Comments on: Human exploration of Phobos and Deimos? http://blogs.discovermagazine.com/badastronomy/2007/07/15/human-exploration-of-phobos-and-deimos/ I am an astronomer, writer, and skeptic. I likes reality the way it is, and I aims to keep it that way. My real name is Phil Plait, and I run the Bad Astronomy blog. Sun, 05 Jul 2009 02:03:39 +0000 http://wordpress.org/?v=2.3.1 By: coolstar http://blogs.discovermagazine.com/badastronomy/2007/07/15/human-exploration-of-phobos-and-deimos/#comment-42141 coolstar Fri, 09 May 2008 21:31:38 +0000 http://blogs.discovermagazine.com/badastronomy/2007/07/15/human-exploration-of-phobos-and-deimos/#comment-42141 Pulsinpirate has got it exactly right. The Moon is a stepping stone to nowhere! The science doesn't compare to a manned Mars mission etc and there's no chance for sustainable colonies (without also exploiting the resources of NEAs, so why no do THAT first?) In fact, going to the Moon first (and again) will likely end the U.S.'s manned presence in space for the foreseeable future. WHY? IT's DANGEROUS!! almost as dangerous as a Martian mission for little payoff. We'll likely LOSE PEOPLE which will be a public relations nightmare and kill the rest of any manned program to the moon. Will we lose people going to Mars? Probably, in time, certainly, but the payoff may out weigh the public outcry while loses in going back to the moon will be impossible to justify. Pulsinpirate has got it exactly right. The Moon is a stepping stone to nowhere! The science doesn’t compare to a manned Mars mission etc and there’s no chance for sustainable colonies (without also exploiting the resources of NEAs, so why no do THAT first?) In fact, going to the Moon first (and again) will likely end the U.S.’s manned presence in space for the foreseeable future. WHY? IT’s DANGEROUS!! almost as dangerous as a Martian mission for little payoff. We’ll likely LOSE PEOPLE which will be a public relations nightmare and kill the rest of any manned program to the moon. Will we lose people going to Mars? Probably, in time, certainly, but the payoff may out weigh the public outcry while loses in going back to the moon will be impossible to justify.

]]> By: Nigel Depledge http://blogs.discovermagazine.com/badastronomy/2007/07/15/human-exploration-of-phobos-and-deimos/#comment-42140 Nigel Depledge Thu, 13 Dec 2007 12:48:40 +0000 http://blogs.discovermagazine.com/badastronomy/2007/07/15/human-exploration-of-phobos-and-deimos/#comment-42140 Ah, yes, I can see the recruitment posters: Manned Space Flight To Visit Fear and Panic! Ah, yes, I can see the recruitment posters:

Manned Space Flight To Visit Fear and Panic!

]]> By: Ken G http://blogs.discovermagazine.com/badastronomy/2007/07/15/human-exploration-of-phobos-and-deimos/#comment-42139 Ken G Thu, 19 Jul 2007 03:50:03 +0000 http://blogs.discovermagazine.com/badastronomy/2007/07/15/human-exploration-of-phobos-and-deimos/#comment-42139 pulsinpirate: Like I said, we need to learn how to survive years in space, and we have no clue how to do that. You don't actually expect me to believe that the time on Mars "doesn't count" because "chemistry can make air" there? Chemistry can make air at the top of Mount Everest too, but I don't see anyone signing up to spend two years there just because no one else has yet. pulsinpirate: Like I said, we need to learn how to survive years in space, and we have no clue how to do that. You don’t actually expect me to believe that the time on Mars “doesn’t count” because “chemistry can make air” there? Chemistry can make air at the top of Mount Everest too, but I don’t see anyone signing up to spend two years there just because no one else has yet.

]]> By: Hank Roberts http://blogs.discovermagazine.com/badastronomy/2007/07/15/human-exploration-of-phobos-and-deimos/#comment-42138 Hank Roberts Tue, 17 Jul 2007 22:19:18 +0000 http://blogs.discovermagazine.com/badastronomy/2007/07/15/human-exploration-of-phobos-and-deimos/#comment-42138 I'm sorry but the most important thing we could be doing (besides of course dealing with any impactor coming our way) is setting up for catch-and-release fishing for near earth passing objects. Who wants to set up a company dedicated to sending out a package that will intercept the path of any large hunk of anything coming our way, land on it (heck, spear it, grab it with a net of bungees, whatever) and survive with a solar panel, a transponder, and perhaps a deployable solar sail or ion engine? At worst we'll know precisely where they go. At best we'll be able to either steer them back into a useful position where they can be recaptured or at least send a precisely targeted and better set of equipment to attach to them for their next run. I'd invest --- all the money I intend to benefit my nephews and niece's grandchildren. It's an obvious move. Why aren't we doing this? I’m sorry but the most important thing we could be doing (besides of course dealing with any impactor coming our way) is setting up for catch-and-release fishing for near earth passing objects.

Who wants to set up a company dedicated to sending out a package that will intercept the path of any large hunk of anything coming our way, land on it (heck, spear it, grab it with a net of bungees, whatever) and survive with a solar panel, a transponder, and perhaps a deployable solar sail or ion engine?

At worst we’ll know precisely where they go. At best we’ll be able to either steer them back into a useful position where they can be recaptured or at least send a precisely targeted and better set of equipment to attach to them for their next run.

I’d invest — all the money I intend to benefit my nephews and niece’s grandchildren. It’s an obvious move. Why aren’t we doing this?

]]> By: pulsinpirate http://blogs.discovermagazine.com/badastronomy/2007/07/15/human-exploration-of-phobos-and-deimos/#comment-42137 pulsinpirate Tue, 17 Jul 2007 22:13:11 +0000 http://blogs.discovermagazine.com/badastronomy/2007/07/15/human-exploration-of-phobos-and-deimos/#comment-42137 "Each mission takes years, and you can’t send the next upgrade before the last one comes back, or until you’ve spent years studying why the last one didn’t come back. And even more, you have to find a way to keep people alive in space for the better part of two years." On the Mars Direct plan, the full cycle time of a crew is about 972 days, with 455 days on the planet and transits of about 260 days. The provisioning for deep space segments is thus well shorter than "years". Moreover the breathing gases, rocket fuel, and some food for the Mars-Earth return can be produced in situ from simple chemistry on the Martian atmosphere and a green house. “The cost of a payload landed on Mars from LEO is about one half the cost of the same payload landed on the Moon from LEO. This seems counter intuitive to me…" In long haul rocketry the cost of mission is mostly fuel mass in LEO. Because the landing on Mars benefits from aerobraking you need not pack nearly as much fuel for retro thrusters as you do for a Lunar mission. That is the factor two in mission mass for an equal payload. Aerobraking on the Moon is not a good idea. The point here is that while HEM demands longer dwell times and larger masses, the cost per kg of payload is significantly in favor of Mars. The relative safety of the missions favors Mars. The relative science payoff favors Mars. Once adequate component reliability is available for Mars — and this is not so hard — any sensible risk/reward calculus will heavily favor Mars as the target with "more bang for the buck". "At the end of a Mars mission what [d]o we have. An abandoned science base and (admittedly) the memory of a grand adventure." No, far more. At the end of a first decade of a Mars Direct class HEM what we will likely have is a clear basis for a permanent settlement, some valuable lessons on issues about extraterrestrial life, and an infrastructure in place to explore and monitor NEO candidates among the asteroids. That's when we visit the little Martian moons as a warm up. “Each mission takes years, and you can’t send the next upgrade before the last one comes back, or until you’ve spent years studying why the last one didn’t come back. And even more, you have to find a way to keep people alive in space for the better part of two years.”

On the Mars Direct plan, the full cycle time of a crew is about 972 days, with 455 days on the planet and transits of about 260 days. The provisioning for deep space segments is thus well shorter than “years”. Moreover the breathing gases, rocket fuel, and some food for the Mars-Earth return can be produced in situ from simple chemistry on the Martian atmosphere and a green house.

“The cost of a payload landed on Mars from LEO is about one half the cost of the same payload landed on the Moon from LEO.
This seems counter intuitive to me…”

In long haul rocketry the cost of mission is mostly fuel mass in LEO. Because the landing on Mars benefits from aerobraking you need not pack nearly as much fuel for retro thrusters as you do for a Lunar mission. That is the factor two in mission mass for an equal payload. Aerobraking on the Moon is not a good idea.

The point here is that while HEM demands longer dwell times and larger masses, the cost per kg of payload is significantly in favor of Mars. The relative safety of the missions favors Mars. The relative science payoff favors Mars. Once adequate component reliability is available for Mars — and this is not so hard — any sensible risk/reward calculus will heavily favor Mars as the target with “more bang for the buck”.

“At the end of a Mars mission what [d]o we have. An abandoned science base and (admittedly) the memory of a grand adventure.”

No, far more. At the end of a first decade of a Mars Direct class HEM what we will likely have is a clear basis for a permanent settlement, some valuable lessons on issues about extraterrestrial life, and an infrastructure in place to explore and monitor NEO candidates among the asteroids. That’s when we visit the little Martian moons as a warm up.

]]> By: Cheeky Kea http://blogs.discovermagazine.com/badastronomy/2007/07/15/human-exploration-of-phobos-and-deimos/#comment-42136 Cheeky Kea Tue, 17 Jul 2007 20:54:15 +0000 http://blogs.discovermagazine.com/badastronomy/2007/07/15/human-exploration-of-phobos-and-deimos/#comment-42136 Space Elevator. Good idea, but currently outside our expertise. This does not mean that we should not study the idea. But should we stop space exploration in the hope that one is developed soon? My personal opinion is no. The need for cheaper launch systems does add to the infrastructure I mentioned above, and supports all sorts of missions. In the short term I suspect these will be rockets. "The cost of a payload landed on Mars from LEO is about one half the cost of the same payload landed on the Moon from LEO." This seems counter intuitive to me... but then lots of things seem counter intuitive so lets accept this for the moment. 2 people can be sent to the Moon and back in quite cramped conditions. The payload to send people to Mars, and to keep them alive and healthy is considerably more. The dangers on the Moon from the sun can be mitigated. For instance hiding in a creator near the poles. At the end of a Mars mission what to we have. An abandoned science base and (admittedly) the memory of a grand adventure. Taking the stepping stone approach we have infrastructure in space for raw materials, and manufacturing, which frees us a little from earth’s gravity well, the ability to send large (safe) payloads to Mars, a grand adventure on the Moon with the possibility of one soon on Mars. Space Elevator. Good idea, but currently outside our expertise. This does not mean that we should not study the idea. But should we stop space exploration in the hope that one is developed soon? My personal opinion is no. The need for cheaper launch systems does add to the infrastructure I mentioned above, and supports all sorts of missions. In the short term I suspect these will be rockets.

“The cost of a payload landed on Mars from LEO is about one half the cost of the same payload landed on the Moon from LEO.”

This seems counter intuitive to me… but then lots of things seem counter intuitive so lets accept this for the moment. 2 people can be sent to the Moon and back in quite cramped conditions. The payload to send people to Mars, and to keep them alive and healthy is considerably more.

The dangers on the Moon from the sun can be mitigated. For instance hiding in a creator near the poles.

At the end of a Mars mission what to we have. An abandoned science base and (admittedly) the memory of a grand adventure. Taking the stepping stone approach we have infrastructure in space for raw materials, and manufacturing, which frees us a little from earth’s gravity well, the ability to send large (safe) payloads to Mars, a grand adventure on the Moon with the possibility of one soon on Mars.

]]> By: Ken G http://blogs.discovermagazine.com/badastronomy/2007/07/15/human-exploration-of-phobos-and-deimos/#comment-42135 Ken G Tue, 17 Jul 2007 15:29:30 +0000 http://blogs.discovermagazine.com/badastronomy/2007/07/15/human-exploration-of-phobos-and-deimos/#comment-42135 Many seem to be forgetting the difference in timeframe between going to the Moon and going to Mars. This is quite important not to forget! You can hardly send people before you've sent robots on the entire mission, there and back-- at least into orbit and back. Each mission takes years, and you can't send the next upgrade before the last one comes back, or until you've spent years studying why the last one didn't come back. And even more, you have to find a way to keep people alive in space for the better part of two years. What's the current record? And was it within the shield of the Earth's magnetic field? Will that cosmonaut ever play sports again? I agree with pulsinpirate- it makes much more sense to concentrate on sending more and more sophisticated machines. It's *much* cheaper, and if you fail, you shrug it off and try again. And have we even scratched the surface on the "virtual reality" capabilities of an instrument of that nature? I think an intelligent robot with vast capacity to "bring the experience home" would capture people's imagination almost as much as actual humans, and actually have more to offer us back home. We just wouldn't get that amazing sense of accomplishment, but that's down the road. Many seem to be forgetting the difference in timeframe between going to the Moon and going to Mars. This is quite important not to forget! You can hardly send people before you’ve sent robots on the entire mission, there and back– at least into orbit and back. Each mission takes years, and you can’t send the next upgrade before the last one comes back, or until you’ve spent years studying why the last one didn’t come back. And even more, you have to find a way to keep people alive in space for the better part of two years. What’s the current record? And was it within the shield of the Earth’s magnetic field? Will that cosmonaut ever play sports again? I agree with pulsinpirate- it makes much more sense to concentrate on sending more and more sophisticated machines. It’s *much* cheaper, and if you fail, you shrug it off and try again. And have we even scratched the surface on the “virtual reality” capabilities of an instrument of that nature? I think an intelligent robot with vast capacity to “bring the experience home” would capture people’s imagination almost as much as actual humans, and actually have more to offer us back home. We just wouldn’t get that amazing sense of accomplishment, but that’s down the road.

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