Mars Direct Mission (Documentary included)

[TeeGee]

Watch this amazing documentary. Comment at will.

https://www.youtube.com/watch?v=uDWvsdEYSqg

What do you ladies and gents think?

[Dkmdlb]

Really cool documentary. It gets a bit optimistic there at the end (no mention of the toxic soil?), but all in all, cool doc. I'm interested to hear the view of others about the viability of the tether system for the transfer vehicle, as well as the Direct vs. Semi-direct plan. Direct calls for the earth return vehicle to land on Mars, whereas Semi-direct calls for the Mars ascent vehicle only to land on Mars. 'The Martian' by Andy Weir uses a variation of the semi-direct method with a few changes.

Also, can someone with more knowledge than me comment on Zubrin's dismissal of the radiation concerns? If what he is saying is true, then why is everybody spending so much time worrying about it?

[Northstar1989]

Watched this documentary ages ago- don't really have the patience to watch it again.

Mars Direct is a great idea- but the thing is, it achieves a lot of its cost-savings by cutting out much of the fat and extraneous safety systems from the traditional NASA approach to a Mars mission.

Many NASA projects these days are gold-plated piles of *I won't say what* precisely for this reason. EVERYTHING has to have a million fail-safes installed, just because they don't want the PR disaster of a failed mission. And then, despite their best efforts, it eventually happens anyways.

Most of the time, NASA would be *MUCH* better off taking an approach less obsessed with astronaut safety. Space Exploration is, and should be, a dangerous, risky enterprise. Any attempt to remove the risks is just stupid and misguided. Even from an ethical/moral perspective where lives are the ultimate good it's indefensible- the money they could save by cutting out some of their fail-safes could save far more starving children in Africa without access to clean water or healthcare (if the US government directed that portion of budget to the World Health Organization instead.)

Regards,

Northstar

[rkman]

Most of the time, NASA would be *MUCH* better off taking an approach less obsessed with astronaut safety. Space Exploration is, and should be, a dangerous, risky enterprise. Any attempt to remove the risks is just stupid and misguided.

So says the private space industry, because following that principal there would be more launches, and for the time being the only profit in spaceflight is in launching other people's stuff. If NASA would have taken more risk in the past, there would have been more catastrophic mission failures, more exploded Space Shuttles.

But that does not matter to the private space industry as long as it happens after the launch. After all, private space industry does not actually invest in space exploration missions, they just launch other people's missions. Private space industry prefers low risk investments while encouraging everyone else to take more risk.

Even from an ethical/moral perspective where lives are the ultimate good it's indefensible- the money they could save by cutting out some of their fail-safes could save far more starving children in Africa without access to clean water or healthcare (if the US government directed that portion of budget to the World Health Organization instead.)

The amount of money that could be saved by taking more risk is offset by the increased risk of having zero return on investment (failed mission).

If saving the lives of starving children in Africa is really the motivation, many more could be saved by redirecting much larger amounts of money from elsewhere. You can literally do a hundred Mars missions for the cost of one war in the Middle East. NASA's budget is only 0.5% of the US federal budget to begin with.

[NASAFanboy]

Whenever people like to say that e don't have the technology to go to Mars, I like to point to Mars Direct and say "Then tell me how this Mars Mission using 1990's technology won't work". That usually gets them to shut up. Mars Direct is a really good idea, and I still don't get why NASA's does not get the funding for it. After all, from the looks of it, way cheaper than Constellation.

However, I'm more interested in the return trip with the ERV. I don't think the crew will like to spend another five months in a cramped compartment in their way to Earth - perhaps the ERV could rendezvous with a smaller Earth Transit Vehicle, use it's remaining stage to boost it out of Mars orbit, then have the ETV fire it's own engines for a short time for the cruise back to Earth and braking within Earth's SOI. The crew them renters in the ERV command pod.

Edited August 7, 2014 by NASAFanboy

[KerbMav]

why NASA does not get the funding for it.

Fixed that for you.

.

Translation:

"We cannot have 100% safety, so lets do not take any precautions in the first place. All the money going into inoculations, condoms, helmets etc. should be used to save other lives."

Who are you to weigh one life against another?

Edited August 7, 2014 by KerbMav

[Northstar1989]

So says the private space industry, because following that principal there would be more launches, and for the time being the only profit in spaceflight is in launching other people's stuff. If NASA would have taken more risk in the past, there would have been more catastrophic mission failures, more exploded Space Shuttles.

There would have been more catastrophic failures- and that would be fine. There would also be either more missions and more total goals accomplished, or more money for other purposes- such as foreign aid.

But that does not matter to the private space industry as long as it happens after the launch. After all, private space industry does not actually invest in space exploration missions, they just launch other people's missions. Private space industry prefers low risk investments while encouraging everyone else to take more risk.

It sounds like you're quite a cynic- and that's understandable if your impression of the space industry comes from companies like United Launch Alliance. There ARE companies taking big risks themselves though- like Space-X, or even Boeing (which has taken some relatively large risks with their Wave Rider spacecraft design, their proposals to NASA to build a Methane/LOX fuel depot in orbit near the Moon and help build the first generation of Meth/LOX engines, and their experimental spaceplane designs for the military) however.

The amount of money that could be saved by taking more risk is offset by the increased risk of having zero return on investment (failed mission).

No, it's not. The whole point is that, if you look at the numbers, many NASA manned mission proposals could be performed for 2/3-1/2 their current NASA cost estimates by cutting out many of the fail-safes. The true cost of NASA's overly-high caution becomes even more apparent when you consider the justification for cancellation of some programs (such as the Ares I rocket) was that they couldn't be made sufficiently safe to satisfy NASA (for instance due to the risk to Launch Escape Systems from SRB rocket exhaust with Ares- the whole concept of a Launch Escape System being needless fluff far too expensive for the current generation of space tech...)

The more than 50% increase in price-tag when NASA took a look at Mars Direct, and came up with their first Design Reference Mission should be just one example of the kind of excessive caution I'm referring to...

If saving the lives of starving children in Africa is really the motivation, many more could be saved by redirecting much larger amounts of money from elsewhere. You can literally do a hundred Mars missions for the cost of one war in the Middle East. NASA's budget is only 0.5% of the US federal budget to begin with.

One program being fat and inefficient, or a waste of money, isn't justification for another being fat and inefficient. And I must remind you that the US Mideast wars were actually useful from a certain geopolitical perspective. Poorly and wastefully-executed to the point of being counter-productive and actually harmful to US interests, yes- but not useless if performed correctly by any means. If Iraq had been carried out specifically to oust an insane dictator, with no lies about WMD's; and with better intel, heavier reliance on infantry tactics, and ground-based policing, rather than expensive bombing missions and high-tech gadgets; it could have actually been USEFUL to American (and other first-world) interests...

But that's a separate point entirely. The fact is that money has a value. It can save lives. And spending hundreds of millions of dollars (and it really does add up to that much when you look at how much the safety systems add to total mission cost and complexity) to ensure the survival of a handful of astronauts is NOT worth the money that could just as well be spent ensuring the survival of hundreds of thousands of starving children in Africa, for instance.

Manned Space Exploration is valuable and SHOULD be carried out. But it SHOULD NOT be carried out inefficiently and blindly, which is really part of the whole point of Mars direct.

Regards,

Northstar

[Northstar1989]

However, I'm more interested in the return trip with the ERV. I don't think the crew will like to spend another five months in a cramped compartment in their way to Earth - perhaps the ERV could rendezvous with a smaller Earth Transit Vehicle, use it's remaining stage to boost it out of Mars orbit, then have the ETV fire it's own engines for a short time for the cruise back to Earth and braking within Earth's SOI. The crew them renters in the ERV command pod.

It's ironic that you criticize Constellation, because if I'm understanding you correctly, what you're suggesting is basically the Constellation mission framework.

Constellation, which was similar to Mars Direct (and the subsequent Mars Direct-inspired NASA Design Reference Missions) in many ways (but less efficient, as I'll explain why shortly) basically had the following mission components:

Mars Transit Vehicle- The stage that would leave Earth orbit, carrying the astronauts to Mars- where it would make a landing on the Martian surface after an aerobraking pass. This stage was typically large in most versions of the mission (and there were several- Constellation was actually a group of similar mission plans rather than one definitive plan), and as such would need to land on its "side" relative to the direction that was "up" on take-off from Earth atop an Ares V rocket.

Earth Return Vehicle- This large stage would be launched to Mars, where it would perform an aerobrake-assisted capture (significant amounts of active propulsion would still be utilized, as the aerobrake would be very high in the Martian atmosphere to keep re-entry heat low) and would wait it orbit to ferry the crew back to Earth. This stage was designed purely for extra-atmospheric use, and would never land again after being launched from Earth's surface. Launched on a separate Ares V rocket from the Mars Transit Vehicle.

Martian Ascent Vehicle- Basically a small lander that would ferry the crew between the Martian surface and the Earth Return Vehicle. In many versions of the plan, this lander would not be large enough to able to carry the entire crew in one trip, but would need to make two or more trips between the landed Mars Transit Vehicle and the Earth Return Vehicle waiting in orbit (it would refuel on the surface after returning from the first trip, and pick up the rest of the crew). Often the mission plans would launch this as part of the Mars Transit Vehicle- so it could equally well be thought of as the ascent stage of the Mars Transit Vehicle rather than as a separate craft.

Mars Surface Mobility Vehicle- Like the Mars Ascent Vehicle, actually launched as a part of the Mars Transit Vehicle. Basically a 2-man pressurized rover (the Mars Transit Vehicle carried a crew between 4 and 8, depending on the mission plan variant).

Mars HAB Module/ Surface Infrastructure- I list this as a combine entry because in many versions of the plan, these components would all launch atop the same Ares V rocket These components would include additional living space and supplies for the crew during their extended surface stay (for the mission plan variants that were more than flag-and-footprints), a power supply (variously solar or nuclear in different mission variants), and in some versions In-Situ-Resource-Utilization equipment to derive Meth/LOX rocket fuel and breathable oxygen from the Martian atmosphere (in some mission variants, the Mars Ascent Vehicle would even carry some of this Meth/LOX up to the Earth Return Vehicle, which would in those versions be waiting mostly-empty in orbit except for very limited amounts of fuel with contingency equipment... Otherwise, this fuel would only be used for the Mars Ascent Vehicle- though this at least meant mass savings on a smaller ISRU reactor and power plant...) At least one version also included a backup power-supply (based on RTG's) and additional scientific equipment.

By the way, how many Ares V launches are we up to already- three? And we haven't even included the 3 Transfer Stages for each of the above payloads, which brings it to 6 total launches... But wait, there's MORE!

Orion Crew Capsules- Because the mission clearly wasn't already heavy/expensive and bloated enough, the mission designers for Constellation decided to launch the crew on entirely-separate Ares I rockets in not one, but TWO or more Orion Crew Capsules (even though the crew capsule would only need to hold the astronauts for a few hours before rendezvous with the Mars Transit Vehicle in Low Earth Orbit, and using a single heavier capsule with additional seats would have been much cheaper/easier). They could of course have always launched the crew aboard the Mars Transit Vehicle in the first place- which would be designed to hold the crew under high G-forces (during Martian re-entry/landing) anyways- but apparently that would have been too efficient, and would have made the Orion Capsule designers very unhappy... One of these Orion Crew Capsules would have hitched a ride with the Earth Return Vehicle to Mars orbit (you know, it really beats me why they wouldn't have just left it in LEO), and the other would have (quite wastefully) been de-orbited...

(OK, I'm being a little cynical about the need for the Orion. The Orion Capsule would be utilized to return the crew to Earth's surface upon returning to LEO instead of riding the Earth Return Vehicle down, which would have been very risky/dangerous and difficult to heat-shield with a vehicle that size. With a fresh transfer stage, technically the Earth Return Vehicle could have been re-used, and even ferried fresh crews to Mars orbit to rendezvous with the Mars Ascent Vehicle which would be left behind in Mars orbit: as the ERV would be left in a stable parking orbit above Earth after the mission...)

So, we're totaling 3 payloads that each require an Ares V launch- plus a separate transfer stage (also launched atop an Ares V rocket) that would dock with in in LEO- as well as 2 Ares I launches for the crew capsules for each mission? (with only a slight possible re-usability for the ERV)

Mars Direct, by contrast, only required two Ares V launches per mission (with no separate transfer stages to my knowledge!) although the crew would have been smaller (3-4 people) and had to deal with MUCH more cramped conditions...

The major mission design differences that saved mass on Mars Direct:

(1) Greater utilization of ISRU capabilities- use of ISRU fuel for the production of ALL fuel beyond what was needed to get to the surface of Mars. This meant all of the vehicles could arrive on Mars empty- including the Earth Return Vehicle (which would launch with its return fuel onboard in most versions of Constellation). Slower production of fuel (due to a longer stay + the ISRU reactor being launched earlier before the manned mission component) also required a smaller reactor and power plant.

(2) The Earth Return Vehicle would also serve as the Mars Transit Vehicle- the same living space would act as lander, surface base, and return vehicle for the crew (though an additional HAB module would still be launched). Sure, it meant a rather heavy ascent stage compared to having a separate Mars Ascent Vehicle (something a NASA engineer criticized it for in the video), but it also meant you didn't need separate living spaces for your surface stay and your return to Earth... (both of which would need to be quite large for anything more than a flag-and-footprints mission) This was a MAJOR mass-saver on Mars Direct vs. the Constellation mission plans/

(3) No contingency equipment- one of the things that added mass to the Constellation mission plan which I hardly even discussed was its inclusion of contingency equipment. Basically extra supplies, (cramped) living space, and even fuel for an emergency early return-voyage to Earth with the tiny Orion capsule that would accompany the Earth Return Vehicle to Mars acting as both a transfer stage and additional living space during the long return-voyage. Fortunately, at least the Constellation mission designers had SOME sense when it came to this aspect of the mission plan- not only was the contingency equipment remarkably lean when it came to mass, (in some mission versions) it would also be left in Mars orbit after the first mission, and not launched again with subsequent missions unless it was ever needed and used up by one of the missions.

(4) Lower-energy Mars transfer. This one should be relatively simple/intuitive for any KSP player. The Mars Direct mission plan called for a minimal-energy (Hohmann) transfer, which would take 6 entire months. The Constellation Mission Plan, by contrast, made use of a shorter transfer that required more fuel: 2-3 months transit time if I remember correctly (though it must be pointed out this would require less than twice the fuel- the Oberth Effect, which derives from E = 1/2 mv^2, whereas Delta-V is proportional to burn time, means that a rocket with a 50% higher Delta-V expenditure near Earth would acquire a *LOT* more than greater 50% energy. Thought of a different way, the faster you leave Earth's SOI, the less time its gravity has to pull you back in, and the faster you make the Earth-Mars transfer, the less time the Sun's gravity has to slow you down...) Of course, most players rely solely on minimal-energy transfers as time is meaningless to them with time-warp and no life-support or crew psychology requirements...

(5) MANY other "luxuries", including but not limited to greater living space on the Constellation mission plans. The Constellation mission included things like toilets that made use of Mars' gravity and equipment to heat up meals, for instance, whereas Mars Direct relied on the kind of waste-in-a-bag and cold-soup diet utilized by Apollo astronauts if I remember correctly... Zubrin meant it seriously when he said the "travel light" part of "travel light and live off the land".

Regards,

Northstar

[Kryten]

Most of the time, NASA would be *MUCH* better off taking an approach less obsessed with astronaut safety. Space Exploration is, and should be, a dangerous, risky enterprise. Any attempt to remove the risks is just stupid and misguided.

If this was true, Zenit (the cheapest launch vehicle available) would be selling like hot cakes, everybody's backup would be Proton (the second cheapest) and none of the others would get a look-in; but in actual fact, Zenit has no upcoming customers and the company behind it is about to go bankrupt (again), the provides of Proton just announced major job losses to fit with a reduced launch schedule, and Ariane V, Atlas V and Falcon 9 are all booked solid for the next several years. Why? Because actual satellite operators dislike risk nearly as much as NASA, and with good reason. The launch cost is always only a small proportion of the mission cost; cutting it in exchange for significantly increased risk to the payload and entire mission simply makes no sense from an economic standpoint.

[CaptainKipard]

Nice documentary. I'm looking forward to all the interplanetary and Martian civil wars

[TeeGee]

I think the major point of the documentary was to also show us as a people that IF we had a goal, like going to mars with a manned crew, it would bring us all together and give us a collective dream. It would galvanize people, young and old, into dreaming about space travel.

We need a goal like this in our society today. We are waaay too focused on Earthly problems and have lost inspiration. Mars can give it back to us and produce people that were captivated by the achievements of those first Mars landings to strive for something greater.

A manned Mars mission is the inspiration the world needs.

[rkman]

There ARE companies taking big risks themselves though- like Space-X

How does Spacex take more risk than NASA?

Not with actual space exploration missions, they don't. The most that Spacex does is deliver cargo to the ISS.

I assume NASA has not reduced their safety standards just for Spacex. Do you think NASA should allow Spacex to take more risk with delivering cargo to the ISS?

or even Boeing (which has taken some relatively large risks with their Wave Rider spacecraft design, their proposals to NASA to build a Methane/LOX fuel depot in orbit near the Moon and help build the first generation of Meth/LOX engines, and their experimental spaceplane designs for the military)

How risky can designs and proposals really be? They spent a couple of bucks on it? They risk lives with it?

There would have been more catastrophic failures- and that would be fine.

That's a hard sell. Good luck with it.

I don't think you are doing private space industry a favor by coming up with such an argument. People will think that industry tends toward sociopathy.

There would also be either more missions and more total goals accomplished,

At the expense of more human lives, and a ....load more money, relatively more of it with zero return on investment. But that would have been tax payers money, so the private space industry would not care very much.

or more money for other purposes- such as foreign aid.

And more cases of zero return on investment. But that to would have been tax payers money, so the private space industry would not care very much.

If Spacex is so eager to help out starving children in Africa, there are more direct ways of doing that.

In the mean time private funding could finance a manned mission to Mars several times over and eradicate global poverty virtually over night - all out of pocket. But the vast majority of private money prefers less risky investments such as booming financial markets.

Edited August 7, 2014 by rkman