Aerospace companies have launched about 2,000 Internet satellites into orbit around Earth over the past 2 years, nearly doubling the number of active satellites. This has sparked concerns among astronomers and other skygazers, who worry about interference with observations of the night sky. From a report: Now, in what would be the biggest international step yet towards addressing these concerns, diplomats at a United Nations forum next month might discuss whether humanity has a right to 'dark and quiet skies.' The debate could initiate a framework for how scientists and the public would deal with the flood of new satellites -- with many more expected.

Tens of thousands of satellites could be added to Earth orbit in the next few years to provide broadband Internet, if companies and governments build and launch all the networks, or 'megaconstellations,' they have publicly announced. The sheer number of these could mean that hundreds are visible all night long, affecting the sky like never before in human history. "These constellations are changing dramatically the way space has been used," says Piero Benvenuti, an astronomer at the University of Padua in Italy and a former general secretary of the International Astronomical Union (IAU). He and other astronomers have been working through the IAU to raise international awareness of how the megaconstellations are affecting scientists and members of the public. They say the goal is not to pit astronomers against satellite companies, but to develop a vision of how to fairly use the shared realm of outer space.

NPR: Wearing a cowboy hat under the West Texas morning sun, Jeff Bezos crossed the bridge to enter the capsule made by his company Blue Origin. He was accompanied by three others -- his brother Mark Bezos, female aviation pioneer Wally Funk and 18-year-old Oliver Daemen. Then the shuttle hatch closed and just before 9:15 a.m. ET, the four blasted into space on the first human flight on Blue Origin's New Shepard launch vehicle. Bezos is the second billionaire this month to reach the edge of space: Richard Branson rocketed there last week aboard a vessel made by his company Virgin Galactic. The date of the New Shepard's maiden launch is no accident: July 20 was the day in 1969 that Neil Armstrong and Buzz Aldrin landed on the moon. Further reading: 'Mercury 13' pilot Wally Funk carried 60 years of history to space on Blue Origin flight.

fahrbot-bot shares a report from Live Science: Imagine a universe where you could point a spaceship in one direction and eventually return to where you started. If our universe were a finite donut, then such movements would be possible and physicists could potentially measure its size. "We could say: Now we know the size of the universe," astrophysicist Thomas Buchert, of the University of Lyon, Astrophysical Research Center in France, told Live Science in an email.

Examining light from the very early universe, Buchert and a team of astrophysicists have deduced that our cosmos may be multiply connected, meaning that space is closed in on itself in all three dimensions like a three-dimensional donut. Such a universe would be finite, and according to their results, our entire cosmos might only be about three to four times larger than the limits of the observable universe, about 45 billion light-years away.

18-year-old Oliver Daemon will become the youngest person ever to travel to space as the fourth passenger on Blue Origin's first crewed mission this week to the edge of outer space (flying with Jeff Bezos, his brother Mark, and 82-year-old aviator Wally Funk).

The Atlantic calls it "a rather unusual bunch": When they take off on Tuesday, they will each fulfill a personal dream, but as a crew, they're making history: No group like this one has ever gone to space together before. Even the participants of the most diverse missions to the International Space Station have had far more in common with one another than this quartet. They were all professional astronauts, with comparable ages, educational backgrounds, and even temperaments, given that potential astronauts must undergo psychological screenings before getting the job. The motley crew of Blue Origin's first passenger flight seems closer to a cast of offbeat characters gathered together for a zany adventure: If The Breakfast Club had the brain, the jock, the basket case, the princess, and the criminal, this Blue Origin flight has the boss, the tag-along, the real deal, and the kid...

Blue Origin has conducted 15 test flights of the New Shepard rocket, but has never before flown the vehicle with people on board.

Of the passengers on Bezos's debut flight, Daemen might be the most unexpected pick. In fact, Daemen wasn't supposed to be on this flight. Blue Origin had held an auction for one of the seats on the flight, culminating in a top bid of a whopping $28 million. But the company said today that the winner, whose name has not been disclosed, decided to skip this particular flight and go later, citing "scheduling conflicts," so the company slotted in Daemen, a soon-to-be physics student at Utrecht University, in the Netherlands. (Blue Origin said the teen was "a participant in the auction," but did not disclose how much the seat cost.)

Daemen and Funk, as Blue Origin pointed out in its announcement, "represent the youngest and oldest astronauts to travel to space." But describing them by age alone elides the very different journeys they have taken to reach this point. Funk is an aviation legend who underwent more difficult tests than John Glenn, the first American to orbit the Earth, had to, and has waited 60 years for this moment. Daemen is a teenager who took a gap year to get his pilot's license, and the son of a private-equity executive... Daemen represents a new class of spacefarers; in the coming years, as private companies such as Blue Origin, Richard Branson's Virgin Galactic, and Elon Musk's SpaceX make people into astronauts more readily than government agencies like NASA can, the distance between a childhood dream and reality is bound to shrink. Expect more smorgasbord space crews like the Blue Origin one, filled with an assortment of very wealthy individuals and the people they choose to go with them...

The rules about who can become an astronaut have changed, and the new "right stuff" is money and luck.

"A new production problem has surfaced with Boeing's 787 Dreamliner, further delaying deliveries of the popular wide-body jets..." writes the Wall Street Journal.

Long-time Slashdot reader phalse phace shares their report: Boeing halted handing over Dreamliners to airlines in late May, after federal air-safety regulators declined to approve the plane maker's proposed method of inspecting the jets for previously disclosed production defects. It was the second such pause in the past year...

The Federal Aviation Administration said the newly discovered quality issue posed no immediate safety threat. While the agency will determine whether to require modifications to 787s already in service, the FAA said: "Boeing has committed to fix these airplanes before resuming deliveries..."

The new problem surfaced on part of the aircraft known as the forward pressure bulkhead at the front of the plane, people familiar with the matter said. It involves the skin of the aircraft and is similar to a previously disclosed Dreamliner issue found elsewhere on the planes, one of these people said. It surfaced as part of the FAA's review of Boeing's quality checks on newly produced undelivered planes, this person said. The delivery pause has been another setback for the aerospace giant, which has been grappling with various problems in its commercial, defense and space programs in recent years. It is also choking off a key source of cash as Boeing tries to overcome twin crises that resulted from two fatal crashes of its 737 MAX aircraft in late 2018 and early 2019, and the Covid-19 pandemic's hit to aircraft demand.

The new problem hasn't raised any immediate safety concerns, but engineers at Boeing and the FAA are trying to understand the defect's potential to cause premature fatigue on a key part of the aircraft's structure, people familiar with the matter said.

Slashdot reader sciencehabit shares news from Science magazine: When a giant space rock struck the waters near Mexico's Yucatán Peninsula 66 million years ago, it sent up a blanket of dust that blotted out the Sun for years, sending temperatures plummeting and killing off the dinosaurs. The impact also generated a tsunami in the Gulf of Mexico that some modelers believe sent an initial tidal wave up to 1500 meters (or nearly 1 mile) high crashing into North America, one that was followed by smaller pulses.

Now, for the first time, scientists have discovered fossilized megaripples from this tsunami buried in sediments in what is now central Louisiana.

"It's great to actually have evidence of something that has been theorized for a really long time," says Sean Gulick, a geophysicist at the University of Texas, Austin. Gulick was not involved in the work, but he co-led a campaign in 2016 to drill down to the remains of the impact crater, called Chicxulub... Cores from the 2016 drilling expedition helped explain how the impact crater was formed and charted the disappearance and recovery of Earth's life. In 2019, researchers reported the discovery of a fossil site in North Dakota, 3000 kilometers north of Chicxulub, that they say records the hours after the impact and includes debris swept inland from the tsunami.

"We have small pieces of the puzzle that keep getting added in," says Alfio Alessandro Chiarenza, a paleontologist at the University of Vigo who was not involved with the new study. "Now this research is another one, giving more evidence of a cataclysmic tsunami that probably inundated [everything] for thousands of miles."

"China conducted a clandestine first test flight of a reusable suborbital vehicle Friday as a part of development of a reusable space transportation system," reports Space News:

The vehicle launched from the Jiuquan Satellite Launch Center Friday and later landed at an airport just over 800 kilometers away at Alxa League in Inner Mongolia Autonomous Region, the China Aerospace Science and Technology Corp. (CASC) announced. No images nor footage nor further information, such as altitude, flight duration or propulsion systems, were provided. The CASC release stated however that the vehicle uses integrated aviation and space technologies and indicates a vertical takeoff and horizontal landing profile.

The test follows a September 2020 test flight of a "reusable experimental spacecraft". The spacecraft orbited for days, releasing a small transmitting payload and later deorbited and landed horizontally. The spacecraft is widely believed to be a reusable spaceplane concept, though no images have emerged. Giant space and defense contractor CASC also developed that vehicle and stated that the new vehicle tested Friday can be used as a first stage of a reusable space transportation system. The implication is that the two vehicles will be combined for a fully reusable space transportation system. The developments have not come out of the blue. China stated in 2017 that it aimed to test a reusable spaceplane in 2020...

Chen Hongbo, from CASC's China Academy of Launch Vehicle Technology (CALT), told Science and Technology Daily (Chinese) in 2017 that the reusable spacecraft would be capable of carrying both crew and payloads... Chen stated the aim was full reusability, moving beyond partial reusability of Falcon 9-like launchers. The spaceplane, the development and testing of which is to be completed by 2030, should be capable of being reused more than 20 times.

"Anthony Di Iorio, a co-founder of the Ethereum network, says he's done with the cryptocurrency world, partially because of personal safety concerns," reports Bloomberg, in a story shared by Slashdot reader tekram: Di Iorio, 48, has had a security team since 2017, with someone traveling with or meeting him wherever he goes. In coming weeks, he plans to sell Decentral Inc. [maker of Jaxx, a digital asset wallet], and refocus on philanthropy and other ventures not related to crypto. The Canadian expects to sever ties in time with other startups he is involved with, and doesn't plan on funding any more blockchain projects. "It's got a risk profile that I am not too enthused about," said Di Iorio, who declined to disclose his cryptocurrency holdings or net worth. "I don't feel necessarily safe in this space. If I was focused on larger problems, I think I'd be safer..."

He was also for a time chief digital officer of the Toronto Stock Exchange. In February 2018, Forbes estimated his net worth was as high as $1 billion. Ether's price has more than doubled since then.
Bloomberg points out that Di lorio's net worth was estimated in 2018 at $1 billion — and that since then Ether's price has more than doubled, with the token holding a total market capitalization around $225 billion (second only to bitcoin).

Bloomberg also notes that Di lorio is involved in Project Arrow, a company building a zero-emission self-driving car. Di Iorio plans to sell Decentral Inc for equity, not cryptocurrency, telling Bloomberg that "I want to diversify to not being a crypto guy, but being a guy tackling complex problems...

"I will incorporate crypto when needed, but a lot of times, it's not. It's really a small percentage of what the world needs."

sciencehabit shares a report from Science Magazine: Over the past 2 decades, researchers have found hundreds of radioactive atoms, trapped in seafloor minerals, that came from an ancient supernova explosion marking the death of a nearby star. Erupting from hundreds of light-years away, the flash of x-rays and gamma rays probably did no harm on Earth. But the expanding fireball also accelerated cosmic rays -- mostly nuclei of hydrogen and helium -- to close to the speed of light. These projectiles arrived stealthily, decades later, ramping up into an invisible fusillade that could have lasted for thousands of years and might have affected the atmosphere -- and life. In a flurry of studies and speculation, astronomers have sketched out their potential effects, including a depleted ozone layer, cancer-causing particles, wildfires, and a cooling of the climate that could have helped initiate the ice ages 2.5 million years ago. Most paleontologists are yet to be convinced, but astronomers argue that such supernovae could explain some extinction events that lack customary triggers like volcanic outbursts or asteroid impacts.

The Hubble Space Telescope has powered on once again. NASA was able to successfully switch to a backup computer on the observatory on Friday following weeks of computer problems. From a report: On June 13, Hubble shut down after a payload computer from the 1980s that handles the telescope's science instruments suffered a glitch. Now, over a month since Hubble ran into issues, which the Hubble team thinks were caused by the spacecraft's Power Control Unit (PCU), NASA switched to backup hardware and was able to switch the scope back on. With Hubble back online with this backup hardware, the Hubble team is keeping a close watch to make sure that everything works correctly, according to a statement from NASA.

Critics said the pandemic would make the industry flee San Francisco and its southern neighbor, Silicon Valley. But tech can't seem to quit its gravitational center. New York Times: The pandemic was supposed to lead to a great tech diaspora. Freed of their offices and after-work klatches, the Bay Area's tech workers were said to be roaming America, searching for a better life in cities like Miami and Austin, Texas -- where the weather is warmer, the homes are cheaper and state income taxes don't exist. But dire warnings over the past year that tech was done with the Bay Area because of a high cost of living, homelessness, crowding and crime are looking overheated. Mr. Osuri [Editor's note: anecdote in the story who is the chief executive of Akash Network] is one of a growing number of industry workers already trickling back as a healthy local rate of coronavirus vaccinations makes fall return-to-office dates for many companies look likely.

Bumper-to-bumper traffic has returned to the region's bridges and freeways. Tech commuter buses are reappearing on the roads. Rents are spiking, especially in San Francisco neighborhoods where tech employees often live. And on Monday, Twitter reopened its office, becoming one of the first big tech companies to welcome more than skeleton crews of employees back to the workplace. Twitter employees wearing backpacks and puffy jackets on a cold San Francisco summer morning greeted old friends and explored a space redesigned to accommodate social-distancing measures.

sciencehabit shares a report from Science Magazine: High on Greenland's ice sheet, particle astrophysicists are this week drilling boreholes in a search for the cosmic accelerators responsible for the universe's most energetic particles. By placing hundreds of radio antennas on and below the surface, they hope to trap elusive particles known as neutrinos at higher energies than ever before. Detectors elsewhere on Earth occasionally register the arrival of ultra-high-energy (UHE) cosmic rays, atomic nuclei that slam into the atmosphere at colossal speed. Researchers want to pinpoint their sources, but because the nuclei are charged, magnetic fields in space bend their paths, obscuring their origins. But theorists believe that as UHE cosmic rays set out from their sources, they spawn so-called cosmogenic neutrinos in collisions with photons and, because neutrinos are not charged, they travel to Earth as straight as an arrow. The hard part is catching them.

An anonymous reader quotes a report from CBC.ca: More than 10,000 species of plants and animals are at high risk of extinction due to the destruction of the Amazon rainforest -- 35 percent of which has already been deforested or degraded, according to the draft of a landmark scientific report published on Wednesday. Produced by the Science Panel for the Amazon (SPA), the report brings together research on the world's largest rainforest from 200 scientists from across the globe. It is the most detailed assessment of the state of the forest to date and both makes clear the vital role the Amazon plays in global climate and the profound risks it is facing. Cutting deforestation and forest degradation to zero in less than a decade "is critical," the report said. It also called for massive restoration of already destroyed areas. Furthermore, the report said the continued destruction caused by human interference in the Amazon puts more than 8,000 endemic plants and 2,300 animals at high risk of extinction. According to the report, of the Amazon basin's original size, 18 per cent has already been deforested -- mostly for agriculture and illegal timber. Another 17 per cent has been degraded.

A separate study published in the journal Nature on Wednesday showed that some parts of the Amazon are emitting more carbon than they absorb, based on measurements of carbon dioxide and carbon monoxide taken from above the rainforest between 2010 and 2018. Lead author Luciana Gatti, a scientist at Brazil's Inpe space research agency, suggests the increased carbon emissions in southeastern Amazonia -- where deforestation is fierce -- is not only the result of fires and direct destruction, but also due to rising tree mortality as severe drought and higher temperatures become more common.

As Cubans take to the streets to protest against the government's mishandling of the economy and coronavirus health crisis, the country's government is turning to censorship to crack down on dissent. According to NBC News, the government "has taken steps to block citizens' use of the encrypted chat apps WhatsApp, Signal and Telegram." They've also shut off the internet. According to a case study from Top10VPN, Cuba went offline for 32 hours, which affected 7 millions users and cost the country more than $13 million. NBC News reports: Widespread internet use in Cuba is still relatively new, and Cubans mostly reach the web through their smartphones. The country only has a single major internet provider, the national telecommunications company ETECSA. That means most Cubans have to rely on a single, centralized, government-affiliated hub, making government censorship substantially easier. NetBlocks, an internet monitoring nonprofit, said Monday that it had detected disruptions to multiple messaging apps through ETECSA's service. A number of messaging apps, including WhatsApp, Signal and Telegram, are all blocked in Cuba, said Arturo Filasto, the project lead at the Open Observatory of Network Interference (OONI).

OONI, an international nonprofit, relies on volunteers around the world to install a program that probes for which types of internet use are being censored and how. Its data showed that ETECSA began blocking WhatsApp on Sunday night, then Signal and Telegram on Monday. All three were still blocked on Tuesday, Filasto said. "We have never seen instant messaging apps being blocked in the country," he said. "It's sort of unprecedented that we would see such a heavy crackdown on the internet in Cuba." Marianne Diaz Hernandez, a fellow at the digital rights nonprofit Access Now, said some Cubans have reported that their specific SIM cards for their phones have been rendered useless, keeping them offline. And some virtual private networks have themselves been blocked, she said. Two major VPNs, Tor and Psiphon, appear to still work. While Cuba has deployed various censorship techniques in the past, this is the first time they have all been deployed at the same time, Hernandez said. "Since they have had internet, this is the largest blackout in history," she said. On Tuesday, Gov. Ron DeSantis said he wants Florida companies to provide internet connection to residents in Cuba.

"What does the regime do when you start to see these images? They shut down the internet. They don't want the truth to be out, they don't want people to be able to communicate," said DeSantis during a roundtable with Republican lawmakers and members of the Cuban exile community in Miami. "And so one of the things I think we should be able to do with our private companies or with the United States is to provide some of that internet via satellite. We have companies on the Space Coast that launch these things," he added. DeSantis said he would make some calls to "see what are the options" to make it happen.

Jupiter's moon Europa contains a voluminous ocean of liquid water under its icy crust that could potentially host extraterrestrial organisms. "But as evidence builds that Europa could be habitable under its crust, a problem remains: the intense radiation that Jupiter emits likely annihilates any signs of life, known as biosignatures, that upwell onto the moon's surface, presenting a challenge to future missions that aim to detect life with Europa landers," reports Motherboard. "Now, a team of researchers led by Emily Costello, a postdoctoral researcher at the Hawaii Institute of Geophysics and Planetology, have shed new light on this obstacle by examining the role of "impact gardening" in the search for life on Europa." From the report: Impact gardening occurs when rocks collide with a planetary body without an atmosphere, causing a mechanical churn that continually exposes new layers of the surface, known as the "gardened zone," to all the erosive effects of space, according to a study published on Monday in Nature Astronomy. "Knowing the depth of the gardened zone is critical for the exploration of Europa as a potentially habitable world," the researchers added. "We will need to sample material below the gardened zone if we wish to discover biomolecules that have never been exposed to hazardous radiation at the surface."

Of course, that raises the question: just how deep is Europa's gardened zone? To provide an answer, the team produced the first comprehensive models of impact gardening on Europa, with the help of Moon rocks returned from the Apollo program that also show a distinct gardened zone. This approach yielded good news and bad news. The bad news is that the models suggest that impact gardening exposes the top 30 centimeters (12 inches) of Europa's global surface to radiation, on average. Contrary to previous studies that proposed the possible presence of juicy biosignatures only a few centimeters under the moon's surface, the new study finds that signs of life would be embedded much deeper in the ice.

That said, the good news is that pristine material from Europa's ocean could be sampled at shallower depths in rare circumstances, such as in the fallout of recent landslides or fresh meteorite impacts. These natural processes can excavate layers of ice from below the gardened zone and position them within centimeters of the surface. Looking for recent examples of such disturbances could reveal samples that have not experienced the damaging long-term effects of radiation yet. Fortunately, scientists will soon benefit from close-up observations of Europa from ESA's Jupiter Icy Worlds Explorer (JUICE) and NASA's Europa Clipper, both scheduled to launch in the 2020s. These spacecraft will conduct intimate flybys of Europa, and they may be able to spot regions with freshly excavated material on the surface that would be prime destinations for future lander missions.

In the largest study of its kind, a team of academics from four US and Canadian universities said they were able to determine the size of China's Great Firewall internet censorship capabilities. From a report: In a research project that lasted nine months, from April to December 2020, academics developed a system called GFWatch that accessed domains from inside and outside China's internet space and then measured how the Great Firewall (GFW) would tamper with the connection at the DNS level in order to prevent Chinese users from accessing a domain, or an external entity accessing Chinese internal sites.

Using GFWatch, researchers said they tested 534 million distinct domains, accessing around 411 million domains on a daily basis in order to record and then verify that the blocks were persistent. After nine months of compiling data, they found that China's Great Firewall currently blocks around 311,000 domains, with 270,000 blocks working as intended, while 41,000 domains appear to have been blocked by accident. The research team said these latter domains appear to have been blocked accidentally when Chinese authorities tried to block a shorter domain and used a broad DNS filtering regular expression (regex) that did not account for situations where that shorter domain was also part of a longer domain name, indirectly banning other sites. For example, researchers said that when Chinese authorities blocked access to reddit.com, they also accidentally blocked access to booksreddit.com, geareddit.com, and 1,087 other sites.

Netflix should welcome -- even celebrate -- the White House's efforts to promote competition. Why? Look closely. From a report: As just about everyone knows, the suits in Washington D.C. have it out for Big Tech these days. Listen to the cocktail conversations about antitrust reform. Or watch the marches into courtrooms where the main objective is to break 'em up. And now read the executive order being signed on Friday by President Joe Biden, determined to undercut these behemoths and shift power from corporate gatekeepers to American workers. Then again, one $235 billion company stands to benefit from Biden's move -- a tech giant that's convinced everyone it's not really a tech giant, the member of FAANG never invited to those grill sessions on Capitol Hill where lawmakers use tech executives as hamburger patties. Just how did Netflix get so lucky?

Netflix is far and away the leader in streaming these days. It's also the star that everyone in the entertainment business with a telescope has been watching with envy. The last few years have brought one nascent streaming service after another. Except to succeed, Hollywood studios have convinced themselves they need scale. And so, we see both vertical integration as well as horizontal consolidation. Now, through his executive order, Biden is directing federal agencies to get tougher on proposed mergers. Very solid and wise reasons exist for more vigorously blocking and even unwinding mergers. Nevertheless, one has to ask: What might be a side effect of putting up more formidable hurdles to large-scale transactions in the entertainment space? Arguably (and yes, these arguments are almost certain to be raised in future legal challenges to blocked mergers), Netflix's position as top dog becomes more entrenched. If the FTC takes Biden's tip and pulls back on Trump-era guidelines for vertical mergers, that could hurt Amazon's prospect for acquiring MGM and transforming its Prime service into Netflix's toughest competitor. (Not that FTC chair Lina Khan needs any more reasons to stick it to Amazon.) And if the DOJ begins scrutinizing proposed mergers for how they impact labor markets, that could hold ramifications for WarnerMedia-Discovery or any other future tie-up that could threaten Netflix's ability to win the streaming wars.

Long-time Slashdot reader fahrbot-bot quotes LiveScience's exploration of the math: To start out 'small,' there are around 7 octillion, or 7x10^27 (7 followed by 27 zeros), atoms in an average human body, according to The Guardian. Given this vast sum of atoms in one person alone, you might think it would be impossible to determine how many atoms are in the entire universe. And you'd be right: Because we have no idea how large the entire universe really is, we can't find out how many atoms are within it.

However, it is possible to work out roughly how many atoms are in the observable universe — the part of the universe that we can see and study — using some cosmological assumptions and a bit of math.

[...]

Doing the math

To work out the number of atoms in the observable universe, we need to know its mass, which means we have to find out how many stars there are. There are around 10^11 to 10^12 galaxies in the observable universe, and each galaxy contains between 10^11 and 10^12 stars, according to the European Space Agency. This gives us somewhere between 10^22 and 10^24 stars. For the purposes of this calculation, we can say that there are 10^23 stars in the observable universe. Of course, this is just a best guess; galaxies can range in size and number of stars, but because we can't count them individually, this will have to do for now.

On average, a star weighs around 2.2x10^32 pounds (10^32 kilograms), according to Science ABC, which means that the mass of the universe is around 2.2x10^55 pounds (10^55 kilograms). Now that we know the mass, or amount of matter, we need to see how many atoms fit into it. On average, each gram of matter has around 10^24 protons, according to Fermilab, a national laboratory for particle physics in Illinois. That means it is the same as the number of hydrogen atoms, because each hydrogen atom has only one proton (hence why we made the earlier assumption about hydrogen atoms).

This gives us 10^82 atoms in the observable universe. To put that into context, that is 100,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 atoms.

This number is only a rough guess, based on a number of approximations and assumptions. But given our current understanding of the observable universe, it is unlikely to be too far off the mark.

UPDATE: Branson's done it. "In a live broadcast during the vehicle's descent, Branson called the trip, 'an experience of a lifetime,'" reports NBC News: Branson's flight took off Sunday morning at around 10:30 a.m. ET, although the launch time was delayed by around 90 minutes because of overnight weather conditions at Spaceport America...

Branson was joined on his flight by pilots Dave Mackay and Michael Masucci and three mission specialists, all of whom are employees of Virgin Galactic: Chief astronaut instructor Beth Moses, lead operations engineer Colin Bennett and government affairs vice president Sirisha Bandla.

Virgin Galactic is expected to conduct several additional test flights before beginning commercial operations with private customers next year. The company has said the suborbital joyrides will likely cost more than $250,000 each, but final pricing has not yet been announced...

"It's taken 17 years to get to this flight, and of course a lot of personal wealth has been poured into it, but it also shows that this takes tenacity," said Greg Autry, a space policy expert at Arizona State University.
Earlier in the day, Virgin Galactic's Twitter feed shared a nice clip of the astronauts arriving on the launch site.

CBS News streamed their own live coverage at the top of this web page (as well as in their CBSN app), but also reported on the other options: With typical Branson fanfare, Sunday's flight will be broadcast live across Virgin Galactic's social media platforms, featuring appearances by Stephen Colbert and retired Canadian space station astronaut Chris Hadfield, along with the performance of a new song by singer-songwriter Khalid. Even SpaceX founder Elon Musk plans to be watching. "Will see you there to wish you the best," he tweeted Saturday.
And what did Jeff Bezos have to say before Branson launched his history-making flight? "Wishing you and the whole team a successful and safe flight tomorrow. Best of luck!"

Saturday CBS News offered this description of Branson's hopes: Richard Branson, the globe-trotting media mogul and founder of Virgin Galactic, plans to rocket into space Sunday morning on a flight that would make him the first owner of a private space company to launch aboard one of his own spacecraft. If all goes well, he will beat rival Jeff Bezos of Blue Origin, who is set to launch on July 20. Branson, two company pilots and three Virgin Galactic crewmates are launching from Spaceport America, near Truth or Consequences, New Mexico, on what's expected to be at least an hour-long flight, reaching altitudes a little over 50 miles above the Earth.

In two hours, Richard Branson (and five other Virgin Galactic employees) will attempt a historic flight to the edge of outer space. Bloomberg points out it will be followed 9 days later by Jeff Bezos's rocket trip with Blue Origin on July 20.

"Yeah, there's a little bit of competition in the who's going first or when things are happening," Virgin President Mike Moses, a former space shuttle manager at NASA, told CBS News. "But it's really not a race. It's not a competition. I know that sounds maybe a little shallow or disingenuous, but it's not. "It's a small community. I know dozens of people who work at Blue Origin, I know dozens and dozens of people at SpaceX, and we all used to work together at NASA. And I wish every single one of them the best.... Because all of us together is what's going to get humans into space and our culture to recognize that space travel is the foundation for the future for everyone..."

"This has been a long journey for him," Mike Moses said of Branson. "He's like a kid in a candy store here in training this week. He's bouncing around, he's happy, excited. ... But that excitement is really infectious. And so the whole crew is feeling it."
CNN points out that Branson has "narrowly avoided being killed numerous times in his nearly 71 years," including dangerous stunts like bunjee jumping that left him bloody and injured, as well as accidents during long-distance balloon flights while attempting to set records.

Here's how Branson describes some of them in his second autobiography, "Finding My Virginity," which includes an appendix called "75 Close Shaves": 1972: Survived a fishing boat sinking on honeymoon with my first wife, Kristen, off Mexico. We decided to jump off the boat and swim for shore, while the others stayed put -- we were the only survivors.

1976: Flew a microlight aircraft by mistake. It was the first time I'd sat in it, I had no idea how to fly it and accidentally took off. I was pulling wires out desperately. I cut the engine and managed to crash-land into a field. My instructor died in an accident the next day...

1986: On my first time skydiving, there was one cord that opened the parachute and one that got rid of it. I pulled the wrong cord by mistake. I was falling through the air before an instructor managed to yank my spare ripcord...

1989: I decided to make an entrance to my wedding with Joan, dangling from a helicopter in an all-white suit. I dropped into the shallow end of the pool by mistake, smashed my legs, and spent the whole wedding hobbling.