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I tried to address inefficiencies in Mars Direct to improve the architecture, and ended up with something similar to NASA's Mars Semi-Direct. I could post what I came up with, but it is rather long. There are two points in NASA's plan I disagree with, points that show fear and an inability to truly lead space technology. The first is expansion of the crew from 4 to 6 and insistence that the crew include a medical doctor with no duties other than healing the crew. The other is avoidance of ISPP for the return trip. The NASA Design Reference Mission (DRM), nick-named Semi-Direct, uses ISPP for the Mars Ascent Vehicle that travels to Mars orbit, but it still carries all the way from Earth the propellant for the return to Earth. In fact, NASA is afraid to use ISPP for a robotic sample return mission. Robert Zubrin's company received a NASA grant to produce a laboratory prototype ISPP plant that already proved the concept. The only next step to prove ISPP is to use it on Mars; that means sample return.
I advocate a 4 man crew, but then I also advocate a chemical TMI stage. Slowly spiralling out on solar electric propulsion is fine for unmanned spacecraft that can afford 2 years to get to Mars, such as delivery of the ERV or cargo lander. A manned spacecraft must get to Mars relatively quickly to reduce food and life support mass as well as reduce radiation exposure. This idea of slowly spiralling out and using a tug to carry astronauts just before departure from Earth orbit may avoid extended exposure to Earth's radiation belt, but it still provides a slow transit to Mars.
I mentioned the Soyuz as a space tug simply to avoid the preconception that a Mars mission requires a large array of entirely new equipment. If we ever hope to get to Mars we must stop trying to reinvent the wheel. Accept the fact that a lot of research is finished (eg. human exposure to zero-G, orbital rendezvous) and a lot of equipment is sitting on the shelf (Soyuz, Energia, Proton, Shuttle, ISS, life support). A lot has been completed to the point of a prototype and only requires polishing to produce flight hardware (MCP spacesuit, ISPP).
I haven't read the article yet, but exploiting lunar ice for rocket fuel is not a good idea. Yes, extracting oxygen from lunar rocks is complex and energy intensive, but there just isn't much water ice on the Moon. If you want to build a colony or just a permanent base on the Moon, water ice has to be reserved for recycling applications such as a greenhouse. While Lunar Prospector was sending back results, NASA reported water ice at the bottom of plar craters that was only 1 cup over an area the size of a football field. And this is the dense concentration. It would be a crime to waste what little lunar water exists on rocket fuel.
That is the catch with a Soyuz. I would suggest a mission with 4 astronauts, but the NASA DRM and Russian mission plans call for 6. In that case, just send 2 Soyuz spacecraft.
The Russian Soyuz spacecraft could be the space tug. Again, I'm in favour of using existing technology. The Soyuz-TM masses 7.25 tonnes, but that includes a 1.3t orbital module. If you flew Soyuz for a short duration mission (such as taxi to the the Mars spacecraft) you could do without the extended lift support; that would reduce it to 6.95t and retain reentry capability in case of emergency. Ariane 5 can lift 6.8 tonnes to geosynchronous transfer orbit (without circularization). ESA is hoping to use Ariane 5 to lift a manned spacecraft to service ISS, so they are at least working on man certifying it.
The Proton 8K82K/11S824F launched Fobos 1 & 2 to Mars. It can send 6.22t into trans-Mars trajectory. It should be able to lift 7.63t to GTO. There was work in the late 1960's to man certify the Proton as a backup for the Moon program. The Proton 8K82K with Block D upper stage would send a Soyuz 7K-L1 spacecraft into a translunar trajectory. That Soyuz was a Soyuz 7K-OK with the oribital module removed and life support added for 1 man for 2 weeks. It was ready for a circumlunar flight on August 1969, too little too late. But this does show the Proton was man certified at one time.
I did a rough calculation of sunshine to find latitude equivalent to Mars. If you ignore absorption by atmosphere, the calculation is simple trigonometry. Mars is an average of 227,940,000 km from the sun, and Earth is an average of 149,600,000 km away. Using the inverse square rule, light intensity per unit area on Mars will be 43.075% that of Earth. Taking the arccosine will give you 64.485 degrees, so Fairbanks Alaska during the spring or autumn equinox on a clear day would have equivalent light intensity as the Mars equator on its equinox. At the summer solstice add the Earth's tilt of its axis (23.4?) to the latitude to get 87.9?; Devon Island is 75?22'N so it should get an equivalent light level on May 10 and August 2. In winter subtract tilt to get 41.1?. Winnipeg is at 49?54'N latitude, so it should get an equivalent light level on October 26 and February 14.
You're right; Winnipeg in winter is a good equivalent to Mars.
The best information I have about energia is from http://www.astronautix.com/lvs/energia.htm
That document describes the most extensive test program of any Russian launch vehicle. The Russians credit the intensive test program to success of the two launches that were flown. You could argue that the 3 Energia core modules that were in storage were 15 years old, I would argue that with proper care they would be just as good as new. The arguement is moot since they were crushed when the roof fell on them. I just hope the remaining RD-120 engines were not damaged. That leaves manufacture of the core module using existing engines.
Additional informations is available on the Russian page of the Winnipeg chapter web site. This includes pictures from a tour group that went through Baikonur in April 1997, and pictures from on-line news articles about the accident on May 12, 2002. There are also links to the Russian Aviation-Space Agency, RSC Energia, and Molniya (manufacturer of the Buran orbiter). It also has copies of my correspondence with RSC energia including the articles they attached about the Russian mission plan.
Rob C Willis reported earlier in this discussion (message 3) that Energia launch pads and associated facilities are in poor condition. All I know about their condition is what I see in the web sites quoted in this message, but the price quoted to NASA in 1995 to restore infrastructure was $60 to $100 million US. It is 7 years later so that would be higher now, and repairing the vehicle assembly building would add to that. RSC Energia was upset that they spent thousands of dollars on a study to determine the cost to restore LV Energia to production, but didn't get any contract from that. If we asked them to do a study today they would want someone to pay for it.
Based on Energia's 2-for-2 success record, the extensive testing, and the fact it uses liquid strap-on boosters rather than segmented solid rockets, I would argue it is more reliable than the US Shuttle.
Another alternative modification of the mission plan is to send the laboratory, greenhouse, and garage tent on a separate unmanned launch with the rover. That would reduce mass of the manned mission.
Any unmanned mission could start in LEO and use electric propulsion to slowly spiral away from Earth and use a least fuel (rather than least energy) flight path to Mars. That may mean 2 years to Mars rather than 6 months, but an unmanned flight could afford it. Electric propulsion (ion engine or hall thruster) has much greater fuel efficiency so it can deliver greater mass. Perhaps we should minimized the mass on the manned flight.
This would break Mars Direct into 3 launches: Earth Return Vehicle, base supplies, and manned habitat. Breaking it into 3 would suit the capabilities of Energia. The manned flight would use the EUS as the TMI stage, so that is off the shelf technology.
Is it just me or does this sound like something we could do by 2010 and within NASA's current budget? If the US congress doesn't want to pay for restoration of Russian infrastructure, then make it an international project and have Russia, Japan, and Europe pay for Energia. Australia can develop the spacesuit, and Canada can pay for specialty equipment. What does that leave the US to pay for? The habitat, ERV, and use of the Deep Space Network.
Ok, since this topic is launch vehicles I would like to add my opinion, and perhaps get it back to launch vehicles.
I am in favour of the Russian Energia for the simple reason that it is the only heavy lift launch vehicle on the shelf. It would cost over $100 million to restore infrastructure, but that is a lot cheaper than developing any new launch vehicle. According to www.astronautix.com the development cost of the Shuttle was $10.1 billion in 1977. Total economic effect of developing Energia was 6 billion roubles. Ariane 5 can only lift 16 metric tonnes to 407km orbit, but its development cost $8 billion.
Today, the US congress has no intention of paying for development of any expendable heavy lift launch vehicle. Argue all you want over the usefulness of such a thing or the economic benefits of a big dumb booster vs a reusable launch vehicle, the bottom line is the US congress still won't pay for it. That leaves only Energia or assembly in Earth orbit using medium lift launch vehicles.
The Vulkan was an alternate configuration of Energia that would use 8 strap-on boosters instead of 4, a cylindrical oxygen tank, and an upper stage expanded to the same diameter as the core stage and mounted on top instead of on the side. This provides a symetrical co-axial configuration with increased lift. It could lift 170 metric tonnes to 200km altitude instead of 88 tonnes that Energia could lift. Some have said that the maximum lift of Energia is 100 tonnes to LEO, but that is very low orbit. To that low orbit Vulkan could lift 200 tonnes. But Vulkan was never developed and the launch facilities (that are left) are configured for Energia.
Another arguement about cost of a manned mission is development cost of the TMI stage. If the Energia Upper Stage were used as the TMI stage, that would use a stage that is already developed. Energia with EUS can only throw 29.3 metric tonnes into trans-Mars trajectory, but it is available now.
I asked the director of the international division of the Rocket Space Corporation Energia. He said the Energia rocket is available to anyone willing to pay the price to restore "certain elements of infrastructure" plus a per-launch cost, but he didn't say what that would be. In 1995 NASA asked what it would cost. At that time the cost was between $60 and $100 million US dollars to restore infrastructure, plus $120 million per launch. Inflation would increase that. On May 12 of this year the Kazakh's working on the roof of the vehicle assembly building caused the roof to collapse. We would have to add rebuilding the roof and repairing the vehicle assembly building to the "cost to restore infrastructure".
At least this is lower than the Stanford estimate that Robert Zubrin quoted in his book.
Anyone doing work on a greenhouse, either a real one for Mars or analogue, can send me a copy. I'll post it on the greenhouse page Winnipeg chapter web site. You can then post the link here.
Robert Dyck
White LEDs:
I'm in favour of using a transparent inflatable greenhouse. That is far simpler than any mirror or electrically illuminated design. As for light details, I'll let the agronomists argue.
I would like to point out that plants like visible light, they get sunburn from UV just like you and me. For more detail about light spectrum and plants see Photosynthesis - Estrella Mountain Community College. Scroll down to the chart "Relative rate of photosynthesis". Anything less than 400nm is ultraviolet, and larger than 750nm is infrared.
Robert Dyck
The inflatable greenhouse is a great idea. I am chair of the Winnipeg chapter, and members here want to build an inflatable greenhouse for Earth. The idea is to do a study for Mars, but build a very realistic analogue for Earth. The Earth greenhouse would be inflatable and designed to grow plants in Canada in winter. (As well as North Dakota and Alaska.) That would prove we can control temperature in a cold environment, but it also permits selling them to grade schools as an education/outreach project. The school year is mostly in winter, so winter operation is important. We should design it to have a low shipping weight, relatively low cost, and deployable on a grass or other unprepared ground. That is ground that is flat, level, and free of sharp rocks that could cut through the envelope. This could also be sold to farmers to grow vegetables in winter. Sale to farmers could raise money for the Mars Society.
I would like to include everyone interested. I mentioned this on the GreenCELSSTaskForce list, and at the Town hall meeting at the conference in Boulder. I really need 2 individuals: one who knows how to do a thermal analysis, and a geologist who knows how to do a CIPW analysis.
The geology is for the second part: an accurate Mars soil simulant. I have the analysis of JPL's Mars soil simulant. I also talked to the primary investigators for the Alpha Proton X-Ray Spectrometer on Sojourner (the rover carried on Mars Pathfinder). I also have a paper from the TES instrument on Mars Global Surveyor. This shows JPL's soil simulant is way off. I would like to do a CIPW analysis of Sojourner's results to estimate minerals, then find minerals sources on Earth to blend an accurate simulant. The result could be exposed to Mars atmosphere, pressure and UV in a Mars jar to create the super-oxides. I also have a paper describing how to do that. We really need a geologist to ensure we create an accurate simulant. The simulant could be used for greenhouse as well as In-Situ Resource Extraction experiments.
The idea so far is to use Tefzel film. That is strong yet light-weight and Dupont claims it is UV stabilized, at least for Florida. (Penney Boston claims it won't withstand UV in Utah). The idea I have to control temperature is to use 2 layers and "Heat Mirror" or "Solex applied window film". That is a spectrally selective film that will transmit visible light but reflect IR and block UV. If that isn't enough, we can fill the gap between layers with argon gas instead of air. Argon is used for high-efficiency windows since it conducts less heat.
The last part is ideas to insulate the floor. We need a simple yet light-weight way to insulate the floor from frozen winter ground that gives you a durable walking surface.
So who is interested?
Robert Dyck
You can see an image of the upper floor of the hab that was sketched for Mars Direct here. I have never seen published a drawing for the lower floor. One criticism I have of the FMARS and MDRS designs is that they don't have any rover storage, storage for the greenhouse structure, landing rocket or propellant tanks. I feel the analogue is not accurate.
As for launch weight, the Russian Energia with the EUS Energia Upper Stage could launch roughly 29.3 metric tonnes directly into trans-Mars trajectory (C3=15). This launch vehicle could be reactivated relatively cheaply (I'm the guy who called the Russians to ask), but there is a couple catches. The EUS is only 5.7 meters in diameter, and it accomodates a lower mass than Zubrin's design. TransHAB was designed to fit in the Space Shuttle then inflate to its full 8 meter diameter. The cargo bay can accomodate a payload 15 feet (4.53 meters) diameter so TransHAB had to be that small when deflated.
You could use a single story TransHAB style design. The laboratory could be separate; if only inflated once on Mars you wouldn't need micrometeor protection since Mars has an atmosphere. That would make the laboratory lighter. TransHAB was 3 stories and 25 tonnes. Reducing to 1 story would reduce mass, but to fit the navigation and landing rockets, propellant tanks, heat shield, parachute, landing legs, and life support for 2 years, you would have to eliminate the rover. You could send the pressurized rover on a separate launch.
Robert Zubrin suggested assembling the hab with pressurized rover and TMI rocket stage in Low Earth Orbit using 2 Energia launches, then proceeding on to Mars. Doing so would still have the constraint of the 5.7 meter diameter EUS. Circularizing the orbit in LEO then proceeding on to Mars would give you less total mass than direct launch to Mars, but the spacecraft has everything together when you leave Earth.
Robert Dyck
