Yesterday I made the observation that it was much cheaper to transmit information than to travel to an interstellar destination, observing that sending a microscopic robot able to use raw materials in the destination system to bootstrap manufacture what it needs.
The Leather Library pointed out that this applies as well to destinations in our solar system. I think that’s definitely right. All we have to do is look at the current state of our exploration of the solar system.
We have sent robot probes on missions to Mars, Venus, Mercury, Jupiter, Saturn, Uranus, and Neptune. Currently four of these probes are headed outside of the solar system. We have, or had, probes in orbit of Venus, Mars, Jupiter, and Saturn. We have rovers on the surface of the Moon and Mars. We have a probe headed to Mercury to orbit and examine the planet, and another probe on its way to a close approach to the sun to study it. We have a probe on its way to fly by Pluto and then explore the Kuiper Belt.
Robots are exploring the entire solar system and sending enormous amounts of data back to us. Humans, in contrast, have only spent a substantial amount of time in near Earth orbit, so low that that the orbiting International Space Station has to periodically fire thrusters to boost its orbit to avoid air drag bringing it down. Except for a brief period of heroic, but largely symbolic, flights to the Moon, this has been the extent of human exploration.
Why is this? Because sending robotic probes is far cheaper than sending humans. Humans are organisms evolved to survive in a narrow biosphere on the outer crust of the Earth. Move us to anywhere outside of that biosphere, and we quickly die. For that matter, move us to many locations within that biosphere, and we still die fairly quickly.
Sending humans into space involves taking a part of the biosphere with us. It involves sending supplies, additional radiation shielding, and a great deal of additional safeguards to minimize the chance of anything happening to the humans. All of these things, along with the requirement to get humans back to Earth, add enormous amounts of mass and energy requirements to any space exploration mission.
By contrast, robots designed from the ground up for operating in space need no biosphere, and no supplies other than a power source. The safeguards on them are only geared toward insuring their functionality. And there’s no requirement for them to ever return to Earth. (Although there have been missions to return samples, and there are discussions for a robotic mission to Mars that would return samples to Earth.)
Robots do have one serious drawback of course. They don’t have the versatility, the knowledge, the dexterity, the judgment of humans. I remember seeing an interview with a NASA engineer who expressed how much more efficient rover operations could be if they could be controlled from Mars orbit. Or if they could be done first hand by humans.
Many people assume that these limitations will eventually compel us to send humans to these locations. Perhaps. But it’s worth noting that the robots have become much better since we started sending them out. The robots of today are far more versatile than the ones in the 60s and 70s, which could do little other than flyby missions or stationary observations.
Robots are constantly improving. The question is, will they get better fast enough to ever make sending humans a completely redundant proposition, at least as far as scientific discovery is concerned? And if they do, should that cause us to abandon the idea of human space exploration?
At this point, it’s worth pondering why exactly we want to send humans to these destinations. For colonization? For the spirit of exploration? To insure survival of the species?
Colonization is the idea that people will want to live on places like Mars. But aside from the glory of being the first people there, what exactly would colonists do when they got there? Particularly if all of the science work could be done by machines? Mars is a brutally inhospitable place. To avoid health damaging radiation, settlers might have to spend the lion share of their time underground.
Once the initial glory has faded, how many people are really going to want to do that? How many people will want to exile themselves to never being able to ever again walk out in the open?
But what about the spirit of exploration? The spirit of the people who explored the world during the European Age of Discovery? There are two important things to understand about the Age of Discovery.
The first is that it had a strong economic incentive. Initially it was to find alternate trade routes to the far east. The old overland routes had become unreliable, dangerous, and expensive.
The second is that settlement in the wake of these discoveries happened on the promise of usable farm land. Land that existed in the same biosphere (and often had existing inhabitants, but that’s a different issue). Even with that benefit, many of these colonies still failed.
I don’t doubt that we will eventually send humans on symbolic journeys to Mars and many other locations. Will long term survival of the species motivate us to do more than that? To establish a permanent human presence at these locations? Survival of the species is a laudable goal, but the payoff is probably too remote to convince taxpayers to give up anything today to insure that it happens in the remote future.
Personally, I’d like to see human space exploration happen, although I’ll fully admit my motivations are romantic rather than cold hard reasoning. Private enterprises like SpaceX do give some hope, but that hope would be stronger if they didn’t need government contracts to fund their operations.
Until and unless someone finds an economic incentive for humans to travel to these destinations, or finds a way to make human space travel far cheaper, progress in this area will likely be slow. It may become even slower as robotic craft continue to improve, and allow us to get more exploration done with them alone.
- Aging ISS a space lab of ‘unlimited’ opportunity (phys.org)
- Things I Would Like To See (Part X) (joshuaziefle.net)
- Scientists closer to solving Mars rock mystery, says Nasa expert (battleofourtimes.com)
- international-space-station-nasa-270114.jpg (themalaysianinsider.com)
- Cosmos 5: Blues for a Red Planet (writescience.wordpress.com)
- NASA’s Opportunity rover celebrates 10 years on Mars with a FILTHY selfie (astronaut.com)
- What’s up in planetary missions in 2014 (planetary.org)