Exoscientist

Actually, the relevant scenario is the two-stage case of a half-size Ariane core with a ca. 10 ton upper stage, so it is loftable by a single Vulcain. That can get ca. 5 tons to LEO. This compared to the ca. 2 tons to LEO payload of the Vega. This half-sized Ariane while being able to launch more than twice that of the Vega would only cost half as much. Again, the high cost of the Vega is solely due to high cost of the large SRB used as its first stage: Monday, October 9, 2023 Towards return of Europe to dominance of the launch market. http://exoscientist.blogspot.com/2023/10/towards-return-of-europe-to-dominance.html This would turn out to be a pretty cool all-hydrolox launch architecture for the ESA: a half-size Ariane powered by a single Vulcain at ca. 5 tons to LEO, a two Vulcain version at ca. 12 tons to LEO and a three Vulcain version at ca. 20 tons to LEO. All would be reusable and manned-flight capable. A manned capsule of a size loftable by a 5 ton launcher is certainly doable as the Gemini capsule massed ca. 3,800 kg: Gemini. http://www.braeunig.us/space/specs/gemini.htm Robert Clark

Ok, but the conclusion you still draw is amortized over flights, the cost for a pair of SRB’s is $600 million per flight. In other words, it’s getting twice as bad as time goes on. Bob Clark

Price discrepancy on the cost of the SLS solid rocket boosters: This article says the costs of the SLS are likely to increase: NASA should consider commercial alternatives to SLS, inspector general says "NASA’s aspirational goal to achieve a cost savings of 50 percent is highly unrealistic." ERIC BERGER - 10/13/2023, 3:07 PM https://arstechnica.com/space/2023/10/inspector-general-on-nasas-plans-to-reduce-sls-costs-highly-unrealistic/ There is a cost discrepancy in this image from the article in regards to the SRB’s. It says the SRB contract, whose total cost is in the last column, is for 10 SRB’s over the five missions from Artemis IV to VIII. That total cost is given as $3 billion. But that means each SRB costs $300 million. But each mission requires two SRB’s. That should mean the per mission cost is $600 million. Yet in the column for the cost of that item per Block 1B launch its only given as $300 million for the two SRB’s. So what’s the resolution of the discrepancy? Bob Clark

This Ultradense Asteroid May Contain Elements We’ve Never Seen Before A new study suggests that atoms could be stable at atomic number 164, which could help explain recent measurements of the ultradense asteroid 33 Polyhymnia. BY DARREN ORFPUBLISHED: OCT 13, 2023 https://www.popularmechanics.com/space/solar-system/a45522962/new-element-asteroid/# Not saying it’s aliens but … ;-) Bob Clark

The ArianeSpace Vega solid rocket launcher is also having trouble competing with SpaceX: The Accidental Monopoly How SpaceX became (just about) the only game in town Jeff Foust October 13, 2023 SpaceX came with these Transporter missions, which have been really disrupting,” said Marino Fragnito, senior vice president of the Vega business unit at Arianespace. They have been a boon for smallsat developers, he acknowledged, offering low-cost access to space. “But at the same time, they have created a big problem in terms of the business case for all of the other players.” He accused SpaceX of, in effect, predatory pricing, willing to lose money on Transporter missions to drive out competition. He noted that past Vega smallsat rideshare missions sold payloads at $25,000 per kilogram, whereas SpaceX has sold Transporter launches for one-fifth that price. “It’s crazy.” https://spacenews.com/the-accidental-monopoly/ This has been warned about for several years now: Europe is starting to freak out about the launch dominance of SpaceX The Falcon 9 has come to dominate commercial satellite launches. ERIC BERGER - 3/22/2021, 11:24 AM However, there now appears to be increasing concern in Europe that the Ariane 6 and Vega-C rockets will not be competitive in the launch market of the near future. This is important, because while member states of the European Space Agency pay for development of the rockets, after reaching operational status, these launch programs are expected to become self-sufficient by attracting commercial satellite launches to help pay the bills. Economic ministers in France and Italy have now concluded that the launch market has changed dramatically since 2014, when the Ariane 6 and Vega-C rockets were first designed. According to a report in Le Figaro newspaper, the ministers believe the ability of these new European rockets to compete for commercial launch contracts has significantly deteriorated since then. https://arstechnica.com/science/2021/03/european-leaders-say-an-immediate-response-needed-to-the-rise-of-spacex/ The leadership of the Vega team can not acknowledge the same issue as the Ariane 6 team, large solid rockets are not price competitive. Like with the Ariane 6, to be price competitive the solid rocket launcher Vega needs to be replaced by an all-liquid rocket: Saturday, November 29, 2014 A half-size Ariane for manned spaceflight. https://exoscientist.blogspot.com/2014/11/a-half-size-ariane-for-manned.html Robert Clark

ArianeSpace is asking for a 150% increase in subsidies to operate Ariane 6 otherwise it’ll go bankrupt: https://europeanspaceflight.substack.com/p/arianegroup-wants-210m-per-year-more The solution is obvious. The only thing ESA has to acknowledge is the cost of large solid side boosters is prohibitive. Eliminating them entirely and using instead multiple Vulcains on the Ariane 6 core would result in launchers cheaper than the Falcon 9, able to be made reusable like the Falcon 9, and capable of manned spaceflight like the Falcon 9: Monday, October 9, 2023 Towards return of Europe to dominance of the launch market. http://exoscientist.blogspot.com/2023/10/towards-return-of-europe-to-dominance.html Robert Clark

Thanks for that. I don’t know why the ESC-A has such a poor mass ratio when the earlier H10 cryogenic upper stage on the Ariane 4 was much better at ca. 10 to 1. Perhaps because the Ariane 5 had to carry much greater payload at 20 tons that the ESC-A needed greater structural strengthening. Bob Clark

It might be some discussions of the ESC-A are including the mass of the “VEB”, the vehicle equipment bay, an instruments package, in its dry mass. Article on the VEB: “The vehicle equipment bay (VEB)is often called the ‘brains’ of a launcher. Situated on top of the main cryogenic stage, it interfaces directly with the upper stage. The VEB is a big cylindrical ‘basket’ 5.4 m in diameter. It stands 1.56 m tall and weighs 1300 kg without propellant; in the centre is the storable propellant stage (EPS).” https://www.esa.int/Enabling_Support/Space_Transportation/Launch_vehicles/Vehicle_equipment_bay If the ESC-A really has a mass ratio of about 8 to 1 it might work for a half-size Ariane or for the proposed two-Vulcain version of the Ariane 6. In my calculations I used the earlier cryogenic stage the H10 from the Ariane 4 because of its small size and high mass ratio: ARIANE 4 STAGE 3 Specifications are given in H10/H10+/H10-3 order. Designation: H10/H10+/H10-3 Engine: single cryogenic open cycle SEP HM-7B Length: 10.73 m/11.05 m/11.05 m Diameter: 2.60 m Dry mass: 1,200 kg/1,240 kg/1,240 kg, excluding interstage 2/3 Oxidizer: liquid oxygen Fuel: liquid hydrogen Propellant mass: 10,800 kg/11,140 kg/11,860 kg Thrust: 63 kN vac/63.2 kN vac/64.8 kN vac http://www.braeunig.us/space/specs/ariane.htm Bob Clark

Perhaps in the video Tom Scott suggests the ELT will be the largest scope ever built because heavier scopes require heavier support equipment and at some point the mass becomes prohibitive. But it could be advancing tech could reduce the mass required. For instance this research proposes using thin Fresnel lenses to replace space mirrors at much reduced weight: A new, thin-lensed telescope design could far surpass James Webb – goodbye mirrors, hello diffractive lenses Published: July 12, 2023 8.39am EDT https://theconversation.com/a-new-thin-lensed-telescope-design-could-far-surpass-james-webb-goodbye-mirrors-hello-diffractive-lenses-206055 Then these thin lenses might work just as well for ground scopes reducing the optical element weight and therefore the support equipment weight. Bob Clark

ESA delays Vega C return to flight to late 2024 Jeff Foust October 2, 2023 https://spacenews.com/esa-delays-vega-c-return-to-flight-to-late-2024/ Large solids like on the Vega and as used on the Ariane 5 and 6 are not price competitive. Note this is true for large solids. Small solid side boosters like used on the Atlas V and Delta IV might be only 1/8th the size of the core stage, with a concomitant small increase in cost. But when the solids are large size such as being as much or more than the size of the core such as on the Ariane 5 and 6 or actually being the core like on the Vega, the bulk of the expense of the rocket comes from the solids. See discussion here: Friday, May 19, 2023 Who in European space will ask the impertinent question: How much would it cost to add a second Vulcain to the Ariane 5/6? https://exoscientist.blogspot.com/2023/05/who-in-european-space-will-ask.html The cost of the two SRB’s on the Ariane 62 cost €40 million out of the €75 million cost. So the rest of the two-stage rocket is only €35 million. Then those two large SRB’s cost more than the entire rest of the rocket. As I argued there it would be cheaper just to put additional Vulcain(s) on the core and dispense with the SRB’s entirely. An additional Vulcain would add €10 million to the price to bring it to €45 million. Using all liquid propulsion also results in a cheaper rocket than the Vega. To see what such an all-liquid replacement for the Vega would look like see discussion here: Saturday, November 29, 2014 A half-size Ariane for manned spaceflight. https://exoscientist.blogspot.com/2014/11/a-half-size-ariane-for-manned.html By cutting down the core’s propellant size to a bit less than half and using a smaller ca. 10 ton upper stage, so it could be launched by a single Vulcain, you get an all-liquid two-stage rocket capable of about 5,000 kg to LEO. This compares to the 2,000 kg payload to LEO of the Vega. Quite important is the better cost per kilo for the all-liquid case. The Vega costs about €35 million for that 2,000 kg to LEO. But taking into account our all-liquid replacement to the Vega is half-size to the all-liquid Ariane 6, the cost conceivably could be in the range of only half the €45 million estimate of the all-liquid Ariane 6, so only ca. €22 million for a 5,000 kg to LEO launcher(!) And what about reusability? The Space Shuttle abundantly showed you don’t save on reusing solids. But SpaceX has abundantly showed you do save significantly on reusing a liquid-fueled booster. SpaceX reduces the price on the Falcon 9 from $60 million to $40 million, by reusing the booster only, so a price reduction of about one-third. If the same price reduction would apply for reusing the booster only for our half-sized Ariane, that would be a price of only €15 million for a 5,000 kg launcher(!) Bob Clark

Rereading that link about the Being lunar lander I see I took it to be “single launch” because it said the lunar lander would be launched on a single launch of the SLS. But what about the Orion and Service Module? You can not do a second SLS launch to carry them because it would take a full year and more likely two years to do a second launch of the SLS. Perhaps they meant them to be launched separately on the Falcon Heavy? However, they meant to do it that is a major omission in their proposal. Nevertheless, it is possible to do a single launch of the SLS with a light-weight Apollo-sized lander with all the components of Orion capsule/Service Module/lunar lander all carried on that one single SLS launch. The NRHO was chosen because it has a lower delta-v requirement to get there than going to low lunar orbit. Here’s the the delta-v requirements: The second group of delta-v’s shows the delta-v to NRHO as 0.45 km/s and the delta-v to and from the lunar surface from NRHO as 2.75 km/s, or 5.5 km/s round trip. I’ve seen various numbers for the Orion and service module dry mass and propellant mass. I’ll use 16.5 total dry mass for the Orion+service module together, and 10 tons propellant mass. Then using 7 tons of Service module propellant to get the Orion/Service Module/lunar lander to NRHO after placed on TLI trajectory by the EUS, for the 16.5 ton Orion/Service Module dry mass, and 15 tons gross mass Apollo-sized lander with 3 tons left over for the return trip: we get: 320*9.81Ln(1 + 7/(16.5 + 15 + 3)) = 580 m/s, or 0.58 km/s, sufficient for placing in the NRHO orbit. Then for 3 tons left over used for the return trip, after the lander is jettisoned, we get: 320*9.81Ln(1 + 3/16.5) = 520 m/s, 0.52 km/s, sufficient for return. Now for the ca. 15 ton gross mass lander, because of the higher delta- v needed from NRHO we’ll use hydrolox rather than storable propellant stage. The Ariane 4 hydrolox upper stage had a 11.8 ton propellant mass and 1.2 ton dry mass. We’ll use a 2 ton dry mass of the crew module: Then using the max 465 s Isp of the RL-10 engine we get: 465*9.81Ln(1 + 11.8/(1.2 + 2)) = 7,000 m/s, 7 km/s. This is quite a bit higher than the 5.5 km/s needed for the round trip from NRHO to the lunar surface and back again. But it uses hydrolox propellant so needs extra mass for low-boiloff tech. The crew module mass could be higher if we used two hydrolox stages, but this single stage version serves as a proof-of-principle. This shows a single launch mission is doable if going to NRHO, but it is not my preferred plan. A complete orbit around the Moon at NRHO altitude takes two weeks. This means the lander has to remain on the Moon for two weeks until the Orion comes back around to be over the landing site. If instead the Orion was at low lunar orbit it takes two hours to complete an orbit and the lunar lander could launch every two hours to rendezvous with the Orion. Robert Clark

My main objection to the Starship HLS is I really don’t like the 8 to 16 refueling flights needed for a single mission. In my mind, a Moon rocket should be A Moon rocket(singular). I don’t remember seeing this when it was first announced but Boeing has proposed a single launch architecture for Artemis: Boeing aims for Moon landing in 'fewer steps' Published 6 November 2019 https://www.bbc.com/news/science-environment-50322402# No $3 billion Starship or $4 billion lunar Gateway required. Of course being Old Space, Boeing would find a way to charge NASA a billion dollars for the lander anyway, no mater how much smaller it was than the Starship lander(see my sig file.) Robert Clark

Yep, the Apollo guys building a separate static test for all the engines took a useless approach. Better to follow the Soviets N-1 approach. Robert Clark

I don’t find it surprising. Considering the number of times the Raptor has leaked fuel and caught fire all through its developing including on the April test launch. What’s surprising is it took the FAA this long to recognize the fact that a rocket engine leaking fuel and catching fire during its normal flight regime is NOT normal. Robert Clark

FAA Closes SpaceX Starship Mishap Investigation Friday, September 8, 2023 The FAA has closed the SpaceX Starship Super Heavy mishap investigation. The final report cites multiple root causes of the April 20, 2023, mishap and 63 corrective actions SpaceX must take to prevent mishap reoccurrence. Corrective actions include redesigns of vehicle hardware to prevent leaks and fires, redesign of the launch pad to increase its robustness, incorporation of additional reviews in the design process, additional analysis and testing of safety critical systems and components including the Autonomous Flight Safety System, and the application of additional change control practices. The closure of the mishap investigation does not signal an immediate resumption of Starship launches at Boca Chica. SpaceX must implement all corrective actions that impact public safety and apply for and receive a license modification from the FAA that addresses all safety, environmental and other applicable regulatory requirements prior to the next Starship launch. Contact SpaceX for additional information. Learn more about mishap investigations. https://www.faa.gov/newsroom/faa-closes-spacex-starship-mishap-investigation This is the big one: The corrective actions include: “redesigns of vehicle hardware to prevent leaks and fires,… SpaceX has been having leaks and fires on the Raptor all through its development, including on the April test launch. I don’t think they are going to make it by doing full-scale test launches, like the (in)famous N-1 rocket did. They’ll have to do instead an incremental approach by building a separate full-up, full thrust, full flight duration static test stand and not certify the rocket for launch until all 33 engines can fire for the full flight duration. Like the guys with Apollo did it. Robert Clark

So you agree with me more static fires increase the risk of explosions. Robert Clark

I’m taking bets on the number of Raptors that will fail during the flight. Robert Clark And much to lose as it increases the chance of explosion. Robert Clark

I agree India should have time to release the data - all the time in the world. Robert Clark

Keep in mind India is still an underdeveloped country. I don’t see any malpractice in the Indian leadership asking the question, “What’s in the best interest of India?” Seeing the new India through the eyes of an invisible woman By Moni Basu, CNN Video by Nick Scott and Jordan Mendys, CNN She is part of a faceless, often-cited statistic: About 60% of India's nearly 1.3 billion people live on less than $3.10 a day, the World Bank's median poverty line. And 21%, or more than 250 million people, survive on less than $2 a day. https://www.cnn.com/interactive/2017/10/world/i-on-india-income-gap/ How much money did Britain take away from India? About $45 trillion in 173 years, says top economist. Patnaik, in her essay published in Columbia University Press recently, said Britain drained out over $45 trillion from India, which to date has hampered the country's ability to come out of poverty. https://www.businesstoday.in/latest/economy-politics/story/this-economist-says-britain-took-away-usd-45-trillion-from-india-in-173-years-111689-2018-11-19 Robert Clark

Chandrayaan-3’s 14 day primary mission is completed and the water and heavy metal detections have not been released. My speculations may turn out to have some validity. Bob Clark

China reveals grand vision for space resource utilization Could you mine all the resources needed for space exploration from space itself? China reveals plans to achieve this goal by 2100. Created: Sep 02, 2023 07:10 AM EST https://interestingengineering.com/innovation/china-reveals-grand-vision-for-space-resource-utilization Bob Clark

SEPTEMBER 3, 2023 Editors' notes India's moon rover completes its walk, scientists analyzing data looking for signs of frozen water. by Ashok Sharma The data is back on Earth and will be analyzed by Indian scientists as a first look and then by the global community, he said. https://phys.org/news/2023-09-india-moon-rover-scientists-frozen.html Seems to suggest both the water and heavy metal results won’t be released until ISRO scientists have a chance to analyze them first. Robert Clark

The Chandrayaan-3 rover has been parked and put in sleep mode in preparation for the upcoming lunar night. The ISRO hopes it can be reactivated when daylight returns Sept. 22nd: Robert Clark

Thanks for that. He suggests two reasons: they want to do higher than 50% thrust tests and the OLM wasn’t designed for that and they want to do longer than just 5 second tests, perhaps full flight duration, and the water deluge system is not capable of delivering that amount of water. Also notable he suggests these new test stands will have true flame diverters, as NASA has always used for their launch stands and static test stands. In this regard it should be remembered the SpaceX engineers wanted to have flame diverters for the SuperHeavy/Starship launch but they were overruled by Elon for cost and time reasons. Elon really wanted to make that 4/20 date. Robert Clark

As I said in the first post of this thread it is a major irritation of mine that the U.S. landers won’t have detectors for detecting them even if they are there. It’s not like these are gigantic detectors that take a huge amount of weight. I showed the image of the little Sojourner rover with its own APXS at the front. So if the Indian and Chinese lander discover these precious metals in high abundance, the U.S. landers would be blind to the fact they are even there. Hypothetical scenario: ISRO scientists are pleased to see large amounts of water in the lunar regolith. They immediately release this data to the world. But looking at the APXS data they are astonished to find high levels of platinum, gold, silver, and uranium and other valuable minerals right in the lunar regolith. You could literally scoop up the lunar soil to get huge amounts of the valuable minerals. The ISRO scientist are about to release the data to the world, when they get a call from the Indian military. They want a consultation before this data is released. Comes the end of the mission after 14 days and the results of the APXS are still not released. U.S. and other scientists around the world inquire when the data will be released. ISRO scientists respond they want to give Indian scientists first crack at publishing on these results. And actually, that is not an uncommon practice for expensive science projects to want the scientists who worked on the project to have first crack at analyzing the data. A year later the data is still not released. U.S. and other scientists around the world inquire when the data will be released. ISRO responds the data is more complicated than expected. It may take 5, 10 years or more before the data is properly analyzed. Meanwhile, after China sends its lander to the Moon it releases the data showing large amounts of water or the Moon, but the results of the APXS instrument are delayed. China responds also it wants to give their scientists proper time to analyze the data. During this time, the U.S. landers also show large amounts of water in the lunar regolith. However, they don’t have instruments for measuring heavy elements. So they just assume they are at the same levels as seen by the previous U.S. robotic landers and Apollo missions to the Moon at locations other than the lunar South Pole. Bob Clark