Getting To Mars Depicted (Part 2)

In Part 1, we went through how much a trip to Mars costs in terms of fuel and hardware.  It takes 8 large rocket launches just for one manned mission.  That is about 75% the launches of the Apollo program to the moon.  Back then, the US Congress was willing to spend the money, but today they are holding back wanting to cut NASA's budget.  That's nothing new.  Congress has been cutting NASA's budget for at least the past 20 years.  A manned mission to Mars is quite a huge undertaking.  I know I did not talk about the radiation concerns or other crew health issues.  NASA likes to mention those.  They don't like to mention how much it would cost, and I think that is an issue that Congress and the public need to address.  The more the public knows about this issue the better.  How could we possibly reduce the cost?  Well, I've got 2 ideas.  Both of them are along the lines of mass transportation and reusable assets.  Reusable transportation assets and multiple manifests could provide more effective financing than one mission going alone by any one government space program.

Many Launchers for 1 Mission

Reusable Assets

When talking about reusable assets, a tug to take payloads from Earth orbit to Mars orbit and a reusable Mars lander/launcher come to mind.    For Mars, these assets have to be very sophisticated to include transferring of fuel and other consumables.  They would have to be able to be controlled remotely with some automation and manually by any crew.

I've talked about a reusable tug before.  For Mars, having a large tug that can travel many times between the planets could provide the means to take multiple missions on each trip.  Distributing the cost of the trip among several customers could make the trip financially possible.  I like to imagine such a tug as being based on the concept of the Saturn S-IVB.  It would have to be much larger.  I could have duo-propulsion: traditional chemical booster; electric propulsion such as ion drive or plasma drive.  Space.com has a great article on electric propulsion called How Electric Spacecraft Could Fly NASA To Mars.  A robitic arm such as the Canadarm 2 could provide a means of capturing and docking many different types of space modules.  Also it should be able to carry many modules to include unmanned and manned modules simultaneously.  Our module technology has become quite sophisticated so I don't think that would be a problem.  One of the biggest issues of such a craft would be electric power.  Solar panels are nice, but large ones would be needed to power the electric propulsion.  They also should be able to retract and deploy on command and often.  I expect that aerobraking maneuver would help reduce the amount of fuel needed for each mission.  Solar panels would need to retract for that maneuver lest they are damaged.  These panels would have to last a long time.  Another option, though less popular, would be giving the craft its own nuclear power reactor.  Of course, responsible handling of the nuclear material is a must; including a disposal plan for the depleted nuclear material.

A reusable lander/launcher is necessary. The idea of landing on an atmospheric planet is enticing and yet hard.  If you going to reuse the lander, it has to launch from the planet as well.  We've never created a craft like that before.  It would need a heat shield that can pop off and be replaced easily (by robotic means), a reliable engine, and large tanks for fuel.  After every launch back into orbit, it would need to be serviced and refueled for the next landing.  This craft is important because for one manned mission, NASA would use 3 landers and 1 launcher.  That's 4 vehicles.  Consolidating hardware complexity and weight into one vehicle should save on cost.  Using this vehicle for many missions should be a savings multiplier.

What do we really want to do on Mars?  Do we want to just plant a flag and walk around a go home?  No, many folks want to do many things.  From geology to colonization to terraforming, Mars has inspired many possible missions.  If we go with throw away assets, we won't be able to afford getting there but once in a generation if at all.  Mars should also only be the first step to exploring and exploiting the inner solar system.  Therefore, reusable assets are a must.  We must build an infrastructure.

Multiple Manifests

Mars Plane

 To spread the cost of trips to Mars and back, it would seem a no brainer to get as many different missions and customers to sign on.  It's like filling up the cargo hold and passenger cabins of a larch ocean fairing ship to make trips between continents across a large ocean.

Imagine multiple unmanned mission accompanied by one manned mission packed on the reusable tug that is about to depart Earth orbit.  These mission could be from all types: orbital, landers, rovers and sample returns.  The landers, rovers, and sample return missions can get loaded up on the reusable lander/launcher to get down to the surface along with the assests of the manned mission.  It seems they would all land in one spot.  Well, that could create the opportunity to have some planetary transportation services such as fast rovers and aircraft.  You can quickly imagine a multitude of missions and activity around and on Mars.

Spreading the cost for each trip and back from Mars among many customers seems reasonable.  Using reusable assets such as a reusable transportation tug and a reusable lander/launcher goes hand in hand with multiple manifests.  Such an effort could easily be a commercial venture.  Such an infrastructure could have the effect of researching the red planet in a much faster fashion than what we do now.  If regular trips to Mars every 3 years is sustainable then we would have established a permanent link worthy of colonization.

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?

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. Space.com 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.