Ted Cruz, Longtime Foe Of NASA And Science, Will Oversee NASA And Science In New Cong

[Darwin333]

Well if we want to do human interplanetary exploration "right" it's something we'll need to do.

I think the best way to convince the public in the safety of launching a reactor is probably just to tell the history of nuclear devices in space and the intrinsic safety of a never run reactor.

For example:

• The US Air Force already launched a nuclear reactor SNAP 10A in the 60's. http://en.m.wikipedia.org/wiki/Systems_for_Nuclear_Auxiliary_Power
• The Russians launched several reactors upto a few KW in size through the 80's. http://en.m.wikipedia.org/wiki/TOPAZ_nuclear_reactor
• The US Airforce had a satellite with an RTG containing several pounds of Plutonium blow up on the pad. They fished the RTG out of the water and re-used it. http://en.m.wikipedia.org/wiki/Radioisotope_thermoelectric_generator
• In 2005 the Bush Administration authorized NASA to start work on a 100KW Reactor for the Jupiter Icy Moon Orbiter. Thus program was cancelled due to budgetary reasons. This reactor could have powered the ISS.
• The reactor grade uranium is less dangerous than the plutonium we regulary fly in RTGs.
• The reactor is intrinsically safe until it has been run. The waste products that are dangerous only occur after the reactor has been run for awhile. So wait till the vehicle is in a stable orbit and ready to begin accelerating away from Earth. The benefit of using an SLS type rocket is it can put the payloads high enough up that we'd have years to do something if there was a failure.
• On the return trip from Mars when the reactor has waste products, return to Lunar Orbit insteated of Earth Orbit. The benefit of Orion is it can do Lunar Taxi missions with no sweat and there's no chance of an accidental Earth re-entry from the moon.

So the US has already flown a reactor and had accidents involving nuclear materials without major issues. We've been given permission before to fly larger reactors. Flying a cold reactor is intrinsically safe and the mission can be done in a manner safe for the public.

It may not be as long as you think.

I did not know that, thank you kindly for the information.

Just to be clear, if we try to shoot a reactor into space we can do so in a way that if the vehicle explodes at 50,000 feet it is not possible for it to spread radioactive material across a large area?

 

[Brovane]

For a nuclear electric Mars transfer vehicle the benefit is the flight can be aborted at anytime. If we apply the steps for a hazard analysis, loss of propulsion would be a catastrophic failure. To design for this our vehicle would need 3 thrusters and 3 complete strings of equipment to power the thrusters and supply propellant. Two thrusters would have to be able to complete the mission to maintain Fail-Ops and a single thruster would have to be sized for all abort and return scenarios for Fail-Safe.

If we use chemical rockets is a anytime abort really needed? Once you complete the TMI burn with a chemical rocket you could be on course for Mars but also for a free-return trajectory back to Earth in-case of thruster failure. If you are tens of Million miles from Earth is paying the delta-V cost in additional propellant to allow a direct abort really worth it? It would still take you Months to get back to Earth.

 

[Brovane]

[*]The reactor is intrinsically safe until it has been run. The waste products that are dangerous only occur after the reactor has been run for awhile. So wait till the vehicle is in a stable orbit and ready to begin accelerating away from Earth. The benefit of using an SLS type rocket is it can put the payloads high enough up that we'd have years to do something if there was a failure.

So the US has already flown a reactor and had accidents involving nuclear materials without major issues. We've been given permission before to fly larger reactors. Flying a cold reactor is intrinsically safe and the mission can be done in a manner safe for the public.

It may not be as long as you think.

Would the SLS really have the flight history to provide a high level of confidence? Even after it is being built and launched it will not have a high flight rate, maybe once a year. I would feel more confident sending up the nuclear reactor core on something like a Delta-IV Heavy or Atlas-V and then the nuclear reactor assembly is finished in orbit.

 

[Paratus]

I did not know that, thank you kindly for the information.

Just to be clear, if we try to shoot a reactor into space we can do so in a way that if the vehicle explodes at 50,000 feet it is not possible for it to spread radioactive material across a large area?

My opinion is, yes a safe launch design can be developed. I have a high confidence in that opinion because of the survival of the RTG that was in a launch explosion. Also in that link they said that the lunar landers contained an RTG. The Apollo 13 lander actually re-entered and impacted the ocean. They never found a trace of the plutonium in the air or water, indicating the RTG survived an uncontrolled re-entry at lunar return velocity.

Based on these extreme failure cases it should be possible to design a reactor that keeps its fuel intact. Again these are my opinions so feel free to take them with a grain of salt.

If we use chemical rockets is a anytime abort really needed? Once you complete the TMI burn with a chemical rocket you could be on course for Mars but also for a free-return trajectory back to Earth in-case of thruster failure. If you are tens of Million miles from Earth is paying the delta-V cost in additional propellant to allow a direct abort really worth it? It would still take you Months to get back to Earth.

Well with a chemical rocket or even nuclear thermal, it's not a question of whether anytime abort is needed, it's that it's not possible at all. As you said, once you do the burn your abort is free return. 180 days there and 180 days back. Even if the issue you are aborting for happens the day after the burn.

With nuclear electric you can easily abort early in the trip. Although you are right , at some point in the trip, the fastest abort becomes going around Mars.

I'm coming at this from my knowledge of how important crew safety is. We had multiple abort modes for the Shuttle, RTLS, Single Engine loss, Two Engine loss, multiple landing sites across the country and world. The ISS requires uninterrupted access to the Soyuzs. Going back to a capsule design for Orion and commercial crew so you can have a launch escape system.

Any system that can return a crew in less than 6 months vs a year or more is going to be hugely attractive. IMHO of course.

Would the SLS really have the flight history to provide a high level of confidence? Even after it is being built and launched it will not have a high flight rate, maybe once a year. I would feel more confident sending up the nuclear reactor core on something like a Delta-IV Heavy or Atlas-V and then the nuclear reactor assembly is finished in orbit.

My assumption is by the time we do this whatever Super Heavy Launch Vehicle we have available will be reliable enough.

My other assumption is it's safer to launch a completed reactor that can be checked out on the ground before launch then try to assemble it piecemeal in orbit. For the ISS we generally launched integrated segments where the module or truss was functional but just needed to have bolts driven, electrical and data cables attached, and fluid Quick Disconnects attached on orbit.

I could wrong about either of these assumptions.

 

[Brovane]

My opinion is, yes a safe launch design can be developed. I have a high confidence in that opinion because of the survival of the RTG that was in a launch explosion. Also in that link they said that the lunar landers contained an RTG. The Apollo 13 lander actually re-entered and impacted the ocean. They never found a trace of the plutonium in the air or water, indicating the RTG survived an uncontrolled re-entry at lunar return velocity.

Based on these extreme failure cases it should be possible to design a reactor that keeps its fuel intact. Again these are my opinions so feel free to take them with a grain of salt.

I do agree. However the US public is so paranoid about nukes in space. The Apollo-13 RTG was just about a worse case scenario.

Well with a chemical rocket or even nuclear thermal, it's not a question of whether anytime abort is needed, it's that it's not possible at all. As you said, once you do the burn your abort is free return. 180 days there and 180 days back. Even if the issue you are aborting for happens the day after the burn.

With nuclear electric you can easily abort early in the trip. Although you are right , at some point in the trip, the fastest abort becomes going around Mars.

I'm coming at this from my knowledge of how important crew safety is. We had multiple abort modes for the Shuttle, RTLS, Single Engine loss, Two Engine loss, multiple landing sites across the country and world. The ISS requires uninterrupted access to the Soyuzs. Going back to a capsule design for Orion and commercial crew so you can have a launch escape system.

Any system that can return a crew in less than 6 months vs a year or more is going to be hugely attractive. IMHO of course.

I am not going to comment about how shaky some of the Shuttle Abort scenarios were, especially the RTLS.

A interesting abort mode that Zubrin talks about in his book "The Case for Mars" is abort to Mars. If you are doing a direct descent trajectory to Mars. Your Earth Return Vehicle is already sitting on the surface of Mars ready to go. So depending on where you are in your outward bound trajectory the nearest safe location might just the Martian surface.

My assumption is by the time we do this whatever Super Heavy Launch Vehicle we have available will be reliable enough.

My other assumption is it's safer to launch a completed reactor that can be checked out on the ground before launch then try to assemble it piecemeal in orbit. For the ISS we generally launched integrated segments where the module or truss was functional but just needed to have bolts driven, electrical and data cables attached, and fluid Quick Disconnects attached on orbit.

I could wrong about either of these assumptions.

My concern would be a HLV would be only launched maybe once or twice a year (if that) and at that flight rate it is hard to build up a solid launch history and expertise on the launch vehicle. Versus a vehicle with other roles that has consistent launch history. Maybe Musk will build a re-usable HLV and it will have a high flight rate.

One concept I have thought about was what was mentioned in "The Martian" book. You have a Spacecraft for the journey between Earth and Mars that is re-usable. It never enters the atmosphere and is nuclear powered. The craft is refurbished between missions. This allows you to re-use the expensive hardware. Maybe assemble the spacecraft at EML-2, very little Delta-V to do TMI from that location.

 

[werepossum]

Dude, its freaking Mars! If I make it there not only do I get to explore a place that no human has ever explored before, I get to be on the absolute cutting edge of science, potentially find evidence that life once existed on a planet other than Earth, potentially find simple life still there, groundbreaking discoveries on our neighboring planet, potentially lead the way to colonizing another planet giving the entirety of the human race a better chance at long term survival but IF I make it back I'll have so much pussy waiting I'll have to start putting pussy on layaway. Bonus points for every kid having to learn about me and memorize my name in 3rd grade for the next 100 years at least. Fuck yeah, give me 10% odds and a ticket to ride baby. Only thing left to do would be to figure out how to radiation proof a few seeds from a umm certain plant so I can sneak them on and grow a few in the hydroponics section of the habitat. Purely for research purposes only obviously.

Exploring a new planet would be cool, but I wouldn't want to do it without at least a 90% chance of survival. And sadly, I suspect that on the pussy magnet scale you'd be significantly below Guns-N-Roses' sometime replacement drummer or a recurring character on Honey Boo Boo. I don't think women interested in science intersect too extensively with the set of women who are fame-fuckers.

Think about this. The only deaths we have suffered in the US space program on a Mission is during ascent and descent. So what do you think is the most dangerous parts of the mission? Anytime you are leaving and descending into a gravity well. The 3 Cosmonauts that died in space, died when they un-docked from the Salyut space station. So your main pain points are Earth Orbit Ascent, any type of rendezvous with say a Mars Departure stage, TMI, Mars Orbit insertion, any type of rendezvous in Mars Orbit, Mars Descent, Mars Ascent, TEI and then Earth Descent. Your coast stages in-between are not really that dangerous, except because of the duration. You can also add in Mars Surface EVA's or any type of EVA for that matter.

The most dangerous thing for US astronauts has been the arrogance of NASA Management in dealing with potential Engineering hazards (IE Challenger and Columbia).

Apollo-1 fire was because lack of imagination, nobody thought about the hazards of a pure Oxygen 16+ PSI environment.

Those are good points.

With the ISS we've flown something like 64 man years without requiring an abort or losing an astronaut. This includes LEO ops but also ascent/entry.

But you guys want to hear about how to mitigate risk in space flight? Well let me fill you in.

For any given hazard we assess its severity. If the hazard can cause loss of crew or vehicle it's deemed a catastrophic hazard. Significant hazards that can increase the risk to crew or cause loss of a major function but don't rise to the level of a catastrophic hazard are deemed critical hazards.

For dealing with a catastrophic hazard 3 inhibits are required to prevent the hazard from occurring. For critical hazards you can generally get away with fewer inhibits depending on the consequences. Critical hazards generally impact mission success as opposed to crew safety.

Inhibits can consist of redundant equipment, software or procedures. When using this paradigm for design we call it Fail-Ops Fail-Safe. Faill-Ops means after the first equipment failure the function is still availabe and mission success is still possible. Fail-Safe means after the second equipment failure the function is still availabe although mission success is now gone, crew safety is still maintained.

For example the space shuttle had three power busses. The mission could continue after the first failed bus, but they were coming home after the second bus failure.

If there is still risk that can't be controlled via the design then risk managment and analysis comes into play. NASA uses a risk matrix approach that assess the likelihood and consequences of a hazard. Depending on the risk, operational controls or further analysis can be used to reduce the likelihood or consequence of the risk until it can be accepted.

This isn't the exact one we use but it gets the point across.

For a nuclear electric Mars transfer vehicle the benefit is the flight can be aborted at anytime. If we apply the steps for a hazard analysis, loss of propulsion would be a catastrophic failure. To design for this our vehicle would need 3 thrusters and 3 complete strings of equipment to power the thrusters and supply propellant. Two thrusters would have to be able to complete the mission to maintain Fail-Ops and a single thruster would have to be sized for all abort and return scenarios for Fail-Safe.

To lower our risk further maintenance technics from the ISS can be implemented. The ISS uses Orbital Replaceable Units. Boxes of equipment that can replaced easily when they fail. They are used both inside and outside the vehicle and can be replaced by crew and in some cases the robotic arm. The operational plan for the vehicle would require a certain number of spares.

For every system and operation required for the trip Mars hazard analysis would be performed. That's how you reduce the risk and get a robust vehicle.

Good info, thanks. But I don't see how one gets away without at least a replacement reactor. So I don't see how this could be done with our customary level of safety for decades, and as in general seems to me that NASA is getting less technically competent, not more, that doesn't argue for the mission's practicality.

 

[Paratus]

I do agree. However the US public is so paranoid about nukes in space. The Apollo-13 RTG was just about a worse case scenario.




I am not going to comment about how shaky some of the Shuttle Abort scenarios were, especially the RTLS.

A interesting abort mode that Zubrin talks about in his book "The Case for Mars" is abort to Mars. If you are doing a direct descent trajectory to Mars. Your Earth Return Vehicle is already sitting on the surface of Mars ready to go. So depending on where you are in your outward bound trajectory the nearest safe location might just the Martian surface.




My concern would be a HLV would be only launched maybe once or twice a year (if that) and at that flight rate it is hard to build up a solid launch history and expertise on the launch vehicle. Versus a vehicle with other roles that has consistent launch history. Maybe Musk will build a re-usable HLV and it will have a high flight rate.

One concept I have thought about was what was mentioned in "The Martian" book. You have a Spacecraft for the journey between Earth and Mars that is re-usable. It never enters the atmosphere and is nuclear powered. The craft is refurbished between missions. This allows you to re-use the expensive hardware. Maybe assemble the spacecraft at EML-2, very little Delta-V to do TMI from that location.

RTLS: What? Does flying backwards at Mach 5 while falling at Mach 1 sound crazy to you.

I may have mentioned in another thread but a number of years ago I had the chance to get a quick lesson on plasma in LEO and its potential effects on the ISS from Franklin Chang-Diaz, the astronaut/physicist behind VASIMR. He gave us a tour of his lab and the then current prototype. His design refrence mission was basically the one used in the Martian. Their transit vehicle even had VASIMR thrusters on it.

Here's a link to their design refrence mission. http://www.adastrarocket.com/Andrew-SPESIF-2011.pdf

My take on it was the Mars Transit vehicle would be based on an ISS like truss. On one end we'd hang thrusters, propellant, a reactor, and control systems. On the other end we'd hang, a Mars habitat, ascent vehicle, and more propellant.

The vehicle would go to Mars unmanned. As it swung by Mars, the Mars Habitat and ascent vehicle would descend to the planet. The ascent vehicle would start producing propellant in-situ for the manned mission. The spare VASMIR propellant would remain in Mars Orbit. The transit vehicle would return to Earth.

Once back at Earth, we'd remove any excess truss segments to reduce weight, resupply the vehicle with propellant and attach a habitation module, and another Mars ascent vehicle. The crew would come aboard in an Orion at the next conjuncture and the vehicle would do a fast trip to Mars.

Once at Mars they would grab the propellant tanks left in orbit and then descend to the surface in the ascent vehicle. The transit vehicle would wait in orbit.

At the end of Martian ops the crew would come back up in the previous ascent vehicle and dock with the Transit vehicle. The they'd come on home leaving their ascent vehicle for the next expedition.

At least that's how I've been seeing it.

Exploring a new planet would be cool, but I wouldn't want to do it without at least a 90% chance of survival. And sadly, I suspect that on the pussy magnet scale you'd be significantly below Guns-N-Roses' sometime replacement drummer or a recurring character on Honey Boo Boo. I don't think women interested in science intersect too extensively with the set of women who are fame-fuckers.


Those are good points.


Good info, thanks. But I don't see how one gets away without at least a replacement reactor. So I don't see how this could be done with our customary level of safety for decades, and as in general seems to me that NASA is getting less technically competent, not more, that doesn't argue for the mission's practicality.

It doesn't necessarily need a replacement reactor. Three seperate smaller reactors or a single reactor core with triply redundant support systems would probably work. This is the kind if thing that gets worked out before the preliminary design review.

 

[Brovane]

RTLS: What? Does flying backwards at Mach 5 while falling at Mach 1 sound crazy to you.

"RTLS abort is a unnatural act of physics" Astronaut Mike Mullane

Found this good video of a recorded RTLS abort simulation with audios and visuals. - https://www.youtube.com/watch?v=t6fSUaZlsWw

Which makes you have a greater appreciation as to what SpaceX is trying to do with the 1st stage boast back and landing. They are essentially trying to do a RTLS with the stage all done by a on-board flight computer and then land it on a very precise target.

I may have mentioned in another thread but a number of years ago I had the chance to get a quick lesson on plasma in LEO and its potential effects on the ISS from Franklin Chang-Diaz, the astronaut/physicist behind VASIMR. He gave us a tour of his lab and the then current prototype. His design refrence mission was basically the one used in the Martian. Their transit vehicle even had VASIMR thrusters on it.

Here's a link to their design refrence mission. http://www.adastrarocket.com/Andrew-SPESIF-2011.pdf

My take on it was the Mars Transit vehicle would be based on an ISS like truss. On one end we'd hang thrusters, propellant, a reactor, and control systems. On the other end we'd hang, a Mars habitat, ascent vehicle, and more propellant.

The vehicle would go to Mars unmanned. As it swung by Mars, the Mars Habitat and ascent vehicle would descend to the planet. The ascent vehicle would start producing propellant in-situ for the manned mission. The spare VASMIR propellant would remain in Mars Orbit. The transit vehicle would return to Earth.

Once back at Earth, we'd remove any excess truss segments to reduce weight, resupply the vehicle with propellant and attach a habitation module, and another Mars ascent vehicle. The crew would come aboard in an Orion at the next conjuncture and the vehicle would do a fast trip to Mars.

Once at Mars they would grab the propellant tanks left in orbit and then descend to the surface in the ascent vehicle. The transit vehicle would wait in orbit.

At the end of Martian ops the crew would come back up in the previous ascent vehicle and dock with the Transit vehicle. The they'd come on home leaving their ascent vehicle for the next expedition.

At least that's how I've been seeing it.

Why does that sound really expensive compared to what Zubrin has proposed with his Mars Direct method? Launch a HLV on a direct descent with the Earth Return Vehicle 2-years before the manned mission. Land on the surface produce your fuel for a Earth Return from Seed Hydrogen.

Then launch a second HLV with the crew and this Vehicle goes direct to Mars and lands on the surface. Crew spend's over a year on the surface doing exploration. They then get into the Earth Return Vehicle and come back to Earth.

No fancy refurbishment's in space or rendezvous. Each mission takes two HLV's and allows for a crew of four. You launch 2 HLV's every 2 years.

 

[werepossum]

RTLS: What? Does flying backwards at Mach 5 while falling at Mach 1 sound crazy to you.

I may have mentioned in another thread but a number of years ago I had the chance to get a quick lesson on plasma in LEO and its potential effects on the ISS from Franklin Chang-Diaz, the astronaut/physicist behind VASIMR. He gave us a tour of his lab and the then current prototype. His design refrence mission was basically the one used in the Martian. Their transit vehicle even had VASIMR thrusters on it.

Here's a link to their design refrence mission. http://www.adastrarocket.com/Andrew-SPESIF-2011.pdf

My take on it was the Mars Transit vehicle would be based on an ISS like truss. On one end we'd hang thrusters, propellant, a reactor, and control systems. On the other end we'd hang, a Mars habitat, ascent vehicle, and more propellant.

The vehicle would go to Mars unmanned. As it swung by Mars, the Mars Habitat and ascent vehicle would descend to the planet. The ascent vehicle would start producing propellant in-situ for the manned mission. The spare VASMIR propellant would remain in Mars Orbit. The transit vehicle would return to Earth.

Once back at Earth, we'd remove any excess truss segments to reduce weight, resupply the vehicle with propellant and attach a habitation module, and another Mars ascent vehicle. The crew would come aboard in an Orion at the next conjuncture and the vehicle would do a fast trip to Mars.

Once at Mars they would grab the propellant tanks left in orbit and then descend to the surface in the ascent vehicle. The transit vehicle would wait in orbit.

At the end of Martian ops the crew would come back up in the previous ascent vehicle and dock with the Transit vehicle. The they'd come on home leaving their ascent vehicle for the next expedition.

At least that's how I've been seeing it.

It doesn't necessarily need a replacement reactor. Three seperate smaller reactors or a single reactor core with triply redundant support systems would probably work. This is the kind if thing that gets worked out before the preliminary design review.

That trip plan sounds awesome. If something fails, simply relaunch. Preferably launch another as the astronauts are heading in, so that if something goes wrong they have another chance.

Three separate reactors works for me. Lose a reactor, shut down the least important power draws.

 

[Paratus]

I do agree. However the US public is so paranoid about nukes in space. The Apollo-13 RTG was just about a worse case scenario.




I am not going to comment about how shaky some of the Shuttle Abort scenarios were, especially the RTLS.

A interesting abort mode that Zubrin talks about in his book "The Case for Mars" is abort to Mars. If you are doing a direct descent trajectory to Mars. Your Earth Return Vehicle is already sitting on the surface of Mars ready to go. So depending on where you are in your outward bound trajectory the nearest safe location might just the Martian surface.




My concern would be a HLV would be only launched maybe once or twice a year (if that) and at that flight rate it is hard to build up a solid launch history and expertise on the launch vehicle. Versus a vehicle with other roles that has consistent launch history. Maybe Musk will build a re-usable HLV and it will have a high flight rate.

One concept I have thought about was what was mentioned in "The Martian" book. You have a Spacecraft for the journey between Earth and Mars that is re-usable. It never enters the atmosphere and is nuclear powered. The craft is refurbished between missions. This allows you to re-use the expensive hardware. Maybe assemble the spacecraft at EML-2, very little Delta-V to do TMI from that location.

"RTLS abort is a unnatural act of physics" Astronaut Mike Mullane

Found this good video of a recorded RTLS abort simulation with audios and visuals. - https://www.youtube.com/watch?v=t6fSUaZlsWw

Which makes you have a greater appreciation as to what SpaceX is trying to do with the 1st stage boast back and landing. They are essentially trying to do a RTLS with the stage all done by a on-board flight computer and then land it on a very precise target.



Why does that sound really expensive compared to what Zubrin has proposed with his Mars Direct method? Launch a HLV on a direct descent with the Earth Return Vehicle 2-years before the manned mission. Land on the surface produce your fuel for a Earth Return from Seed Hydrogen.

Then launch a second HLV with the crew and this Vehicle goes direct to Mars and lands on the surface. Crew spend's over a year on the surface doing exploration. They then get into the Earth Return Vehicle and come back to Earth.

No fancy refurbishment's in space or rendezvous. Each mission takes two HLV's and allows for a crew of four. You launch 2 HLV's every 2 years.

I think Zubrins design has a lot of good ideas. I think from a budget perspective it's probably as cheap as possible.

I also think he cuts the margin extremely thin for crew safety. I also think he drastically underestimates the up-mass needed for over 8 man-years worth of consumables. (The VASIMR guys do too). Basically it feels like another Apollo. Cram a couple of guys into as small a container as possible and give them just enough to get the mission done assuming nothing goes wrong.

What I've recommended would be more expensive. I also think it's much safer for the crew. Each hab module can be optimized for the appropriate living conditions. Mars ascent and entry can be handled by dedicated and optimized vehicles. Same with Earth ascent and entry. Mars Direct requires the Habitat and ERV vehicles to be a jacks of all trades which means trade offs.

The other benefit of a configurable nuclear electric vehicle is it doesn't just have to go to Mars. Other destinations can be opened up due to the faster transit times.

Anyway, it's been awhile since I read up on Mars Direct, wiki wasn't very informative, and the link on the Mars Society page failed, do you have a more detailed link? I'd like to make sure I'm being fair.

It's been a fascinating conversation so far. :thumbsup:

(Oh Ya, on HLV safety, if we can certify an HLV for manned launched without a significant flight history, we can rate it to carry a nuke. besides both ideas require an HLV carrying a nuke anyway.)

 

[manimal]

wouldnt starting a unmanned space station in orbit around mars be cheaper in the long run? Something that say Nasa could start populating with non essential systems that wont change much design wise over the next few years.


Getting some experience planet to planet before going down again would seem safer and would develop existing technologies wouldnt it?

 

[Brovane]

I think Zubrins design has a lot of good ideas. I think from a budget perspective it's probably as cheap as possible.

I also think he cuts the margin extremely thin for crew safety. I also think he drastically underestimates the up-mass needed for over 8 man-years worth of consumables. (The VASIMR guys do too). Basically it feels like another Apollo. Cram a couple of guys into as small a container as possible and give them just enough to get the mission done assuming nothing goes wrong.

What I've recommended would be more expensive. I also think it's much safer for the crew. Each hab module can be optimized for the appropriate living conditions. Mars ascent and entry can be handled by dedicated and optimized vehicles. Same with Earth ascent and entry. Mars Direct requires the Habitat and ERV vehicles to be a jacks of all trades which means trade offs.

The other benefit of a configurable nuclear electric vehicle is it doesn't just have to go to Mars. Other destinations can be opened up due to the faster transit times.

Anyway, it's been awhile since I read up on Mars Direct, wiki wasn't very informative, and the link on the Mars Society page failed, do you have a more detailed link? I'd like to make sure I'm being fair.

It's been a fascinating conversation so far. :thumbsup:

(Oh Ya, on HLV safety, if we can certify an HLV for manned launched without a significant flight history, we can rate it to carry a nuke. besides both ideas require an HLV carrying a nuke anyway.)

I have his book "The Case for Mars" sitting in my office so that is what I have been using for reference.

He has two different modes proposed. One is what is called Mars Direct which is two HLV's every two years. The Earth Return Vehicle goes and lands directly on Mars and produces fuel for it's return journey. Also as part of that fuel production the vehicle also produces water for the crew. The crew then follows 2-years later. The Semi-Direct breaks out everything into 3-launches every 2-years. The first year you launch a Hab un-manned, a separate MAV (Mars Ascent Vehicle) and then a separate ERV (Earth Return Vehicle) that stays in orbit of Mars. Two years later another 3-vehicle launch except the Hab is manned this time (the first is a reserve on the surface) and your first crew is on Mars.

Looking at his book the Consumable Mass is 10 tons for the 4-man crew for a total of 1000 days which is 4,000 man days. A big Mass savings is that the Processing plant on the MAV or ERV produces the water for the crew's surface exploration which is 9 tons of Mass for 600-days of surface time and is a big savings.

I am tweaking you a bit on the HLV thing. I am sure the HLV would be safe without a significant flight history. I just think it is funny that a HLV can be rated for humans after only one launch. Yet the USAF EELV program is requiring SpaceX to demonstrate 3 launches in a row for the Falcon 9 and a review before EELV certification. The EELV certification appears to be more difficult than a human rating certification.

 

[Hayabusa Rider]

I also think he cuts the margin extremely thin for crew safety. I also think he drastically underestimates the up-mass needed for over 8 man-years worth of consumables. (The VASIMR guys do too). Basically it feels like another Apollo. Cram a couple of guys into as small a container as possible and give them just enough to get the mission done assuming nothing goes wrong.

It does sound like he's selling the idea. If he gets a commitment then we might he might be able to get an f-35 scenario, where too much money is sunk already so the task must be completed regardless of cost. I'm not sure it would go that way, but it seems to be the thinking. A four person crew? That does sound like Apollo. Squeeze everyone in a box like sardines and expect them to just sit there for half a year?

Habitat has to go beyond technical survivability. Out of the thousands who would line up I'd wager that almost all of them would be screaming to get out in a month or two, and my become completely unhinged by the time they get to Mars. Submarine crews have to be special individuals who can withstand confined spaces for long periods of time, but compared to a Mars vehicle, being in a modern nuclear sub might be a vast estate. The ISS would be a safe harbor, with a possibility of rescue.

The more I read about these projects the less realistic they seem as they stand because of the emphasis on economy and efficiency. I'm sure there are four people or a dozen who could be found that could endure the mental and physical punishment under the right circumstance, but there are limits to the human organism.

We should have an advert for a test-

"Wanted- individuals who are highly fit, intelligent, and educated. If selected you will be trained and may be chosen to be launched into earth orbit. You will be in a small space for minimum of six months. You will be relying solely on the supplies you have on hand, and the resources on board. In the event of emergency you may or may not have access to ground control resources depending on the nature of your malfunction. It is most important to note that in case of a situation which would prevent you from landing on Mars you will remain in orbit for up to one year and no one will come and rescue you. You live and die by your wits and those of the Earth crew, provided communication continues. There will be increasing time delay as the mission progresses to reflect distance traveled in a real flight. Upon successful completion you may qualify for the real mission to Mars. In any case you will have significantly contributed towards human space exploration. This will allow for refinement or changes needed. The vehicle will be closely examined and modified as necessary, and in the event of failure redesigned. You will be thoroughly examined and given medical care and treatment as appropriate. In the event of your death we will carefully and respectfully perform a full forensic analysis that will be of priceless value to the program.

Thank you and sign up now!"

 

[Brovane]

It does sound like he's selling the idea. If he gets a commitment then we might he might be able to get an f-35 scenario, where too much money is sunk already so the task must be completed regardless of cost. I'm not sure it would go that way, but it seems to be the thinking. A four person crew? That does sound like Apollo. Squeeze everyone in a box like sardines and expect them to just sit there for half a year?

Habitat has to go beyond technical survivability. Out of the thousands who would line up I'd wager that almost all of them would be screaming to get out in a month or two, and my become completely unhinged by the time they get to Mars. Submarine crews have to be special individuals who can withstand confined spaces for long periods of time, but compared to a Mars vehicle, being in a modern nuclear sub might be a vast estate. The ISS would be a safe harbor, with a possibility of rescue.

The more I read about these projects the less realistic they seem as they stand because of the emphasis on economy and efficiency. I'm sure there are four people or a dozen who could be found that could endure the mental and physical punishment under the right circumstance, but there are limits to the human organism.

For reference the Apollo Command module had a living space volume of 218 cubic feet. The Mars Habitat that would be used on the outward bound journey and for surface operations would have a volume of around 7,000 cubic feet for four people. The Earth Return Vehicle would be smaller at around 3500 cubic feet for four people.

 

[Hayabusa Rider]

For reference the Apollo Command module had a living space volume of 218 cubic feet. The Mars Habitat that would be used on the outward bound journey and for surface operations would have a volume of around 7,000 cubic feet for four people. The Earth Return Vehicle would be smaller at around 3500 cubic feet for four people.

So that's a volume of a cube about 19 and 15 feet on a side. Of course it doesn't have to be a cube, so that's good.

I still think that a test ought to be designed along the lines I've described. I worded it the way I did to reflect reality to those who would hop aboard a firework if it had any chance at all, well according to what they seem to say.

Of course the wording of the contract would be different and we could state the harsh conditions pretty much as they are. If you screw up or something goes wrong and you can't fix it you die. Of course saying that doesn't mean we can't have some rescue operation on standby, but it would be vital that the crew believe that is not happening, even if that means a secret launch to the vehicle. Death must thought to be inevitible under certain conditions. That does not mean the facts must match reality.

Even if everything goes well, I'd think that fake emergencies carefully planned would be most important to any test. Something which seems real, which needs solutions and could be "fixed" by taking certain steps. Then there's the real nasty bit. A problem which will result in death which cannot be repaired.

I'm not sure how to pull that off because we wouldn't want the crew tearing apart vital systems in desperation, and I admit right now it would be cruel, however we really need to know how both the people and the machines work under as realistic conditions as possible. Simulations on earth have a few things which render them less than entirely reliable. First there's gravity to account for. Any rotation in space to cause an artificial gravity environment would most likely not be felt as earth normal. But the psychology is entirely different. Any simulation no matter how realistic or uncomfortable carries with it a certainty of it being terminated if there were serious danger. Not so on this trip. Once you are gone you are done. We don't know how people will live with that over such a voyage, and I don't think that can be lightly dismissed.

 

[Paratus]

So that's a volume of a cube about 19 and 15 feet on a side. Of course it doesn't have to be a cube, so that's good.

I still think that a test ought to be designed along the lines I've described. I worded it the way I did to reflect reality to those who would hop aboard a firework if it had any chance at all, well according to what they seem to say.

Of course the wording of the contract would be different and we could state the harsh conditions pretty much as they are. If you screw up or something goes wrong and you can't fix it you die. Of course saying that doesn't mean we can't have some rescue operation on standby, but it would be vital that the crew believe that is not happening, even if that means a secret launch to the vehicle. Death must thought to be inevitible under certain conditions. That does not mean the facts must match reality.

Even if everything goes well, I'd think that fake emergencies carefully planned would be most important to any test. Something which seems real, which needs solutions and could be "fixed" by taking certain steps. Then there's the real nasty bit. A problem which will result in death which cannot be repaired.

I'm not sure how to pull that off because we wouldn't want the crew tearing apart vital systems in desperation, and I admit right now it would be cruel, however we really need to know how both the people and the machines work under as realistic conditions as possible. Simulations on earth have a few things which render them less than entirely reliable. First there's gravity to account for. Any rotation in space to cause an artificial gravity environment would most likely not be felt as earth normal. But the psychology is entirely different. Any simulation no matter how realistic or uncomfortable carries with it a certainty of it being terminated if there were serious danger. Not so on this trip. Once you are gone you are done. We don't know how people will live with that over such a voyage, and I don't think that can be lightly dismissed.

We actually know quite a bit about how to live for long durations in space, how to train to handle failures, and how to deal with failures that actually occur.

Every system aboard the ISS for example has detailed procedures written by ops folks on how to use the system and how to safe or recover failed systems. The ground has extensive rule books called Flight Rules that detail in advance how systems are to be configured when, nominal, after a failure, and in some cases after a 2nd failure.

Every flight controller and astronaut goes through extensive training on how to exercise these procedures including full up simulations in a mockup ISS and flight control room. The training leads take great pleasure in putting the screws to the team.

Astronauts get refresher training for emergencies on board the ISS and ground controllers must maintain certifications to sit console. (I have/had an operator cert and two specialist certs.)

When a failure occurs, flight rules are consulted, procedures are run by the crew and ground depending on the situation, and options for hardware R&R are put together for the crew if required.

We've had some fairly nasty failures that occasionally show up in the news.

Now going to Mars has some major differences. Communications latency and durations being the biggest two.

But even there, we're doing some preliminary studies on the ISS.
I believe there was a study done where for awhile, we artificially increased the telemetry and comm latency to mimic a Mars mission, (at least they were talking about doing it).

For the duration, as you may have heard in the SoTU were sending astronaut Scott Kelly up for year. His twin brother Mark, (married to Gabbie Giffords), is a former astronaut whose medical status they'll compare.

The ISS actually gives us a pretty good platform for preparing for long duration flights.