Two wealthy businessmen achieved a thrill this month that had been reserved for astronauts on government-financed missions. Richard Branson of the United Kingdom and Jeff Bezos of the United States flew to the edge of Earth's atmosphere and experienced weightlessness aboard spacecraft their companies designed, built and launched. A brief flight last week by Bezos, founder of Amazon and owner of The Washington Post, came nine days after Branson spent an hour on his Virgin Galactic space plane. Both billionaires hope to pioneer a new era of space tourism for those who can afford it. "We're here to make space more accessible to all," Branson said shortly after that July 11 flight, which rose 53 miles. "Welcome to the dawn of a new space age."

Bezos and three others -- his brother, an 82-year-old female aviation pioneer and an 18-year-old student from the Netherlands -- went up nearly 67 miles on a July 20 flight lasting 10 minutes. The quick trip was a significant milestone for Blue Origin, a company Bezos founded in 2000 — its first human spaceflight, though not as high as dozens of NASA astronauts have gone since 1961. The firm plans two more New Shepard passenger trips this year and says it has nearly $100 million worth of bookings -- including one from another adventurous billionaire, Tesla electric car company founder Elon Musk. He started SpaceX, a maker of rockets used by NASA, and plans to send an all-civilian crew on a several-day orbital mission aboard his Crew Dragon capsule in September.

Critics deride the recent flights as unseemly examples of rich boys playing with costly toys, in effect. They accuse Bezos and Branson of damaging the environment with unnecessary emissions and wasting resources that could have been spent on more urgent earthbound needs. Bezos responds: "We have lots of problems here and now on Earth and we need to work on those, and we always need to look to the future. We've always done that as a species, as a civilization. We have to do both." Washington Post columnist Megan McArdle shares that view. "What Branson and Bezos are doing matters immensely," she writes. "Such flights are a great platform for the kind of incremental innovation that eventually transformed Orville and Wilbur Wright's motorized box kite into a Boeing 737, and Karl Benz's gasoline-powered tricycle into a sleek C-class [sedan]. That is the kind of innovation that private entities tend to do better than government."

Jeff Bezos says: "It felt so serene and nice and peaceful." – Describing zero gravity

Senator says: "Here on Earth, in the richest country on the planet, half our people live paycheck to paycheck, people are struggling to feed themselves, struggling to see a doctor — but hey, the richest guys in the world are off in outer space! Yes, it's time to tax the billionaires." – Sen. Bernie Sanders of Vernmont, in tweet

Columnist says: "Let's dispense with the notion that any of these flights will add anything to our scientific knowledge, unless it's the establishment of a new metric for how long it takes for money to burn a hole in your pocket when you have more than you could possibly need." – Michael Hiltzik, Los Angeles Times