunur published May 31, 2023 https://www.space.com/china-moon-landing-before-2030 Then China beating us back to the Moon is not just a theoretical possibility. It is now a REAL possibility. Bob Clark