Read the following passage and answer the questions that follow. Some words are highlighted. Pay close attention to those words.

We would argue that inspirationally led private companies should front all missions involving humans as cut-price high-risk ventures. There would still be many volunteers—a few perhaps even accepting one-way tickets—driven by the same motives as early explorers and mountaineers. The phrase “space tourism” should be avoided. It lulls people into believing such ventures are routine and low-risk. If that’s the perception, the inevitable accidents will be as traumatic as those of the space shuttle were. These exploits must be sold as dangerous, extreme sports, or intrepid exploration.

The most crucial impediment to space flight stems from the intrinsic inefficiency of chemical fuel, and the requirement to carry a weight of fuel far exceeding that of the payload. So long as we are dependent on chemical fuels, interplanetary travel will remain a challenge. Nuclear power could be transformative. Allowing much higher in-course speeds would drastically cut the transit times in the solar system, reducing not only astronauts’ boredom but their exposure to damaging radiation. It’s more efficient if the fuel supply can be on the ground; for instance, propelling spacecraft into orbit via a “space elevator”—and then using a “star-shot”-type laser beam generated on Earth to push on a “sail” attached to the spacecraft.

Elon Musk has said he wants to die on Mars—“but not on impact.” It’s a realistic goal, and an alluring one to some. But don’t expect mass emigration from Earth. It’s a dangerous delusion to think that space offers an escape from Earth’s problems. We’ve got to solve those here. Coping with climate change or the COVID-19 pandemic may seem daunting, but it’s a piece of cake compared to terraforming Mars. There’s no place in our solar system that offers an environment even as clement as the Antarctic or the top of Mount Everest. Simply put, there’s no Planet B for ordinary risk-averse people.

Still, we (and our progeny here on Earth) should cheer on the brave space adventurers. They have a pivotal role to play in spearheading the post-human future and determining what happens in the 22nd century and beyond. Pioneer explorers will be ill-adapted to their new habitat, so they will have a compelling incentive to re-design themselves. They’ll harness the super-powerful genetic and cyborg technologies that will be developed in the coming decades. This might be the first step toward divergence into a new species.