Participants of the Mars500 experiment, which simulated a 520-day flight to Mars, pose for a picture during a news conference in Moscow, November 8, 2011
Participants of the Mars500 experiment, which simulated a 520-day flight to Mars, pose for a picture during a news conference in Moscow, November 8, 2011

HOUSTON - In August, NASA's Curiosity rover is set to arrive on the surface of Mars, where, if all goes well, it will begin a wide range of scientific tests. Such missions provide a great deal of scientific data, but the general public is most excited about the prospect of sending humans to Mars, which NASA hopes to accomplish by 2030. As costs soar and budget battles intensify, however, some notable critics in the scientific community are questioning the whole idea of putting humans in space.

Experiments run continually on the International Space Station and the orbiting Hubble Space Telescope provides dazzling images of deep space, adding to our knowledge of the universe. But University of Texas professor Steven Weinberg, who won the Nobel Prize in Physics in 1979, says humans in space have accomplished little.

“When you have a facility that involves people, like the International Space Station, which is an order of magnitude more expensive than these unmanned observatories, no important science comes out of that,” Weinberg said.

Scientists Debate Value of Human Spaceflight

NASA has developed a long-range plan to send a human crew to Mars, following up on robotic missions.  But Weinberg says robots can do a lot more than humans on Mars.

“For the $1 trillion cost of sending human beings to Mars, perhaps to just one location on Mars, we could have unmanned rovers wandering all over the planet,” Weinberg said.

The Director of the Hayden Planetarium in New York, Neil deGrasse Tyson, agrees with Weinberg on the cost-effectiveness of robots for pure science, but he says having humans in space fulfills another need.

“The issue is what does it mean culturally to send a robot versus send a person? We don't give ticker-tape parades to robots, we don't name schools after robots, we don't build statues to robots,” Tyson said.

Tyson says human beings have an inherent need to explore and that many people would sacrifice their lives to do so.

“If I said I need astronauts to go on a one-way mission to explore Jupiter, I am going to get a line wrapped around the block. There are people out there who want to explore,” Tyson said.

Weinberg understands the appeal of sending humans on short space flights, but he says astronauts cannot stay long in a hostile place like Mars.

“We cannot even do that on Antarctica. There is no economically self-sustaining colony on Antarctica and, compared to Mars, Antarctica is heaven,” Weinberg said.

But such prominent scientific figures as Steven Hawking argue that humans need to explore space because the earth cannot sustain them forever.  While this is not an immediate concern, it is something that informs long-range thinking, according to NASA Deputy Administrator Lori Garver.

“As we can go further, I believe we will, and what we learn will be critical to the future of our very survival,” Garver said.

Weinberg says humans probably will develop the capability to travel far into space someday, but they have plenty of time.

“In the long run, the sun will become a red giant and will swallow the earth and we had better get off the earth before that happens; (but) that is billions of years from now,” Weinberg said.

Weinberg and other scientists say that humans should limit fantasies of living on another planet and put more effort into protecting the environment that sustains them here on this planet.