"Today, around 9:20 a.m., we received information from employees of one of the companies from Komornik near Poznań that, after starting work, they noticed an unspecified object resembling a reservoir on its premises," said Łukasz Paterski of the Poznań Police, according to a website that provides news for the city. "No one was affected as a result of this incident."

Jonathan McDowell @planet4589
·
The Falcon 9 second stage from the Starlink 11-4 launch failed to deorbit itself on Feb 2. It reentered over Northern Europe last night, with entry over the Irish Sea at 0343 UTC Feb 19 and the reentry track extending to Poland and Ukraine a couple of minutes later
11:45 AM · Feb 19, 2025

The math that makes refueling from the Moon appealing is pretty simple. "As a rule of thumb," write the authors of the new study on the topic, "rockets launched from Earth destined for [Earth-Moon Lagrange Point 1] must burn ~25 kg of propellant to transport one kg of payload, whereas rockets launched from the Moon to [Earth-Moon Lagrange Point 1] would burn only ~four kg of propellant to transport one kg of payload." Departing from the Earth-Moon Lagrange Point for locations deeper into the Solar System also requires less energy than leaving low-Earth orbit, meaning the fuel we get there is ultimately more useful, at least from an exploration perspective. //

the researchers decided to focus on isolating oxygen from a mineral called ilmenite, or FeTiO3. It's not the easiest way to get oxygen—iron oxides win out there—but it's well understood. Someone actually patented oxygen production from ilmenite back in the 1970s, and two hardware prototypes have been developed, one of which may be sent to the Moon on a future NASA mission.

The researchers propose a system that would harvest regolith, partly purify the ilmenite, then combine it with hydrogen at high temperatures, which would strip the oxygen out as water, leaving behind purified iron and titanium (both of which may be useful to have). The resulting water would then be split to feed the hydrogen back into the system, while the oxygen can be sent off for use in rockets.

(This wouldn't solve the issue of what that oxygen will ultimately oxidize to power a rocket. But oxygen is typically the heavier component of rocket fuel combinations—typically about 80 percent of the mass—and so, is the bigger challenge to get to a fuel depot.). //

The team found that almost all of the energy is consumed at three steps in the process: the high-temperature hydrogen reaction that produces water (55 percent), splitting the water afterward (38 percent), and converting the resulting oxygen to its liquid form (5 percent). The typical total usage, depending on factors like the concentration of ilmenite in the regolith, worked out to be about 24 kW-hr for each kilogram of liquid oxygen. //

Obviously, we can build larger arrays than that, but it boosts the amount of material that needs to be sent to the Moon from Earth. It may potentially make more sense to use nuclear power. While that would likely involve more infrastructure than solar arrays, it would allow the facilities to run around the clock, thus getting more production from everything else we've shipped from Earth.

On any given day, SpaceX is probably launching a Falcon 9 rocket, rolling one out to the launch pad or bringing one back into port. With three active Falcon 9 launch pads and an increasing cadence at the Starbase facility in Texas, SpaceX's teams are often doing all three.

The company achieved another milestone Friday with the 25th successful launch and landing of a single Falcon 9 booster. This rocket, designated B1067, launched a batch of 21 Starlink Internet satellites from Cape Canaveral Space Force Station, Florida. //

But SpaceX's accomplishment of 25 flights offers an opportunity to step back and take in some context. The newest and final iteration of the Falcon 9 design, known as Block 5, debuted in 2018. At the time, SpaceX officials said they planned to fly each booster 10 times before standing down for more thorough refurbishment.

SpaceX now plans to launch each Falcon 9 booster up to 40 times. Engineers temporarily removed two Falcon 9 boosters from SpaceX's launch rotation in 2023 for in-depth inspections after their 15th flight. That allowed SpaceX to extend each booster's certification to 20 flights, and last year, officials announced they were going for 40. //

SpaceX is also recovering and reusing payload fairings, the shell that encloses satellite payloads during their initial climb through the atmosphere. Last month, the company confirmed it flew a fairing shell for the 22nd time, another new record. SpaceX's factory in Hawthorne, California, must also churn out new upper stages for each Falcon 9 and Falcon Heavy flight. That's 135 of these multimillion-dollar stages for each Falcon mission in the last 365 days, or one flight (and one new upper stage) every 2.7 days. //

Imagine, for a moment, the sprawling footprint and bloated headcount of SpaceX's factory if it had to manufacture a new Falcon 9 booster, nine engines, and a payload fairing set every 2.7 days. How cost-effective could that be? Would it even be possible? It's mind-boggling enough to visualize the blistering production pace for Falcon 9's upper stages in Hawthorne or SpaceX's Starlink satellites in Redmond, Washington. //

Elon Musk, SpaceX's founder and CEO, has suggested that his company must produce 100 or more Starships per year to fulfill his Mars settlement ambitions, even with full reusability. //

While SpaceX's competency with reusing Falcon 9 boosters gets a lot of attention—landing a rocket is still incredible, even after seeing it nearly 400 times—its manufacturing prowess with Falcon 9 upper stages suggests that building 100 Starships each year just might be doable someday.

Starship will test its payload deployment mechanism on its seventh test flight. //

blackhawk887 Ars Tribunus Angusticlavius
8y
18,175
Keith Tanner said:
2.7 megawatts of electrical power! It's running the computers, the gimbal actuators and the flaps. Anything else?
Mostly flaps. They need to apply a lot of torque at a high speed, which means lots of power.

2.7 MW isn't really that much, though, except for the fact that it's electric power. Each Raptor turbopump puts out 75 MW of shaft power, and each Raptor combustion chamber puts out 7,000 MW of thermal power.

During boost, Starship's thermal power output is roughly equal to half the entire United States' average electric generation power output.

Since those initial reports were published in Western media, a small band of dedicated space trackers have been using open source data to try to identify precisely which space object fell into Kenya. So far, they have not been able to identify the rocket launch to which the large ring can be attributed.

Now, some space trackers believe the object may not have come from space at all. //

However, an anonymous X account using the handle DutchSpace, which despite the anonymity has provided reliable information about Ariane launch vehicles in the past, posted a thread that indicates this ring could not have been part of the SYLDA shell. With images and documentation, it seems clear that neither the diameter nor mass of the SYLDA component matches the ring found in Kenya.

Additionally, Arianespace officials told Le Parisien newspaper on Thursday that they do not believe the space debris was associated with the Ariane V rocket. Essentially, if the ring does not fit, you must acquit.

So what was it?

The first human mission to land on the Moon is one of the only NASA mission patches that does not include the names of the crew members, Neil Armstrong, Buzz Aldrin, and Michael Collins. This was a deliberate choice by the crew, who wanted the world to understand they were traveling to the Moon for all of humanity.

Another NASA astronaut, Jim Lovell, suggested the bald eagle could be the focus of the patch. Collins traced the eagle from a National Geographic children's magazine, and an olive branch was added as a symbol of the mission's peaceful intent.

The result is a clear symbol of the United States leading humanity to another world. It is simple and powerful. //

With the space shuttle, astronauts and patch artists had to get more creative because the vehicle flew so frequently—eventually launching 135 times. Some of my favorite patches from these flights came fairly early on in the program.

As it turns out, designing shuttle mission patches was a bonding exercise for crews after their assignments. Often one of the less experienced crew members would be given leadership of the project.

"During the Shuttle era, designing a mission emblem was one of the first tasks assigned to a newly formed crew of astronauts," Flag Research Quarterly reports. "Within NASA, creation of the patch design was considered to be an important team-building exercise. The crew understood that they were not just designing a patch to wear on their flight suits, but that they were also creating a symbol for everyone who was working on the flight."

In some cases the crews commissioned a well-known graphic designer or space artist to help them with their patch designs. More typically they worked with a graphic designer on staff at the Johnson Space Center to finalize the design. //

In recent years, some of the most creative patch designs have come from SpaceX and its crewed spaceflights aboard the Dragon vehicle. Because of the spacecraft's name, the missions have often played off the Dragon motif, making for some striking designs.

There is a dedicated community of patch collectors out there, and some of them were disappointed that SpaceX stopped designing patches for each individual Starlink mission a few years ago. However, I would say that buying two or three patches a week would have gotten pretty expensive, pretty fast—not to mention the challenge designers would face in making unique patches for each flight.

If you read this far and want to know my preference, I am not much of a patch collector, as much as I admire the effort and artistry that goes into each design. I have only ever bought one patch, the one designed for the Falcon 1 rocket's fourth flight. The patch isn't beautiful, but it's got some nice touches, including lights for both Kwajalein and Omelek islands, where the company launched its first rockets. Also, it was the first time the company included a shamrock on the patch, and that proved fortuitous, as the successful launch in 2008 saved the company. It has become a trademark of SpaceX patches ever since.

Taking stock of spaceflight one-quarter of the way through the 2000s. //

2. Ingenuity flies on Mars
   Almost everyone reading this article remembers the seven minutes of terror associated with the landing of the Curiosity rover on Mars in 2012. A similar thing happened nine years later when the Perseverance rover landed on Mars (this time, with some amazing video of the dynamic experience). Yet as cool as these landings were, and as impressive as the capabilities of Curiosity and Perseverance are, a tiny payload named Ingenuity carried by Perseverance stole the show on Mars. //

3. Falcon Heavy launch, dual rocket landing
   By popular demand, this mission in February 2018 ranks in the top spot. The visuals were irresistible. The rocket launch itself was impressive, with the combination of 27 Merlin rocket engines generating a brightness that one almost had to look away from. Then the twin boosters separated and returned to Earth, landing like a pair of synchronized swimmers. Finally, there was the arresting view of a cherry red Tesla (and Starman) flying away from Earth in the general direction of Mars.

It was a spectacle that understandably captured the public’s attention. But the new rocket was more than a spectacle. By designing, building, and launching the Falcon Heavy, SpaceX demonstrated that a private company could independently fund and fly the largest and most powerful rocket in the world. This showed that commercial, heavy-lift rockets were possible. By providing competition to the Delta IV Heavy, the Falcon Heavy saved the US government billions. It's likely that the US government will never design and develop a rocket ever again.

A successful engine relight demonstration would pave the way for future Starships to ascend into stable, sustainable orbits. It's essential to test the Raptor engine's ability to reignite in space for a deorbit burn to steer Starship out of orbit toward an atmospheric reentry. //

The second change SpaceX will introduce on this test flight involves the vehicle's heat shield. These modifications will allow engineers to gather data before future attempts to return Starship to land at SpaceX's Starbase launch site in South Texas.

Perhaps as soon as next year, SpaceX wants to bring Starship back to Starbase to be caught by mechanical arms on the launch tower, similar to the way the company recovered the rocket's Super Heavy booster for the first time last month. Eventually, SpaceX aims to rapidly reuse Super Heavy boosters and Starships.

"The flight test will assess new secondary thermal protection materials and will have entire sections of heat shield tiles removed on either side of the ship in locations being studied for catch-enabling hardware on future vehicles," SpaceX wrote on its mission overview page.

SpaceX installed catch fittings on the Super Heavy booster to allow it to be captured by the launch tower's catch arms. The ship will need similar fittings jutting out from its heat shield.

"The ship also will intentionally fly at a higher angle of attack in the final phase of descent, purposefully stressing the limits of flap control to gain data on future landing profiles," SpaceX said. //

SpaceX seeks to fly Starships as many as 25 times next year, so cutting down the turnaround time between flights is fundamental to the company's plans. Making Starship capable of sustained orbital operations—something the in-space engine relight should enable—is a prerequisite for launching Starlink satellites or refueling Starships in orbit.

The Falcon 9 rocket is truly delivering on the promise of rapid, reusable launch.

SpaceX recently hit some notable milestones with its workhorse Falcon 9 rocket, and even in the full context of history, the performance of the vehicle is pretty incredible.

Last Tuesday, the company launched a batch of Starlink v2-mini satellites from Kennedy Space Center in Florida on a Falcon 9 rocket, marking the 400th successful mission by the Falcon 9 rocket. Additionally, it was the Falcon program's 375th booster recovery, according to SpaceX. Finally, with this mission, the company shattered its record for turnaround time from the landing of a booster to its launch to 13 days and 12 hours, down from 21 days.

But even though it was mere hours before the Thanksgiving holiday in the United States, SpaceX was not done for the month. On Saturday, November 30, the company launched twice more in a little more than three hours. The payloads were more Starlink Internet satellites in addition to two Starshield satellites—a custom version of Starlink for the US Department of Defense—for the US military. //

So far this year, SpaceX has launched a total of 119 Falcon 9 rockets, for an average of a launch every 2.3 days. The company has already superseded its previous record total for annual Falcon 9 launches, 92, completed last year. If SpaceX achieves its goal of 15 additional Falcon 9 launches this month, it would bring the company's total this year to 134 flights. If you add two Falcon Heavy missions to that, it brings the total to 136 launches.

That is a meaningful number, because over the course of the three decades it flew into orbit, NASA's Space Shuttle flew 135 missions.

The space shuttle was a significantly more complex vehicle, and unlike the Falcon 9 rocket, humans flew aboard it during every mission. However, there is some historical significance in the fact that the Falcon rocket may fly as many missions in a single year as the space shuttle did during its lifetime. //

The principal goal of the Falcon program was to demonstrate rapid, low-cost reusability. By one estimate, it cost NASA about $1.5 billion to fly a single space shuttle mission. (Like the Falcon 9, the shuttle was mostly but not completely reusable.) SpaceX's internal costs for a Falcon 9 launch are estimated to be as low as $15 million. So SpaceX has achieved a flight rate about 30 times higher than the shuttle at one-hundredth the cost.

Space enthusiast Ryan Caton also crunched the numbers on the number of SpaceX launches this year compared to some of its competitors. So far this year, SpaceX has launched as many rockets as Roscosmos has since 2013, United Launch Alliance since 2010, and Arianespace since 2009. This year alone, the Falcon 9 has launched more times than the Ariane 4, Ariane 5, or Atlas V rockets each did during their entire careers. //

Booster no. 1067 completed its 23rd flight by launching the Koreasat 62 mission into geostationary transfer orbit. Maybe we'll see it go for two dozen before 2024 is out? //

PhillyJimi Wise, Aged Ars Veteran
7y
154
Missing another really important point. SX is going to build over 100 2nd stages this year and they have build over 400. Yes, reusing the 1st stage is great but that is some impressive production from SX to kick out that many 2nd stages. //

Wickwick Ars Legatus Legionis
14y
37,082
OrvGull said:
Goes to show what a cul-de-sac manned space flight was.

The Shuttle's flight rate was not limited to what it was because it was manned.

By the time it retires, Atlas V will have flown about 115 flights in 24 years. That's a worse cadence than the Shuttles maintained. By your logic, it's an example of what a cul-de-sac unmanned flight was. //

pavon Ars Tribunus Militum
17y
2,206
Subscriptor
That shuttle comparison isn't apples to apples. First, Crew Dragon missions cost a lot more than a normal Falcon 9 launch. SpaceX is paid $350 million per mission, and OIG has estimated Space X's internal cost to be around $220 million per mission. In addition the Shuttle was able to launch both crew and cargo at once, and usually did so with ISS missions. The shuttle cargo capacity was roughly double a reusable Falcon 9 or half a reusable Falcon Heavy. Published Falcon Heavy mission prices vary a lot (from $117-330 million), but lets take a WAG and say $100 million internal cost. So depending on mission needs the comparison would range from:

Crew Dragon + Falcon Heavy Cargo $330M ~= 1/4.5 Shuttle
Crew Dragon + Falcon 9 Cargo $235M ~= 1/6 Shuttle
Falcon Heavy Only $100M ~= 1/15 Shuttle
Falcon 9 Only $15M ~= 1/100 Shuttle

So for the most common ISS case the Shuttle was about 5 times more expensive than Space X, and that is internal cost - it would be closer comparing the actual price NASA pays. That is still a big multiplier, but it was only when the humans weren't a mission requirement and were only along for the ride that it was stupid expensive. //

mhalpern Ars Praefectus
6y
42,765
latteland said:
SpaceX is amazing, world beating even, but this comparison is misleading. The shuttle was human rated and a generic falcon 9 is not. The human rated versions of falcon 9 have performed extremely well, but they don't launch them over and over for human use, just once afaik.
all F9s flying today are human rated, they just don't put people on them after their 5th flight

SpaceX has unlocked an impressive achievement – 400 launches of its workhorse Falcon 9 rocket.

The launch on November 27 at 0441 UTC was to deploy another batch of 24 Starlink satellites into orbit. The Falcon 9 took off from LC-39A at Kennedy Space Center, and the booster landed successfully on SpaceX's A Shortfall of Gravitas droneship, marking the 375th booster landing. //

117 of the 400 Falcon 9 launches were conducted in 2024 alone, and it is likely the company could achieve 136 total launches this year if things go according to plan. //

Male bovine excrement.

...it's difficult not to connect the company's breathtaking launch pace and acceleration with the emergence of some quality issues...

A 0.495% (99.505% success) chance of loss of cargo is phenomenal—Soyuz has launched 1800 times, and has a ~5% chance of failure. The recent incidents aren't quality issues. Space is hard. The fact that SpaceX's teams have achieved this reliability is a testament to their gold-standard quality control practices.

Re: Male bovine excrement.
They have probably learnt from Richard Feynman's statement regarding the Space Shuttle Challenger disaster, when he compared the NASA management's estimation of the catastrophic failure rate of the spacecraft with the engineers' estimates:

It appears that there are enormous differences of opinions to the probability a failure with loss of vehicle and of human life. The estimates range from roughly 1 in 100 to 1 in 100,000. The higher figures come from working engineers, and the very low figures come from management. What are the causes and consequences of this lack of agreement? Since 1 part in 100,000 would imply that one could launch a shuttle every day for 300 years expecting to lose only one, we could properly ask, "What is the cause of management's fantastic faith in the machinery?"

(From Appendix F: Personal Observations on the Reliability of the Shuttle, in 'What do you care what other people think?'.)

Easy Rider
SpaceX has made space look ... easy. Which, of course, it still isn't. But their achievements really cannot be underestimated - they have rewritten the book. Far and away Musk's most interesting company, although he obviously doesn't deserve all the credit. He certainly employs some stellar engineers. I'll always remember the first demo launch of Crew Dragon in 2020 - such an incredible thing, seeing that uber-slick capsule and those uber-slick suits, cruising up to space like a bus ride to town. One of the few highlights of lockdown!

Deputy Defense Press Secretary Sabrina Singh, speaking at the daily Pentagon press briefing, identified the missile as " an experimental intermediate-range ballistic missile" based on an existing ICBM design. She also confirmed that Russia had alerted the Pentagon to the launch in accordance with nuclear risk reduction protocols. //

The fact that this was not an ICBM indicates that the strike was not Putin signaling an increase in escalation. Russia has used missiles in the same class since the early days of the war, particularly the Iskander IRBM. //

Russia's use of the existing nuclear risk reduction channels to warn the US of the launch indicates that Putin is concerned about how the United States and NATO perceive his actions. //

Now that we know what the missile was, we still aren't sure what we saw in the video.

The video shows the same attack twice, probably to make it longer. The first problem is that there are no explosions at impact. A MIRV has a lot of kinetic energy; what is missing from the video is evidence of chemical energy. There seem to be about 17 individual warheads. If we use the Iskander as a proxy, this would reduce the throw-weight of each to about 100 pounds.

Compare this video with that of US MIRV tests at Kwajalein Atoll.
https://youtu.be/3ZM3y5qpMgY
https://youtu.be/Eh96NdcgE2Y

The lack of damage and casualties reported from Dnipro also hints that the warheads were purely kinetic, which begs the question of their guidance system.

thinkreal Ars Praetorian
22y
573
I’m still boggled by the contrast of approaches to engineering. How long have the Orion team been wringing hands over heat shield tiles after some anomalous but not disastrous effects? SpaceX - “let’s rip off a couple thousand tiles and see how the steel holds up, next year we want to try some new hardware somewhere around there” //

AverageDutchGuy Ars Scholae Palatinae
5y
822
Super3DPC said:
3 things that surprise me on this flight:

1. How routine it feels. I no longer hurry to catch the launch live. I wait until the whole thing is over and skip the video forward a few times. 6 launches this and it's almost boring already. I'm just too spoiled.
2. After re-entry we can see parts of Starship stainless steel change color to have rainbow tint. Can those skin be reuse without changing them? Rainbow tint on stainless means excessive oxidation IIRC.
3. I thought they'd use RCS to reorient Starship before engine relight. I mean the whole point of relight test is to make sure Starship can re-enter the atmosphere right? Can't do re-enter atmosphere without RCS reorienting Starship before re-entry burn right?

Rainbow discoloration on stainless just means a (thin) oxidation film has happened (and the color can be a nice indicator of what temperature was reached (for the dark purple to dark blue observed on the ship it would be between 450 to 600 degrees centigrade respectively, with bright blue being reached around 540) If it didn't deform I see no reason why it would have to be replaced, unless excessive tempering would occur in the likely cold-rolled skin material and ultimate strength was impacted.

Edit to add: heat range given is accurate for AISI304, since Starship uses (iirc) AISI 301 it might be slightly off. Source: https://bssa.org.uk/bssa_articles/heat-tint-temper-colours-on-stainless-steel-surface-heated-in-air/. //

Endymio Smack-Fu Master, in training
2m
53
jeremyp66 said:
Reusable spacecraft have been done before.

None anywhere near this size and scale.

jeremyp66 said:
for perspective, the sixth launch of Saturn V put two men on the Moon.

At a cost of several percent of the nation's total GDP: roughly $290 billion in 2024 dollars. Musk is doing it for a little over 1% of this.

jeremyp66 said:
OK so let's stop pretending that SpaceX is doing this "privately". Starship is substantially funded by the US tax payers. Starship is part of Artemis.

No, more precisely, the preexisting Starship concept is being used in Artemis, among many other things. That's how Musk was able to underbid the competition. His original Artemis bid was ~$2.8B: competitors ranged from $4B to $10B, for proposals which were less competent and flexible as well. All the Artemis funds are only about a third of Starship's R&D costs alone, not even counting the operational costs of the moon mission itself. //

Endymio Smack-Fu Master, in training
2m
53
MagicDot said:
Another very small step forward, almost matching the achievements of 1962.

Saturn V put 2 men on the moon -- by throwing away the vast majority of the hardware used to get there. Starship will place 100 on the moon, plus cargo, at a cost of ~1% of Saturn V ... and keep all that pricey hardware to boot.

MagicDot said:
That definitely is an acid test...and Elon is clearly on acid to think he's pulling that off in his lifetime.

Interesting. I recall the exact thing said about Tesla's ability to compete against entrenched automakers, or their ability to manufacture their own batteries at scale, or SpaceX's ability to manufacture reusable rockets or launch a 6000+ satellite constellation.

the FAA indicated that it will grant SpaceX permission to increase the number of Starship launches in South Texas to 25 per year from the current limit of five. Additionally, the company will likely be allowed to continue increasing the size and power of the Super Heavy booster stage and Starship upper stage. //

For example, the number of large trucks that deliver water, liquid oxygen, methane, and other commodities will increase substantially. According to the FAA document, the vehicle presence will grow from an estimated 6,000 trucks a year to 23,771 trucks annually. This number could be reduced by running a water line along State Highway 4 to supply the launch site's water deluge system. //

During recent public meetings, SpaceX's general manager of Starbase, Kathy Lueders, has said the company aims to launch Starship 25 times next year from Texas. The new regulations would permit this.

Additionally, SpaceX founder Elon Musk has said the company intends to move to a larger and more powerful version of the Starship and Super Heavy rocket about a year from now. This version, dubbed Starship 3, would double the thrust of the upper stage and increase the thrust of the booster stage from about 74 meganewtons to about 100 meganewtons. If that number seems a little abstract, another way to think about it is that Starship would have a thrust at liftoff three times as powerful as NASA's Saturn V rocket that launched humans to the Moon decades ago. The draft environmental assessment permits this as well.

Finally, the document also grants SpaceX permission to land all 25 of the first and second stages back at the Starbase facility.

The Starship launch system is about to reach a tipping point, Gwynne Shotwell said, as it moves from an experimental rocket toward operational missions.

"We just passed 400 launches on Falcon, and I would not be surprised if we fly 400 Starship launches in the next four years," Shotwell said at the Baron Investment Conference in New York City. "We want to fly it a lot."

That lofty goal seems aspirational, not just because of the hardware challenges but also due to the ground systems (SpaceX currently has just one operational launch tower) as well as the difficulty of supplying that much liquid oxygen and methane for such a high flight rate. However, it's worth noting that SpaceX will launch Starship four times this year, twice the number of Falcon Heavy missions. An acceleration of Starship is highly likely. //

"Starship obsoletes Falcon 9 and the Dragon capsule," she said. "Now, we are not shutting down Dragon, and we are not shutting down Falcon. We'll be flying that for six to eight more years, but ultimately, people are going to want to fly on Starship. It's bigger. It's more comfortable. It will be less expensive. And we will have flown it so many more times.". //

As Starlink has come online, it has significantly increased the valuation of the privately held company. A decade ago, SpaceX was valued at about $12 billion, and this grew to $36 billion in 2020. Most recently, the company was valued at about $255 billion. //

DDopson Ars Tribunus Militum
22y
2,397
Subscriptor++
daddyboomalati said:
Can someone unpack this for me? I cannot understand how a massive rocket is a better choice than the Falcon 9 for medium-weight payloads. My only thought is that it delivers multiple satellites at once. I do it all the time in Kerbal Space Program, but is this a thing in real life, or an eventual likelihood?
It's simpler than that. Starship costs less to launch than F9.

Each F9 launch expends a second stage that costs roughly $20M to fabricate. They do recover the $40M booster and the $6M fairings, but they have to fabricate a new second stage for every launch. And that second stage consumes one Merlin engine, but that's only a relatively small fraction of the stage's cost, on account of SpaceX's spectacular efficiency at manufacturing rocket engines for <$1M, literally hundreds of times cheaper than, eg, the RS-25 engines NASA buys.

The cost to fuel a Starship is on the order of a few million, possibly in the $2M or $3M ballpark (this was estimated in a prior thread), probably more when including their current fueling logistics costs, possibly a bit less at scale when they are manufacturing their own LOX and can amortize various bits of fueling infra over a consistent level of demand.

Ground logistics add additional costs (control center staff, ground crew, amortized share of launch complex, etc), but these are hard to estimate. Dividing the entire Boca Chica facility cost over ~5 test launches would produce an unfavorable number, but that's silly. The ground facilities should amortize fairly well as the launch cadence increases. And this stuff is probably mostly comparable between the two platforms.

Sticking with relatively conservative numbers, I expect their all-up internal marginal cost per Starship launch to be well under $10M per flight, much less than the cost of fabricating a new F9 second stage.

Launching Starship is thus cheaper than launching F9.

Now that's an internal cost that we may never learn with precision, and SpaceX will make a business decision about what price to charge to their customers. They may create very attractive rates for rideshares. They will likely maintain high prices for "white glove" launch contracts that include significant payload preparation and other services, especially DoD and NASA, which already typically pay more per F9 launch contract than the sticker price on the website for "just a launch". //

Delta-V required for transfer orbit between planets

KSP Visual Calculator, online tool that determines delta-v required for multiple checkpoint missions

Like a lot of competitors in the global launch industry, Russia for a long time dismissed the prospects of a reusable first stage for a rocket.

As late as 2016, an official with the Russian agency that develops strategy for the country's main space corporation, Roscosmos, concluded, "The economic feasibility of reusable launch systems is not obvious." In the dismissal of the landing prospects of SpaceX's Falcon 9 rocket, Russian officials were not alone. Throughout the 2010s, competitors including space agencies in Europe and Japan, and US-based United Launch Alliance, all decided to develop expendable rockets.

However, by 2017, when SpaceX re-flew a Falcon 9 rocket for the first time, the writing was on the wall. "This is a very important step, we sincerely congratulate our colleague on this achievement," then-Roscosmos CEO Igor Komarov said at the time. He even spoke of developing reusable components, such as rocket engines capable of multiple firings.

A Russian Grasshopper
That was more than seven years ago, however, and not much has happened in Russia since then to foster the development of a reusable rocket vehicle. Yes, Roscosmos unveiled plans for the "Amur" rocket in 2020, which was intended to have a reusable first stage and methane-fueled engines and land like the Falcon 9. But its debut has slipped year for year—originally intended to fly in 2026, its first launch is now expected no earlier than 2030.

The answer is significantly dependent on how much aerodynamic pressure and heating you can tolerate, and whether it's possible to achieve high specific impulse from a rocket engine exhausting into Venusian atmosphere.

At 10km above the Venusian "reference altitude", a speed of only 46 m/s (~100 mph) puts you at a Q of 39.5kPa -- a little higher than "max Q" of most Earth-orbit launchers. If your Q limit is on that order of magnitude, it's going to take you a very long time to get out of the Searing Black Calm, which means you're going to lose a lot of delta-v to gravity -- it takes about 8 minutes going straight up before you can even think about pitching over into a gravity turn.

At least one person has estimated the delta-v to reach Venusian orbit at 27km/s, but they did not provide much detail on their methodology.

By having elfin engineers provide a magical rocket engine capable of ~240s specific impulse when exhausting into 60 atmospheres of pressure, I was able to reach orbit in my home-brewed simulation, lifting off from Maat (to save me 8km and 30 atmospheres of vertical suffering), with about 15000 m/s of delta-v. Max Q achieved was 55 kPa.

It would be physically possible, but there's no practical way to do it just with chemically-propelled rockets. The extremely high density of the atmosphere caps the top speed of the rocket until it's at high altitude, exacerbating gravity loss, so you'd need a ridiculous propellant mass ratio. (At only 100mph, the dynamic pressure at low altitude is comparable to the supersonic max-Q of a terrestrial rocket launch.)

What could conceivably work would be to use balloon ascent to get up to a high altitude "for free" and then use a chemical rocket from there. Designing and engineering something that can land, collect samples, inflate a balloon in the Venusian surface environment, and conduct an interplanetary launch from there is left as an exercise for the reader. //

@jwenting don't forget being chemically resilient to sulfuric acid at 700 K

BOCA CHICA BEACH, Texas—I've taken some time to process what happened on the mudflats of South Texas a little more than a week ago and relived the scene in my mind countless times.

With each replay, it's still as astonishing as it was when I saw it on October 13, standing on an elevated platform less than 4 miles away. It was surreal watching SpaceX's enormous 20-story-tall Super Heavy rocket booster plummeting through the sky before being caught back at its launch pad by giant mechanical arms. //

What's not so easy to address is how SpaceX can top this. A landing on the Moon or Mars? Sure, but realistically, those milestones are years off. There's something that'll happen before then.

Sometime soon, SpaceX will try to catch a Starship back at the launch pad at the end of an orbital flight. This will be an extraordinarily difficult feat, far exceeding the challenge of catching the Super Heavy booster.