Is it Time to Play With Spaceships Again?

Out ThereAfter 50 years of Apollo nostalgia, we have yet to fully answer the central question: Why send humans into space?CreditCreditMike McQuadeSupported byBy Dennis Overbye[Read all Times reporting on the 50th anniversary of the Apollo 11 moon landing. | Sign up for the weekly Science Times email.]Most earthlings alive today were not yet around when humans landed on the moon. President Trump has said he wants to return Americans to the moon by 2024, and a new generation of swashbuckling rocket oligarchs has joined the action, lured by government contracts and grandiose science-fiction visions.Amid all the excitement and nostalgia, however, it is easy to forget that over the past five decades we never really answered the central question: Why do we want to go to space?Humankind’s space aspirations can be traced in part to the early days of the 20th century, when a bunch of rocket engineers and science-fiction prophets cajoled political, military and business leaders into following and financing their dreams to explore the cosmos. And, not least, it returned 842 pounds of moon rocks, which provided a diary of the birth of the solar system.But it was not science, cosmic destiny or any great public yearning that put humans on the moon —  it was Cold War politics. In 1961, about a month after the failed Bay of Pigs invasion of Cuba, which began just five days after the Soviet cosmonaut Yuri Gagarin became the first man in space, Kennedy announced that America should undertake to put a man on the moon by the end of the decade.[Sign up to get reminders for space and astronomy events on your calendar.]His idea was met with a lukewarm reception at best. Is the moon or Mars next?These days the most outspoken apostles of the old space mysticism are the rocket oligarchs, all of whom hope to make a fortune from it: Elon Musk, of SpaceX, the engineer who has built rockets that return and land tail-first; Jeff Bezos, of Blue Origin, the founder of Amazon; and Richard Branson, known for his various Virgin businesses and his adventures as a long-distance balloonist and sailor.They have been taking reservations for space tickets for years. (Mr. Branson once promised a free ride to Stephen Hawking on Virgin Galactic, but Dr. Hawking died last year, a prisoner of gravity.) With NASA’s blessing, the International Space Station is about to become a tourist destination — for $35,000 a day, not including the cost of the rocket flight to get there.Lately, Mr. Musk and Mr. Bezos have ventured dueling visions of the far future: settlements on Mars, according to Mr. Musk, who has said he wants to die there (but not soon), or space colonies, according to Mr. Bezos — spinning, cylindrical cities floating among the asteroids, a callback to ideas of the “High Frontier” popularized by Gerard K.