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Fossilized dinosaur eggshells can preserve amino acids, the building blocks of proteins, over millions of years

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theconversation.com – Evan Thomas Saitta, Postdoctoral Scholar in Paleontology, University of Chicago – 2024-04-09 07:16:55
A dinosaur eggshell cross section, as imaged under fluorescence microscopy.
Evan Saitta

Evan Thomas Saitta, University of Chicago

As a scientist, lab work can sometimes get monotonous. But in 2017, while a Ph.D. student of paleobiology at the University of Bristol in the U.K., I heard a gleeful exclamation from across the room. Kirsty Penkman, head of the North East Amino Acid Racemization lab at the University of York, had just read the data printed off the chromatograms and was practically jumping up and down.

The instrument had detected telltale signatures of ancient amino acids in eggshell. Amino acids are the building blocks that make up protein sequences in living organisms. But this wasn't just any eggshell; it was a fossil from a titanosaur, a giant herbivorous dinosaur that lived about 70 million years ago.

A line graph with about 20 sharp peaks
The chromatograph printout that Kirsty Penkman saw. Each peak represents an amino acid detected by the instrument during the analysis.
Evan Saitta

Not much organic material survives over millions of years, which limits scientists' ability to study the biology of extinct organisms compared to modern ones, whose proteins and DNA can be sequenced. As Penkman's enthusiasm suggested, these amino acids were extraordinary.

In fact, this result came unexpectedly amid our team's efforts to test claims of near-pristine protein preservation in dinosaur bone. I had brought various fossil bones to Penkman, but the results suggested no original amino acids had been preserved, and that they were even contaminated by microbes from the they'd been buried in.

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Testing eggshell fossils was not even in our original research plan.

Orphan fossil fragments

However, I had just seen that my colleague Beatrice Demarchi, Penkman and their team had detected short protein sequences in 3.8-million-year-old bird eggshell. I predicted that if dinosaur eggshells didn't preserve any original proteins, then their bones likely wouldn't preserve any either, and wanted to see whether that was the case. Luckily, we had a source of dinosaur eggshell.

Around 2000, many eggshell fragments were illegally exported from Argentina into the commercial market. As a fossil-obsessed child, I was even gifted a coin-sized fragment from a U.S. mineral store. Penkman and I tested that fragment, as well as another fragment from a European 's gift .

These fossil fragments in some ways gained scientific value because they didn't belong to any museum collections. We didn't have to worry about damaging them during the analysis. To our surprise, we had stumbled upon a rare opportunity to study ancient organic remains from a dinosaur.

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Amino acids in eggshell

Prompted by this initial discovery, our large, international team analyzed more dinosaur eggshells from Argentina, Spain and China, using a wide variety of techniques. Although some eggshells preserved amino acids far better than others, the evidence overall suggested that these molecules were ancient and original, possibly ranging from 66 million to 86 million years old.

During life, proteins that helped to calcify the eggshell became trapped within the mineral crystals. The remaining amino acids we detected, however, consisted of molecules that had broken off from their protein chains by reactions with . We only detected a few of the most stable amino acids. Less stable ones were absent, as they had degraded away.

A figure showing the silhouette of a titanosaur, a dinosaur with a long neck and stocky legs, as well as ball and stick models of four amino acids and a chemical reaction where a protein and water turn into free amino acids.
A titanosaur, models of the four preserved amino acids, and the breakdown reaction from a protein sequence into free amino acids.
Arthur S. Brum (silhouette), Ben Mills (ball-and-stick models), V8rik (hydrolysis reaction)

The amino acids still preserved were what chemists call racemic. Amino acids can occur in left- or right-handed configurations. Living organisms regulate their amino acids such that they appear almost exclusively in the left-handed configuration. After the organism dies, amino acids can convert between handedness until they reach 50-50 mixtures of both configurations.

A 50-50 mix is known as racemic and suggests that the amino acids had separated from their protein chains very long ago.

A drawing of two hands holding two configurations of a chemical model. The two configurations mirror each other.
Left- and right-handed versions of amino acids. While so-called stereoisomers have the same chemical formula, they're organized as mirror images of each other.
NASA

Calcite, an amino acid archive

Our dinosaur eggshell results showed more extreme degradation than seen in younger fossils of bird eggshell and mollusk shell. Our results also those from experiments that expose eggshell to heat in the lab, simulating degradation over thousands or millions of years.

Organisms reinforce these shells with a type of calcium carbonate mineral called calcite. Unlike the calcium phosphate that makes up bone, calcite can act as a closed system by trapping the products of proteins involved in calcification as they break down, free amino acids separated from protein sequences. This closed system allowed us to observe the amino acids in our analyses.

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Bird eggshell is even among the best materials to find preserved protein sequences in fossils, let alone free amino acids. Demarchi's team has detected short, intact sequences of amino acids still bound in a chain from bird eggshell at least 6.5 million years old.

Other researchers have claimed to have found more ancient amino acids, as well as more extreme and less likely claims of preserved protein sequences. But, our study uses a wider range of methods and reports the best signal for stable molecules in a tissue we now know preserves molecules well.

Our dinosaur amino acids might hold the record for the oldest protein-related material yet found for which the evidence is very strong, and the first clear evidence from a Mesozoic dinosaur.

Using calcite to look back in time

The genetic sequence in DNA that is ultimately expressed in proteins provides a source code for organisms that scientists can study. But if only a subset of amino acids are preserved in the fossil, it's like removing all but five letters from a book – little literary analysis is possible. So, what messages from ancient life might persist in these calcite time capsules?

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One biologically informative signal might involve stable isotopes, which are atoms of the same element with different masses. Scientists can look at the stable isotope ratios of carbon, oxygen or nitrogen to learn about their source, such as the animal's diet. Since eggshell calcite is a closed system, stable isotope ratios in their amino acids are more likely to directly from the dinosaur, rather than outside contamination.

In future research, our team will use fossils to search even further back in time. Organisms other than egg-laying dinosaurs reinforced their tissues with calcite. For example, marine arthropods called trilobites that lived more than half a years ago had calcite in their eyes.

Studying older remains could scientists understand the molecular changes that happen in fossils over long periods of time. Fossil calcite, Earth's molecular time capsule, may send faint tales from long-gone life for researchers to better understand their biology.

The orphan eggshells used in our initial analysis found a happy ending. They eventually gained a new home at Argentina's Museo Provincial Patagonico de Ciencias Naturales, a natural sciences museum in Patagonia, repatriated to the only province known to produce that type of eggshell microscopic structure.The Conversation

Evan Thomas Saitta, Postdoctoral Scholar in Paleontology, University of Chicago

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This article is republished from The Conversation under a Creative Commons license. Read the original article.

The Conversation

Animal behavior research is getting better at keeping observer bias from sneaking in – but there’s still room to improve

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theconversation.com – Todd M. Freeberg, Professor and Associate Head of Psychology, of Tennessee – 2024-05-03 07:16:49

What you expect can influence what you think you see.

Auscape/Universal Images Group via Getty Images

Todd M. Freeberg, University of Tennessee

Animal behavior research relies on careful observation of animals. Researchers might spend months in a jungle habitat watching tropical birds mate and raise their young. They might track the rates of physical contact in cattle herds of different densities. Or they could record the sounds whales make as they migrate through the ocean.

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Animal behavior research can fundamental insights into the natural processes that affect ecosystems around the globe, as well as into our own human minds and behavior.

I study animal behavior – and also the research reported by scientists in my field. One of the challenges of this kind of science is making sure our own assumptions don't influence what we think we see in animal subjects. Like all people, how scientists see the world is shaped by biases and expectations, which can affect how data is recorded and reported. For instance, scientists who in a society with strict gender roles for women and might interpret things they see animals doing as reflecting those same divisions.

The scientific corrects for such mistakes over time, but scientists have quicker methods at their disposal to minimize potential observer bias. Animal behavior scientists haven't always used these methods – but that's changing. A new study confirms that, over the past decade, studies increasingly adhere to the rigorous best practices that can minimize potential biases in animal behavior research.

Black and white photo of a horse with a man and a small table between them displaying three upright cards.

Adding up?

Karl Krall/Wikimedia Commons

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Biases and self-fulfilling prophecies

A German horse named Clever Hans is widely known in the history of animal behavior as a classic example of unconscious bias leading to a false result.

Around the turn of the 20th century, Clever Hans was purported to be able to do math. For example, in response to his owner's prompt “3 + 5,” Clever Hans would tap his hoof eight times. His owner would then reward him with his favorite vegetables. Initial observers reported that the horse's abilities were legitimate and that his owner was not being deceptive.

However, careful analysis by a young scientist named Oskar Pfungst revealed that if the horse could not see his owner, he couldn't answer correctly. So while Clever Hans was not good at math, he was incredibly good at observing his owner's subtle and unconscious cues that gave the math answers away.

In the 1960s, researchers asked human study participants to code the learning ability of rats. Participants were told their rats had been artificially selected over many generations to be either “bright” or “dull” learners. Over several weeks, the participants ran their rats through eight different learning experiments.

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In seven out of the eight experiments, the human participants ranked the “bright” rats as being better learners than the “dull” rats when, in reality, the researchers had randomly picked rats from their breeding colony. Bias led the human participants to see what they thought they should see.

Eliminating bias

Given the clear potential for human biases to skew scientific results, textbooks on animal behavior research methods from the 1980s onward have implored researchers to verify their work using at least one of two commonsense methods.

One is making sure the researcher observing the behavior does not know if the subject from one study group or the other. For example, a researcher would measure a cricket's behavior without knowing if it came from the experimental or control group.

The other best practice is utilizing a second researcher, who has fresh eyes and no knowledge of the data, to observe the behavior and code the data. For example, while analyzing a video file, I count chickadees taking seeds from a feeder 15 times. Later, a second independent observer counts the same number.

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Yet these methods to minimize possible biases are often not employed by researchers in animal behavior, perhaps because these best practices take more time and effort.

In 2012, my colleagues and I reviewed nearly 1,000 articles published in five leading animal behavior journals between 1970 and 2010 to see how many reported these methods to minimize potential bias. Less than 10% did so. By contrast, the journal Infancy, which focuses on human infant behavior, was far more rigorous: Over 80% of its articles reported using methods to avoid bias.

It's a problem not just confined to my field. A 2015 of published articles in the sciences found that blind protocols are uncommon. It also found that studies using blind methods detected smaller differences between the key groups being observed to studies that didn't use blind methods, suggesting potential biases led to more notable results.

In the years after we published our article, it was cited regularly and we wondered if there had been any improvement in the field. So, we recently reviewed 40 articles from each of the same five journals for the year 2020.

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We found the rate of papers that reported controlling for bias improved in all five journals, from under 10% in our 2012 article to just over 50% in our new review. These rates of still lag behind the journal Infancy, however, which was 95% in 2020.

All in all, things are looking up, but the animal behavior field can still do better. Practically, with increasingly more portable and affordable audio and video recording technology, it's getting easier to carry out methods that minimize potential biases. The more the field of animal behavior sticks with these best practices, the stronger the foundation of knowledge and public trust in this science will become.The Conversation

Todd M. Freeberg, Professor and Associate Head of Psychology, University of Tennessee

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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The Conversation

A look inside the cyberwar between Israel and Hamas reveals the civilian toll

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theconversation.com – Ryan Shandler, Professor of Cybersecurity and International Relations, Georgia Institute of Technology – 2024-05-03 07:16:12
The conflict between Israel and Hamas is happening online as well as on the ground.
Gwengoat/iStock / Getty Images Plus

Ryan Shandler, Georgia Institute of Technology; Daphna Canetti, University of Haifa, and Tal Mimran, Zefat Academic College

The about the Israel-Hamas war is filled with reports of Israeli families huddling in fear from relentless rocket attacks, Israeli tanks and artillery flattening buildings in the Gaza Strip, hundreds of kidnapped hostages imprisoned in subterranean tunnels, and millions of people driven from their homes by fighting.

But beyond the visceral violence lies a hidden layer of the war – an online conflict. We are scholars of cyberwarfare who have cataloged and analyzed the various cyber operations conducted during the war by Hamas, Israel and other nations and hacking groups supporting one side or the other. The data paints a picture of an unseen facet of the conflict, and it offers insights about the nature of cyber conflict more broadly.

The main conclusion we've drawn is that the consequences of cyber conflict are primarily felt by civilians, not the soldiers or militants actively engaged in the fighting. We find that the damage cyberattacks inflict on digital is far less significant than the resulting harm to humans, and the resulting upward spiral of violence.

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Hamas' cyberwarfare activities

The cyberattacks Israeli and civilian systems have had mixed effects. Some technically simple attacks succeeded in obtaining crucial intelligence that assisted Hamas fighters' incursion into Israel. Other attacks employed a scattershot approach, targeting anything within digital reach – hospitals, universities, banks and newspapers. These attacks didn't serve any military purpose, but simply aimed to disrupt Israeli life and terrorize the public.

The quantity and sophistication of the attacks have made clear that hackers working for the government of Iran, a key Hamas funder and supplier, are supporting Hamas' online warfare. Other “hacktivists” and private hacking groups based in countries as varied as , Pakistan and Russia have also joined the fray.

Before the deadly Oct. 7, 2023 terror attack on Israel that sparked the current war, Hamas cyber operatives were working to support the attack planning. A Hamas hacking unit called Gaza Cybergang spied on Israel in search of sensitive information about Israeli military installations. The information they gleaned was instrumental during the attack.

Hamas hackers also conducted phishing attacks, relatively simple attacks in which fake email or text messages resemble legitimate ones and encourage a user to either reply with sensitive information or click on a link that downloads malicious software to their computer or mobile phone.

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As the Oct. 7 attack unfolded, the pro-Palestinian hacktivist group AnonGhost released a mobile app with the same name as a prominent reputable app that gives Israeli citizens warnings about impending attacks from Hamas into Israel. AnonGhost issued false alerts – including, reportedly, one about a nuclear attack – and collected users' data, including their contacts, call logs and text messages.

However, since full-fledged hostilities erupted, Hamas has been largely unable to carry out effective cyberattacks that aid its war efforts. As a result, the group turned to information warfare, seeking to evoke panic and shift public opinion.

The most common type of attack that Hamas' cyberwarriors and their allies use now is a distributed denial-of-service, when a barrage of nonsense internet traffic is aimed at one or more websites, email servers or other internet-connected systems. They get overwhelmed by the nonsense traffic and either shut down or cease to function properly.

Denial-of-service attacks have hit websites for news media outlets, banks, financial institutions and government agencies. One attack took the Jerusalem Post website offline for two days. The group that claimed responsibility for that attack was a religious hacktivist group called Anonymous Sudan, with known connections to Russian hacking groups.

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Hamas and its online allies are also using wiper malware, which infects a computer and destroys its data. This kind of attack does not serve a purpose such as extortion or surveillance – it just aims to destroy everything in its wake.

We also recorded several attacks that infiltrated databases and released their contents, such as one where the private data of at Ono Academic College was published online.

Another series of attacks took control of digital billboards to display the Palestinian in sites around Israel, along with false news about military defeats. These attacks are part of a broader misinformation effort designed to shape domestic debate and terrorize Israeli civilians.

A billboard reads 'Hacked' and contains a pro-Palestinian message.
Electronic billboards have been to display pro-Palestinian messages around the world, including this one in Spain.
Horacio Villalobos/Corbis via Getty Images

Israel's activities

By contrast with Hamas, Israel is a global cyber power whose military possesses some of the strongest cyber warfare capabilities in the world.

Yet the effectiveness of Israel's cyber arsenal is limited because Hamas doesn't depend on the internet very much. Without any targets to strike on a digital battlefield, Israel's primary strategy has been to turn on or off internet connectivity in Gaza. It can do this because Israel controls the electricity and internet cables that serve Gaza.

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On Oct. 27, 2023, Israel imposed a near-total telecommunications blackout that lasted for approximately 34 hours. The telecommunications blackout was condemned by international organizations, including the World Organization, whose director general posted that the blackout made it “impossible for ambulances to reach the injured.” Without internet or telephone connections, injured Palestinians in Gaza can't call an ambulance, nor can medical staff stay connected with their dispatch centers.

Similar internet shutdowns have occurred frequently since then. Due to damage, displacement and power and internet disruptions, internet connectivity in Gaza has been reduced to 15% of the typical rate.

During periods when there was internet service in Gaza, pro-Israeli hacktivists got involved. For example, the group WeRedEvils crashed the Gaza Now news site. As hostilities intensified, up to 60% of all traffic to Palestinian websites was made up of denial-of-service attack traffic, according to Cloudflare, a U.S.-based data-transfer and tracking company. The bulk of the attacks were aimed at banks and technology companies.

The U.S. is involved, too. The federal Cybersecurity and Security Agency is working with the Israelis to help thwart some cyberattacks.

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A few observations about online conflict

In contrast to Hollywood depictions of cyber warfare, where unstoppable hackers can cripple entire armies and countries with the push of a button, the reality of cyber power is more constrained. Digital battles cannot win wars. Most of the online operations in the Israel-Hamas war have little effect on the actual battlefield. They involve spying or propaganda, not wholesale destruction.

Our data shows that cyber warfare doesn't necessarily give terror groups the ability to face major powers on more equal terms. Hamas' online operations have not been able to offset Israel's military superiority. But Israel's online capabilities are not a significant advantage against a largely offline opponent.

Perhaps most importantly, though, is our recurring finding that civilians are the foremost victims of cyberattacks during war. In our experiments, conducted among more than 10,000 people over 10 years, we have seen that cyberattacks arouse severe psychological distress – akin even to the harm generated by physical terrorism. When confronted with cyberattacks, people feel trapped and anxious, and their sense of safety plummets. As a result, victims lash out and demand strong retaliation in a way that fuels cycles of violence.

As Israel and Hamas volley cyberattacks back and forth, innocent people are caught in the crossfire. This human dimension of cyber warfare is the threat that worries us.The Conversation

Ryan Shandler, Professor of Cybersecurity and International Relations, Georgia Institute of Technology; Daphna Canetti, Professor of Political Science, University of Haifa, and Tal Mimran, Associate Professor of International Law, Zefat Academic College

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This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Boeing’s Starliner is about to launch − if successful, the test represents an important milestone for commercial spaceflight

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theconversation.com – Wendy Whitman Cobb, Professor of Strategy and Security Studies, – 2024-05-02 07:24:25

Boeing's Starliner spacecraft on approach to the International Space Station during an uncrewed test in 2022.

Bob Hines/NASA

Wendy Whitman Cobb, Air University

If all goes well late on May 6, 2024, NASA astronauts Butch Wilmore and Suni Williams will blast off into space on Boeing's Starliner spacecraft. Launching from the Kennedy Space Center, this last crucial test for Starliner will test out the new spacecraft and take the pair to the International Space Station for about a week.

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Part of NASA's commercial crew program, this long-delayed mission will represent the vehicle's first crewed launch. If successful, it will give NASA – and in the future, space tourists – more options for getting to low Earth orbit.

Two people wearing blue jumpsuits hug in front of a plane.

Suni Williams, right, and Butch Wilmore, the two astronauts who will crew the Starliner test.

AP Photo/Terry Renna

From my perspective as a space policy expert, Starliner's launch represents another significant milestone in the of the commercial space industry. But the mission's troubled history also shows just how difficult the path to space can be, even for an experienced company like Boeing.

Origins and development

Following the retirement of NASA's space shuttle in 2011, NASA invited commercial space companies to help the agency transport cargo and crew to the International Space Station.

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In 2014, NASA selected Boeing and SpaceX to build their respective crew vehicles: Starliner and Dragon.

Boeing's vehicle, Starliner, was built to carry up to seven crew members to and from low Earth orbit. For NASA missions to the International Space Station, it will carry up to four at a time, and it's designed to remain docked to the station for up to seven months. At 15 feet, the capsule where the crew will sit is slightly bigger than an Apollo command module or a SpaceX Dragon.

Boeing designed Starliner to be partially reusable to reduce the cost of getting to space. Though the Atlas V rocket it will take to space and the service module that supports the craft are both expendable, Starliner's crew capsule can be reused up to 10 times, with a six-month turnaround. Boeing has built two flightworthy Starliners to date.

A conical vehicle sitting on a flat vehicle.

The Starliner capsule in transit.

AP Photo/John Raoux

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Starliner's development has with setbacks. Though Boeing received US$4.2 from NASA, compared with $2.6 billion for SpaceX, Boeing spent more than $1.5 billion extra in developing the spacecraft.

On Starliner's first uncrewed test flight in 2019, a series of software and hardware failures prevented it from getting to its planned orbit as well as docking with the International Space Station. After testing out some of its systems, it landed successfully at White Sands Missile Range in New Mexico.

In 2022, after identifying and making more than 80 fixes, Starliner conducted a second uncrewed test flight. This time, the vehicle did successfully dock with the International Space Station and landed six days later in New Mexico.

The inside of a Starliner a few astronauts. Crew members first trained for the launch in a simulator.

Still, Boeing delayed the first crewed launch for Starliner from 2023 to 2024 because of additional problems. One involved Starliner's parachutes, which help to slow the vehicle as it returns to Earth. Tests found that some links in those parachute lines were weaker than expected, which could have caused them to break. A second problem was the use of flammable tape that could pose a fire hazard.

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A major question stemming from these delays concerns why Starliner has been so difficult to develop. For one, NASA officials admitted that it did not as much oversight for Starliner as it did for SpaceX's Dragon because of the agency's familiarity with Boeing.

And Boeing has experienced several problems recently, most visibly with the safety of its airplanes. Astronaut Butch Wilmore has denied that Starliner's problems reflect these troubles.

But several of Boeing's other space activities beyond Starliner have also experienced mechanical failures and budget pressure, including the Space Launch System. This system is planned to be the main rocket for NASA's Artemis program, which plans to return humans to the Moon for the first time since the Apollo era.

Significance for NASA and commercial spaceflight

Given these difficulties, Starliner's success will be important for Boeing's future space efforts. Even if SpaceX's Dragon can successfully transport NASA astronauts to the International Space Station, the agency needs a backup. And that's where Starliner in.

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Following the Challenger explosion in 1986 and the Columbia shuttle accident in 2003, NASA retired the space shuttle in 2011. The agency was left with few options to get astronauts to and from space. a second commercial crew vehicle provider means that NASA will not have to depend on one company or vehicle for space launches as it previously had to.

Perhaps more importantly, if Starliner is successful, it could compete with SpaceX. Though there's no crushing demand for space tourism right now, and Boeing has no plans to market Starliner for tourism anytime soon, competition is important in any market to drive down costs and increase innovation.

More such competition is likely coming. Sierra Space's Dream Chaser is planning to launch later this year to transport cargo for NASA to the International Space Station. A crewed version of the space plane is also being developed for the next round of NASA's commercial crew program. Blue Origin is working with NASA in this latest round of commercial crew contracts and developing a lunar lander for the Artemis program.

A conical white spacecraft with two rectangular solar panels in space, with the Earth in the background.

SpaceX's dragon capsule.

NASA TV via AP

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Though SpaceX has made commercial spaceflight look relatively easy, Boeing's rocky experience with Starliner shows just how hard spaceflight continues to be, even for an experienced company.

Starliner is important not just for NASA and Boeing, but to demonstrate that more than one company can find success in the commercial space industry. A successful launch would also give NASA more confidence in the industry's ability to operations in Earth's orbit while the agency focuses on future missions to the Moon and beyond.The Conversation

Wendy Whitman Cobb, Professor of Strategy and Security Studies, Air University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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