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Another is a solar parabolic reflector that is setup with a fiber optic feed light pipe that can be refanned out once brought to the chamber to provide the energy to heat the sample. The dish can be shuttered when working on the chamber for safety. This is one method that I have seen for lunar regolith seperation.
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Back to site selection: earlier in this thread there were several good candidates proposed. Since then, we have been discussing more the issue of living off the land.
Here's a concept: why not visit more than one site while there?
I think there might be two ways to do this, and the choice probably depends upon achieving ISPP capability at tons per day output rates.
(1) base from orbit, use landing propellants brought from Earth sufficient to support a baseline mission to 2 or 3 sites, and augment the mission scope to many sites with ISPP propellants, in so far as the technology succeeds.
(2) base on the surface, but leave your return vehicle and its propellant in orbit (the Apollo lunar orbit rendezvous lesson), and make as much lander propellant with ISPP as you can to support suborbital trips to other sites; yet as a safety thing, bring down sufficient propellant from Earth to make that ascent to orbit even if the ISPP fails.
I think betting lives on the ISPP alone for ascent is a single point failure mode that would be very unwise to risk. Remember, there is nothing as expensive as a dead crew. That leaves out all the minimalist ideas as unsafe.
Option (1) requires that you assemble the larger expedition in LEO, but also ensures more sites get explored. Option (2) requires a much smaller assembly in LEO, perhaps even an SLS or two would do it, but only ensures that one site gets visited if ISPP doesn't work at high-rate production.
You get what you pay for.
Here's another concept: if you were to go with option (1) orbit basing, you could explore multiple sites the first few months, and then shift to surface basing at the best site the remaining months, and create a base there. It is the "best site" evaluation that creates the highest probability of creating a "successful base".
That hybrid approach gets the greatest return, but also costs the most. Yet it probably would be the best bang-for-the-buck. You cannot optimize bang-for-the-buck at small investment sizes, that just doesn't work.
Again, you get exactly what you pay for.
I guess my point is that site selection ties in integrally with mission architecture, and with technologies available, in ways that are not initially apparent. The selection can very quickly constrain you into not being able to accomplish what you really want to do.
I think what we really want to do is finish the exploration at multiple sites with real ground truth, try out our live-off-the-land technologies at the best site, and establish an operating base at that that site. We leave the base operating on automatic when we return to Earth. That's the target for any second missions or commercial ventures.
"If you build it, they will come". If you don't, it's chicken-and-egg paralysis forever.
I see no point to an Apollo style flag-and-footprints stunt on Mars.
GW
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
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Mars Direct is based entirely from the surface. It lands the Earth Return Vehicle on the surface. It can't be called risky, because propellant is produced and fuel tanks full before crew ever leaves Earth. My idea is a bit different, it parks the return vehicle in Mars orbit. However, I do not bring propellant from Earth. Instead I count on the Mars Assent Vehicle to deliver propellant to the return vehicle. But again, propellant tanks would be full before crew leaves the surface of Earth. I still argue for the Zubrin/Baker style of ISPP for the initial mission: LOX/LCH4 made from H2 from Earth and CO2 from Mars atmosphere. The atmosphere is reliable and known, ground ice will have to be proven. Rather than on-orbit propellant transfer, my design uses the MAV as the TEI stage.
But we do completely agree about building a base. The first mission will not be one way, but has to start building a permanent presence.
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Hi RobertDyck:
You and I agree completely about establishing that base on the first trip.
You very clearly have more confidence in ISPP than I do; so, what do we do if it never makes enough propellant before we want to send the men, wait and try again before ever sending men? That's multiple years' delay.
All the previous aside, that leaves the "more-than-one-site ground truth" issue unresolved. Very few mission plans I have seen address that. I did try to address it in my concepts. I think that's a very important issue. It is here, and has been for all of history.
GW
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
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Mars Direct is based entirely from the surface. It lands the Earth Return Vehicle on the surface. It can't be called risky, because propellant is produced and fuel tanks full before crew ever leaves Earth. My idea is a bit different, it parks the return vehicle in Mars orbit. However, I do not bring propellant from Earth. Instead I count on the Mars Assent Vehicle to deliver propellant to the return vehicle. But again, propellant tanks would be full before crew leaves the surface of Earth. I still argue for the Zubrin/Baker style of ISPP for the initial mission: LOX/LCH4 made from H2 from Earth and CO2 from Mars atmosphere. The atmosphere is reliable and known, ground ice will have to be proven. Rather than on-orbit propellant transfer, my design uses the MAV as the TEI stage.
But we do completely agree about building a base. The first mission will not be one way, but has to start building a permanent presence.
You park the Earth return habitat in orbit and send on Mars a lander with a little habitat and a big tank. The lander produces LOX-LCH4, using mars CO2 and imported LH2, and fills the big tank (I assume the astronauts will land in a habitat when the lander is full of propellant). When the mission is finished, the lander rendez-vous with the Earth return habitat and departs. It is correct?
Your proposal seems more logical than Zubrin's idea to land the whoole ERV, because you need to produce less propellant.
I've heared Zubrin didn't like orbital rendez-vous, because he considered it a risky operation and Apollo's lunar rendez-vous never failed only because NASA pilots were very very very very good pilots.
But now orbital rendez-vous can be performed automatically.
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I have an Interplanetary Transit Vehicle (ITV) instead of an ERV; astronauts live there during transit from Earth to Mars, and again during transit from Mars back to Earth. The surface habitat goes with astronauts from Earth, so if free-return is required, all the food for the surface habitat is with them. If all goes well, then descend from Mars orbit to Mars surface. The MAV is sent ahead, with just a seat per astronaut and space for sample containers, but a oversized propellant tank. It docks, astronauts transfer to the ITV, then they fire up the MAV engines again to push them toward Earth. As an additional backup, a surface lab is landed beside the MAV. Again, sent ahead before astronauts leave Earth. The lab has a pressurized rover with life support. The lab could act as a backup surface hab, although you would have to dump all the lab equipment outside to make room for living space. And the pressurized rover would have to stay parked, connected to the lab so it's life support equipment supplies the lab. If everything works, then the surface hab will provide life support to the lab. So this has even more backups than Zubrin's plan. However, it does require both surface rendezvous and orbitial rendezvous.
Zubrin doesn't like the idea of requiring more than one rendezvous. Yea, he considers orbital rendezvous risky. Everything you said is correct. However, also remember he and his partner Dr. Baker came up with Mars Direct in 1989. We have better computers and better guidance systems now. In fact one company is working on a 3D laser scanner than can map the ground as the lander is coming down, with an autopilot to ensure it picks a safe landing spot. Spirit, Opportunity, and Curiosity landed with such extreme precision that I argue JPL has landing down extremely well. If they add the laser thing, then they could land on a dime. And not only did Apollo do orbital rendezvous well, but regular visits to ISS by Dragon show how well even automated systems work today. I think it's safe now.
Also realize one of Zubrin's arguments about life support was to use technology as it existed. NASA wanted oxygen and water recycling efficiency at 95% before going. Zubrin argued that if we waited for that, then it would be the 21st century before we could go! Oh, wait, the 21st century became on January 1, 2001. That came and went 13 years ago. At this point you could say Zubrin was right, and still give NASA their high efficiency stuff.
Any more excuses, or can we just go already?
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RobertDyck wrote:Mars Direct is based entirely from the surface. It lands the Earth Return Vehicle on the surface. It can't be called risky, because propellant is produced and fuel tanks full before crew ever leaves Earth. My idea is a bit different, it parks the return vehicle in Mars orbit. However, I do not bring propellant from Earth. Instead I count on the Mars Assent Vehicle to deliver propellant to the return vehicle. But again, propellant tanks would be full before crew leaves the surface of Earth. I still argue for the Zubrin/Baker style of ISPP for the initial mission: LOX/LCH4 made from H2 from Earth and CO2 from Mars atmosphere. The atmosphere is reliable and known, ground ice will have to be proven. Rather than on-orbit propellant transfer, my design uses the MAV as the TEI stage.
But we do completely agree about building a base. The first mission will not be one way, but has to start building a permanent presence.
You park the Earth return habitat in orbit and send on Mars a lander with a little habitat and a big tank. The lander produces LOX-LCH4, using mars CO2 and imported LH2, and fills the big tank (I assume the astronauts will land in a habitat when the lander is full of propellant). When the mission is finished, the lander rendez-vous with the Earth return habitat and departs. It is correct?
Your proposal seems more logical than Zubrin's idea to land the whoole ERV, because you need to produce less propellant.
I've heared Zubrin didn't like orbital rendez-vous, because he considered it a risky operation and Apollo's lunar rendez-vous never failed only because NASA pilots were very very very very good pilots.
But now orbital rendez-vous can be performed automatically.
Yes! Orbital rendezvous is the least of our worries!
Let's Go to Mars...Google on: Fast Track to Mars blogspot.com
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I have an Interplanetary Transit Vehicle (ITV) instead of an ERV; astronauts live there during transit from Earth to Mars, and again during transit from Mars back to Earth. The surface habitat goes with astronauts from Earth, so if free-return is required, all the food for the surface habitat is with them. If all goes well, then descend from Mars orbit to Mars surface. The MAV is sent ahead, with just a seat per astronaut and space for sample containers, but a oversized propellant tank. It docks, astronauts transfer to the ITV, then they fire up the MAV engines again to push them toward Earth. As an additional backup, a surface lab is landed beside the MAV. Again, sent ahead before astronauts leave Earth. The lab has a pressurized rover with life support. The lab could act as a backup surface hab, although you would have to dump all the lab equipment outside to make room for living space. And the pressurized rover would have to stay parked, connected to the lab so it's life support equipment supplies the lab. If everything works, then the surface hab will provide life support to the lab. So this has even more backups than Zubrin's plan. However, it does require both surface rendezvous and orbitial rendezvous.
Zubrin doesn't like the idea of requiring more than one rendezvous. Yea, he considers orbital rendezvous risky. Everything you said is correct. However, also remember he and his partner Dr. Baker came up with Mars Direct in 1989. We have better computers and better guidance systems now. In fact one company is working on a 3D laser scanner than can map the ground as the lander is coming down, with an autopilot to ensure it picks a safe landing spot. Spirit, Opportunity, and Curiosity landed with such extreme precision that I argue JPL has landing down extremely well. If they add the laser thing, then they could land on a dime. And not only did Apollo do orbital rendezvous well, but regular visits to ISS by Dragon show how well even automated systems work today. I think it's safe now.
Also realize one of Zubrin's arguments about life support was to use technology as it existed. NASA wanted oxygen and water recycling efficiency at 95% before going. Zubrin argued that if we waited for that, then it would be the 21st century before we could go! Oh, wait, the 21st century became on January 1, 2001. That came and went 13 years ago. At this point you could say Zubrin was right, and still give NASA their high efficiency stuff.
Any more excuses, or can we just go already?
I like your approach - I have always supported the approach of a "Mars-Earth" ferry system. How many missions could an ITV make? This could be quite crucial for keeping costs down. My working assumption is 10 round trips.
Let's Go to Mars...Google on: Fast Track to Mars blogspot.com
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I have an Interplanetary Transit Vehicle (ITV) instead of an ERV; astronauts live there during transit from Earth to Mars, and again during transit from Mars back to Earth. The surface habitat goes with astronauts from Earth, so if free-return is required, all the food for the surface habitat is with them. If all goes well, then descend from Mars orbit to Mars surface. The MAV is sent ahead, with just a seat per astronaut and space for sample containers, but a oversized propellant tank. It docks, astronauts transfer to the ITV, then they fire up the MAV engines again to push them toward Earth. As an additional backup, a surface lab is landed beside the MAV. Again, sent ahead before astronauts leave Earth. The lab has a pressurized rover with life support. The lab could act as a backup surface hab, although you would have to dump all the lab equipment outside to make room for living space. And the pressurized rover would have to stay parked, connected to the lab so it's life support equipment supplies the lab. If everything works, then the surface hab will provide life support to the lab. So this has even more backups than Zubrin's plan. However, it does require both surface rendezvous and orbitial rendezvous.
It seems a very robust mission architecture.
Zubrin doesn't like the idea of requiring more than one rendezvous. Yea, he considers orbital rendezvous risky. Everything you said is correct. However, also remember he and his partner Dr. Baker came up with Mars Direct in 1989. We have better computers and better guidance systems now. In fact one company is working on a 3D laser scanner than can map the ground as the lander is coming down, with an autopilot to ensure it picks a safe landing spot. Spirit, Opportunity, and Curiosity landed with such extreme precision that I argue JPL has landing down extremely well. If they add the laser thing, then they could land on a dime. And not only did Apollo do orbital rendezvous well, but regular visits to ISS by Dragon show how well even automated systems work today. I think it's safe now.
Probably he was right: in 1989 a manual controlled orbital rendez-vous would be dangerous with pilots who are spent 500 days on surface and are out of training.
Any more excuses, or can we just go already?
Thanks and go!
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Aren't they also called Cycling spaceships? The ships are in elliptical orbits around the Sun timed so the planets Earth and Mars are aligned to minimize time for the outbound journey. and another cycling orbit is timed so the planets Mars and Earth are aligned to minimized travel time for the inbound orbit.
The mission profile works this way:
1. The Outbound cycling spaceship with Mars Lander is launched from Earth orbit, perhaps taking advantage of high efficiency ion propulsion,
2. then the Inbound Cycling spaceship is launched into its orbit with an Orion Capsule.
3. An unmanned Mars hab is launched with an SLS and landed on the Surface of Mars
4. A heavy lift SLS with an Orion capsule and Mars lander is launched from Earth on an intercept course with the outbound cycling spaceship, docks with the space ship and the crew lives on the Cycler until Mars is within range.
5. Crew gets onboard the Mars Lander, lands on the surface of Mars next to the hab
6. Surface exploration
7. Crew lifts off in upper stage of Mars lander, Mars lander upper stage intercepts the inbound Cycler
8. Crew stays onboard the inbound cycler until Earth is within range of the Orion.
9. Crew gets onboard Orion spacecraft with Mars rocks, seperates from Cycler and reenters Earth's atmosphere.
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You have accurately described a cycler, but that's not what I'm talking about. A cycler doesn't use any fuel, just orbits the Sun. You have to use fuel to rendezvous with the cycler, and more fuel to get to Mars. The only advantage is the cycler is the in-space habitat that you can live on. My idea is to send a much more modest spaceship from Low Earth Orbit, specifically from ISS, direclty to Mars. It would aerocpature into Mars orbit, then stay in highly eliptical, high Mars orbit. Barely in Mars orbit, so fuel to depart Mars is minimum. The MAV would push this vehicle out of Mars orbit toward Mars, then the MAV would be ejected. The craft would aerocapture into Earth orbit, then aerobrake down to LEO. It would use a little propellant to circularize orbit and rendezvous with ISS. This allows use of ISS as a construction shack, as well as a "transit station". The ship would remain parked there until the next trip to Mars.
http://newmars.com/forums/viewtopic.php … 45#p116645
Last edited by RobertDyck (2014-01-21 14:37:24)
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You have accurately described a cycler, but that's not what I'm talking about. A cycler doesn't use any fuel, just orbits the Sun. You have to use fuel to rendezvous with the cycler, and more fuel to get to Mars. The only advantage is the cycler is the in-space habitat that you can live on. My idea is to send a much more modest spaceship from Low Earth Orbit, specifically from ISS, direclty to Mars. It would aerocpature into Mars orbit, then stay in highly eliptical, high Mars orbit. Barely in Mars orbit, so fuel to depart Mars is minimum. The MAV would push this vehicle out of Mars orbit toward Mars, then the MAV would be ejected. The craft would aerocapture into Earth orbit, then aerobrake down to LEO. It would use a little propellant to circularize orbit and rendezvous with ISS. This allows use of ISS as a construction shack, as well as a "transit station". The ship would remain parked there until the next trip to Mars.
Then we're down to the question of whether the ISS is equipped to properly maintain a reusuable interplanetary spaceship. The ISS has a crew of 6, with each subsequent mission of this reusable space vehicle, the chances of a failure increases without proper maintenance. Much depends on the form of propulsion used. For instance a Solar sail, an ion drive, a nerva, a nuclear electric drive, and chemical rocket etc.
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With just 4 crew on the Mars vehicle, then ISS would definately work. Especially with a DreamChaser docked, as well as the usual Soyuz for ISS maintenance crew.
I envision chemical propulsion initially. The TMI stage would use LOX/LH2, while MAV would use LOX/LCH4. But eventually the propulsion stage would be replaced by a reusable one. Replacing the entire stage means we don't have to commit to what that would be.
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I do agree with a mars transport vehicle designed for TMI and for TEI that loiters in orbit is ideal. Parking it at the ISS should be no big deal as it allows for an international crew for each mission to mars.
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