Thursday, May 9, 2013

Getting To Mars Depicted (Part 1)

There is a lot of talk about going to Mars these days.  It's an old goal, and one that captures people's imaginations.  So much so that many movies and science fiction series episodes depict such a trip.  What are the current plans?  Why haven't we gone yet?

Artist's rendition
NASA's Mars Transfer Vehicle
NASA has a plan to get to Mars.  It involves 7 launches of the Heavy Lift Vehicle rocket, then 1 launch of a crew rocket,  and 3 transfer vehicles, 2 landers, and 1 launcher from the surface of Mars.  Unfortunately, that was for 1 manned mission.  That's an insane amount of hardware and consumables.  That gives you an idea of what a monumental task it is to land on Mars and to come back.

Unfortunately the plan was geared for the now dead Constellation Program. Russia has a plan for a manned Mars mission.  I've heard it's to the Martian moon Phobos.  Elon Musk wants to go to Mars as well as the Mars Society members.  Even Buzz Aldrin is looking forward to a manned Mars mission.  He has a book out now called Mission To Mars: My Vision For Space Exploration.

Mars by Viking 1
There are a couple of non-government proposals to the red planet.  Dennis Tito, who visited ISS in , proposed a sling shot mission around Mars involving two people but no landing.  What I like about this mission is that it's quite concise and understood.  I mean we've done this with unmanned craft. has an article about it called Dennis Tito's 2018 Human Mars Flyby Mission Explained.

Another proposed mission seems a little crazy to me because it sidelines the problem of returning to Earth by not returning.  Mars One Foundation wants to conquer Mars with a colony and is looking for people willing for this one way ticket mission.  The settlement idea is impressive.  They seem to use their resources wisely.  Yet, once people arrive, then you have to supply them with provisions like food for the long term.  That is at least a launch to Mars every 3 years.  If it's all the same to you, I'd be happier with a way back home to Earth, please.

The Mars Society is a group of people interested in colonizing the red planet.  They also create papers and do research that will aid in manned missions.  They have been conducting some interesting simulated manned mission on the martian surface.  These are being conducted at Mars Desert Research Station (MDRS).  It's a simulated base with all kinds of experiments going on.  They are always looking for volunteers.  I you wondered what would people do on the red planet, check Mars Society out.  You'd be amazed.

Mars - JPL Solar System Simulator
So, why haven't we been to Mars yet?  That's a really good question.  It's a question that is not easily answered.  We wanted to go in the Apollo era.  We've been talking about going for many decades.  We've sent rovers there and that has renewed interest for a manned mission.  I suppose the answer is embarrassing to engineers and scientists.  These guys are 'can do' people.  They take a 'can't don't' challenge and tackle it.  Manned mission to Mars happen to be extremely difficult.  The areas of difficulty are not in technology but finances and logistics.

There are two big problems with such a trip:

1. Mars is so far away its very expensive to land 1 lb on it.
2. Mars is hard to launch from, unlike the moon.

Mars is quite far away and that's understandable. 34.8 million miles is the closest Earth has come to Mars.  The moon is only 0.25 of a million miles from Earth.   Mars is going about 54,493.9 mph.  Earth is going about 66,673.5 mph.  Now, that may seem counter intuitive that Earth is actually traveling faster than Mars, but were dealing with the gravitational field of the Sun and it's not linear, but curved.  So, a spacecraft has to overcome the Earth's gravitational pull to cruise to Mars.  That would require several times the fuel needed to get to the moon per pound or kilogram.

To launch from the surface of Mars, you need to account for the gravity and the atmospheric friction.  Mars has about twice the gravity of the moon and a third that of the Earth.  The martian atmosphere pressure is like that at about 100k ft in Earth's atmosphere.  I figure you could compare it to launching from the Moon with the Apollo lander or launching from Earth with a Mercury launch.  Either way, you end up with a launcher that is several times the mass of the lunar lander.  You need to take all that weight to Mars from Earth, and that at multiple times what it costs to go to the moon.

The distance between Mars and the Earth and the conditions on Mars itself make it extremely expensive in fuel and hardware to do any mission.  That may help answer why we haven't gone yet.  Who is going to afford it?  Is there a better way than throw away hardware?

Click here for Part 2.