Meter forms 3, 4, 5, 6, 8, 9

The descent from lunar orbit to landing was broken into three phases, and each of these phases had a specific computer program associated with it. Here’s the way it worked on all six lunar landings:

The descent began with the braking phase — the first and longest phase. It was flown entirely automatically by the computer (Program 63). Its goal was to slow the spacecraft from about 3,800 miles/hour to about 700 miles/hour, and to decrease the LM’s altitude from about 50,000 feet to 7,000 feet.
The approach phase began when the LM was about 7,000 feet in altitude and about 2 miles from the landing site. The computer was still doing all the flying (Program 64), but the crew could now see the landing site and offer adjustments to the computer.
The landing phase began around 500 - 700 feet in altitude. The Commander flipped a switch next to his left thumb, causing the computer to switch to Program 66. The computer was now in what was known as attitude hold. The Commander selected the spot where he wanted to land, and used his controls to tell the computer where to go. The computer was also responsible for keeping the LM upright. The landing phase ends with the LM on the lunar surface. //

Here are the times (in minutes and seconds) that each of the missions spent in the landing phase:

Apollo 11: 2:23

Apollo 12: 1:44

Apollo 14: 2:01

Apollo 15: 1:16

Apollo 16: 1:00

Apollo 17: 1:08

Apollo 11 had by far the longest landing phase — almost 2 and a half minutes. That’s how long it took Armstrong to find a suitable landing spot and guide the computer toward it.

At the other extreme was Apollo 16 — when it entered the landing phase, a suitable landing spot was right there and it took John Young only a minute to guide the computer through the last few hundred feet and onto the lunar surface.

All of these missions went through the same phases — they differed only in how long each phase lasted.

As far as Armstrong being the one to fly the LM, that was also the plan, and again, it was the Commander who guided the LM during the landing phase on all six lunar landing missions. The job of the LMP (Lunar Module Pilot) was to provide crucial support during the landing, monitoring systems and calling out numbers throughout the landing phase. If you listen to the audio of any of the lunar landings, the voice you hear calling out numbers is the LMP.

A drive down Bolivia's infamous "Death Road" takes travellers into a world where two resources have provoked fascination, misunderstanding and controversy for centuries: coca and gold.

After cresting the 4,800m Cumbre pass, the trufi (shared taxi) plunged into a cloud of swirling mist. Inside the vehicle it felt strangely peaceful, as if we were trapped in a bubble, which was perhaps for the best given we were travelling along the "Camino de la Muerte", or Death Road.

Running from the high-altitude Andean city of La Paz to the subtropical Yungas valleys and the Amazonian lowlands beyond, the 64km Yungas Road involves a sharp 3,500m descent. Parts of the highway are only 3m wide; there is a series of sharp turns and blind corners; and mini waterfalls splash down the surrounding rockface. Safety barriers make only a rare appearance – far more common are roadside shrines: white crosses, bunches of flowers, yellowing photos.

During the 1990s, so many people died in accidents on the highway – built by Paraguayan prisoners of war following the catastrophic Chaco War (1932-35) – that the Inter-American Development Bank described it as "the world's most dangerous road".

Stretching 2,700km from Laverton in Western Australia to Winton in far-off Queensland, the Outback Way is a great diagonal "shortcut" across the nation that saves weeks of travel.

It's mentioned in the Bible, it been used by a succession of empires and it links some of Jordan's most important historical sites.

"Welcome to Jordan!" a group of kids shouted excitedly, as I stepped out of the car to admire the sun setting over the vast sandstone canyon of Wadi Mujib.

While I stood on the cliff's edge, awestruck by the mountain ranges stretching to the Dead Sea, a black-and-white hooded wheatear swooped down near me. I wondered how something so delicate could survive in such desolate ravines, fluttering across the arid mountains and building nests in rock crevices.

From my perch, I could see a narrow, serpentine road winding down the ridges and gorges. This route, known as the King's Highway, or Darb ar-Raseef ("paved road", in Arabic), is believed to be one of the world's oldest continuously used roads. For millennia, merchants, pilgrims, warriors and kings travelled north to south through Jordan's central highlands, and this thoroughfare served as a vital artery connecting ancient kingdoms and empires.

A towering cotton tree which has stood for several hundred years in Sierra Leone's capital, Freetown, has been brought down by a heavy storm.

President Julius Maada Bio said the tree fell after a downpour on Wednesday night. He described it as a "great loss to the nation".

He said the tree was a symbol of liberty for early settlers. It also appears on Sierra Leone banknotes.

But some Christians hailed its demise, saying it was used for witchcraft.

A heavy rainstorm a week ago caused one of the tree's branches to fall, but it had been thought it would survive.

However, in another storm on Wednesday, the entire tree came down, leaving just part of the trunk still standing.

The city's skyline has changed dramatically as a result - some would say, for ever.

The 70m (230 ft)-high cotton tree was said to be the oldest of its kind in the country - a government statement estimated it to be 400 years old.

Just 300m away are the Freedom Steps, climbed by newly arrived freed slaves who offered prayers at the tree before making Freetown their home.

As the city grew over the years, it expanded around the ancient tree at its heart.

President Julius Maada Bio and other officials are expected to visit the site to determine what to do.

"We will have something at the same spot that bears testament to the great Cotton Tree's place in our history," he tweeted.

Jason • May 25, 2023 11:01 AM

This is 0th order thinking, probably not novel, and possibly GPT generated…

How long would it take for GPTs to generate the amount of text of all humans ever and basically have 50% of all language generation market share? 75%? 99%?

How would LMMs ‘know’ they are being trained on their own generative text vs human-created text?

Would LMMs suffer from copy-of-a-copy syndrome or maybe even a prion-type mad cow disorder?

Let’s say the term “American Farm” correlates 27% to “corn”, 24% to “soybeans”, 16% “wheat”. After many, many GPT cycles, with LMMs and it’s handlers unable to distiguish the source of the data, would it go to 78% corn, 18% soybeans, 3% wheat?

I don’t know if it will be poisonable, humans will not outpace GPT production for long (maybe the point has been passed). But it may be suseptible to it’s reinforcing it’s own predictions. Oh wait, it’s just like us!

Post Script • May 25, 2023 11:05 AM

Aren’t they already self-poisoned by being built on undifferentiated slop? They should have to start over with clean, inspectable data sets, curated and properly licensed and paid for, not scraped out of the worst cesspools on the internet and blended in with anything else they can steal.
If you steal indiscriminately, people are going to start defensive measures, whether it’s closing public access to sites to foil scrapers or setting out gift-wrapped boxes of poop.

TimH • May 25, 2023 11:06 AM

My concern is for the times when AI is used for evidential analysis, and the defendent asks for the algorithm, as in “confront the accuser”. There isn’t an algorithm. If courts just accept that AI gotta be correct and unbiassed, and the output can’t be challenged, then we are so stuffed as a society.

Winter • May 25, 2023 11:08 AM

@Jason

Would LMMs suffer from copy-of-a-copy syndrome or maybe even a prion-type mad cow disorder?…

Yes to all.

And this is not even joking, as much I would like to.

Anyone who wants to build LLMs will have to start with constructing filters to remove the output of other LLMs from their training data. //

Winter • May 25, 2023 2:46 PM

@Clive

“How would such a circuit be built?”

It cannot be done perfectly, or even approximately. But something has to be done to limit training on LLM output.

But, think about how much speech a child needs to learn a language? And how much reading is needed to acquire a university reading level? That is not even a rounding error of what current LLMs need. That amount can easily be created from verified human language.

So, construct an LM that can be trained on verified human language, then use that to extract knowledge from written sources that do not have to be human. Just like humans do it.

Not yet technically possible, but one has to prepare for the future.

Late last month, we reported on the case of 94-year-old grandmother Geraldine Tyler, whose Minneapolis condo was sold by Hennepin County in Minnesota for $40,000 to pay off a $15,000 tax debt: 94-year-old Grandmother Fights Home Equity Theft at the U.S. Supreme Court

The kicker was that instead of returning the $25,000 surplus over the amount Geraldine owed the state, Hennepin County decided to keep the whole amount! Even worse, the County’s retention of those funds was entirely in keeping with Minnesota state law, as we reported: //

in a unanimous opinion authored by Chief Justice Roberts, the Court gave short shrift to the Eighth Circuit’s “state law controls” argument:

The Takings Clause does not itself define property…For that, the Court draws on ‘existing rules or understandings’ about property rights…State law is one important source…But state law cannot be the only source. Otherwise, a State could sidestep the Takings Clause by disavowing traditional property interests in assets it wishes to appropriate.

In other words, a state cannot just pass a state statute that lets them take your property without compensation, which is apparently what the County, and the federal district and appeals court thought. Or as the Supreme Court puts it: “The Takings Clause would be a dead letter if a state could simply exclude from its definition of property any interest that the state wished to take.” //

The Court then gives a history lesson, going all the way back to the Magna Carta, which said that “when [a] sheriff or bailiff came to collect any debts owed [the King] from a dead man, they could remove property ‘until the debt which is evident shall be fully paid to us; and the residue shall be left to the executors to fulfill the will of the deceased.” Blackstone, the leading legal authority in England in the 1700s, said, “[i]f a tax collector seized a taxpayer’s property, he was ‘bound by an implied contract in law to restore [the property] on payment of the debt, duty, and expenses, before the time of sale; or, when sold, to render back the overplus.'” //

The taxpayer must render unto Caesar what is Caesar’s, but no more.

Microsoft Excel's undo / redo feature behaves unlike any other program I know. The undo stack seems to be global across all open files, so that undoing sometimes switches to another file and undoes something you didn't want to undo. And if an edit you want to undo was before an edit in another file, you have no choice but to undo the other file.

I am not the first to complain about this - see "Excel's undo madness", about halfway down.

Besides "edit only one file at a time", is there a way to make Excel's Undo apply to the current file only?

I'm using Excel 2003 if it makes a difference. //

A: Open Excel itself in a new instance

For Excel's main shortcut you could simply add a /x flag after the address in the shortcut's Target field:

"C:\Program Files\...\EXCEL.EXE" /x

It also works for pinned start menu shortcuts in Windows 10 (You need to access the shortcut file in Start Menu\Programs directory)

Open Excel documents in a new instance

This solution works but makes the documents' icon changed which some may find it unpleasant.

To run .xls, .xlsx, .xlsm, etc documents directly in a new instance, you could first create a .bat file with the following content:

@ECHO off
start "" "C:\Program Files...\EXCEL.EXE" /x %1

Then you could simply associate each file format to your .bat file with Always use... checked. [Use a shortcut .lnk to the .bat file and associate the files with the .lnk with correct icon.]

Keep the ability to open files in the current instance
It's still necessary to open files in the current instance if you want to access the other files' content through formulas or VBA. In these cases, you could first open one file and then drag the other file(s) on the opened Excel window.

You could also use File > Open through the opened file. //

MS does this for Excel only due to cross-workbook references. The only way they can maintain integrity of formula relationships in that context is to maintain a single undo history. Further, to make it optional is extremely complicated: how does a user choose whether to have a single history or multiple histories? When would a user choose that? They could make it automatic basing on formula dependencies, but that can easily become impossible to manage logically and performance wise. Remember, they need to deliver a product that WORKS. –
Mr. TA Apr 19, 2016 at 15:47

@Mr.TA: Libre/Apache Office has links between files/sheets and they do undo on a per file/sheet level... just saying (that it is doable, totally doable, if you're not a lazy x -- which apparently seems to be the case with MS developers). –
Erk Feb 7, 2017 at 16:13

I can create cross-document links in Word, while also undoing in a single document. Clearly it can be done. Yes, the link may get broken, but that's my fault. I would greatly prefer that behaviour over this window-jumping undo-hell. –
JMD Jan 19, 2018 at 0:49

Bucking and weaving along the rugged contours of Norway's fractured coastline, the 670km road to the Artic is a triumph of human ingenuity and perseverance.
N

Norway's coastal road from the town of Stiklestad to the Arctic city of Bodø is a 670km journey between two very different worlds. It's also one of the most beautiful road trips on the planet.

At one end is the quiet sophistication of central Norway, with its perfectly manicured meadows and oxblood-red wooden cabins. At the other is the spare, serene beauty of the north: a world of glaciers, ice-bound mountains and empty, far horizons. Connecting the two, the Kystriksveien – a route also known as the Coastal Way or Fv17 – charts a sinuous path along the coast, bucking and weaving along rugged contours all the way to the Arctic.

The Scandinavian nation is blessed with one of the most beautiful yet difficult stretches of coast in Europe. Seeming to wrap itself around the country like a protective shield from the freezing Arctic, Norway's coastline appears to have shattered under the strain, riven as it is with islands and fjords cutting deep fissures inland. Along such a coast, it seems impossible that a road should exist here at all. In short, it seems like a miracle.

Known as "torfbæir", these ingeniously designed homes helped settle one of Europe's least-hospitable environments.

Stretching 185km across the mountains to the Iraq-Iran border, it's a stunning feat of engineering that nearly didn't happen.

Stretching 185km from Erbil across the imposing Zagros Mountains to the town of Haji Omeran on the Iraqi Kurdistan-Iran border, the road is not only considered one of western Asia's most spectacular routes, but one of its most audacious feats of engineering.

Thatched buildings are deeply connected to Japan's history and culture, yet few survive. However, a cluster of villages near Kyoto are keeping this ancient tradition alive.

Laocoon
an hour ago edited
EXCELLENT post!

Paxton ran for the AG job in 2014. He eventually defeated TX Representative Dan Branch in the Republican primary. Dan Branch was a very powerful, very connected, and very wealthy member of the TX Legislature. I went to college with Dan Branch. He's a charming and outgoing guy. In some ways he kinda reminds me of Greg Marmalard from "Animal House". NTTAWWT. Branch is a senior partner in a big Dallas law firm with a nice family, most likely a cat, a faithful dog, and an immaculately manicured lawn. Branch and his friends in the TX Legislature were VERY unhappy with losing.

As soon as the primary was over, uncounted allegations on various issues immediately emerged against Paxton and more have surfaced ever since. They went after him on everything from securities fraud, to mopery with intent to loiter, to spreading the freakin' heartbreak of psoriasis, to lying, to alowing his feet to stink, to not lovin' Jesus.

As much as I dislike the slimy games being played here...the Return On Investment (ROI) with Paxton just might not provide a sufficient value with the 2024 election coming up fast. I don't like giving in to the kind of sleazy politics being played here. It's unfair and unjust. But the heavy hitters around Phelan have been working 24/7/365 since 2014 to get rid of Paxton...and it looks like Phelen has Paxton this time. Even though he just won re-election, I'm not sure Paxton is a hill worth politically dying on.

Like you say: "Texas can’t afford to have an attorney general at war with his own party. The Texas GOP can’t afford to go into the 2024 election with seriously wounded Ken Paxton on the ballot."

Wickwick Ars Legatus Legionis
13y
30,072
Terakh said:

let's see the promises actually get delivered on "near" agreed upon time and cost given that some of the stuff don't even exist.

As long as Congress funds the programs on the agreed-upon schedules, I think both landers will be ready before their respective Artemis missions are flown.

Unfortunately, Congress has a history of reducing funding levels below what the delivery time requires then complaining that the programs are delayed. But those sorts of shenanigans only seem to happen to fixed-price contracts where they have no control over where and how the money is spent. The cost-plus rocket contracts seem immune to any sorts of cuts. //

EricBerger Ars Scholae Palatinae
7y
1,067
ARS STAFF
pipe13 said:

...and a large source of energy. You know, to mine the water, collect the CO2, and put the proverbial toothpaste back in the tube.

The numbers are pretty sobering: Approximately 750 kilowatts of continuous energy, for two years, to produce 1,000 tons of liquid oxygen and methane. //

RichyRoo Wise, Aged Ars Veteran
5y
113
Subscriptor
Hopefully Smarter said:

I love seeing the enthusiasm about spreading the toxic virus of humanity throughout the universe.

without us there is no point to the rest of the universe //

abie Ars Scholae Palatinae
5y
719
Hopefully Smarter said:

I love seeing the enthusiasm about spreading the toxic virus of humanity throughout the universe.

What you call a toxic virus, I call the light of consciousness. We've found no signs of life anywhere in the universe. Life might be incredibly rare, intelligent life rarer still. Taking the first hesitant steps to establishing life off Earth should be a cause for celebration, not miserable cynicism such as yours.

An independent report published Thursday had troubling findings about the money spent by the agency on propulsion for the Space Launch System rocket. Moreover, the report by NASA Inspector General Paul Martin warns that if these costs are not controlled, it could jeopardize plans to return to the Moon. //

"The agency’s reliance on cost-plus awards increases its financial risk," Martin wrote. "In our judgment, NASA has used cost-plus contracting structures for its SLS booster and engine contracts to a greater extent than warranted. Although the SLS is a new vehicle, its heritage boosters and RS-25 engines are well-established."

Cost-plus contracts pay the recipient the total amount of their costs plus a fee. This is in contrast to the fixed-price contracts NASA has given SpaceX and Blue Origin for landers, the design of which is much more experimental and cutting-edge in nature than repurposing space shuttle hardware. //

For example, the current cost of manufacturing a new RS-25 main engine—which will be used for the Artemis V mission and onward—is about $100 million. NASA and Aerojet are trying to achieve a 30 percent cost savings by the end of this decade, bringing the cost down to $70.5 million. //

Compared to the private sector, even getting the cost of an RS-25 engine down to $70.5 million is a preposterously high price. Blue Origin manufactures engines of comparable power and size, the BE-4, for less than $20 million. And SpaceX is seeking to push the similarly powerful Raptor rocket engine costs even lower, to less than $1 million per engine.

Based on all of the new data in his latest report, Martin said his office has had to revise its estimate of the total cost of a Space System Launch, inclusive of ground systems and the Orion spacecraft. It is now $4.2 billion.

The unit consists of two stages of filtration, a coarse screen and a fine screen.

Dirty water enters the inlet, passes through the coarse screen outside-in, and enters the inside of the fine screen. The water then passes through the fine screen from the inside out and exits the outlet.

Unwanted solids accumulate on the inner surface of the fine screen, making it harder for water to pass through the fine screen and creating a pressure differential between the inlet and the outlet. Once the pressure differential reaches a preset level, the factory-supplied control system activates a rinse cycle by opening the rinse valve and starting the motor.

When the rinse valve opens to atmosphere, pressure drops in the rinse chamber. The dirt collector is hollow and connects the rinse chamber and the fine screen chamber, so pressure drops inside the dirt collector and its nozzles as well. The pressure drop causes the nozzles to work like vacuum cleaners, sucking in nearby particles. The nozzles are self-adjusting, allowing the nozzle openings to touch the surface of the fine screen. The water rushes into the nozzles at over 50 feet/second, carrying with it any material stuck on the fine screen. The intense energy can suck off even the stickiest particles.

Meanwhile, the dirt collector is slowly rotating and moving linearly. The drive shaft rotates the dirt collector, while the linear motion shaft moves it linearly. Both are controlled by the motor, on the back of the filter. Together, they ensure that the dirt collector nozzles pass over each part of the screen at least twice during the 45-second rinse cycle.

Steve Baker
Senior Software Engineer (2013–present)Apr 24

Will SpaceX upgrade Starship to more than three vacuum Raptor engines?

The problem is with the space available.

Although you can fit 33 sea-level Raptors into the 9 meter diameter space at the tail end of the SuperHeavy - the vacuum optimized Raptors need a HUGE engine bell.

Just look at the difference in size (sea-level raptor on the left - vacuum-optimized on the right)…the two engines are almost identical aside from that!

It’s interesting to look at the 1st and 2nd stages of the Falcon-9. It has nine sea-level Merlin engines packed underneath the main rocket - but the second stage has the same diameter - and it’s is pretty much FULL with just one vacuum optimized Merlin!

Same exact rocket motor - but giant bell required for vacuum work.

Andrew Swenson
MS in Space Systems Engineering, US Naval Postgraduate School (Graduated 1993)May 14

Why does NASA not allow anyone to inspect the lunar module (lunar excursion module) that traveled to the Moon during Apollo missions?

Which one would you like to inspect and how would you get there? Here are the locations of each one….good luck with your inspection:

Apollo 5- Destroyed in Earth's Atmosphere.
Apollo 9- Destroyed in Earth's Atmosphere.
Apollo 10- Heliocentric orbit
Apollo 11- released in lunar orbit, location unknown.
Apollo 12- Impacted Moon 20 November 1969 at 22:17:17.7 UT (5:17 PM EST) 3.94 S, 21.20 W
Apollo 13- Burned up in Earth's atmosphere.
Apollo 14- Impacted Moon 07 February 1971 at 00:45:25.7 UT (06 February, 7:45 PM EST) 3.42 S, 19.67 W
Apollo 15- Impacted Moon 03 August 1971 at 03:03:37.0 UT (02 August, 11:03 PM EDT) 26.36 N, 0.25 E
Apollo 16- Released around moon, impact site unknown. Orbited for about a year.
Apollo 17- Impacted Moon 15 December 1972 at 06:50:20.8 UT (1:50 AM EST) 19.96 N, 30.50 E

Home to Portugal's "mountain of stars" and some of Europe's least light-polluted skies, the Alentejo region is best seen at night.
A

A long twisting road leads up Portugal's highest mountain, and here, unlike many other European summits, visitors can drive right to the top. The peak rises 1,993m above sea level, and although its actual name is Torre (tower), most people just call it by the same designation as the range it lofts over: Serra da Estrela or "mountain of the stars".

By day, the drive offers wonderful views across the undulant landscape of this narrow country – from the red hills of Spain in the east to the blue Atlantic Ocean in the west. However, the real spectacle comes as the sun starts to drop. Not only is this mountain a popular spot to watch golden sunsets, but for those who stay later, it offers a glimmering night-time fresco that covers the heavens, made up of millions of white pinpricks scattered in glorious imperfection.

Over the past decade, Portugal has gained recognition for being one of the top places in the world for travellers to observe the night sky, thanks to the creation of the 3,000 sq km Dark Sky Alqueva reserve, in Portugal's central Alentejo region. In 2011, the reserve was certified as the world's first Starlight Tourism Destination by the Starlight Foundation, a Unesco-supported international organisation that promotes science and tourism. This status celebrates the region's ideal viewing conditions (low levels of light pollution and an average of 286 cloudless nights per year, which result in some of Portugal's darkest skies), but also the wider tourism infrastructure it has inspired, which is set up to cater specifically to stargazers.

Along a single road cutting across the heart of Iraq, you can see where people first learned to write, use maths and invent the wheel.

"This is not a scenic drive," said James Willcox, of adventure travel specialist Untamed Borders. "But what's incredible about Route 1 is where it takes you: to the birthplace of some of the world's earliest civilisations, the home of many of humankind's greatest innovations."

Willcox, who was charged with logistics and security for my journey, was briefing me before I embarked on a 530km, two-day road trip from Basra to Baghdad. My trip would be using Iraq's first and longest freeway, the 1,200km-long Route 1, as a conduit to explore the heart of ancient Mesopotamia. Though the region has experienced decades of recent conflict, it was also once home to a series of illustrious historical empires (the Babylonians, Assyrians and Sumerians to name a few), and Willcox reassured me that the journey would be unforgettable so long as I followed some simple rules: "Keep a low profile, dress conservatively and don't photograph any of the armed checkpoints," he said.

Tech entrepreneur David Sacks, who co-hosted the Twitter event alongside Musk, had a different theory, saying:

I think it crashed because when you multiply a half-million people in a room by an account with over 100 million followers, which is Elon’s account, I think that creates just a scalability level that was unprecedented. //

Kyle Griffin @kylegriffin1
·
New York Times calls the DeSantis announcement a "fiasco."

NBC News calls it a 'melt down.'

The Washington Post calls it "awkward."

Politico calls it "horrendous."

Elon Musk @elonmusk
·
I call it “massive attention”

Top story on Earth today
10:03 PM · May 24, 2023

Last Friday, NASA awarded a $3.4 billion contract to a team led by Blue Origin for the design and construction of a second Human Landing System to fly astronauts down to the Moon.

The announcement capped a furious two-year lobbying campaign by Blue Origin owner Jeff Bezos to obtain a coveted piece of NASA's Artemis program. NASA also notched a big win, gaining the competition with SpaceX it sought for landing services. But there is a more profound takeaway from this.

After losing the initial lander contract to SpaceX two years ago, Blue Origin did not just bid a lower price this time around. Instead, it radically transformed the means by which it would put humans on the Moon. The Blue Moon lander is now completely reusable; it will remain in lunar orbit, going up and down to the surface. It will be serviced by a transport vehicle that will be fueled in low-Earth orbit and then deliver propellant to the Moon. This transporter, in turn, will be refilled by multiple launches of the reusable New Glenn rocket.

To be sure, that is a lot of hardware that has yet to be built and tested. But when we step back, there is one inescapable fact. With SpaceX's fully reusable Starship, and now Blue Moon, NASA has selected two vehicles based around the concept of many launches and the capability to store and transfer propellant in space.

This is a remarkable transformation in the way humans will explore outer space—potentially the biggest change in spaceflight since the Soviet Union launched the Sputnik satellite in 1957. It has been a long time coming. //

The German physicist Max Planck is credited with the notion that science advances only when older practitioners die off, leaving room for new ideas. The philosopher of science Thomas Kuhn more pithily summarized the sentiment by writing, "Science advances one funeral at a time."

Goff offered a variation on this idea for spaceflight: "Space policy seems to progress one congressional retirement at a time," he said.

Like Sowers, he welcomed NASA's entry into an era of reusable spaceflight. But Goff noted that it is really only happening because two billionaires, Elon Musk and Jeff Bezos, are aggressively pushing the idea forward.

NASA has spent so much over the last decade on the development of the SLS rocket—north of $40 billion, including ground systems—that there has been little money left over for exploration payloads to fly on them. Therefore, when it came time to fund the lunar landers, NASA had to go with the least expensive options. Both Starship and Blue Moon are, roughly, at least $10 billion development programs. But because it can purchase them with fixed-price contracts, NASA is only paying about a third of the overall cost for both, $6.3 billion.

"The only way NASA could really afford to do this was by not doing business as usual," Goff said.