A few weeks ago, I asked the NN to share their opinions of manned space missions. What should the goal be? The Moon? Mars? Asteroids? None of the above? Many chimed in with excellent ideas and opinions, and it made for a very interesting conversation.
I was prompted to write that initial post after hearing a talk by a professor in meteor physics. The discussion afterward was much the same as the comments the NN bloggers made – some had strong opinions to get rid of manned missions, some couldn’t imagine not having them as part of the future goals of NASA/ESA/etc, while others sat on the fence (myself included).
Here is a summary of what came from that discussion.
The Moon
Pros:
It is close by: travel time can be much less than exploration time. It also means the astronauts are relatively close to home in case of an emergency.
Science: contrary to popular belief, there is a heck of a lot about the Moon that we don’t know about. It can also serve as a great testing ground for missions to further objects, such as Mars.
Cons:
Been there, done that: public interest isn’t so high for this one. Let’s face it, we did this already, 40 years ago.
Delta V: one of the most important factors when planning a mission. This is basically the amount of energy (and therefore fuel/money) needed to fly the mission to and from the Earth’s surface. The Delta V for the Moon is higher than for asteroids, even though they are farther away (because of the Moon’s larger gravitational well).
Mars
Pros:
It’s frickin’ Mars, people!!: humans would visit another planet! In general, there is the most interest in this type of mission because of what it symbolizes (going above and beyond what we were able to do in the 1960s).
Science: there’s a heck of a lot of new science that can be done…on another planet (did I mention that already?)!
Cons:
Distance: Mars is really far away. Depending on the route, it could take up to two years to reach the planet. How long would the astronauts have to stay in order to make that worthwhile?
Health & Safety: what would be the physical, emotional, and psychological affects on the astronauts? Also, there is a good chance that they would not return, given the large distance from home. Is it worth the risk?
Delta V: Mars has the largest gravitational well of the three options. That, combined with the large distance, makes it for an expensive mission. One way to save on this is to “dock” with one of the satellites of Mars (Phobos or Deimos), and take a smaller vehicle on and off the surface of Mars.
Asteroids
Pros:
Delta V: the lowest of the three choices, and therefore the least expensive.
Science: like Mars, this would be new science. We can find out if we could indeed mine asteroids for fuel resources, or use them as shields from the Sun (important because of radiation). Because of the low Delta V, it would be easy to do sample returns. Also, small bodies (asteroids and comets) are the key to understanding the formation and evolution of the Solar System.
Targets: there would be many targets to choose from, which means launch windows would be larger and more frequent.
Excitement: since it’s something new, the public would be more excited about it. It also shows us moving in steps toward going to Mars, instead of just going back to the Moon, or heading straight to Mars.
Cons:
Science: is there enough science to do to make missions useful and relevant?
Distance: though closer than Mars, it could still take months to reach an asteroid. Is it worthwhile to travel for 3-6 months to spend 2 weeks exploring an asteroid? What would be the risks for the astronauts?
Really, there are large lists of pros and cons for each of these options. The big question that remains, though, is if it is worth it to man these missions in the first place? Is it necessary to risk human lives in order to fulfill what is basically a fantasy (as I’m sure we all realize we do not need humans going out in space)?
I, for one, keep flip-flopping on this one. On one hand, there really is no reason for humans to be up in space when machines can do the job more efficiently and can last for much longer. On the other hand, when I think about how big the universe is, and how little we have seen with our own eyes, I feel like we need to start reaching out, star exploring. It’s in our nature, and it’s something that has been lost in recent times.