NASA's human spaceflight program seems mired in the goal of learning about the effects of long term weightlessness on the body. We know it's hazardous to health so why do we keep struggling with it at great cost? Couldn't future spacecraft just simulate gravity with the centrifugal effect of rotation, thus making survival in the weightless environment a moot point?
Image from Wikipedia
NASA's unmanned space program is doing some exciting things. Just think about the Rovers on Mars, for instance.
Also private enterprise is starting to develop a space tourism industry.
In 1969 to early 1970s, Americans walked on the moon. Now NASA can't even afford a seat on the Russian Soyuz spacecraft which is currently the only way to get humans to the space station. Seat to the highest bidder, singer Sarah Brightman bumps NASA for the flight, but space tourism is starting to takeoff, however.
We have plenty of wealthy people expressing interest for traveling in space. Good news even though some might say we should send our wealthy to space and leave them there. In reality, a round trip to space is becoming more routine; not anywhere near as routine as international jet travel, but possibly headed that way.
Article in above link mentions Spaceship II and some other private enterprise projects to send tourists on short rides above the atmosphere. Starting with the rich, of course, but in the future, who knows. International travel even faster than today's jets? Planes that coast into space on their way between continents?
Sounds far fetched, but modern jet travel would be far fetched to the Lewis & Clark expedition of 1804 - 1806.
NASA still plays a successful role as partner with some of these projects. For instance Space X corporation's private capsule called the Dragon which recently docked with the International Space Station on a supply mission. There are plans for Manned Dragon capsules in the future.
Space can be an ultimate frontier, but at today's level of technology and economic constraints, it seems like we could be focusing our space exploration efforts on more exciting goals than long term survival in weightless environments.