DDopson Ars Tribunus Militum
22y
2,038
Subscriptor

ROOT1803 said:
Serious question: With this much material floating around in orbit, would re-purposing it be something that is feasible? Or is it just irredeemably junk for the most part?
It's infeasible to recover and utilize.

This came up in a previous thread, where I said:
...
On orbit recycling aspirationally saves some launch mass, the cheaper half of the equation, but it forces you to engineer a vast array of complicated system elements for the recovery process and then use in-space manufacturing and assembly processes that will certainly never be cheaper than their terrestrial equivalents where we can walk over to the machine in our shirt-sleeves and clear out a broken milling bit, call the parts warehouse down the road, and have a replacement bit installed same afternoon. The economic network effects are very very difficult to overcome, far harder than any one of the individual engineering problems. //

HuntingManatees Wise, Aged Ars Veteran
11m
100

andygates said:
The problem is that the stuff isn't particularly special, it's just big empty beer cans. The cost is in getting it up there. And it'd be more straightforward (and less expensive) to bring it down than to tugboat the stuff to a space junkyard.

Actual orbital mechanics are left as an exercise for the Kerbals.

I actually spent an unhealthy amount of time in KSP trying to retrieve space junk using a series of giant folding claw mechanisms that would -- in theory -- latch onto dead satellites and then burn for reentry.

This resulted in two or three successful de-orbiting missions, but I gave up after I caught myself tasking my Kerbals with sending up fresh claw ships to retrieve previously-launched claw ships that had run out of fuel.

SpaceX returned its first 21 Dragon cargo missions to splashdowns in the Pacific Ocean southwest of Los Angeles. When an upgraded human-rated version of Dragon started flying in 2019, SpaceX moved splashdowns to the Atlantic Ocean and the Gulf of Mexico to be closer to the company's refurbishment and launch facilities at Cape Canaveral, Florida. The benefits of landing near Florida included a faster handover of astronauts and time-sensitive cargo back to NASA and shorter turnaround times between missions.

The old version of Dragon, known as Dragon 1, separated its trunk after the deorbit burn, allowing the trunk to fall into the Pacific. With the new version of Dragon, called Dragon 2, SpaceX changed the reentry profile to jettison the trunk before the deorbit burn. This meant that the trunk remained in orbit after each Dragon mission, while the capsule reentered the atmosphere on a guided trajectory. The trunk, which is made of composite materials and lacks a propulsion system, usually takes a few weeks or a few months to fall back into the atmosphere and doesn't have control of where or when it reenters. //

In May, a 90-pound chunk of a SpaceX Dragon spacecraft that departed the International Space Station fell on the property of a "glamping" resort in North Carolina. At the same time, a homeowner in a nearby town found a smaller piece of material that also appeared to be from the same Dragon mission.

These events followed the discovery in April of another nearly 90-pound piece of debris from a Dragon capsule on a farm in the Canadian province of Saskatchewan. SpaceX and NASA later determined the debris fell from orbit in February, and earlier this month, SpaceX employees came to the farm to retrieve the wreckage, according to CBC. //

This means SpaceX can no longer splash down off the coast of Florida because the trajectory would bring debris from the trunk down over populated areas in the United States or Mexico.

When recoveries shift to the West Coast, the Dragon capsule will fire its Draco thrusters to slow down, and then once on course for reentry, release the trunk to burn up in the atmosphere on a similar trajectory. Any debris from the trunk that doesn't burn up will impact the Pacific Ocean while the capsule deploys parachutes for a slow-speed splashdown. //

“One benefit of the move to the West Coast is much better weather," Walker said. "We have a number of sites in Florida, that we feel like we’re sometimes threading hurricanes a lot. When we look at the flight rules for wind, rain, wave height, all of the criteria that determine our flight rules for return, we actually saw that the West Coast sites that we’re looking at have much better weather, which allows us to have much better return availability.”

We're standing by for news on NASA's decision on what to do about Orion's heat shield. //

The central piece of NASA's second Space Launch System rocket arrived at Kennedy Space Center in Florida this week. Agency officials intend to start stacking the towering launcher in the next couple of months for a mission late next year carrying a team of four astronauts around the Moon.

The Artemis II mission, officially scheduled for September 2025, will be the first voyage by humans to the vicinity of the Moon since the last Apollo lunar landing mission in 1972. NASA astronauts Reid Wiseman, Victor Glover, Christina Koch, and Canadian mission specialist Jeremy Hansen will ride the SLS rocket away from Earth, then fly around the far side of the Moon and return home inside NASA's Orion spacecraft. //

NASA's inspector general reported in 2022 that NASA's first four Artemis missions will each cost $4.1 billion. Subsequent documents, including a Government Accountability Office report last year, suggest the expendable SLS core stage is responsible for at least a quarter of the cost for each Artemis flight.

The core stage for Artemis II is powered by four hydrogen-fueled RS-25 engines produced by Aerojet Rocketdyne. Two of the reusable engines for Artemis II have flown on the space shuttle, and the other two RS-25s were built in the shuttle era but never flew. Each SLS launch will put the core stage and its engines in the Atlantic Ocean. //

Artemis III's launch date is highly uncertain. It primarily hinges on SpaceX's progress in developing a human-rated lunar lander and Axiom Space's work on new spacesuits for astronauts to wear while walking on the Moon.

NASA spent $11.8 billion developing the SLS rocket, and its debut was delayed five years from an original target date in 2017. But for Artemis II, the readiness of the Orion spacecraft is driving the schedule, not the rocket.

Boeing won't start flying operational crew missions with Starliner until a year from now. //

The astronauts who rode Boeing's Starliner spacecraft to the International Space Station last month still don't know when they will return to Earth.

Astronauts Butch Wilmore and Suni Williams have been in space for 51 days, six weeks longer than originally planned, as engineers on the groundwork through problems with Starliner's propulsion system.

The problems are twofold. The spacecraft's reaction control thrusters overheated, and some of them shut off as Starliner approached the space station June 6. A separate, although perhaps related, problem involves helium leaks in the craft's propulsion system. //

MHStrawn Ars Scholae Palatinae
11y
1,142
Subscriptor
Emon said:
The competent engineers and managers were driven out long ago, or they bailed because they were sick of the nonsense.

They're probably working at a variety of competitors or other companies in and around aerospace.

Brain drain is real and Boeing's useless manchild execs either don't understand, don't care, or more likely, both.
So much this.

Boeing going from a company run by engineers whose purpose was to build safe, reliable aircraft to a company run by MBAs whose purpose is to maximize shareholder value was one of the worst developments of the last 50 years in the aerospace industry.

The Falcon 9 is grounded pending an investigation, possibly delaying upcoming crew flights. //

"Upper stage restart to raise perigee resulted in an engine RUD for reasons currently unknown," Musk wrote in an update two hours after the launch. RUD (rapid unscheduled disassembly) is a term of art in rocketry that usually signifies a catastrophic or explosive failure. //

Going into Thursday's mission, the current version of SpaceX's Falcon 9 rocket, known as the Falcon 9 Block 5, was indisputably the most reliable launch vehicle in history. Since debuting in May 2018, the Falcon 9 Block 5, which NASA has certified for astronaut flights, never had a mission failure in all of its 297 launches before the ill-fated Starlink 9-3 mission. //

The Falcon 9's only total in-flight launch failure occurred on its 19th flight on June 28, 2015, when the upper stage's liquid oxygen tank burst a couple of minutes after launch from Cape Canaveral Space Force Station, Florida. The rocket disintegrated in the upper atmosphere, dooming a Dragon cargo capsule en route to the space station.

SpaceX resumed Falcon 9 launches six months later in December 2015. On that flight, SpaceX landed the Falcon 9's first stage booster back at Cape Canaveral for the first time, a historic achievement and a harbinger of the company's later success in reusing rockets. //

SpaceX's Falcon family of rockets, which counted 335 consecutive successful launches since the on-pad explosion in 2016, or 344 flights since an in-flight failure. Both numbers are all-time industry records.

A booster landing would be a calculated risk to SpaceX's launch tower infrastructure. //

In a short video released Thursday, possibly to celebrate the US Fourth of July holiday with the biggest rocket's red glare of them all, SpaceX provided new footage of the most recent test of its Starship launch vehicle.

This test, the fourth of the experimental rocket that NASA is counting on to land its astronauts on the Moon, and which one day may launch humans to Mars, took place on June 6. During the flight, the first stage of the rocket performed well during ascent and, after separating from the upper stage, made a controlled reentry into the Gulf of Mexico. The Starship upper stage appeared to make a nominal flight through space before making a controlled—if fiery—landing in the Indian Ocean.

The new video focuses mostly on the "Super Heavy" booster stage and its entry into the Gulf. There is new footage from a camera on top of the 71-meter-tall first stage as well as a nearby buoy at water level. The video from the buoy, in particular, shows the first stage making an upright landing into the ocean.

SpaceX teases an image of Starship's large launch tower in South Texas at the Starbase facility. Prominently featured are the two "chopsticks," large arms intended to catch the first stage booster as it slowly descends back toward its launch pad.

Then, in simulated footage, the video shows Starship's first stage descending back toward the launch tower with the title "Flight 5." And then it fades out.

https://www.youtube.com/watch?v=j2BdNDTlWbo

Dtiffster Ars Praefectus
8y
3,075
Subscriptor

expand...As has been pointed out by others they have gotten cheaper on an absolute basis inflation adjusted as well. And there isn't much competition that is cheaper than them on an absolute basis, and all of it with only a fraction of their capacity. You got Electron at 200/300 kg for SSO/LEO for 8.5 mil, PSLV for 1.6/3.2 tonnes SSO/LEO for 18 mil, Vega C at 1.45 tonnes SSO for 37 (very subsidized) mil euro, and GSLV for 2.5/3/6 tonnes GTO/SSO/LEO for 47 mil. F9 does that with a droneship landing 5.4/12/18+ tonnes GTO/SSO/LEO for 69.5 mil. If all you need is exactly the performance of one of those rockets for one payload, then yes they are cheaper. And that is true for some payloads, but not for a substantial amount of the market. Otherwise those rockets would be out launching SpaceX right now, right? And rocket lab wouldn't be building neutron, right? Sounds like you are the one falling victim to hater math.

And you've got plenty of their commerical (i.e. non starlink) missions use a pretty substantial amount of F9 and FHs capabilities. They've launches F9 with expended boosters and FHs with expended center cores many times in the last few years. Most of the GTO birds are bigger than GSLV can handle, and F9 can handle most upper birth GTO sats to synchronous and the smaller lower birth GTO to supersynchronous that Ariane V used to handle for a fraction of what customers used to pay for the ride share without a hassle. Crew and Cargo dragon missions obviously need SpaceXs vehicles and use about 2/3 of the F9s capacity.

And although we haven't yet got substantially better rockets on the market yet, SpaceX has driven competitors to try. An Atlas V 551 used to cost 250+ mil, and DIVH over 600 mil. The top of the line Vulcan with 6 boosters which is roughly on par with DIVH is being sold for 200ish mil. There are a whole mess of at least partially reusable rockets that are only going to exist because of SpaceX. Fanboy math or not the market is working and it's thanks to SpaceX spurring innovation. Hate all you want, things are going swimmingly, and notice that it is not launch customers that are complaining about SpaceX.

Edit: forgot Alpha at 630/1030 kg SSO/LEO for 17.5 mil, which is again too small to eat many launches. //

expand...We've seen reporting recently that SpaceX appears to execute a Starlink launch for an internal cost of about $20M. That suggests they could offer ASDS launches profitably for $30M and RTLS launches for even less. If they were doing that, who the hell would invest in Stoke Space or Rocket Lab or any company not backed by Jeff Bezos? //

You'd think they had promised to make launch free at this point. They're 17% lower per-launch than they were just seven years ago and well below half of what the industry norm was prior to their entrance on the market.

Over 5,000 orbital rocket launches from nearly 30 different sites are depicted, starting in 1957 when Sputnik became the first artificial object in orbit.

The space agency did consider alternatives to splashing the station. //

NASA has awarded an $843 million contract to SpaceX to develop a "US Deorbit Vehicle." This spacecraft will dock to the International Space Station in 2029 and then ensure the large facility makes a controlled reentry through Earth's atmosphere before splashing into the ocean in 2030.. //

"This decision also supports NASA’s plans for future commercial destinations and allows for the continued use of space near Earth."

NASA has a couple of reasons for bringing the space station's life to a close in 2030. Foremost among these is that the station is aging. Parts of it are now a quarter of a century old. There are cracks on the Russian segment of the space station that are spreading. Although the station could likely be maintained beyond 2030, it would require increasing amounts of crew time to keep flying the station safely.

Additionally, NASA is seeking to foster a commercial economy in low-Earth orbit. To that end, it is working with several private companies to develop commercial space stations that would be able to house NASA astronauts, as well as those from other countries and private citizens, by or before 2030. By setting an end date for the station's lifetime and sticking with it, NASA can help those private companies raise money from investors. //

The station, the largest object humans have ever constructed in space, is too large to allow it to make an uncontrolled return to Earth. It has a mass of 450 metric tons and is about the size of an American football field. The threat to human life and property is too great. Hence the need for a deorbit vehicle. //

volcano.authors Smack-Fu Master, in training
6y
73

flerchin said:
The idea that SpaceX wouldn't even bid unless it was fixed price, and then came in well under the estimates for cost-plus is wild.

It's almost as though the cost-plus era has some political baggage that challengers like to point out.

RTWAP Smack-Fu Master, in training
1y
12

afidel said:
I assume SpaceX prefers the firm fixed price contract because it reduces the army of paper pushers needed and the amount of time that engineers and technicians need to waste documenting their work on the contract? I guess if you can actually execute correctly it's more profitable to just submit a bill and get paid than to do the old cost plus change order malarkey.

My speculation is that it enforces a certain discipline in the requirements. SpaceX isn't going to just happily go down every rabbit hole of dithering on requirements and possible changes because unless it's a costed and signed change order they'd be losing money on it. And anyone at NASA looking to change things knows it requires a highly visible contract change ($$$), not just a larger bill from the contractor. //

Tridus Ars Tribunus Militum
17y
2,189
Subscriptor

afidel said:
I assume SpaceX prefers the firm fixed price contract because it reduces the army of paper pushers needed and the amount of time ....

Yeah, exactly. They're not paying people handle the paperwork end of cost-plus.

Also if they think they can do it for significantly under that, the potential profit margin is higher since they'll get paid that no matter what it actually costs them to do it. It takes a high degree of confidence to want to go this way, but if any space company has the experience with this type of contract to make it work, it's SpaceX.

It REALLY showcases the differing mindset and abilities between them and a company that won't bid on fixed price contracts like Boeing, though.

“Safety tends to not be on the front burner until it really needs to be on the front burner.” //

Since the beginning of the year, landowners have discovered several pieces of space junk traced to missions supporting the International Space Station. On all of these occasions, engineers expected none of the disposable hardware would survive the scorching heat of reentry and make it to Earth's surface.

These incidents highlight an urgency for more research into what happens when a spacecraft makes an uncontrolled reentry into the atmosphere, according to engineers from the Aerospace Corporation, a federally funded research center based in El Segundo, California. More stuff is getting launched into space than ever before, and the trend will continue as companies deploy more satellite constellations and field heavier rockets.

"Look, there's no accidental monopoly. They are a ruthless competitor." //

Most of our customers, you know, we still have new customers, but there's a tremendous amount of returning customers. And if you look at it from their point of view, even if someone turns up with a rocket that is half the price, really the reliability of Electron and the precision of it, it's hard for someone to move onto a new platform. Now, I don't I don't mean that to sound arrogant at all. It's just that price is not the number one thing. It's important, but it's just not the number one thing anymore. I mean, we're inserting to an accuracy of 400 meters at this point. So that's almost good enough to rendezvous straight off the rocket. //

We sold over 22 launches this year, and next year is looking even better. There is a definite demand that small launch has, and a capability that small launch gives. We have just so many customers now that absolutely rely on Electron. They've designed their constellation or their spacecraft around Electron. It does things that you just can't get on other missions. I think a lot of people compare Transporter (SpaceX's rideshare missions on the Falcon 9 rocket) to Electron and dedicated launch, and there is no comparison. Transporter can do it for free for all we care, because the customer who is coming to Electron really needs instantaneous launch, the right inclination or orbital plane. If we just stopped doing Electron, there would be a whole lot of people with nowhere to go. There's been a market built up around the product, and it continues to grow. //

TheWarOnSilence Seniorius Lurkius
9y
10
Subscriptor
I did enjoy this quote:

"We have a saying here at Rocket Lab that we have no money, so we have to think." It is, of course, the re-stating of another famous New Zealand knight of the realm, Sir Ernest Rutherford, who memorably said "We haven't got the money, so we'll have to think".

More than a hundred years after Rutherford made the statement in the context of nuclear physics, it's a delight to see that same drive and determination shine through at Rocket Lab.

"They're the largest satellite operator in the world." //

We discussed Starlink's rapid road to profitability—it took just five years from the first launch of operational satellites—and the future of the technology.

One of the keys to Starlink's success is its vertical integration as a core business at SpaceX, which operates the world's only reusable rocket, the Falcon 9. This has allowed the company not just to launch a constellation of 6,000 satellites—but to do so at relatively low cost.

"At one point, SpaceX had publicly said that it was $28 million," Henry said of the company's target for a Falcon 9 launch cost. "We believe today that they are below $20 million per launch and actually lower than that... I would put it in the mid teens for how much it costs them internally. And that's going down as they increase the reuse of the vehicle. Recently, they've launched their 20th, maybe 21st, use of a first-stage rocket. And as they can amortize the cost of the booster over a greater number of missions, that only helps them with their business case." //

SpaceX was founded as a launch company in 2002, first with the Falcon 1 and then the Falcon 9 and Falcon Heavy rockets. But it is clear today that a significant portion of the company's revenue, if not a majority, comes from its Starlink satellite internet business. So is it still primarily a rocket company?

"I think today they're a satellite communications company," Henry said of SpaceX. "I think it's interesting that Stéphane Israël from Arianespace—in the early days, like 2015, 2016 when Starlink was just announced—would try to court customers and say, 'Do you want to fund your competitor?' And no one really took him seriously. Now people are taking him very seriously. [SpaceX is] the largest satellite operator in the world. They have literally more than doubled the number of consumer subscribers for satellite internet in the world.. This is a humongous, nearly unrivaled impact that they've had on the industry."

On Tuesday, Stoke Space announced the firing of its first stage rocket engine for the first time earlier this month, briefly igniting it for about two seconds. The company declared the June 5 test a success because the engine performed nominally and will be fired up again soon.

"Data point one is that the engine is still there," said Andy Lapsa, chief executive of the Washington-based launch company, in an interview with Ars.

The test took place at the company's facilities in Moses Lake, Washington. Seven of these methane-fueled engines, each intended to have a thrust of 100,000 pounds of force, will power the company's Nova rocket. This launch vehicle will have a lift capacity of about 5 metric tons to orbit. //

Lapsa and Stoke, which now has 125 employees, have also gone for an ambitious design in the first-stage engine tested earlier this month. The engine, with a placeholder name of S1E, is based on full-flow, stage-combustion technology in which the liquid propellants are burned in the engine's pre-burners. Because of this, they arrive in the engine's combustion chamber in fully gaseous form, leading to a more efficient mixing.

Such an engine—this technology has only previously been demonstrated in flight by SpaceX's Raptor engine, on the Starship rocket—is more efficient and should theoretically extend turbine life. But it is also technically demanding to develop, and among the most complex engine designs for a rocket company to begin with. This is not rocket science. It's exceptionally hard rocket science. //

Dtiffster Ars Praefectus
8y
3,002
Subscriptor

deadman12-4 said:
How is a big bulky weight penalty on your second stage good for reuse?

The extra drymass that come from the low density hydrolox is partially mitigated by it's Isp. If the upper stage was expendable, the more than double the volume (and thus likely cost) would be a bad tradeoff for what is close to a push in performance for payload to LEO. But as a reusable upper, hydrogens much better heat of vaporization vs methane and the really low ballistic coefficient are definitely big wins. The low ballistic coefficient combined with lift from their asymmetric design means they can shed velocity very high in the atmosphere where they can reradiate a lot of it back into space. And then when they get lower they use the excellent heat carrying capacity of the hydrogen to protect them from high heat fluxes. From an integrated system perspective, the trades start to make a lot of sense. //

greybeardengineer Ars Tribunus Militum
5y
12,948

Malmesbury said:
Seems like yesterday that Henry Spencer was telling us (and we all agreed) that developing new rocket engines for new launchers was a terrible idea. It would always cost billions. Even warming over old engines was fraught.

And it seemed to be true - see the J2-X comedy.

And no one could match the Russian engines from the Forgotten Years.

Now we have slack handfuls of rocket nerds creating orbital class FFSC engines.

That, right there, is New Space

Once a leadership company achieves something new and very difficult it does two important things: 1) it tells entrepreneurs and investors that it can be done, and 2) a cadre of engineers and managers is created familiar with the technology who are free to move on and disseminate the general understanding of the new technology elsewhere.

As someone once said the greatest secret of the atomic bomb was that it can be built and that it works. Same goes for ORSC. :sneaky: //

That, right there, is New Space

It's quite an accomplishment to blow past the performance of the Soviet/Russian/Ukrainian ORSC engine designs. //

jandrese Ars Legatus Legionis
22y
12,795
Subscriptor++

Bad Monkey! said:
This is amusing considering how long it took BO to get a not terribly ambitious staged combustion engine into production, yet Stoke is all of four years old. Did BO lose all the good ones to Stoke?

Blue Origin is run like an old Aerospace company, which is more risk adverse and slow to develop. Rockets are hard, and being able to prototype designs and work out problems is an enormous productivity boost. Years and years of experience shows that trying to do everything on paper first before building the rocket results in very slow and expensive development. Building engines and blowing up your first half dozen is much faster and cheaper and leads to a better product in the end. //

Wickwick Ars Legatus Legionis
14y
34,700

deadman12-4 said:
How does resources matter. We are talking about a 50 year improvement in technology. This has nothing to do with it being a "commercial" company. Look at China - it'd be embarrassing for them if their engines also didn't blow away old soviet stuff.

I'm not saying "soviet stuff is bad cause its soviet", we need to realize its 50 year old tech. Worshiping it is silly. Everyone should be able to do better than 50 yr old tech, no matter who made it. Its strange how soviet tech is a sacred cow. Its just tech made by someone like anything else. It was good for its time, but that was half a century ago.

You seem to think that "technology" improving just makes everything easier. Sometimes, someone's expertise matters more than technology.

Pratt & Whitney actually had a license to manufacture the RD-180 engine domestically. They literally had the blueprints and everything they needed to know on the metallurgical side to make it happen. They eventually chose not to execute on the license because just duplicating the Russian/Ukrainian design was sufficiently outside of the capabilities of P&W that they felt they would never be cost competitive with the price ULA could buy the engines as imports - duties and all. And lest you think P&W were just a bunch of schleps, they were the makers of the RL-10 engine.

So it's not just a 50 year-old technology. Less than 20 years ago, one of the premier rocket engine manufacturers in the US couldn't make it work even with the recipe. //

I Like Pi Seniorius Lurkius
16y
23

deadman12-4 said:
) How is a big bulky weight penalty on your second stage good for reuse?

Um…you get the stage back… //

Malmesbury Smack-Fu Master, in training
1m
91

deadman12-4 said:
hmm... I would disagree at this point. We're talking about 1970s tech. Yes they were amazing for time, but their time was like 2 generations ago. They are only still relevant because so few engines have been made and used in the last 50 years.
I would say it would be embarrassing if a company couldn't blow past the benchmarks of soviet engines today.

Not long ago, the Received Wisdom from professionals in the industry was that only incremental improvements on existing engines were worthwhile. And possible.

Now, everyone and his dog is building new engines. Using cycles that the pros said they couldn’t do. //

greybeardengineer Ars Tribunus Militum
5y
12,948
Just to be clear, this Stoke first stage engine is methalox. They use hydrolox for their second stage. The article doesn't make that clear and it appears that some in the comments don't realize this. //

phat_tony Ars Centurion
18y
291
Subscriptor

Joey S-IVB said:
445 kilonewtons for each engine, or 3.1 meganewtons for all seven engines combined on the first stage. That's under half of the Falcon 9's approximately 6.9 meganewtons. So, if it can put 5 tonnes into LEO, I'm guessing the second stage isn't as powerful/efficient as the F9's second stage? If this first stage is roughly half as powerful as the F9's booster stage, it is putting less than half the tonnage in comparison (should be about 8.5 tonnes to LEO if half). Still, it's great to see that Stoke is making rapid progress.

Others have pointed out the reusable second stage adds mass vs expendable; but furthermore, you just shouldn't expect rockets to scale linearly at all. Other things being equal, the larger the rocket, the higher percentage of the rocket's total launch mass can be payload.

The SS-520 is the smallest orbital rocket and it's 5,700 lbs and the mass to orbit is effectively 0 - it's 9 lbs. Any smaller and the rocket could not even get itself to orbit.

Some things on the rocket don't scale - the avionics and sensors for a tiny rocket and Starship aren't necessarily very different, so there's a flat mass you need to take. But the most important thing in rocket scaling is that the volume of a fuel tank goes up faster than the surface area when you make it bigger, keeping all proportions identical. The bigger the tank, the lower the ratio of tank mass to fuel mass.

SpaceX demonstrated Thursday that its towering Super Heavy booster and Starship rocket might one day soon be recovered and reused in the manner Elon Musk has envisioned for the future of space exploration.

For the first time, both elements of the nearly 400-foot-tall (121-meter) rocket not only launched successfully from SpaceX's Starbase facility near Brownsville, Texas, but also came back to Earth for controlled splashdowns at sea. This demonstration is a forerunner to future Starship test flights that will bring the booster, and eventually the upper stage, back to land for reuse again and again.

The two-stage rocket took off from Starbase at 7:50 am CDT (12:50 UTC) and headed east over the Gulf of Mexico with more than 15 million pounds of thrust, roughly twice the power of NASA's Saturn V rocket from the Apollo lunar program of the 1960s and 1970s.

With the first three Starship launches, the FAA license required SpaceX conduct a mishap investigation with federal oversight if the rocket failed to reach its destination intact. The outcome of the last test flight—Starship's breakup over the Indian Ocean—triggered such an investigation by SpaceX. //

But this approach isn't congruent with SpaceX's roadmap for Starship development. SpaceX's iterative approach is rooted in test flights, where engineers learn what and what doesn't work, then try to quickly fix it and fly again. A crash, or two or three, is always possible, if not likely. The FAA is making an adjustment for this week's mission.

"As part of its request for license modification, SpaceX proposed three scenarios involving the Starship entry that would not require an investigation in the event of the loss of the vehicle," the FAA said in a statement.

Based on language in the code of federal regulations, the FAA has the option to approve these exceptions. The FAA accepted three possible outcomes for the upcoming Starship test flight that would not trigger what would likely be a months-long mishap investigation.

These exceptions include the failure of Starship's heat shield during reentry, if the ship's flap system is unable to provide sufficient control under high dynamic pressure, and the failure of the Raptor engine system during the landing burn. If one of these scenarios occurs, the FAA will not require a mishap investigation, provided there was no serious injury or fatality to anyone on the ground, no damage to unrelated property, and no debris outside designated hazard areas.

This change is quite significant for the FAA and SpaceX. It shows that federal regulators, suffering from staffing and funding shortages, are making moves to try and keep up with SpaceX's rapid, and often ever-changing, development of Starship.

"If a different anomaly occurs with the Starship vehicle, an investigation may be warranted, as well as if an anomaly occurs with the Super Heavy booster rocket," the FAA said. //

Bannerdog Ars Praetorian
8y
410
Only SpaceX can say, "not all of our rockets crash".
Hopefully someday, "none of our rockets crash*". //

taxythingy Ars Centurion
7y
397
Subscriptor

uhuznaa said:
Just using somewhat contaminated preburner exhaust for pressurization the oxygen tanks (hot oxygen with some steam and CO2 in it) would be much simpler and lighter though than having pure propellant go through heat exchangers first. Best part is no part and so on. It would be a quite typical approach for them.

At least all the valve and filter clogging in the last flight is hard to explain otherwise, where was all the ice coming from? Usually filters are just for protecting the engines (especially the pumps) from ingesting random debris ending up in the tanks but to have the filters of several engines clogged by ice there needs to be quite a lot of that. It's a mystery to me where all this ice came from. If you use clean oxygen for pressurization and purge the tanks with dry nitrogen before tanking there just should be no ice anywhere.

(They could tap hot methane off the nozzle cooling but there is no source for clean hot oxygen gas except using a dedicated heat exchanger just for that, and it seems the ice was in the oxygen tanks.)

The oxygen is super cooled to improve density and is getting close to the triple point (within 20K) at tank pressure, where solids can form. The general understanding is that solid O2 forms, probably at the liquid gas interface (boil off is cooling it further) and that then settles to the tank bottom as a slush. This is more likely to occur after the main burn when the tank is near empty.

On relight, that has to be filtered out, else it will either block the injectors or otherwise run rough.

The Shuttle had filters, but that was more for debris, if I remember correctly.

The ground launch sequencer computer called a hold at T-minus 3 minutes, 50 seconds. //

Saturday's aborted countdown was the latest in a string of delays for Boeing's Starliner program. The spacecraft's first crew test flight is running seven years behind the schedule Boeing announced when NASA awarded the company a $4.2 billion contract for the crew capsule in 2014. Put another way, Boeing has arrived at this moment nine years after the company originally said the spacecraft could be operational, when the program was first announced in 2010. //

Crying Croc Wise, Aged Ars Veteran
8m
449

Matthew J. said:
The Boeing Curse...

The McDonnell Douglas Curse.

[Edit to correct]: Actually, it's just McDonnell. Douglas was once a proud airplane maker that sadly became an earlier victim of McD. Boeing is Victim 2.0. //

FabiusCunctator Ars Scholae Palatinae
4y
857
Subscriptor

OccasionallyLeftHanded said:
The term “kludge” comes to mind.

Or more like: “something that was originally designed back in the early days of the Delta program and kept going with bubble gum and baling wire for forty years.”

And I can understand this! The software’s been fully debugged and is well proven. Why change it if you don’t have to? //

Wandering Monk Wise, Aged Ars Veteran
4y
128
Subscriptor
There’s definitely something to be said for the general plan of, “get the system working while shipping cargo, and then add life support”. If these delays happened with a boring payload, it wouldn’t get nearly the attention. //

Lone Shepherd Ars Tribunus Angusticlavius
24y
6,868
Subscriptor

All three computers must be fully functioning in the final phase of the countdown to ensure triple redundancy.

This sentence does not make sense. If all three must be functioning, then there is zero redundancy.

Triplex redundant systems are usually set up to enable majority (2 out of 3) voting to allow mission success while being robust to any single operational fault.

If this was actually a triple redundant system then fault of one computer would be detected by the other two and that unit would have been "voted out" and the launch would have proceeded. ///

But they have to be operational first. If all three aren't operational to begin with, then you don't have a triplex system, you've already lost one to a failure. //

The computers have to provide functionality in the event of a failure after launch commit. That is mission critical, and thats why they need fault tolerance.

Before that, a failure results in a hold/scrub, because it means the necessary failt tolerance wont be present after commit.

Holding/scrubbing isn't an option after commit. At that point the vehicle must go, and the GSE must work. //

ninjaneer Ars Praetorian
10y
540
Subscriptor

galahad05 said:
Wait, this is a joke right? Like a de-motivational poster or something?

He said it in 2004 and it resurfaced everywhere in 2020. The guy's still alive but likely has too much of a psychopathic ego to feel it bite him in the ass.

Ctrl-F "culture" in the Fortune article below and you'll spot it in action

https://fortune.com/longform/boeing-737-max-crisis-shareholder-first-culture/. //

Jharm Wise, Aged Ars Veteran
6y
125

ninjaneer said:
"When people say I changed the culture of Boeing, that was the intent, so that it's run like a business rather than a great engineering firm."
-- Harry Stonecipher

I couldn't believe he would have said so. But sure he did!

Hopefully other business will learn of these mistakes. Many articles (e.g.
https://www.euronews.com/business/2024/02/07/boeings-tragedy-the-fall-of-an-american-icon ) about what went wrong but so far those I have read have all in common that they slashed the R&D for short term gains and then they believed they could easily restart again. This happens when you have bean counters to run the company.

I am sitting in a company of 40.000 people, here we see the same going on. EBIT and cashflow before everything else. No training of new young talent, no visions, just reaction to the competition and not what the customer wants. //

Zylon Ars Scholae Palatinae
3y
838
Subscriptor
I haven't been to this particular facility, but I've crawled around under computer flooring and installed racks at several NASA facilities, and the idea that anything about them is jury-rigged is laughable. You don't truly understand the meaning of the word "nitpicky" until you've been through a NASA QC audit. I spent more time on documentation than I did installing the equipment!

These are stupendously complex systems, and shit happens. I had a timing system that had behaved perfectly during burn-in testing go nuts, and the automatic fail over, didn't. Even though we had tested fail over and fail back. It took the site down for an hour. So you learn from your mistakes, build in redundancy, and when only two of the three voting computers are online at T-4:00, you abort the launch.

Oh, and I wouldn't read too much into the phrase "boot up" when used by a manager, even one who used to be an engineer. Something wasn't ready when it was supposed to be. They'll figure it out. If it was a "network glitch", it will be in the Wireshark archiver. //

Is Boeing having an unusually high number of scrubbed launches? A normal amount? A low amount?

Compared to the Shuttle? Not so unusual. Compared to what we’ve become used to with SpaceX? A lot.

The main reason SpaceX chose a methane-fueled engine wasn't really about efficiency. Rather, it comes from a more practical consideration: methane is plentiful on Mars, which is the final destination of Starship. //

Like the BE-4, the Raptor uses a staged combustion scheme to achieve better fuel efficiency. However, the Raptor has a full-flow, twin-shaft configuration. This means the Raptor has double the number of pre-burners, each driving a single propellant pump. What SpaceX got out of this design is greater reliability and safety.

The downside is that the engine is also far more complicated to build. Thankfully, over the years, SpaceX has simplified and iterated on the engine with each hot-fire test. Today, the latest version of the Raptor (Raptor 3), isn't just cheaper than the first one, it also has nearly 50% the nominal thrust — increasing from 408,000 pound-force at sea level on the Raptor 1, to almost 593,000 pound-force on the Raptor 3. //

However, while the design of the BE-4 has remained largely unchanged since its conception point in 2011, the Raptor series has gotten to its third iteration. The Raptor 3 — the latest version — was a complete redesign of the engine to make it smaller, more streamlined, reliable, and most importantly, offering more thrust. The Raptor 3 can deliver up to 593,000 pound-force of thrust, making it by far the most powerful Methalox engine ever. With 33 Raptor cores powering the Super Heavy first stage of Starship, SpaceX's massive launch system can bring up to 330,000 pounds to orbit, dwarfing Vulcan's best by nearly five times. //

Efficiency is everything in rocketry, which is why specific impulse (Isp) is such a big deal in this field. Simply put, this number represents the amount of thrust an engine can generate when burning a certain amount of propellant over a set period — typically in seconds. The higher the Isp of a particular rocket engine, the more efficient it is since it can produce more thrust, while consuming less fuel.

According to measurements made by Everyday Astronaut, the Isp for the BE-4 sits at around 310 seconds, while the initial version of the Raptor goes up to 330 seconds. The 20-second difference may not sound like much for most of us, it's actually very important for a rocket engine.

Basically, when you attach the two engines to the same rocket, each carrying an equal amount of propellant, the Raptor will be able to burn for 20 extra seconds compared to the BE-4. //

There's also the matter of availability. SpaceX is churning out one Raptor engine core per day at their in-house manufacturing plant in McGregor, Texas. Meanwhile, the BE-4 has (infamously) encountered troubles during development and production, resulting in a four-year delay in the engine's launch. In fact, it was because of all the issues surrounding the BE-4 that ULA had to postpone the launch of their flagship Vulcan rocket several times. And since the Vulcan's maiden flight in January, it has been the only time the BE-4 has been used in a realistic launch mission so far.

As for the Raptor? It performed brilliantly in the last few tests of the Starship system.

Clearing blocked filters and clogged valves is the order of the day. //

SpaceX is targeting June 5 for the next flight of its massive Starship rocket, the company said Friday.

The highly anticipated test flight— the fourth in a program to bring Starship to operational readiness and make progress toward its eventual reuse—will seek to demonstrate the ability of the Super Heavy first stage to make a soft landing in the Gulf of Mexico and for the Starship upper stage to make a controlled reentry through Earth's atmosphere before it falls into the Indian Ocean. //

Glorified Desktop Support Ars Praetorian
5y
547.
jhodge said:

Valves are the devil's own devices, aren't they?

I'm very curious about the clogged filters

I'm going to guess air. Tanks aren't a vacuum when the LOX is pumped in (although they are perhaps flushed with an inert gas). Dry ice is warmer than LOX. There might be other avenues where air enters the system, and then you have dry ice slush that could clog filters.

NASA's senior leaders in human spaceflight gathered for a momentous meeting at the agency's headquarters in Washington, DC, almost exactly 10 years ago. //

Now, with the shuttle's retirement, these princely figures in the human spaceflight community were tasked with selecting a replacement vehicle to send astronauts to the orbiting laboratory.

Boeing was the easy favorite. The majority of engineers and other participants in the meeting argued that Boeing alone should win a contract worth billions of dollars to develop a crew capsule. Only toward the end did a few voices speak up in favor of a second contender, SpaceX. At the meeting's conclusion, NASA's chief of human spaceflight at the time, William Gerstenmaier, decided to hold off on making a final decision.

A few months later, NASA publicly announced its choice. Boeing would receive $4.2 billion to develop a "commercial crew" transportation system, and SpaceX would get $2.6 billion. It was not a total victory for Boeing, which had lobbied hard to win all of the funding. But the company still walked away with nearly two-thirds of the money and the widespread presumption that it would easily beat SpaceX to the space station.

The sense of triumph would prove to be fleeting. Boeing decisively lost the commercial crew space race, and it proved to be a very costly affair. //

So what happened? How did Boeing, the gold standard in human spaceflight for decades, fall so far behind on crew? This story, based largely on interviews with unnamed current and former employees of Boeing and contractors who worked on Starliner, attempts to provide some answers. //

The problem is that while a company might do something that unlocks a payment, the underlying work may not actually be complete. It's a bit like students copying homework assignments throughout the semester. They get good grades but haven't done all of the learning necessary to understand the material. This is only discovered during a final exam in class. Essentially, then, Boeing kept carrying technical debt forward so that additional work was lumped onto the final milestones.

Ultimately, the flight software team faced a reckoning during the initial test flight of Starliner in December 2019. //

The bottom line is that Boeing technically earned the flight software milestones in its commercial crew contract. But by not putting in the work for an end-to-end test of its software, the company failed its final exam. As a result, Boeing had to take the disastrously expensive step of flying a second uncrewed flight test, which it did in May 2022. //

All of Boeing's struggles with Starliner played out against a much larger backdrop of the company's misfortunes with its aviation business. Most notably, in October 2018 and March 2019, two crashes of the company's relatively new jet, the 737 MAX 8, killed 346 people. The jets were grounded for many months.

The institutional failures that led to these twin tragedies are well explained in a book by Peter Robison, Flying Blind. Robison covered Boeing as a reporter during its merger with McDonnell Douglas a quarter of a century ago and described how countless trends since then—stock buybacks, a focus on profits over research and development, importing leadership from McDonnell Douglas, moving away from engineers in key positions to MBAs, and much more led to Boeing's downfall.

It's estimated that, in addition to paying customers and the families of victims, the grounding of the 737 Max for nearly two years cost Boeing $20 billion since 2019. This critical loss of cash came just as Boeing's space division faced crunch time to complete work on Starliner.

There were so many other challenging issues, as well. The onset of the COVID-19 pandemic in the spring of 2020 occurred when Boeing was dealing with the fallout from all the software issues on Starliner's debut flight. Additionally, the pandemic accelerated the retirement of experienced engineers who had brought spaceflight experience from the shuttle program. Boeing's best people were focused on the aircraft crisis, and the experienced space hands were leaving.

So it was all a pretty titanic struggle. //

In hindsight, it seems obvious that the strain of operating in a fixed-price environment was the fundamental cause of many of Boeing's struggles with Starliner and similar government procurement programs—so much so that the company's Defense, Space, & Security division is unlikely to participate in fixed-price competitions any longer. In 2023, the company's chief executive said Boeing would "never do them again."

A Boeing spokesperson pushed back on the idea that the company would no longer compete for fixed-price contracts. However, the company believes such contracts must be used correctly, for mature products.

"Challenges arise when the fixed price acquisition approach is applied to serious technology development requirements, or when the requirements are not firmly and specifically defined resulting in trades that continue back and forth before a final design baseline is established," the spokesperson said. "A fixed price contract offers little flexibility for solving hard problems that are common in new product and capability development.". //

The surprise is not that Boeing lost to a more nimble competitor in the commercial space race. The surprise is that this lumbering company made it at all. For that, we should celebrate Starliner’s impending launch and the thousands of engineers and technicians who made it happen. ///

Except it still hasn't succeeded

A Rocket A Day Keeps the High Costs Away asks why it is, considering that the V2 cost about US$13,000 each (1945 dollars) and could be launched at rates approaching 100 a week, that today's launchers cost 1000 times as much. A market-oriented approach to overcome the current cost barrier to space development is suggested. //

September 27, 1993

There's a pretty general consensus that one of the greatest barriers to the exploration and development of space is the cost of launch to low earth orbit. The incessant and acrimonious arguments among partisans of the Shuttle, DC-*, NASP, TSTO, Big Dumb Boosters, bringing back the Saturn V, buying launches from the Russians and/or Chinese, or of developing exotic launch technologies (laser, electromagnetic, skyhook, etc.) conceal the common premise of all those who argue—that if we could launch payloads for a fraction of today's cost, perhaps at a tenth to a thousandth of today's rates of thousands of US$ per kilogram, then the frontier would open as the great railway to orbit supplanted the first generation wagon trains. The dispute is merely over which launch technology best achieves this goal.

Conventional wisdom as to why industry and government choose not to invest in this or that promising launch technology is that there aren't enough payloads to generate the volume to recoup the development cost and, in all likelihood, there never will be.

How much would it cost to find out if this is true? //

Consider the following mass-produced expendable rocket.

• Number manufactured: 6,240 //

These are actual figures for the first mass-produced rocket vehicle, the V-2 (A-4)—fifty years ago. //

... after the war U.S. intelligence expert T. P. Wright estimated that at full production, unconstrained by wartime shortages, the Mittelwerk plant could have produced 900 to 1000 V-2s per month.

One thousand rockets per month…fifty years ago. Think about that. ///

This is almost what SpaceX is doing with Falcon9, 30 years later...