Mars Orbiters Chip Away at an Icy World

Space.com ^ | 6/27/03 | Leonard David

[KevinDavis]

NASA's Mars Odyssey is chipping away at how and where ice forms on the red planet. New data is helping shape future strategies of exploring Mars, looking for life, and supporting future human explorers.

[KevinDavis]

The next logical step is send humans to Mars. Why delay any futher??

[KevinDavis]

Space Ping! This is the space ping list! Let me know if you want on or off this list!

[demlosers]

Put me on your list. :)

[BenLurkin]

If its not like this then I don't want to go:

[Malsua]

>>The next logical step is send humans to Mars. Why delay any futher?? <<

Because we can't send them there and get them home easily.

If we could just send them there to explore and let them suicide, we could probably do it tomorrow. I'm sure quite a number of folks would volunteer for that suicide mission, but we can't in good conscience do such a thing even though it would be in the best interest of humanity overall.

Fuel is the issue. How do you get enough fuel to get, to use as a brake for landing and then blast off again and use as a brake here on the Earth.

Look at how much fuel the Shuttle uses to take off. Mars has about 1/3 the gravity of the earth, that still means you need 1/3 of that external tank to take off and 2 SRBs 1/3 the size. Not to mention the rockets to break the landing. After all there are no runways on Mars. You can't glide down and the atmoshere is thin enough you can't rely on parachutes unless they are gigantic.

Unless Islam takes over the world, humans will eventually make it to Mars, but right now the hurdles are phenominal.

[Malsua]

To add to my previous post.

Here's how I would do it.

Shuttle Boosters and fuel to orbit. Ship all of that to Mars with 5 time redundancy. Keep trying until those things actually make it.
Shuttle a vehicle to orbit and fuel for the trip to Mars.
Once everything is in place, shuttle the crew to the vehicle...they go to Mars, connect with the lander/take off units, land, spend time and take off. Once in orbit again, they connect with the return to home fuel, blast towards the Earth. Once here, they dock to the Shuttle and ride home.

Would cost hundreds of billions. It'd be okay by me :)

[PUGACHEV]

At the moment, and for the near future, sending a human to Mars would be homicide. The space traveler would be exposed such huge amounts of radiation he would not make it to Mars alive, much less survive the trip back.

[KevinDavis]

Based on current technology. We will find a way to protect humans on a voyage to Mars and back.

[e_engineer]

Actually, there is a lot more information that can (should) be gathered by probes before sending humans.

An example is the recent claims of vast amounts of water on Mars. These claims need to be verified so that a manned mission can be planned properly. The cost and design of a manned mission is dramatically different if you need to carry all of your water with you.

If probes determine that there is water frozen in the polar regions, then we need to develop a reliable method to extract the water. Ideally, some automated extraction and storage devices would be placed on Mars, so that large amounts of water would be waiting when the humans arrive.

[Malsua]

>>At the moment, and for the near future, sending a human to Mars would be homicide. The space traveler would be exposed such huge amounts of radiation he would not make it to Mars alive, much less survive the trip back. <<

Huh? Explain.

The space station is outside of the magnesphere, the people on it get exposure, but it is within a survivable amount. One thing that is fortunate is that the human body can tolerate a level of radiation without much harm. The most intense radition they would get would be in the Van Allen Belt. The engergetic particles trapped there would irradiate them more than anything in free space.

While I'm not discounting your argument until I know more, I wish to understand why you state this. It's new to me and while I'm not an expert, I'm a reasonably informed guy :).

[MalcolmS]

Look at how much fuel the Shuttle uses to take off. Mars has about 1/3 the gravity of the earth, that still means you need 1/3 of that external tank to take off and 2 SRBs 1/3 the size.

Fortunately, that's not true. There is no simple mathematical relationship as there is an integration (calculus) involved in the calculation.

However, for a simple case, consider the moon landings. The moon has 1/6th earth's gravity. The moon lander took off with no visible external tanks at all--much smaller than 1/6th the size of the massive Apollo boosters.

The problem is that in earth's gravity, as you start adding fuel, you have to add even more fuel so that you can carry the weight of that fuel to the altitude where you will burn it.

It's complicated, but it's not rocket science. Oh wait, maybe it is. Umm, how about, it's complicated, but it's not brain surgery.

[BlazingArizona]

If we could just send them there to explore and let them suicide, we could probably do it tomorrow. I'm sure quite a number of folks would volunteer for that suicide mission, but we can't in good conscience do such a thing even though it would be in the best interest of humanity overall.

This raises an interesting point. We might send a shipload of sufficiently athletic old people who accept the strong possibility that it will be a one-way mission for them.

With Story Musgrave and John Glenn, we have already proven that we can send geezers into space.

[BlazingArizona]

However, for a simple case, consider the moon landings. The moon has 1/6th earth's gravity. The moon lander took off with no visible external tanks at all--much smaller than 1/6th the size of the massive Apollo boosters.

Mars has a much thinner atmosphere than Eath, even in proportion to its size. This reduces the thrust needed to lift payloads out of it.

[PUGACHEV]

In the legnth of time it would take to travel from earth to Mars the space traveler would be exposed to fatal amount of radiation. Here's an article from the NASA website that explains it better than I could: http://www.nsbri.org/Radiation/HumanAffects.html. With the materials and methods we have at hand today, the weight shielding needed to protect the astronaut would be so great we would be unable to boost the capsule into space.

[PUGACHEV]

Sorry, bad link. Try this and click on the link for "radiation": http://astrobiology.arc.nasa.gov/news/expandnews.cfm?id=9339

[RightWhale]

The next logical step is send humans to Mars. Why delay any futher??

There is no reason to delay. NASA alone could do this with no increase in its budget if the ISS were either splashed or modified to serve as the core of the Mars ship. Severely large tonnage would have to be launched to earth orbit because the Mars mission would have to be huge.

However, it is not necessary for the first expedition to land on Mars. It can be an orbital mission: set up an orbital station at Mars, use one of the moons if you like. Operate the Mars orbital station for a while and, when you are ready, send a small manned lander to the surface from there. This should be easy.

[RightWhale]

the weight shielding needed to protect the astronaut would be so great we would be unable to boost the capsule into space.

Why boost the capsule into space? Let's use our noodle. Not to be obtuse, but this has all been worked out 1000s of times.