Exoscientist

Thanks for that. I was wondering if any of the splashdown areas would be observable from satellite imaging. Planet Labs claims to provide continuous, world wide imaging at 3.7 meter resolution, but I found their coverage quite spotty. I couldn’t find images of the expected landing areas. Perhaps someone would be able to find it. Real-Time Satellite Monitoring with Planet. With roughly 200 Dove satellites in orbit, PlanetScope Monitoring provides a high-resolution, continuous, and complete view of the world from above, every day. https://www.planet.com/products/monitoring/ Bob Clark

The Raptor had consistent problems of leaking fuel and catching fire on relights on prior tests of the Starship landing procedure: Even on the SN15 test that SpaceX called a “success” because it landed without exploding, a fire had developed in a Raptor before it touched down. SpaceX was just able to extinguish the fire before it exploded. My opinion, it was mistake for SpaceX to stop these Starship landing tests because SN15 landed without exploding first. The tests should have continued until all Raptors were able to do all the relights needed with no engines catching on fire. That is a necessary requirement for a reliable, reusable engine. And on IFT-3 and just now on IFT-4 a Raptor exploded on relight during the landing burn. SpaceX would do well to remember the famous warning of Richard Feynman after the Challenger disaster, “For a successful technology, reality must take precedence over public relations, for Nature cannot be fooled." Bob Clark

There still is the issue the engine lit indicators on the SpaceX video stream did not light up for the ship landing burn. Note that for both this flight and previous flight they did correctly light up for landing burns. EDIT: the engine lit indicators worked correctly both times showing which engines fired during the landing burn for the booster. Bob Clark

I was watching a stream without the SpaceX commentary. Was there a call out that at a certain time during reentry there was supposed to be an engine firing to slow down the ship? Obviously, the degree of damage to one of the flaps during reentry was not normal, which suggests there should have been a burn then. There is uncertainty if there was a landing burn for the ship just before touchdown. The graphic at the bottom right showing which engines are lit did not come on. On the other hand the ship did reorient itself just before landing. It is possible the RCS and the flap control surfaces are sufficient to reorient the ship when tanks are near empty. A major irritation of mine is SpaceX is continuing to promote the idea the Raptor is already at sufficient reliability level for an engine intended to carry crew. The reality is it is nowhere near that level which should be 99.9+% Bob Clark

Is it possible the high temperature alloys used for the engine combustion are being confused with the metals used for the tanks? Bob Clark

Good that both booster and ship managed to reach the surface albeit clearly in a damaged form. But I repeat my earlier complaints, the Raptor is nowhere near the reliability level needed for a reusable engine. The Falcon 9 was spectacularly successful by first going for an expendable launcher. Then, progressing towards reusability. If SpaceX had taken that approach with the Starship, they would already be making operational launches, and making a profit on those launches. And it could be making single launch flights to both the Moon and Mars now. No refueling flights or even SLS required. Also, by now both SpaceX and the FAA must acknowledged there is a problem with the Raptor reliability. No mishap reports required my rear end! Robert Clark

FAA grants Starship launch license with wide latitude: https://twitter.com/marcushouse/status/1798136232402370622 Nice cover by SpaceX beforehand asking the FAA not to require a mishap report if any of these cited failings occur. SpaceX can then continue to point the finger away from the Raptor as the cause. A question: shouldn’t SpaceX be required to answer questions honestly to the FAA, the agency responsible for launch safety? Then here is a majorly important question that SpaceX needs to answer to the FAA, and the FAA as a public agency should be expected to ask: Was the apparent fuel venting seen for *both* the booster and ship after their burns actual fuel leaks? If so, that suggests the problem is with the Raptor itself: https://x.com/djsnm/status/1768268571531235669?s=61 https://x.com/nricolas360/status/1785764709313946057?s=61 https://x.com/goingballistic5/status/1769401675687579764?s=61 It is notable as well in the recent Raptor test stand explosion that there was a fuel leak first, then the RUD occurred. This goes directly to the question of whether the Raptor has the tendency to undergo fuel leaks, further justifying the necessity of asking the question if there were fuel leaks after both stage’s burns. Bob Clark

I can see your posts. Bob Clark

IF the fuel venting seen for both the booster and ship after their burns was real that suggests the problem is with the Raptor itself. It is also notable that in the recent test stand explosion there was a fuel leak after the engine start, the engine was shutdown, and then the RUD occurred. Then this is a highly important question for SpaceX to answer, and for the FAA to ask about, if whether the fuel or LOX venting seen on both stages after their burns was real or not. Bob Clark

Just released video by “Angry Astronaut”: SpaceX asks the FAA to bend the rules and return Starship to flight NOW! PLUS RFA ONE static fire!! https://www.youtube.com/watch?v=nG8T2HUe-Lo Points out the point I’ve been making. The reason SpaceX still has not released a mishap report is they do not want to acknowledge the reason the booster failed on landing is the Raptor still has the problem observed previously of leaking fuel on relights: Starship SN8 SN9 SN10 SN11 SN15 High Altitude Flight test synced. https://m.youtube.com/watch?v=Ww83pSeuGuA But I don’t agree with “Angry Astronaut” in his video where he says, IFT-3 offered no danger to the public so Starship can be recertified by the FAA to fly without a mishap report. The booster landed far outside the expected landing zone, probably because of flaws in the Raptor firing during the boostback burn. It should have landed 30 km off shore, but actually landed ca. 100 km off shore: Starship Booster 10 Descent Simulation. https://m.youtube.com/watch?v=O6a10KbkGro It could have been a danger to fishing or shipping in the area where it landed unexpectedly. Bob Clark

The concept Artemis is cheaper than Apollo was in response to this video: NO WAY we’re landing on the moon in 2026. https://youtu.be/pQufaHiAark?si=gYJKXgzQf-hjkuiv About at the 5:25 point is mentioned a NASA lunar lander might normally be developed for $10 to $20 billion. And in this link about the cost of Apollo, the total costs of the Apollo lunar lander over the entire Apollo program adjusted to 2020 dollars did indeed cost ca. $20 billion: https://www.planetary.org/space-policy/cost-of-apollo For the seven Apollo lander missions that’s in effect ca. $3 billion per mission. The contract NASA gave SpaceX for the Starship HLS totals about $4 billion for two lander missions, or $2 billion per mission. That’s not a terribly great saving over what we did during Apollo. Even worse, that’s the same as the cost for the entire SLS rocket, with the two SRB’s, the core stage with the four over-priced reincarnations of the SSME’s, and interim upper stage. But the key point I’m making is considering how much the space program in general has developed world-wide now, with a wide variety of launchers, in-space stages, and spacecraft, we can use essentially off-the-shelf components to construct a lunar lander. And as SpaceX has shown costs are cut drastically if the spacecraft is privately funded. So don’t construct the lander from scratch, which as experienced space observers we know makes costs balloon greatly, and don’t use the typical government financed approach, which we also know make costs balloon greatly, instead use already existing and operationally in use components and use private funding to construct it. In this, way the lander might only cost in the tens of millions range, instead of billions. Dave Masten gave another interview where he discussed his Centaur-derived lunar lander: Spacevidcast Live - What if Apollo never happened? https://youtu.be/oQ4lLTblx5M About 30 minutes in, he suggests its costs would be ca. $50 million to purchase the Centaur, and only a few more million to add on Masten’s side thrusters for horizontal landing. Plus, some millions more for testing. The host suggests under $200 million total, and Masten responds, “Oh, easily.” Bob Clark

The concept of Artemis being “better” than Apollo based on cost grounds comes from this assessment of Apollo’s costs in inflation-adjusted dollars: How much did the Apollo program cost? The United States spent $25.8 billion on Project Apollo between 1960 and 1973, or approximately $257 billion when adjusted for inflation to 2020 dollars. Adding Project Gemini and the robotic lunar program, both of which enabled Apollo, the U.S. spent a total of $28 billion ($280 billion adjusted). Spending peaked in 1966, three years before the first Moon landing. The total amount spent on NASA during this period was $49.4 billion ($482 billion adjusted). https://www.planetary.org/space-policy/cost-of-apollo The max expenditure in a single year was ca. $45 billion in 2020 dollars. And the total cost of the lunar lander alone was ca. $20 billion in 2020 dollars. The total cost of Artemis so far is ca. $50 billion: The Cost of SLS and Orion From its inception in 2011 through the year of its first flight, the Space Launch System rocket program has cost $23.8 billion. The Orion deep space capsule has cost $20.4 billion since the program began in 2006. Related ground infrastructure upgrades cost an additional $5.7 billion since 2012. In total, NASA spent $49.9 billion on these programs between 2006 and their first test launch in 2022. https://www.planetary.org/space-policy/cost-of-sls-and-orion But how much cheaper Artemis is than Apollo exemplifies another key advantage we have now over Apollo that we must make use of: the plentiful commercial launchers, in-space stages, and spacecraft already operational and in regular use. Then USE that advantage. Construct your lander, small like Apollo’s, from EXISTING components, not developing the lander from scratch. Knowledgeable observers of the space program are aware of the fact development costs for entirely new systems from scratch incur ballooning costs. There are multiple ways of following this approach. Here’s one: Possibilities for a single launch architecture of the Artemis missions, Page 3: Saving the lander mission for Artemis III. https://exoscientist.blogspot.com/2023/08/possibilities-for-single-launch_11.html Bob Clark

This can’t be correct for a minimal lander to and from low lunar orbit since we know Apollo LEM was able to do it at ca. 15 tons gross mass. Bob Clark

The right size for an Artemis lander(the one on the right.) (Image credit Ken Kirtland.) Bob Clark

I agree with you contracting Boeing or Lockheed to do it they would figure out a way to charge NASA a billion+ dollars for it. (See my sig file.) But I think Masten was thinking of using the stage and modifying it by his company to do it, at the millions of dollars range instead of billions of dollars range. The key point is getting a company to develop the lander privately funded. That is how SpaceX was able to effect development cost cuts in the range of 90%(!) off the usual government funded costs on the Falcon 9. Bob Clark

Dave Masten of Masten Space Systems in a SpaceVidcast video discussed adapting a Centaur upper stage to serve as a lunar lander. In the video he estimates it to cost in the range of only $50 million(!) The discussion on the lunar lander takes place about 15 minutes into the one hour video. Masten also mentions this modified Centaur could transport 6 metric tons between a Lagrange point, L1 or L2, and the lunar surface. Such a lander could also be used between low lunar orbit and the lunar surface, as for a manned mission from Earth. If true, then it is unconscionable that NASA claims a return to the Moon can’t be done because a lander would cost ca. $10 billion, when it can actually be done two orders of magnitude more cheaply than that. In any case NASA needs to do a study to see if this conversion of a Centaur to a lander can actually be done so cheaply. Bob Clark Edit: that is that’s what NASA was saying back in 2012 when Masten made this video. Remember that statement made by former NASA administrator Charles Bolden that, “We won’t return to the Moon in my lifetime.”

The major problem with NASA implementing Artemis to land on the Moon can be summed up in one sentence: they are still thinking of Artemis as like the Constellation program being “Apollo on steroids”. No, Constellation was much larger with a much larger launcher in the Ares V with plus an additional, separate launcher in the Ares I to get Orion to orbit. No, the correct way of thinking of Artemis is as comparable to Apollo in the sense of the size of its payload capacity and the fact the SLS also has to be used to get the Orion capsule to orbit. And actually on cost grounds you can consider it “better” than Apollo since it is CHEAPER than Apollo since in inflation adjusted dollars it’s about a quarter the program cost. So, the problem is that in still thinking in “Apollo on Steroid” terms, the idea is retained the lander has to be these humongous landers like the Starship HLS or even the over-large Blue Origin lander. No, just think of the lander as being Apollo size, at ca. 13 ton gross mass of the Apollo LEM. Then the lander doesn’t have to be some $10 to $20 billion development cost. It can be done for just a few hundred million dollars because the needed propulsive stage(s) and crew capsule already exist. You just have to ask our European partners for those components that already exist and are in operational status. But the desire is to get Artemis to serve as the launcher for a continually occupied Moon base, a la how the ISS is for LEO. This is actually another sense of how Artemis, or more accurately the current space program in general, is “better” than Apollo. Back in the Apollo era NASA had to develop all the various launchers and stages and spacecraft from scratch, at great expense. But now, don’t think of the SLS or any of the over-large proposed landers to carry cargo to the Moon. Think of any of the several commercial orbital launchers for the purpose. The surprising conclusion you draw is that instead of using the $2 billion per launch SLS for cargo delivery at, at best, a once per year cadence, you can launch cargo to the Moon for costs at about the same as what we spend now to send cargo to the ISS, in the $100 million per launch range and on a weekly basis, by using commercial launchers and small, already existing stages as the landers. See: Possibilities for a single launch architecture of the Artemis missions. https://exoscientist.blogspot.com/2022/10/possibilities-for-single-launch.html Bob Clark

Former Air Force officer Livingston Holder is the chief technology officer and co-founder of Radian Aerospace. He gave a lecture on the design of their spaceplane here: Livingston Holder, Radian Aerospace - It’s Good to Know How Things Work | Iteration22 https://m.youtube.com/watch?v=exeZnrQt8YE I enjoyed the lecture. He discusses why their sled-launched spaceplane is technically and financially feasible. However, the horizontal launch method they propose has the disadvantage of needing heavy wings to support the fully-fueled weight of the spaceplane. In contrast a vertical launch method would use wings that only had to support the dry mass of the craft on return, resulting in much lighter wing weight. I advise Radian to do the trades to find which is the optimal method. Additionally, I advise they base the core of their vehicle on existing upper stages to save on development costs and technical risk. I discuss using the Falcon 9 upper stage or Centaur upper stage for the purpose here: Radian Aerospace Spaceplane. https://exoscientist.blogspot.com/2024/05/radian-aerospace-spaceplane.html Robert Clark

The “chopstick catch” was proposed by the same guy who proposed the stage separation technique of flinging out the second stage. More evidence than ever SpaceX needs a true Chief Engineer. Robert Clark

I am arguing that NASA was blindsided by the low 40 to 50 ton capability of the current version of the SuperHeavy/Starship. A couple of reasons why I say this. First, while Elon was extolling the “success” of the latest test flight in his recent update at Starbase on the Starship development, NASA soon after wards started making plans for use Starship in Artemis III that won’t use the Starship as a lander. (NASA did not openly reveal this; it had to be leaked.) Note also the proposed options NASA is considering also would not use refueling of the Starship. The low 40 to 50 tons to orbit would cause impractically large number of refueling missions. Then V2 or even V3 would be needed for this and I’m suggesting NASA believes neither of those would be ready by Artemis III. Note the SpaceX plan for a lander using multiple refuelings absolutely can not work if the Raptor can not operate reliably for both boostback and landing burns. Relighting, apparently, successfully at boostback is not sufficient if a Raptor explosion on landing causes vehicle RUD. So I’m also arguing NASA has no confidence SpaceX can solve the relighting reliability issue, that requires three Raptor firings per flight both for the booster and ship, by Artemis III. Beyond that, another key reason why I say NASA was blind-sided by the low payload capability of the current version is if you run the numbers SpaceX cited for the specifications on the current version, it should easily make 100+ tons to orbit even as a reusable. That it makes at best half that suggests the dry mass or Raptor values or more likely both are significantly worse than the values cited by SpaceX. Bob Clark

NASA is now opening up the Mars Sample Return mission to the commercial space approach. The usual NASA government financed approach is estimated to cost ~$10 Billion. But following the commercial space approach it probably could be done at literally 1/100th that at ~$100 million including launch cost. I had estimated it as less than ~$200 million using the Falcon Heavy as launcher: Low cost commercial Mars Sample Return.
 http://exoscientist.blogspot.com/2023/07/low-cost-commercial-mars-sample-return.html This could get ~750 kg back from Mars with the Falcon Heavy as the launcher. However, it probably could in fact be launched on the Falcon 9. The Falcon 9 can launch about a quarter of the mass of the Falcon Heavy to Mars, for all the in-space stages, so estimate the sample size returned from Mars of ca. 180kg. At a $40 million launch cost of the reused F9, then all together with all the in-space stages, the mission cost probably could be less than than ~$100 million. Such a low mission cost probably could be paid for by advertising alone. But to encourage participants to take up the task of such a fully privately financed mission, NASA could offer a prize of say $200 to $500 million to whoever could accomplish it, with some smaller incentive prizes to those who accomplish some key required steps. Bob Clark

An article on the Starship performance shortcomings for the Artemis missions: Starship Faces Performance Shortfall for Lunar Missions by Alex Longo https://www.americaspace.com/2024/04/20/starship-faces-performance-shortfall-for-lunar-missions/ Bob Clark

Reading the article it’s clear the delay in the development in the Starship specifically in the refueling capability is a primary reason for why these alternative missions for Artemis III are being considered. “An unrealistic timeline The space agency's date for Artemis II is optimistic but potentially feasible if NASA can resolve the Orion spacecraft's heat shield issues. A lunar landing in September 2026, however, seems completely unrealistic. The biggest stumbling blocks for Artemis III are the lack of a lander, which SpaceX is developing through its Starship program, and spacesuits for forays onto the lunar surface by Axiom Space. It is not clear when the lander or the suits, which NASA only began funding in the last two to three years, will be ready.” Note the alternative missions being mentioned now for the Starship in Artemis III will require no refueling flights. Bob Clark

The sea level Raptor 2 sea level thrust is 230 tons. For its vacuum thrust estimate it as proportionally higher by how much higher the vacuum Isp is over the sea level Isp: 230*(353/327) = 248 tons. The Raptor Vacuum thrust is given as 258 tons. Then the total thrust for the 3 sea level Raptors and 3 vacuum Raptors should be 1,520 tons. But the thrust for the ship of the current version is given as only 1,250 tons: So it was started at 82% of full thrust. Commonly, you throttle down a rocket engine as most of the propellant burned off. The result is the overall average thrust was less than 75%. Bob Clark

It should not be lost sight of the fact the delays in Stasrship are a primary cause in these delays in the Artemis landing missions. Who in space reporting will put to NASA the tough questions: Was NASA aware the current version of Starship could only get 40 to 50 tons to orbit, so they would have to wait for V2 or even V3 to do Artemis? Did SpaceX inform them they throttled down the Raptor for reliability on IFT-2 and IFT-3? Bob Clark