National Space Society - Calls for settlement as the goal

Ian Flint · 2004-05-11 10:21:14

I know GCNR really wants to go to Mars, clark, he's just so negative.

Sorry GCNR, I don't mean to pick on you, but all I see you doing is saying 'such and such can't be done' and then you don't seem to propose and solutions. Ok, I know your favored solutions involve nuclear propulsion and other undeveloped technologies, but you don't seem to want to work with what we already have.

Now, to answer some of your questions:

For a space colony though, we're talking down to the meters with a far larger vehicle in a far stronger gravity well using a much less precise (aerobraking entry) means of entry through an atmosphere which varies daily. Its not as easy as a carefully controlled rocket decent over the airless Moon

I agree that Mars is a bit tougher than the Moon. But instead of just stating the problem, let's look at possible solutions.

1. First off, the Mars Direct aerobraking is not much different than aeroentry. We did it fine with every Mercury, Gemini, and Apollo crew, so I don't see any problem doing it on Mars.
2. To make a pinpoint landing on a planet with an atmosphere (Mars), just use the atmosphere to your advantage. I'm thinking parachutes and aerofoils here. Aeroentry will get the landing vehicle in the general area then an aerofoil can be used to fly to the specific landing site. Once the aerofoil has brought the Hab above the landing site, it can be released to let the rockets take the Hab in the rest of the way.

These things can be built and tested today. Let's use them.

GCNRevenger · 2004-05-11 21:25:37

I would love to see man go to Mars, but what I fear is trying to go before we should... betting on adaptions of current technology and learning years down the road that they aren't practical, and I love to combat the "Soviet adoration syndrome" that anything simple is automaticly preferable to that "crappy American stuff."

Mars is quite a bit harder than the Moon, since the atmosphere is too thin to be very useful but too thick to ignore:

We aren't all that good at accurate, reliable aerocapture yet. Getting a 400lbs solar go-cart to its destination "give or take 20km" is not acceptable for colonization missions. This is largely because of the low density of the Martian atmosphere and its daily varying height make it difficult to hit a target with precision... This isn't like Gemini and Apollo, where your deceleration is quick plus the thickness of the atmosphere is pretty constant. Gemini and Apollo were "give or take a few miles" too. I also don't think we've got aerocapture down yet either... Nasa needs to get to the point where they don't yell and hug and eachother if their little probe survives entry before we think about people.

Unfortunatly for using the Martian air for post-entry course correction is that its thin. Really thin. So its not much good to employ a wing of any sort (parafoil) like it would be on Earth. Last minute course correction would have to be done under rocket power, maybe using oversized OMS engines like on DC-X.

idiom · 2004-05-11 22:42:19

On $10 BN a year...

Firing stuff at the same site... (first few rounds is all beacons and automated dozers...)

How much stuff could you send if you spent half the budget on launch vehicles and the other half on stuff. Over a 20 year period. Also adding in not sending people during the first 10...

Would that be enough to leave someone there forever after 15 years of program.

Oh and that someone can have a really short life expectancy and enjoy tuna cans.

RobertDyck · 2004-05-11 23:32:05

I would love to see man go to Mars, but what I fear is trying to go before we should... betting on adaptions of current technology and learning years down the road that they aren't practical, and I love to combat the "Soviet adoration syndrome" that anything simple is automaticly preferable to that "crappy American stuff."
Mars is quite a bit harder than the Moon, since the atmosphere is too thin to be very useful but too thick to ignore:
We aren't all that good at accurate, reliable aerocapture yet. Getting a 400lbs solar go-cart to its destination "give or take 20km" is not acceptable for colonization missions. This is largely because of the low density of the Martian atmosphere and its daily varying height make it difficult to hit a target with precision... This isn't like Gemini and Apollo, where your deceleration is quick plus the thickness of the atmosphere is pretty constant. Gemini and Apollo were "give or take a few miles" too. I also don't think we've got aerocapture down yet either... Nasa needs to get to the point where they don't yell and hug and eachother if their little probe survives entry before we think about people.
Unfortunatly for using the Martian air for post-entry course correction is that its thin. Really thin. So its not much good to employ a wing of any sort (parafoil) like it would be on Earth. Last minute course correction would have to be done under rocket power, maybe using oversized OMS engines like on DC-X.

GCNRevenger, you really sound like you would be happier elsewhere. This is the message board of the Mars Society, an organization dedicated to sending humans to Mars now. We do have the technology to go; yes Mars is more difficult than the Moon, but it's been 35 years since Apollo 11, technology has come a long way. To learn about the technology read Robert Zubrin's book "The Case for Mars".

To address the issues you raise, I for one do not say that anything American is crappy or that everything Soviet is good, but I will not say the reverse either. The Russian Energia launch vehicle is a good ship, and the only HLLV that can be re-activated easily. The Saturn V is long since gone, it will never come back. An Apollo command module could have been used as the basis for a return capsule to Earth, but why when Soyuz is in production now. Is it not better to focus American efforts on technology that doesn't exist and use the Energia and Soyuz descent modules? Let America build the Mars spacecraft, in Mars Direct terms that is the habitat and ERV.

You also mentioned the thin atmosphere. Mars Direct uses that atmosphere as a resource to create fuel for return. It also uses it for direct entry, not just aerocapture. Direct entry has been used by Mars Pathfinder and the two Athena rovers, Spirit and Opportunity. Aerobraking has been used by Mars Global Surveyor. It works, but further practice with unmanned probes is warranted. In 2005 we will see Mars Reconnaissance Orbiter, in 2007 Phoenix, and in 2009 Mars Science Laboratory. Sufficient practice is already underway. NASA is also working on airplanes for Mars; yes there is sufficient atmosphere to support an aircraft. And lidar has already been developed to map terrain beneath a lander for precision touch-down. This is used with a rocket landing system like Viking as opposed to the airbag system like Pathfinder or the Athena rovers.

We have sufficient technology to go now, it just takes the will.

Shaun Barrett · 2004-05-12 05:30:40

Good post, Robert!

Ian Flint · 2004-05-12 09:11:59

Aeroentry...aerofoil...does anybody understand me?

I remind myself of our glorious president:

http://www.bushisms.com/NewQuotes.html]Bushisms

Bill White · 2004-05-12 09:21:12

Hmmmm. . .

How to say this?

I agree with BOTH Robert Dyck and GCNRevenger. Our feet must be held to the fire because the arguments that GCNRevenger raises MUST be addressed and overcome if we are to persuade Congress and the American public.

Russian stuff is not per se better than American, its just cheaper. To get from $1500 per pound to LEO (Zenit-2) to $100 / $200 per pound is a conundrum.

Chickens and eggs.

deagleninja · 2004-05-12 09:41:21

"They misunderestimated me." too, dont't feel bad. ???

Wow, that was great stuff Ian. I've seen some of those Bushisms before, but like a fine wine they get better with age. Makes me wonder how anyone can respect that man knowing how stupid he is.

deagleninja · 2004-05-12 09:52:19

Btw, great post Robert. It seems that Mars Directs' biggest opponents haven't read 'The Case For Mars'. I've read my copy twice, yes it's that good.

Ian Flint · 2004-05-12 10:00:35

Oh yeah, I've read mine at least 5 times -- nyaaa!

It's all tattered and torn with a bunch of notes written in it and little pieces of paper with drawings and calculations on them stuck throughout the book. Is there some kind of medication for my condition?

idiom · 2004-05-12 16:07:45

It would be nice to be able to buy "The Case for Mars" in a laminated ring bound edition... Would prevent coffee stains and stuff...

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#26 2004-05-11 10:21:14

Re: National Space Society - Calls for settlement as the goal

#27 2004-05-11 21:25:37

Re: National Space Society - Calls for settlement as the goal

#28 2004-05-11 22:42:19

Re: National Space Society - Calls for settlement as the goal

#29 2004-05-11 23:32:05

Re: National Space Society - Calls for settlement as the goal

#30 2004-05-12 05:30:40

Re: National Space Society - Calls for settlement as the goal

#31 2004-05-12 09:11:59

Re: National Space Society - Calls for settlement as the goal

#32 2004-05-12 09:21:12

Re: National Space Society - Calls for settlement as the goal

#33 2004-05-12 09:41:21

Re: National Space Society - Calls for settlement as the goal

#34 2004-05-12 09:52:19

Re: National Space Society - Calls for settlement as the goal

#35 2004-05-12 10:00:35

Re: National Space Society - Calls for settlement as the goal

#36 2004-05-12 16:07:45

Re: National Space Society - Calls for settlement as the goal

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