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.

Lunar exploration is undergoing a renaissance. Dozens of missions, organized by multiple space agencies—and increasingly by commercial companies—are set to visit the Moon by the end of this decade. Most of these will involve small robotic spacecraft, but NASA’s ambitious Artemis program aims to return humans to the lunar surface by the middle of the decade.

There are various reasons for all this activity, including geopolitical posturing and the search for lunar resources, such as water-ice at the lunar poles, which can be extracted and turned into hydrogen and oxygen propellant for rockets. However, science is also sure to be a major beneficiary.

The Moon still has much to tell us about the origin and evolution of the Solar System. It also has scientific value as a platform for observational astronomy. //

Several types of astronomy would benefit. The most obvious is radio astronomy, which can be conducted from the side of the Moon that always faces away from Earth—the far side.

The lunar far side is permanently shielded from the radio signals generated by humans on Earth. During the lunar night, it is also protected from the Sun. These characteristics make it probably the most “radio-quiet” location in the whole solar system, as no other planet or moon has a side that permanently faces away from the Earth. It is, therefore, ideally suited for radio astronomy. //

At that time, most of the matter in the Universe, excluding the mysterious dark matter, was in the form of neutral hydrogen atoms. These emit and absorb radiation with a characteristic wavelength of 21 cm. Radio astronomers have been using this property to study hydrogen clouds in our own galaxy—the Milky Way—since the 1950s.

Because the Universe is constantly expanding, the 21 cm signal generated by hydrogen in the early Universe has been shifted to much longer wavelengths. As a result, hydrogen from the cosmic “dark ages” will appear to us with wavelengths greater than 10 m. The lunar far side may be the only place where we can study this. //

Moreover, there are craters at the lunar poles that receive no sunlight. Telescopes that observe the Universe at infrared wavelengths are very sensitive to heat and therefore have to operate at low temperatures. JWST, for example, needs a huge sun shield to protect it from the sun’s rays. On the Moon, a natural crater rim could provide this shielding for free. //

But there is also a tension here: human activities on the lunar far side may create unwanted radio interference, and plans to extract water-ice from shadowed craters might make it difficult for those same craters to be used for astronomy. As my colleagues and I recently argued, we will need to ensure that lunar locations that are uniquely valuable for astronomy are protected in this new age of lunar exploration.

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 agency tasked government labs, research institutions, and commercial companies to come up with better ideas to bring home the roughly 30 sealed sample tubes carried aboard the Perseverance rover. NASA deposited 10 sealed tubes on the surface of Mars a couple of years ago as insurance in case Perseverance dies before the arrival of a retrieval mission.

"We want to have the quickest, cheapest way to get these 30 samples back," Nelson said. //

"It has been more than two years since NASA paused work on MSR," the Planetary Society said. "It is time to commit to a path forward to ensure the return of the samples already being collected by the Perseverance rover.

"We urge the incoming Trump administration to expedite a decision on a path forward for this ambitious project, and for Congress to provide the funding necessary to ensure the return of these priceless samples from the Martian surface."
China says it is developing its own mission to bring Mars rocks back to Earth. Named Tianwen-3, the mission could launch as soon as 2028 and return samples to Earth by 2031. While NASA's plan would bring back carefully curated samples from an expansive environment that may have once harbored life, China's mission will scoop up rocks and soil near its landing site.

"They’re just going to have a mission to grab and go—go to a landing site of their choosing, grab a sample and go," Nelson said. "That does not give you a comprehensive look for the scientific community. So you cannot compare the two missions. Now, will people say that there’s a race? Of course, people will say that, but it’s two totally different missions."

Still, Nelson said he wants NASA to be first. He said he has not had detailed conversations with Trump's NASA transition team.

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.

Almost no one ever writes about the Parker Solar Probe anymore.

Sure, the spacecraft got some attention when it launched. It is, after all, the fastest moving object that humans have ever built. At its maximum speed, goosed by the gravitational pull of the Sun, the probe reaches a velocity of 430,000 miles per hour, or more than one-sixth of 1 percent the speed of light. That kind of speed would get you from New York City to Tokyo in less than a minute. //

However, the smallish probe—it masses less than a metric ton, and its scientific payload is only about 110 pounds (50 kg)—is about to make its star turn. Quite literally. On Christmas Eve, the Parker Solar Probe will make its closest approach yet to the Sun. It will come within just 3.8 million miles (6.1 million km) of the solar surface, flying into the solar atmosphere for the first time.

Yeah, it's going to get pretty hot. Scientists estimate that the probe's heat shield will endure temperatures in excess of 2,500° Fahrenheit (1,371° C) on Christmas Eve, which is pretty much the polar opposite of the North Pole. //

I spoke with the chief of science at NASA, Nicky Fox, to understand why the probe is being tortured so. Before moving to NASA headquarters, Fox was the project scientist for the Parker Solar Probe, and she explained that scientists really want to understand the origins of the solar wind.

This is the stream of charged particles that emanate from the Sun's outermost layer, the corona. Scientists have been wondering about this particular mystery for longer than half a century, Fox explained.

"Quite simply, we want to find the birthplace of the solar wind," she said.

Way back in the 1950s, before we had satellites or spacecraft to measure the Sun's properties, Parker predicted the existence of this solar wind. The scientific community was pretty skeptical about this idea—many ridiculed Parker, in fact—until the Mariner 2 mission started measuring the solar wind in 1962.

As the scientific community began to embrace Parker's theory, they wanted to know more about the solar wind, which is such a fundamental constituent of the entire Solar System. Although the solar wind is invisible to the naked eye, when you see an aurora on Earth, that's the solar wind interacting with Earth's magnetosphere in a particularly violent way.

Only it is expensive to build a spacecraft that can get to the Sun. And really difficult, too.

Now, you might naively think that it's the easiest thing in the world to send a spacecraft to the Sun. After all, it's this big and massive object in the sky, and it's got a huge gravitational field. Things should want to go there because of this attraction, and you ought to be able to toss any old thing into the sky, and it will go toward the Sun. The problem is that you don't actually want your spacecraft to fly into the Sun or be going so fast that it passes the Sun and keeps moving. So you've got to have a pretty powerful rocket to get your spacecraft in just the right orbit. //

But you can't get around the fact that to observe the origin of the solar wind, you've got to get inside the corona. Fox explained that it's like trying to understand a forest by looking in from the outside. One actually needs to go into the forest and find a clearing. However, we can't really stay inside the forest very long—because it's on fire.

So, the Parker Solar Probe had to be robust enough to get near the Sun and then back into the coldness of space. Therein lies another challenge. The spacecraft is going from this incredibly hot environment into a cold one and then back again multiple times.

"If you think about just heating and cooling any kind of material, they either go brittle and crumble, or they may go like elastic with a continual change of property," Fox said. "Obviously, with a spacecraft like this, you can't have it making a major property change. You also need something that's lightweight, and you need something that's durable."

The science instruments had to be hardened as well. As the probe flies into the Sun there's an instrument known as a Faraday cup that hangs out to measure ion and electron fluxes from the solar wind. Unique technologies were needed. The cup itself is made from sheets of Titanium-Zirconium-Molybdenum, with a melting point of about 4,260° Fahrenheit (2,349° C). Another challenge came from the electronic wiring, as normal cables would melt. So, a team at the Smithsonian Astrophysical Observatory grew sapphire crystal tubes in which to suspend the wiring, and made the wires from niobium.

Does “Pix or it didn’t happen” apply to traveling to the edge of space on a balloon-lofted solar observatory? Yes, it absolutely does.

The breathtaking views on this page come courtesy of IRIS-2, a compact imaging package that creators [Ramón García], [Miguel Angel Gomez], [David Mayo], and [Aitor Conde] recently decided to release as open source hardware. It rode to the edge of space aboard Sunrise III, a balloon-borne solar observatory designed to study solar magnetic fields and atmospheric plasma flows.

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.

Here's the math behind making a star-encompassing megastructure.

In 1960, visionary physicist Freeman Dyson proposed that an advanced alien civilization would someday quit fooling around with kindergarten-level stuff like wind turbines and nuclear reactors and finally go big, completely enclosing their home star to capture as much solar energy as they possibly could. They would then go on to use that enormous amount of energy to mine bitcoin, make funny videos on social media, delve into the deepest mysteries of the Universe, and enjoy the bounties of their energy-rich civilization.

But what if the alien civilization was… us? What if we decided to build a Dyson sphere around our sun? Could we do it? How much energy would it cost us to rearrange our solar system, and how long would it take to get our investment back? Before we put too much thought into whether humanity is capable of this amazing feat, even theoretically, we should decide if it’s worth the effort. Can we actually achieve a net gain in energy by building a Dyson sphere? //

Even if we were to coat the entire surface of the Earth in solar panels, we would still only capture less than a tenth of a billionth of all the energy our sun produces. Most of it just radiates uselessly into empty space. We’ll need to keep that energy from radiating away if we want to achieve Great Galactic Civilization status, so we need to do some slight remodeling. We don’t want just the surface of the Earth to capture solar energy; we want to spread the Earth out to capture more energy. //

For slimmer, meter-thick panels operating at 90 percent efficiency, the game totally changes. At 0.1 AU, the Earth would smear out a third of the sun, and we would get a return on our energy investment in around a year. As for Jupiter, we wouldn’t even have to go to 0.1 AU. At a distance about 30 percent further out than that, we could achieve the unimaginable: completely enclosing our sun. We would recoup our energy cost in only a few hundred years, and we could then possess the entirety of the sun’s output from then on. //

MichalH Smack-Fu Master, in training
4y
62

euknemarchon said:
I don't get it. Why wouldn't you use asteroid material?
The mass of all asteroids amounts to only 3% of the earth's moon. Not worth chasing them down, I'd guess. //

DCStone Ars Tribunus Militum
14y
2,313
"But [Jupiter]’s mostly gas; it only has about five Earth’s worth of rocky material (theoretically—we’re not sure) buried under thousands of kilometers of mostly useless gas. We'd have to unbind the whole dang thing, and then we don’t even get to use most of the mass of the planet."

Hmm. If we can imagine being able to unbind rocky planets, we can also imagine fusing the gas atmosphere of Jupiter to make usable material (think giant colliders). Jupiter has a mass of about 1.9 x 10^27 kg, of which ~5% is rocky core. We'd need to make some assumptions about the energy required to fuse the atmosphere into something usable (silicon and oxygen to make silicates?) and the efficiency of that process. Does it do enough to change the overall calculation though? //

Dark Jaguar Ars Tribunus Angusticlavius
9y
11,066
The bigger issue is the sphere wouldn't be gravitationally locked in place because the sun is cancelling it's own pull in every direction. Heck even Ringworld had to deal with this flaw in the sequel. That's why these days the futurists talking about enclosing the sun recommend "Dyson swarming" instead.

Edit: A little additional note. You can't really get the centrifugal force needed to generate artificial gravity across an entire sphere like you can with a ring. A swarm doesn't negate this. If you orbit fast enough to generate that artificial gravity, you're now leaving the sun behind. Enjoy drifting endlessly! No, rather each of these swarm objects are just going to have to rotate themselves decently fast.

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

The Voyager probes have entered a new phase of operations. As recent events have shown, keeping the venerable spacecraft running is challenging as the end of their mission nears.

As with much of the Voyager team nowadays, Kareem Badaruddin, a 30-year veteran of NASA's Jet Propulsion Laboratory (JPL), divides his time between the twin Voyager spacecraft and other flight projects. He describes himself as a supervisor of chief engineers but leaped at the chance to fill the role on the Voyager project. //

With physical hardware long gone, the team has an array of simulators. "We have a very clear understanding of the hardware," said Badaruddin. "We know exactly what the circuitry is, what the computers are, and where the software runs."

And the software? It's complicated.

There have been so many tweaks and changes over the years that working out the exact revision of every part of Voyager's code is tricky. "It's usually easier to just get a memory readout from the spacecraft to find out what's on there," said Badaruddin.

We're sure there are more than a few engineers on Earth who are not entirely sure what their systems are running. The challenge for the Voyager team is that the spacecraft are nearing the half-century mark, as is the documentation. //

The Voyager spacecraft are unlikely to survive another decade. The power will eventually dwindle to the point where operations will be impossible. High data rates (relatively speaking – Voyager's high data rate is 1.4 kilobits per second) will only be supported by the current Deep Space Network (DSN) until 2027 or 2028. After that, some more creativity will be needed to operate Voyager 1's digital tape recorder.

Badaruddin speculates that shutting off another heater (the Bay One heater) used for the computers would free up power for the recorder, according to the thermal model, but it'll be a delicate balancing act. //

Badaruddin hopes to stick with the mission until the final transmission from the spacecraft.

"I love Voyager. I love this work. I love what I'm doing. It's so cool. It just feels like I've got the best job at JPL." ®. //

The Farthest
The Farthest is an excellent documentary on Voyager produced by a friend of mine, Clare Stronge.

Watch it here - https://youtu.be/1g6uFe3vZE0?si=BIQR-GjLt1E2a4Xh

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

In reporting on a radiation study, a nearly universal practice of the 'experts' is to show us only the subjects' total doses. They do this despite the fact that usually what is measured is the dose rate profile, often in the form of daily doses. The total dose is computed by adding up these daily doses, and then tossing aside everything but the total. Analyzing radiation harm by only looking at total dose is like an electrical engineer attempt to analyze a complicated circuit by only looking at the annual energy input.

The human body is an extremely complex circuit. It has to be analyzed dynamically. The essential element of SNT [Signmoid No Threshold] is not the shape of the acute dose response curve, it is chopping the dose rate profile into repair periods, and analyzing each period separately. //

Where would we encounter 1 and 2 mSv/d dose rate profiles for decades? That's an easy one. Space travel. The astronauts in Low Earth Orbit get between 0.5 and 1.0 mSv/d, with occasional spikes during solar flares. High Earth Orbit or a trip to Mars will about double that. If LNT were valid, the shielding requirements would be prohibitively expensive.

NASA can't afford LNT. That's why it ignores all the EPA and NRC limits. The EPA says more than 1 mSv per year is unsafe. NASA says 1 mSv per day is routine. That's the difference between the top and bottom of Figure 1.

NASA is not the only entity that cannot afford LNT. Space travel is a luxury that humanity may or may not be able to afford. The benefits of manned space travel are at best speculative. The benefits of cheap nuclear electricity are undeniable and cornucopic. If we can correctly trash LNT to go into space, surely we can junk this counterfactual hypothesis to get cheap nuclear.

NASA uncovers 50 ‘areas of concern’ including leaks and cracks on the 25-year-old space station. //

Over the past two decades, the ISS has been a hub for groundbreaking scientific research. The microgravity environment has enabled significant advancements in studying diseases like Alzheimer’s, Parkinson’s, cancer, asthma, and heart disease. The unique conditions allow researchers to observe cellular and molecular changes impossible on Earth.

Without the interference of Earth’s gravity, Alzheimer’s researchers have studied protein clusters that can cause neurodegenerative diseases. Cancer researchers studied the growth of endothelial cells on the space station.

Endothelial cells help supply blood in the body, and tumors need that blood to form. Space station-grown cells grow better than those on Earth and can help test new cancer treatments.

Why do this in space? Studying cells, organoids, and protein clusters without the influence of gravity – or even the forces of container walls – can help researchers get a clearer understanding of their properties, behaviors, and responses to treatments.

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

I'm over the left pretending like it cares about the human race when it consistently exhibits a disdain and sometimes hostile attitude toward it. All the venerated minds that the left holds in high regard, seem to think that humanity is killing the planet, chiding and lecturing us about our use of fossil fuels and claiming we've stolen the hopes and dreams of future generations. //

As Susie Moore reported on Sunday, Elon Musk and SpaceX are making huge advancements all the time, bringing humanity closer and closer to being a space-faring species. In an incredible display of technological advancement, SpaceX was able to catch a Super Heavy booster with "Mechazilla" arms. An engineering feat that will go down in history as one of the greatest achievements in space travel. //

Of course, there are people out there who are so shortsighted, they see these advancements as negatives. They see it as billionaires wasting money that could be used for other things like feeding the hungry, saying that if the world does end, then the only people who will be able to leave are the billionaires building these rockets.

Dr. Grouf @DGrouf
·
Government efficiency to billionaires it means taking from the poor and enriching the wealthy and their servants, which is what this sob is going to do, people keep getting poorer while these b@stards keep building their net worths and wasting societal wealth on flying rockets.

Elon Musk @elonmusk
I hope I am able to serve the people in this regard. It is sorely needed.
10:37 AM · Oct 14, 2024 //

Sci-fi author Devon Erikson put it beautifully in his post on X:

Devon Eriksen @DevonEriksen
·
This is what will matter 1000 years from now.

Not your politics. Not your stupid tantrums about who platformed who on some website. Not your incomprehensible desire to send NASA's entire budget to the third world.

This guy reignited the Space Age.

He spent his own money,… Show more

Instead of fighting over little patches of land, we will have an infinite 3d volume. Enclose it in steel, pump it full of air, spin it, and it's a habitat. Instead of scratching tiny scraps of metal out of the crust of one planet, we will break down entire asteroids and smelt them. Instead of drilling for hydrocarbons and turning water wheels, we will harness entire suns, split the atom, and eventually draw our fuel from the substance that makes up 99% of the entire universe. None of your local, temporal Earth politics matter compared to this. This is more important than pride parades and abortions, more important than tribal conflicts in eastern Europe and southwest Asia, more important than tensions with Russia and China. //

If the left truly cares about people like they say, or pretend they do, then with every successful advancement, every launched rocket, every person sent to space by a private company, they would whoop and cheer... but they aren't. It should make the left's ideological foundations morally suspect.