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I think one of the biggest issue (for now) is how long it will take to get there.
How Long Does it Take to Get to Saturn? - Universe Today
Quote:
In the past spacecraft have taken greatly different amounts of time to make it to Saturn. Pioneer 11 took six and a half years to arrive. Voyager 1 took three years and two months, Voyager 2 took four years, and the Cassini spacecraft took six years and nine months to arrive. The New Horizons spacecraft took a short two years and four months to arrive on the scene. Why such huge differences in flight time?
End Quote.
How Long Does it Take to Get to Mars? - Universe Today
Quote:
Mariner 9, the first spacecraft to successfully go into orbit around Mars launched on May 30, 1971, and arrived November 13, 1971 for a duration of 167 days. This is the same pattern that has held up for more almost 50 years of Mars exploration: approximately 150-300 days.
Here are some more examples:
- Viking 1 (1976) – 335 days
- Viking 2 (1976) – 360 days
- Mars Reconnaissance Orbiter (2006) – 210 days
- Phoenix Lander (2008) – 295 days
- Curiosity Lander (2012) – 253 days
Travel time is too long for current technology. Building reliable source for air, water, food and energy for travelers is impossible with current technology. Our atmosphere gives roughly same protection against cosmic radiation than 10 m of water. It is not perfect protection. Perhaps it does not kill wannabe Martians, but even that is not certain.
Study: Collateral damage from cosmic rays increases cancer risks for Mars astronauts
"Previous studies have shown the health risks from galactic cosmic ray exposure to astronauts include cancer, central nervous system effects, cataracts, circulatory diseases and acute radiation syndromes. Cosmic rays, such as iron and titanium atoms, heavily damage the cells they traverse because of their very high rates of ionization."
Mars-bound astronauts face chronic dementia risk from galactic cosmic ray exposure
Idea of using hydrocarbons of Titan as energy source is stupid. Scientist should know better, but she is promoting her book. To burn you need oxygen. Splitting it from water takes about as much energy as you get from burning. If I remember correctly, burning carbon releases slightly more energy than splitting water takes, but difference is so small that it is not usable energy source. To get carbon you would need split methane. So only fusion energy is available on Titan. All heavy minerals are somewhere deep under hydrocarbons and water. So Titan is very resource poor moon!
If travel time and range is significant, then generating fuel on the lunar surface robotically and assembling/launching spacecraft there gives you the best heavy lift, high speed, long range launch platform. The Mars Curiosity mission required an Earth launch weight of 531,000kg to put 899kg of usable payload on the surface of Mars. But that mission was not in a hurry to get there either, it took 253 days to cover the 350 million miles. Note that Mars can be as close as 47 million miles to Earth, you need to travel 350 million because we are slow. In an ironic twist, the faster you go, the less distance you need to travel to begin with.
Everything changes if we come up with better solution than chemical rockets that can be launched safely from the Earth's surface. But for now, launching from a pad that is already moving faster with 1/5 gravity where there is fuel present, and where nuclear or toxic propulsion systems are allowed can seriously reduce flight times.
Yes that is correct. Too bad the "pad" you are envisioning is 239,000 miles from Earth and everything required to build that pad has to be lifted off Earth and all the fuel needed to launch a spacecraft from that pad would need to be manufactured on the moon, meaning the equipment required to make the fuel would have to be lifted off Earth.
In theory rocket fuel can be made on the moon. Just like in theory rocket fuel can be made on Mars, though many experts think making it on Mars would be easier. And we will need to make fuel on Mars whether we launch Mars missions from Earth or from the moon since we want to send rockets and people back from Mars to the Earth.
So to me it seems simpler and less resource intensive simply to launch from Earth (where rocket fuel is abundant and cheap) to Mars, instead of first making a very large number of launches from the Earth to the moon (to build the moon launch base and fueling facility) and then make launches from the moon to Mars.
I don't pretend to be able to run the numbers and demonstrate conclusively that a "Mars Direct" mission is the best choice. Obviously many people have already done that, including Elon and the SpaceX team. Their plan differs somewhat from Robert Zubrin's approach, but both plans ignore the moon. See The Mars Society
My usual response is "We need to practice terraforming Mars, so that we will be able to terraform Earth."
Thank you kindly.
p.s. Elon will ultimately fail with making Homo sapiens a multi-planet species, since Martians will rapidly become a new species. But so what, still a good idea.
Thank you kindly.
p.s. Elon will ultimately fail with making Homo sapiens a multi-planet species, since Martians will rapidly become a new species. But so what, still a good idea.
The definition of a "species" is a group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding.
It will more likely take tens thousands of years for a population of humans living on Mars to become a different species because there will probably be a continuing inflow of humans from Earth. It will only take a few generations for "Martians" (humans born on Mars) to look somewhat different than "Terrans" (humans born on Earth). I envision them becoming on average more slender, taller, slightly longer limbs, thinner bones. But that will just be an adaption to Martian gravity. Genetically they will be the same.
No comments on a million people on Mars this century?
The emperor has no clothes.
The emperor has no clothes.
habanero69
I Dont Need Cialis. I Drive an EV.
It's a goal, not a statement of fact. Elon sets incredibly difficult goals. That is how you accomplish incredibly difficult things.
The "emperor" who has no clothes is the #lyinglunatic in the White House.
Why not a billion people on Mars by 2100? Would that goal not produce better results than a measly million?
Stupid is stupid. Both Trump and Musk produce plenty to feed their followers.
anticitizen13.7
Not posting at TMC after 9/17/2018
James S.A. Corey sent me a ice cream birthday cake.
I hope the MCRN sends you a present.
ccutrer
Active Member
Because he doesn't think a billion would be possible. He does think a million is possible, if all the stars line up and no black cats cross his path and he wins the lottery. Long shot, but possible. My general rule is add 50-100% to Elon time. Not three orders of magnitude.
The big difference is that Elon Musk actually meets his ambitious goals. He is often late but they usually happen. ITS is being tested right now. It's an incredibly ambitious plan. It's also a plan he's been working on even before he created SpaceX. Now he's actually created a launch company with rockets that prove such a goal is possible. Elon keeps proving skeptics wrong over and over. He doesn't seem to care that people don't believe he can do it. He'll keep trying. Maybe fail. He understands that. He'll keep trying though and learning from what mistakes are made. This goal will go beyond his lifetime and he knows that too.
anticitizen13.7
Not posting at TMC after 9/17/2018
No one can deny that SpaceX is on a path towards making space travel more and more affordable. To say they have nothing is simply untrue.
SpaceX successfully launched and landed a used 1st stage booster during the BulgariaSat mission today, which you can read about and weep here: SpaceX successfully launches and lands a used rocket for the second time
And that is the second time SpaceX has done it.
The aerospace industry said that it would be impossible to recover and re-use a first stage. Elon said "SpaceX can do it and it is essential that it be done to make space flight affordable and to colonize Mars."
And SpaceX did it.
If you want to bet against SpaceX colonize Mars, feel free. It's going to happen anyway.
The new emperor at SpaceX is fully clothed.
To add:
Bulgaria’s first communications satellite heaved into orbit – Spaceflight Now
Quote:
Maxim Zayakov, CEO of BulgariaSat and its affiliate Bulsatcom, said the satellite was healthy following Friday’s launch. He said ground controllers established contact with BulgariaSat 1 as expected a few minutes after deployment from the launcher.
.......
In an interview with Spaceflight Now before the launch, he credited SpaceX’s cost-cutting ways with making space accessible for small nations and money-conscious companies like his own.
“People don’t realize that, for small countries and small companies like us, without SpaceX, there was no way we would ever be able to even think about space,” Zayakov said. “With them, it was possible. We got a project. I think, in the future, it’s going to be even more affordable because of reusability.”
End quote.
WannabeOwner
Well-Known Member
I struggle with that : Why didn't the other advanced civilisations backup themselves?
Reciprocity
Active Member
Good question. Maybe advanced was the wrong term. For example, we have no plans to backup our civilization (aside from 1 man.) The idea is that civilizations destroy themselves before they become multi-planetary. The other idea is that aliens design ai that eventual destroys them even on multiple planets. The ai is given the instructions to cure humanity or the environment then they determine the only fix is killing all the humans or freezing them permanently. Another theory is that we are all just in an simulation and that simulation doesn't have alien life. Most of Elon's crazy ideas can be traced back to this one theory. You gotta back up the human race or the ai will destroy you, so you better create an organization to help guide the development of ai (open ai). Or we are all just in a simulation, so you might as well enjoy it while your doing it, which explains Amber Heard and all the other models.
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