Deep Space Habitat

SpaceNut · 2016-01-24 19:07:14

We have been talking about what a deep space habitat might entail for some time and what we could use to make it possible from components of the ISS as a reference point to build what we need.

A recent topic which gave suggestions was in the JPL Mars mission proposal

Here is the JPL version of the deep habitat:
2A1DC3F900000578-0-The_new_proposals_to_sending_astronauts_to_Mars_proposes_a_stepw-a-23_1435685621948.jpg

Nasa recently got the go ahead to put funds towards making it happen. In the latest omnibus spending bill approved by Congress, NASA was awarded $55 million in order to help accelerate development of a deep space habitation module.

NASA leverages ISS as it gets go ahead for a deep space habitat

The ISS-derived Deep Space Habitat concept demonstrator evaluation will focus on the following elements, from left to right, Lab/Hab, tunnel, and Multi-Purpose Logistics Module (MPLM).
“We have a number of habitation and Environmental Control and Life Support Systems (ECLSS) activities in development, with several ready for demonstration on the space station this year and more in the next couple of years,”

Bigelow-Aerospace-BEAM-module-International-Space-Station-NASA-image-posted-on-SpaceFlight-Insider.jpg

Up and coming missions to the ISS:

o Bigelow Expandable Activity Module (BEAM) will be berthed to the ISS for a two-year demonstration and analysis of inflatable habitats. The primary goals include the deployment process, thermal, radiation, and general operations during this test period. Launch is planned aboard the next SpaceX space station cargo resupply mission, CRS-8, currently scheduled for no earlier than March 20.
o Spacecraft Fire Safety (SAFFIRE) includes a planned set of test flights to seek fundamental understanding of flame spread in large-scale microgravity fires, demonstrate the performance of combustion product monitor systems, and conduct test of post-fire cleanup technologies for Orion, the space station and future habitation systems. These tests will be conducted on three Cygnus cargo ships after the spacecraft has safely departed from ISS.
o Aerosol Sampler will perform a demonstration of a modified off-the-shelf aerosol sampler on the space station to gather quantitative data on ambient air quality on the station. The station has high concentration of airborne particles that cause allergies and irritate crew members’ eyes and noses.
o More efficient air and water systems: Systems under development that are planned for demonstration on the space station over the next five years will increase efficiency and reduce dependence on resupply from Earth. These systems will improve waste water recovery (currently at 74 percent), air filtration and monitoring, atmospheric carbon dioxide (CO2) removal, and oxygen recovery from CO2, advancing from the current 43 percent to more than 75 percent.

So in addition to know what we want we will just give out more cash to get companies to create a possibility of what it is that we could make.

Next Space Technologies for Exploration Partnerships (NextSTEP) program which awarded one year contracts for habitation studies in March 2015. Four companies—Boeing, Lockheed Martin, Bigelow Aerospace and Orbital ATK—were each awarded $1 million to study the issue and design preliminary solutions.

GW Johnson · 2016-01-25 11:05:56

2 (actually, 5) cent's worth for the pot:

1. The JPL concept looks great for a mission that does not land on Mars. You get to take your habitat with you both ways, and you will need the space. I don't see any way to spin that concept for the artificial gravity we already know we will need. I doubt even the SEP electric tug they show can shorten the round trip time under the 400 day limit known from the Russian station, and that discounts the need to survive 12-15 free return gees.

2. For a landing mission, you cannot send just one of these, you'll need some sort of surface habitat, and you'll need one for the return. Architectures that neglect this by using the hab on the outbound and then on the surface, but riding home in a capsule, will kill a crew. It'll be a toss-up as to whether microgravity disease or confinement insanity will kill them first.

3. Myself, I'd design the surface hab function into the lander vehicle, by converting cargo space to pressurized hab after unloading. It means using a larger lander the longer you plan to stay. The larger the lander, the more feasible a reusable landing boat design becomes, which favors orbital basing with shorter stays at more locations while there.

4. The inboard profile of the NASA deep space hab looks about like what I expect. It's the same thinking folks have used since the 1950's: put the gear on the walls and the passageways in the middle. We already learned that's a bad idea from the depressurization of one of the Salyut modules, following a collision. They could never get to the leak to repair it. To be able to fix leaks in your shell, you put the gear in the core down the middle, and make all the shell wall space your passageways and open areas. It's the only way to find and fix a hole fast enough.

5. I like the inflatables from Bigelow. They inherently adapt to gear-down-the-middle design, because of the way they stow and deploy.

GW

Last edited by GW Johnson (2016-01-25 11:08:44)

Antius · 2016-01-25 13:13:36

I would be wary of using the ISS as a baseline for anything. The ISS is a boondoggle dreamed up by NASA bureaucrats in a desperate attempt to find something useful for the shuttle to do. It may give you some idea as to what systems you need for a long term habitat, but the project itself is an utter failure.

kbd512 · 2016-01-25 13:32:45

GW,

If the inflatable habitat is punctured, does Bigelow or NASA have a patching solution available for that? Has the patching solution been tested in a vacuum chamber?

RobertDyck · 2016-01-25 13:34:09

Antius wrote:

I would be wary of using the ISS as a baseline for anything. The ISS is a boondoggle dreamed up by NASA bureaucrats in a desperate attempt to find something useful for the shuttle to do. It may give you some idea as to what systems you need for a long term habitat, but the project itself is an utter failure.

Harsh and unfair. Actually, NASA wanted a space station since 1968. They had dreams of a temporary space station for 7 astronauts, then a permanent wheel with artificial gravity for 50 astronauts. The latter is highly unlikely. NASA wanted a small shuttle to carry 7 astronauts plus some luggage to an international space station in the orbit it is now. Actually, the shuttle they wanted in 1968 was to be fully reusable two-stage-to-orbit, lifting body orbiter with piloted fly-back booster, and carry 11 metric tonnes of supplies. But president Nixon slashed their budget. Then during Ronald Regan's administration, they wanted space station Freedom. It got scaled back and scaled back; president Clinton was given several options. He chose the smallest and cheapest: Alpha. The Soviet Union collapsed under his watch. NASA wanted a bigger station, they worried Alpha was too small to do anything. So NASA made a proposal to the Russian space agency to cooperate, use pieces of US space station Alpha together with pieces for Russian space station Mir2, and build a big international space station. So that's what they did. One reason modules are the size they are, were to fit on a Russian Proton launch vehicle. And yes, NASA had Shuttle, but didn't have Saturn 1B any more.

Before we go to Mars, we have to test life support in space. That requires a space station of some sort. If not ISS, then something else. And if you de-orbit/destroy ISS, expect it won't be replaced by anything. You would get nothing. I have called for operating ISS with no cargo resupply for the full duration of a Mars mission. If we can't do it on ISS, how will we ever get to Mars? That actually requires a few upgrades to the life support system. And that's the point, to ensure we test life support for the full duration of a Mars mission. Once it's tested on ISS, then we're ready to go.

kbd512 · 2016-01-25 14:49:58

Rob,

I actually like that idea best. Rather than sending any new vehicles or habitats up, we test the CL-ECLSS demonstrator first. Once that has been proven to function as intended, then we outfit a deep space habitat with the new CL-ECLSS technology and fly it in LEO for 2 years without resupply. If that goes relatively smoothly, then we send up another habitat or perhaps refit the existing habitat to test habitat reusability, mate it to a chemical kick stage, and send it to L2 for two years to determine what the effects of the radiation environment are on the habitat. Hopefully we'll be ready to test artificial gravity one the first deep space mission.

RobertDyck · 2016-01-25 17:17:49

I would move faster. Test life support for 26 months, or 28.5 months, on ISS.

Also demonstrate manoeuvring while rotating in tethered flight. That can be done with Dragon crew vehicle tethered to a Dragon cargo vehicle that is stuffed with garbage from ISS and destined to burn up in the atmosphere anyway. Change orbit while rotating in tethered flight, just to prove you can. That will demonstrate we can tether a Mars Direct style habitat to a spent TMI stage.

And Dava Newman was hired by NASA, coming from MIT. She's the last researcher actively working on MCP spacesuits. I would like to see a full-up spacesuit. One issue has been shape memory alloys or contractile polymers to make donning and doffing easier. That's putting on and taking it off. I wouldn't bother; that's an unnecessary complication. Just pull on tight layers the way Dr. Paul Webb did. That suit was originally intended for the surface of the Moon, but wasn't ready in time for Apollo 11. So can be used for a future Moon mission as well as Mars.

Demonstrate ISPP with a robotic sample return mission. It doesn't have to be nearly as big as Mars 2020. Just a small lander like Mars Pathfinder, Phoenix, or the size of Spirit/Opportunity. Ideally with landing rockets and legs like Phoenix, not bounce-and-roll like Pathfinder or Spirit/Opportunity. Include a tiny rover the size of Sojourner to collect samples. Bring the sample container back to Earth, using the same return capsule as Stardust or Genesis. But the key is ISPP for the return rocket. That demonstrates ISPP before committing human lives to that technology.

Then test the habitat by using as a base on the Moon. That would make the Moon guys happy. And would test our habitat where you can leave for Earth at any time, returning in 3 days. Would probably require an Apollo style LM to return crew to lunar orbit, then Orion to return to Earth. The reason the Mars Direct ERV works is ISPP. That won't work on the Moon, and I don't see SLS being able to launch an Earth return capsule with fully fuelled return stage, and landing stage. Even if you use a Dragon capsule, which is substantially lower mass than Orion. If you did all that, the Moon guys would be ecstatic!

Land a Mars vehicle on the surface of Mars, but the first one unmanned. Just to demonstrate it works. For Mars Direct, could you land an ERV, follow with a hab full of unmanned rovers, drop sample containers in the ERV, then have the ERV return by itself?

My mission plan uses the MAV for TEI. Drop an MAV on Mars, have it fill tanks with ISPP. My mission plan includes a reusable Interplanetary Transit Vehicle, which is essentially a deep space habitat. Send the ITV unmanned. Have everything sit there until the return window, then the MAV would ascend and dock to the vehicle in Mars orbit. Then push the vehicle into trans-Earth trajectory. Could it enter Earth orbit and rendezvous/dock with ISS? All unmanned?

One fail-safe mode is free return. So do that with crew: launch them to Mars, loop around the planet without entering orbit, and return directly back to Earth. That's the Inspiration Mars, or Gemini Mars mission, but with full crew and full size habitat.

But don't leave them parked in Mars orbit. Extended duration in zero-G and radiation is very bad. The surface of Mars is the safest place in our solar system; second only to the surface of Earth. Astronauts must either land on Mars, or return to Earth immediately. Mars Direct uses the spent upper stage as counterweight for artificial gravity. That's a great idea, so I included that in my plan too. But you have to discard the counterweight for aerocapture, so zero-G during the entire stay in Mars orbit. My plan would use the MAV for TEI, once spent use it as counterweight for artificial gravity on return to Earth. But it won't be available until spent, so after the TEI burn. So don't park in Mars orbit.

After all that, we're ready to land crew on the surface of Mars.

SpaceNut · 2016-01-25 21:01:44

MPLM

Three modules were built by the Italian Space Agency (ASI), Leonardo, Raffaello and Donatello...
http://www.nasa.gov/externalflash/ISSRG/pdfs/mplm.pdf

looks sort of like less the solar panels in the updated version

We could also use the
https://en.wikipedia.org/wiki/Tranquili … _module%29
https://en.wikipedia.org/wiki/Harmony_(ISS_module)

to round it out.....

RobertDyck · 2016-01-25 22:54:04

Or one of these...

GW Johnson · 2016-01-26 10:14:57

To answer KBD512 in post 4 above:

question: "If the inflatable habitat is punctured, does Bigelow or NASA have a patching solution available for that? Has the patching solution been tested in a vacuum chamber?"

answer:

Factual --- I do not know.

Opinion 1 --- I suspect NASA has never even thought about the issue, because all their designs are still gear-on-wall obstructing any patching activities that are not EVA.

Opinion 2 --- I would hope Bigelow has thought about it, and I would hope they have tested something, but I suspect they keep this to themselves because of fears about embarrassing their government customer.

Technical observation -- it is easier to patch from the inside than the outside, because inside, the remaining air pressure helps to seat your patch more firmly over the hole. Outside, the remaining air pressure always acts to blow your patch off the shell. For an inside patch, almost any semi-flexible plastic panel with a thick, very-sticky "goo-glue" on one side will work. At least long enough to do something more permanent. The "trick" is not to lose all the air in the first place.

GW

SpaceNut · 2016-01-26 19:38:51

RobertDyck I do like the professional images but KBD512 did raise a good point with any craft being struck by a micrometeor on the journey out or for that fact back after surviving on the surface. GW does give the possible solutions to both styles of living quarter designs in that it would be best to not have exterior walls with anything on them to cause a blocking of the path to making any repair.

RobertDyck · 2016-01-26 21:00:48

ILC Dover makes the soft parts of spacesuits for NASA. Hamilton Sundstrand makes hard stuff, like helmets and PLSS backpacks. ILC Dover first proposed TransHAB, and NASA funded development of it. NASA wanted to abandon the US habitat module in favour of TransHAB. It's the same size during launch, but once inflated it is 3 times the diameter, which makes a cross section through the cylinder 9 times the area, and since it has the same length that makes it 9 times the volume. The problem is they wanted to do that after the hull for the US hab module was finished. After they spent millions of dollars on the hull, they wanted to throw it away. So Congress cancelled both the hab and TransHAB. Since it was cancelled, Bigelow has continued work on TransHAB.

That's long winded. But TransHAB has 3 layers of micrometeoroid protection. And 3 layers of air bladder. Plus a scuff layer on the inside. So it has multiple redundancies. Do they have a patch kit? That I don't know.

To be complete, the hull for the US hab was later modified to become Node 3. It's currently installed on ISS. My little bug to say this issue is over, please build some sort of habitat module on ISS.

Metal hull modules for ISS have standardized racks. For each side (top, bottom, left, right) they have a rod extend the length of the module. The "top" end of the rack latches onto this rod, and the entire rack can swing on it like a hinge. A latched on the "bottom" holds it in place. This is how racks are installed in the first place. Racks can be swapped out on-orbit. And they have done so. This means if a hull puncture occurs, they can easily unfasten the latch at the bottom, and swing the entire rack up to the ceiling. This provides complete access to the inside of the metal hull. The next question is whether they have a patch kit. I don't know that either.

NASA had worried about Shuttle heat shield failure. Two missions tested a free-floating camera to inspect Shuttle heat shield tiles. It was about the size of a soft ball, covered in Styrofoam. So if it bumped into a heat shield tile, it would cause damage. The ball used cold nitrogen gas thrusters to maneuver, again so they don't damage the Shuttle. But these devices were never issued as standard equipment, they were funded as experiments only, and did fly on two Shuttle missions simply as a small experiment to fill an empty nook in the cargo hold. They had funded research into patch kits for tiles, but never finished it. Then Columbia happened.

Because of this history, my paranoid side suspects they have thought about patch kits, but haven't finished anything.

Last edited by RobertDyck (2016-01-26 21:05:09)

Tom Kalbfus · 2016-01-27 12:45:15

SpaceNut wrote:

We have been talking about what a deep space habitat might entail for some time and what we could use to make it possible from components of the ISS as a reference point to build what we need.
A recent topic which gave suggestions was in the JPL Mars mission proposal
Here is the JPL version of the deep habitat:
http://i.dailymail.co.uk/i/pix/2015/06/ … 621948.jpg
Nasa recently got the go ahead to put funds towards making it happen. In the latest omnibus spending bill approved by Congress, NASA was awarded $55 million in order to help accelerate development of a deep space habitation module.
NASA leverages ISS as it gets go ahead for a deep space habitat
http://www.spaceflightinsider.com/wp-co … nts-lg.jpg
The ISS-derived Deep Space Habitat concept demonstrator evaluation will focus on the following elements, from left to right, Lab/Hab, tunnel, and Multi-Purpose Logistics Module (MPLM).
“We have a number of habitation and Environmental Control and Life Support Systems (ECLSS) activities in development, with several ready for demonstration on the space station this year and more in the next couple of years,”
http://www.spaceflightinsider.com/wp-co … nsider.jpg
Up and coming missions to the ISS:
o Bigelow Expandable Activity Module (BEAM) will be berthed to the ISS for a two-year demonstration and analysis of inflatable habitats. The primary goals include the deployment process, thermal, radiation, and general operations during this test period. Launch is planned aboard the next SpaceX space station cargo resupply mission, CRS-8, currently scheduled for no earlier than March 20.
o Spacecraft Fire Safety (SAFFIRE) includes a planned set of test flights to seek fundamental understanding of flame spread in large-scale microgravity fires, demonstrate the performance of combustion product monitor systems, and conduct test of post-fire cleanup technologies for Orion, the space station and future habitation systems. These tests will be conducted on three Cygnus cargo ships after the spacecraft has safely departed from ISS.
o Aerosol Sampler will perform a demonstration of a modified off-the-shelf aerosol sampler on the space station to gather quantitative data on ambient air quality on the station. The station has high concentration of airborne particles that cause allergies and irritate crew members’ eyes and noses.
o More efficient air and water systems: Systems under development that are planned for demonstration on the space station over the next five years will increase efficiency and reduce dependence on resupply from Earth. These systems will improve waste water recovery (currently at 74 percent), air filtration and monitoring, atmospheric carbon dioxide (CO2) removal, and oxygen recovery from CO2, advancing from the current 43 percent to more than 75 percent.
So in addition to know what we want we will just give out more cash to get companies to create a possibility of what it is that we could make.
Next Space Technologies for Exploration Partnerships (NextSTEP) program which awarded one year contracts for habitation studies in March 2015. Four companies—Boeing, Lockheed Martin, Bigelow Aerospace and Orbital ATK—were each awarded $1 million to study the issue and design preliminary solutions.

I'm not sure astronauts would be standing on Phobos, the condition on the surface of Phobos would be near weightlessness. Also why would you need a separate hab just to walk the surface of Phobos, wouldn't the ship that brought you their have its own life support and living quarters?

SpaceNut · 2016-01-27 18:15:37

The JPL mission to Phobo's requires the crew to be launched in what appears to be Orion which serves as the earth landing vehicle which can not be parked in LEO awaiting any crews return so it is brought with them. The orion capsule is docked with the Deep space habitat which has all the life support and food within it. Just not sure why the transfer stage for Orion is facing in the direction that it is as there is no way to park it in that manner. Without the rest of the mission launch profile its hard to tell why we are this way in the image.

In either case lets focus on what makes the right deep space habitat, with the right costs associated with it going on any mission beyond LEO....

RobertDyck · 2016-01-27 19:24:44

My comments are for a deep space habitat. The two graphics I posted are the lower level of Skylab, and upper level of Mars Direct. These are habitation levels with a clear ceiling and floor. Axis of the cylinder is vertical not sideways; that permits artificial gravity. Attach a tether to the roof, connected to the spent upper stage. This habitat can be used for Mars, or an asteroid. Actually, Mars Direct landed the habitat on the surface. It used a simple capsule to return crew to Earth. And mass budget for that capsule would not permit Orion, but would permit Dragon. My mission plan had separate habitats for in-space vs surface. The interplanetary habitat could be used for various destinations, including an asteroid. But I didn't come up with a separate floor plan, instead I keep posting the original design for the Mars Direct habitat, the design that only had a single story. The only difference is to place life support equipment and batteries in place of the laboratory, and add a navigation console in the common room (labelled Galley, Lounge, and Library). You could locate life support equipment against the outer wall, ensuring entire racks can be moved out to access the outer hull to address GW's concerns. But remaining space depicted for the laboratory could be used for EVA prep. In this version of Mars Direct, the central radiation shelter is the air lock. You could condense the bedrooms a bit: retain separate rooms but make the beds bunks like MDRS. Arranged as wedges like Mars Direct, that would leave a bit more floor area for other things. The width of the beds for SQ1 and SQ4. If you move the Exercise and Health room into that space, and the laboratory (now life support and EVA prep), then it would increase the width of the common room that much. Plenty of room for a navigation console.

GW Johnson · 2016-01-29 11:20:51

I have long suggested that somebody will beat NASA (and all the other government agencies around the world) to Mars with people. I may be proven correct.

An excerpt from a story found on MSNBC internet news 1-29-16, in the “tech news” section, absent from “science” and its subsection “space”. I could find no attribution to any of the news wire services. The article in its entirety says Musk will reveal soon yet another spacecraft of some kind. There was no hint what that might be.

excerpt:

BY KEITH WAGSTAFF

Nobody can accuse Elon Musk of not shooting for the stars.

The SpaceX and Tesla founder said this week that he personally wants to visit space within the next five years and thinks that his company will send somebody to Mars by 2025.

Speaking at the StartmeupHK Festival in Hong Kong this week, Musk said that he had already taken parabolic flights to prepare for space, but had not done much else.

end excerpt

If Musk and his people are as smart as they seem to be, the new craft just might be a deep space habitat to keep the crew healthy during the "to" and "from" transits. At least we can hope.

GW

SpaceNut · 2016-01-29 20:21:47

Musk's MTV the colonial ... has been leaking out about big announcements for this year but its a means of hyping up stocks and emotions for funding....
As for the private industry landing on Mars first, it sure would be a slap in the face even to have a flyby to Nasa and government funding conditions of the pork barrel companies....
The recent plans that we have put together shows that with existing pieces we are almost capable of doing the flyby and with a few more pieces and funds we could land to stay on mars....
The collective knowledge of the group of frequent posters show that its not unobtainium.....Lets keep building this knowledge base and bring forth more ideas on how to do Mars.....

Tom Kalbfus · 2016-01-30 10:06:09

SpaceNut wrote:

The JPL mission to Phobo's requires the crew to be launched in what appears to be Orion which serves as the earth landing vehicle which can not be parked in LEO awaiting any crews return so it is brought with them. The orion capsule is docked with the Deep space habitat which has all the life support and food within it. Just not sure why the transfer stage for Orion is facing in the direction that it is as there is no way to park it in that manner. Without the rest of the mission launch profile its hard to tell why we are this way in the image.
In either case lets focus on what makes the right deep space habitat, with the right costs associated with it going on any mission beyond LEO....

I think you will need a seep space habitat in those places, where you expect to spend a long time there, separate from the ship which brought you. I guess the idea is you preposition supplies for your survival there for the duration of your stay. I believe it takes a number of months to go from Earth to Mars and from Mars to Earth. So maybe you want to just supply the interplanetary ship with the supplies you need for going to and fro. I think for a larger habitat with the ship delivers just a fraction of what and who is there, maybe it makes sense. There are certain low thrust options which wouldn't be ideal for transporting people to and from Mars, but which might make sense for equipment and supplies. Say for instance an ion drive or a solar sail.

RobertDyck · 2016-01-30 11:47:19

Current proposals by "Old Space" contractors remind me of the 1965 studies for humans to Mars. In 1965 they wanted to "leverage" as much Apollo technology as possible. Result was designs that just wouldn't work. Now they want to "leverage" as much ISS technology as possible. Result are huge habitats that are far too large, too clumsy, too little usable living space, and still have zero gravity. One problem is use of "solar electric propulsion" (SEP). If you do that, what you get is a Russian design. Here is the proposal from Energia for a human mission to Mars. That is an "old space" corporation in Russia, and this mission plan is from 1988.

In the 1990s, Russia sold every technology they could. NASA hired engineers from Russia to teach NASA engineers everything they know about electric propulsion. NASA had developed ion engines with 3,000 second Isp, demonstrated on Deep Space One. The guys who built that were the guys who were ordered by NASA management to learn from Russian engineers. One engineer I spoke with was glad someone appreciated his work. Until that, NASA thought the best you could get from a hall thruster was 1,700 second Isp. But they learned Russia had developed hall thrusters to perform as well as the best ion thrusters NASA made. And Russia didn't leave them on a shelf, like NASA did. Russia used them for station-keeping thrusters of military satellites, flying them since the late 1960s. NASA didn't have working ion thrusters in the late 1960s. So much for the claim that Russia technology is crap.

Today many people gush about hall thrusters, and have seriously proposed hall thrusters for deep space applications like this. What you end up with is exactly the Russian design from 1988. Together with it's giant solar arrays.

I also want to point out, the Glenn Research Centre took all the knowledge they developed for ion thrusters, plus everything they learned from Russians, plus all the work from Princeton University on MagnetoPlasmaDynamic thrusters, and integrated them together. That's how they developed an MPD thrusters with 8,400 second Isp. Would MPD work better than Hall? No, because the solar array would still be just as gigantic.

The Russian design uses thin film photovoltaic cells, with thin film stainless steel backing. Two edges of each solar array has a truss structure for support. From tip to tip it's 700 metres wide. That's 2,296.5879265 feet, or 0.43495983457 mile. Round that off for significant figures, you get half a mile. I saw a news article on CNN when this first came out, they claimed this was a solar sail. When I got the article directly from Energia and translated it into English, it turned out to be solar electric propulsion (SEP), not solar sail. But look at the damn thing! This is what it takes to use solar power to generate enough power for electric propulsion. Even MPD requires that much power, and VASIMR requires significantly more electric power for the same thrust.

Terraformer · 2016-01-30 15:51:03

Which is why you really need power beaming if you want to use solar power for electric thrusters. Leave the array back in orbit, and use microwaves or lasers to send the energy to the craft. Probably microwaves. People get funny if you build a satellite capable of tightly focusing a high powered laser beam.

kbd512 · 2016-01-31 00:20:34

RobertDyck wrote:

Current proposals by "Old Space" contractors remind me of the 1965 studies for humans to Mars. In 1965 they wanted to "leverage" as much Apollo technology as possible. Result was designs that just wouldn't work. Now they want to "leverage" as much ISS technology as possible. Result are huge habitats that are far too large, too clumsy, too little usable living space, and still have zero gravity. One problem is use of "solar electric propulsion" (SEP). If you do that, what you get is a Russian design. Here is the proposal from Energia for a human mission to Mars. That is an "old space" corporation in Russia, and this mission plan is from 1988.

I just don't understand the requirement to connect absolutely every piece of the mission architecture together and ship all of it to Mars at the same time.

This may not be the ideal way to do a Mars mission, but it takes available technology and funding realities into account:

1. Land the surface habitat and the MAV on Mars.

[1] Falcon Heavy 1 - MAV and SEP tug

[1] Falcon Heavy 2 - MAV and SEP tug (backup sent to secondary landing site)

[1] Falcon Heavy 3 - Surface Habitat

[1] Falcon Heavy 4 - Surface Habitat (backup sent to secondary landing site)

2. Send the MDV and TEI chemical kick stage to HMO using SEP.

[1] Falcon Heavy 5 - TEI and SEP tug

[1] Falcon Heavy 6 - TEI and SEP tug (backup)

3. Send the MTV and TMI chemical kick stage to ISS.

[1] Falcon Heavy 7 - MTV

[1] SLS 1 - TMI chemical kick stage (LOX/LH2)

[1] Falcon 1 - Dragon

4. Send the crew to ISS using Dragon. The crew inspects their MTV and TMI stage at ISS. If the MTV and TMI stage check out, depart for Mars. If not, the Mars crew returns to Earth and we send another MTV and/or TMI stage to ISS.

A potential variation on this is to use the ISS crew to inspect the MTV and TMI stage and then use a SEP tug to transfer the MTV / TMI stack to L1. The crew would be sent to L1 using Falcon Heavy instead of ISS using Falcon.

[2] Falcon Heavy 7 - MTV

[2] Falcon Heavy 8 - TMI chemical kick stage (LOX/LCH4)

[2] Falcon Heavy 9 - Dragon 1

5. The MTV uses SEP integrated into the MTV to spiral in to LMO. The MDV's SEP tug will spiral into LMO and dock with the MTV. The crew will then transfer to the MDV and descend to Mars to perform their surface exploration. A month or two before the crew leaves, the SEP tug that transferred the TEI stage to HMO will spiral in to LMO and dock with the MTV.

6. Upon completion of surface exploration, the MAV ascends to LMO and the crew transfer to the MTV.

7. The MTV departs for Earth using the TEI kick stage.

8. The MTV captures at L1 or LEO using its integrated SEP.

9. If the MTV captures in LEO, then the MTV docks at ISS and the crew returns to Earth using Dragon.

[1] Falcon 2 - Dragon 2

If the MTV captures at L1, then another Falcon Heavy sends another Dragon to L1 to retrieve the crew to return them to Earth. A SEP tug returns the MTV to ISS for inspection and refurbishment.

[2] Falcon Heavy 10 - Dragon 2

10. Refit the MTV for another mission cycle at ISS.

By delivering smaller and lighter individual payloads on affordable rockets like Falcon Heavy, launch costs are kept well within NASA's budget. This permits a regular launch cadence and funding for spares. There is also a degree of modularity achievable using more affordable rockets. If you want more mission hardware, you add launches.

All cargo to Mars (habitats, rovers, MDV, MAV, MTV) can be delivered to LEO using Falcon Heavy. However, if you want to depart from ISS you need a massive chemical kick stage that only SLS can deliver. SLS was intended to deliver payloads that no other rocket could and MTV TMI from LEO certainly qualifies.

If you lose any component of the 4 SLS mission architecture, then the mission is scrubbed because there's no time or funding to build a replacement SLS and payload.

Given the massive cost differential between heavy lift rockets like Falcon Heavy and super heavy lift rockets like SLS, I think the minimum launch architecture is wrong. For exploration, you don't need a minimum number of launches, you need maximum tonnage delivered. I think commodity rockets like Falcon Heavy and SEP tugs best service that requirement.

If you insist on using mega rockets and mega vehicles, this is the result:

RobertDyck wrote:

http://www.energia.ru/english/energia/mars/im/concept-01.gif
http://www.energia.ru/english/energia/mars/im/concept-05.jpg

NASA needs to tightly focus all available funding on enabling technologies:

1. CL-ECLSS - The feasibility of long duration space flight is directly tied to recycling of water and oxygen

2. ISRU - The ability to produce oxygen, water, and rocket fuel on Mars makes every aspect of manned exploration easier and cheaper to accomplish

3. MCP suits - Legacy technology space suits are impractical for use on a planet like Mars and a liability in microgravity environments contaminated with debris

4. Active radiation shielding - There's simply no suitable substitute for deflection of high energy particles

5. Satellite aided navigation - Landing within 100M or so of the intended target is an absolute requirement if the habitat and MAV will be landed separately.

RobertDyck · 2016-01-31 02:47:56

Interesting post. My plan would land the MAV separately. You listed a single Falcon Heavy launching the MAV to Mars with an SEP tug. I question whether that would fit on a single Falcon Heavy. This does require direct launch from Earth surface to Mars surface, including Mars atmospheric entry, and Mars surface soft landing. And it has to lift astronauts and samples to Mars orbit, and rendezvous with the Interplanetary Transit Vehicle aka Mars Transit Vehicle. I argued to not pressurize the MAV capsule, which eliminates life support and replaces the capsule pressure hull with a fairing. Astronauts would ride in their spacesuits. That should reduce mass significantly. But my plan would have the MAV carry enough propellant to act as the TEI stage, your plan wouldn't.

My plan assembled the ITV aka MTV, with the TMI stage, and lander / surface habitat. This avoids the problem of orbit rendezvous before landing. Robert Zubrin doesn't like my plan because it requires both surface rendezvous (lander with MAV) and orbit rendezvous (MAV with ITV). Your plan has that, and adds two additional orbit rendezvous for lander and TEI stage. One reason my plan does this is for free return. If a failure like Apollo 13 happens, then you can use the gravity of Mars to swing into a trajectory to return to Earth. Inspiration Mars would use a free return trajectory. It takes a lot more than 3 days to return, but not a lot of propellant. By integrating the TEI stage with crew before they leave ISS, that stage is available in case of emergency. And integrating the surface habitat and intended return habitat, they have food and life support for the entire mission duration. Free return is supposed to take less than the normal mission duration, but carrying food and life support for the entire mission means that if something goes wrong, they have backups.

My plan would also land a separate laboratory before the crew depart ISS. And a pressurized rover with recycling life support. If everything works, the surface habitat will be connected to the lab. Which means landing them sufficiently close together to connect them. If the lab is all inflatable, then equipment could be moved separately. Basically, the lab would be a big tent. Carry equipment separately, and place inside. So the surface habitat doesn't have to land less than a metre away, it can land a significant distance. A safe distance, considering landing rockets will kick up rocks. But if something goes wrong, the lab can be used as a backup lab. And life support in the rover can be connected to the lab. Those arguing for a nuclear rover could chime in here.

Enabling technologies:
1. Life Support
a) Fix the urine processing assembly (the one on ISS got clogged with calcium deposits, from dissolved astronaut bones)
b) Replace the toilet with one that recovers moisture from feces. I have suggested a reality TV show find this as a contest between NASA and the Russian space agency. Electro-resistive oven (aka electric oven) to bake out moisture, or vacuum desiccation?
c) Shower and sink, connected to the water processing assembly to recycle wash water.
d) Laundry machine. You can't wear the same clothing until it's stinky, then throw it out, like they do on ISS. A Mars mission will not get new clothing every couple months. And operating in the dirty environment of Mars surface will put greater demands on clothing. So laundry, and connected to the water processing assembly to recycle that water too.
e) Direct CO2 electrolysis. This doesn't replace the current system, it augments it. The Sabatier reactor is limited by hydrogen from the water electrolysis unit. That means it can only use half of the CO2 recovered from cabin air. The other half is dumped in space. A direct CO2 electrolysis unit will recover oxygen from CO2 that is currently just dumped.

1.5. Demonstrate life support is ready for Mars by operating ISS without any cargo resupply for the entire duration of a Mars mission. - Crew could be swapped, because a Mars mission will not spend all its time in zero-G. It will be on the surface of Mars much of the time. But no cargo. A Mars mission won't get cargo, it will only have what it brings along, or has been pre-positioned.

2. ISRU - Demonstrate this with a robotic Mars sample return mission. But not Mars 2020, that's just insane. Instead a single mission the size of Pathfinder or Phoenix that lands a tiny rover the size of Sojourner, and returns the sample to Earth with a capsule like Stardust or Genesis. This requires ISPP to produce propellant for the return rocket.

3. MCP suit - This year NASA hired Professor Dava Newman from MIT. She's the last researcher actively working on MCP who hasn't retired or died of old age. Great, they have her, now do it. And you don't need anything fancy like contractile polymers or shape memory alloys. Opponents to MCP complain about donning and doffing. Do what Dr. Paul Webb did: just ignore it. Yes, the suit will be uncomfortable when only part way on. The solution is finish putting it on!

4. Active radiation shielding - nice to have, but I argue not required.

5. Satellite aided navigation - not required. Instead put a beacon on modules landed. Later modules can home in on that. Current navigation technology can get close enough without any aid to pick up the signal from a pre-landed module. And crude satellite aided navigation currently exists: MGS, Odyssey, Mars Express, and MRO all have a Mars relay antenna. That includes the ability to range find. You can use intersecting spheres to find your position in 3 dimensions from that. Not as accurate as Earth's GPS, but it is something.

6. Manoeuvring while rotating in tethered flight - this is key to light-weight artificial gravity. If you want to do it Robert Zubrin's way, then you have to do course adjustments while rotating. This can be demonstrated in LEO by connecting a Dragon cargo ship that's destined to be de-orbited anyway, to a Dragon crew ship. Or Progress to Soyuz, but it would be easier to get Congress and NASA to do this with American technology. You could do it with CST-100 connected to Cygnus.

7. Methane thrusters - Orion was supposed to use LCH4/LOX for its service module. When Lockheed-Martin and Boeing (their subcontractor for Orion) ran short of money, they replaced it with MMH/N2O4. Then they completely ran out of money, so made a swap deal with Europe to provide a couple service modules from ATV. That also uses MMH/N2O4, but greater dry mass and less propellant, so even less delta V. We need to demonstrate LCH4/LOX in space; it's key for ISPP.

8. Aerocapture - demonstrate this by placing an unmanned orbiter into Mars orbit. MGS and Odyssey and MRO used rocket fuel to capture into Mars orbit, then aerobraked down to mapping orbit. We need to demonstrate aerocapture before committing human lives to it.

Last edited by RobertDyck (2016-01-31 15:15:26)

kbd512 · 2016-01-31 06:42:36

RobertDyck wrote:

Interesting post. My plan would land the MAV separately. You listed a single Falcon Heavy launching the MAV to Mars with an SEP tug. I question whether that would fit on a single Falcon Heavy. This does require direct launch from Earth surface to Mars surface, including Mars atmospheric entry, and Mars surface soft landing. And it has to lift astronauts and samples to Mars orbit, and rendezvous with the Interplanetary Transit Vehicle aka Mars Transit Vehicle. I argued to not pressurize the MAV capsule, which eliminates life support and replaces the capsule pressure hull with a fairing. Astronauts would ride in their spacesuits. That should reduce mass significantly. But my plan would have the MAV carry enough propellant to act as the TEI stage, your plan wouldn't.

A 15t pressurized MAV with seating for four crew members, ADEPT aeroshell, and modified Block 1A SEP tug will all fit within Falcon Heavy's payload shroud. The MAV will be approximately 3M in diameter and 4M in length with the landing legs stowed. I'm not in favor of pressurized MAV's, nominal use being 60 minutes or less, but some people are insistent on pressurized vehicles.

RobertDyck wrote:

My plan assembled the ITV aka MTV, with the TMI stage, and lander / surface habitat. This avoids the problem of orbit rendezvous before landing. Robert Zubrin doesn't like my plan because it requires both surface rendezvous (lander with MAV) and orbit rendezvous (MAV with ITV). Your plan has that, and adds two additional orbit rendezvous for lander and TEI stage. One reason my plan does this is for free return. If a failure like Apollo 13 happens, then you can use the gravity of Mars to swing into a trajectory to return to Earth. Inspiration Mars would use a free return trajectory. It takes a lot more than 3 days to return, but not a lot of propellant. By integrating the TEI stage with crew before they leave ISS, that stage is available in case of emergency. And integrating the surface habitat and intended return habitat, they have food and life support for the entire mission duration. Free return is supposed to take less than the normal mission duration, but carrying food and life support for the entire mission means that if something goes wrong, they have backups.

Orbital rendezvous is not the major problem that Dr. Zubrin makes it out to be. Every single crew and cargo transfer to ISS is another successful orbital rendezvous. We've done it many times and we're very good at it. ISS would not have been completed if orbital rendezvous posed any significant problems.

Name a MTV failure that a free return abort somehow makes survivable. I can't think of any. We already have a backup MAV and backup surface habitat. Once you get to Mars, you need to land on Mars. Speaking of which, I forgot to include the MDV and that's one more Falcon Heavy flight. With eleven Falcon Heavy flights, we've officially matched or exceeded the cost for one SLS and have officially orbited five times as much tonnage.

If an Apollo 13 type failure happens aboard the MTV, the result is loss of crew and loss of mission. With my MTV, the TMI and TEI stages will be the only likely sources for Apollo 13 type failures. If TMI or TEI fails, the result is loss of crew and loss of mission for any realistic architecture.

Some things have to work properly or you don't come home.

Do we want to spend billions of dollars on super heavy lift rocket development and leave ourselves with no funding for payloads or do we want to spend billions of dollars on payloads and then figure out how to break those payloads into pieces that comparatively low cost commodity rockets can deliver? Personally, I'd rather fund payloads than rockets. If there's no payload development, then the rocket development was pointless.

RobertDyck wrote:

My plan would also land a separate laboratory before the crew depart ISS. And a pressurized rover with recycling life support. If everything works, the surface habitat will be connected to the lab. Which means landing them sufficiently close together to connect them. If the lab is all inflatable, then equipment could be moved separately. Basically, the lab would be a big tent. Carry equipment separately, and place inside. So the surface habitat doesn't have to land less than a metre away, it can land a significant distance. A safe distance, considering landing rockets will kick up rocks. But if something goes wrong, the lab can be used as a backup lab. And life support in the rover can be connected to the lab. Those arguing for a nuclear rover could chime in here.

If you want to send more hardware to Mars using my mission architecture, you add Falcon Heavy launches.

I think nuclear powered rovers are a fantastic idea, provided that the shielded reactor mass stays sane. Unlimited range surface vehicles would be very nice to have, but vehicles are not required.

I simply want us to go to Mars. I think the greatest possibility for that to occur in a reasonable time frame would come about as a result of using our strengths (orbital rendezvous and docking, SEP), not attempting to address every aspect of the mission at the same time with the same hardware stack (combination MDV/MAV, MDV/MTV/TMI/TEI), and spending development funding on technologies critical to success (CL-ECLSS, ISRU, MCP).

RobertDyck · 2016-01-31 13:18:43

kbd512 wrote:

Orbital rendezvous is not the major problem that Dr. Zubrin makes it out to be.

True. That was an issue in the 1960s. Dr. Zubrin and his partner David Baker developed Mars Direct in the last quarter of 1989, and the first half of 1990. They presented it to NASA at a conference in June 1990. That was before ISS, and before Shuttle rendezvoused with Mir. However, even then Shuttle had rendezvoused with Hubble a couple times. At that time we didn't have automated rendezvous, the Shuttle required a pilot. Now we do. So 21st century technology makes that easier. That's one point I've made several times.

kbd512 wrote:

Name a MTV failure that a free return abort somehow makes survivable. ... If an Apollo 13 type failure happens aboard the MTV, the result is loss of crew and loss of mission.

Apollo 13 had an explosion in the service module. They never did determine the exact cause. The two possibilities were either stirring the hypergolic aerozine 50 fuel tank caused it to explode, a hypergolic explosion, or a meteoroid hit it causing that same fuel tank to explode. The Apollo service module used MMH for RCS thruster quads, but aerozine 50 for the primary engine. That's a 50:50 mixture UDMH and simple hydrozine. NASA was worried that zero-G would cause separation of the fuel into layers, so they included a "stir" mechanism. Russia avoided that by using pure UDMH. Aerozine 50 is slightly more dense, and slightly higher Isp. Wikipedia says the AJ10-137 engine used by Apollo SM had Isp=314s, while Astronautix says 312s. Fuel density 0.903 g/cc (g/ml). Astronautix says Soyuz TMA main engine has Isp=304s. Soyuz TMA-M used currently and the Soyuz MS to be introduced this year both use the same engine. UDMH density 0.791 g/cc. So one way to avoid an Apollo 13 type accident is don't use aerozine 50. MMH has density 0.875 g/cc. Main engine of the European ATV, or Orion's ATV-based service module, Isp=312s. So MMH is a safe compromise.

However, to put it bluntly, shit happens. Every Apollo mission had something go wrong. The sole exception was Apollo 17. The very last Apollo had everything work correctly, but only the last one.

Apollo 9 was a test of the CSM and LM in high Earth orbit. Apollo 10 was a dress rehearsal: everything to the Moon, and the LM descended with crew to approach the surface, but they deliberately activated the abort. The LM abort caused the ascent stage to separate from the descent stage, and the ascent stage returned to lunar orbit. Apollo 8 was going to be an unmanned test of the Apollo CSM. They had tested the Apollo CM and its heat shield from high Earth orbit, but this would be the first time it returned all the way from the Moon. So this would test that the CSM could survive the trip all the way to the Moon and back. But Russia tested their Soyuz spacecraft with the exact same manoeuvre, the mission was called Zond-5. Yes, it was the Soyuz L1 spacecraft rather than the Soyuz LOK, but the Soviets were seen to be ahead in the space race. The next mission after Zond-5 would have been a manned flyby with one cosmonaut in a Soyuz L1 spacecraft. Zond-5 launched September 15, 1968, Apollo 8 launched December 21 of the same year. So NASA asked for volunteers for Apollo 8. Absolutely every astronaut volunteered, NASA had to pick crew. But the point is if an Apollo 13 type failure occurred with Apollo 8, crew would have died. Apollo 13 used the LM as a life boat. The LM was not ready in time for Apollo 8.

My plan would carry the surface habitat with the ITV. So if an Apollo 13 style failure happens, then crew can use the surface hab just like Apollo 13 did.

We already have bureaucrats in NASA claiming NASA won't be ready to go to Mars for at least 20 years, if not longer. Statements like "Apollo 13 type failure...result is loss of crew" simply reinforces their claim that we can't go to Mars.

kbd512 wrote:

Do we want to spend billions of dollars on super heavy lift rocket development and leave ourselves with no funding for payloads

This is a contradiction. I don't know the solution, but you don't want to even face the problem. Congress wants to keep jobs in their congressional districts, and I suspect "Old Space" contractors donate funding to their election campaigns. That means they want to keep SLS. But they're also concerned about cost. Abandoning SLS in favour of Falcon Heavy will reduce cost, but that cost basically means voter salaries. And those jobs are highly skilled jobs for NASA and their contractors. Congress has already overruled Presidential budget requests, giving NASA more money to finish SLS and Orion. Ok, they want SLS. So we have to find an excuse to use SLS. Even my mission plan could be broken into smaller launches, not assembled exactly your way, but could use Falcon Heavy instead of SLS. The question is whether Congress would approve it.

kbd512 wrote:

If you want to send more hardware to Mars using my mission architecture...

To be blunt, I presented my mission architecture at the Mars Society convention of 2002. I've tweeked it a bit, but it's essentially the same. We came to the same conclusion, I'm not taking your ideas.

kbd512 wrote:

nuclear powered rovers...

My mission plan includes life support in the pressurized rover as a backup. I don't specify whether the rover is nuclear or conventional fuel. It could generate power using LCH4/LOX, or even batteries. The idea is the lab could be used as backup habitat, and life support for the rover could provide life support to the lab. Normally the surface hab would do that, but this is a backup in case the surface hab fails.

kbd512 wrote:

I simply want us to go to Mars. I think the greatest possibility for that to occur in a reasonable time frame would come about as a result of using our strengths (orbital rendezvous and docking, SEP), not attempting to address every aspect of the mission at the same time with the same hardware stack (combination MDV/MAV, MDV/MTV/TMI/TEI), and spending development funding on technologies critical to success (CL-ECLSS, ISRU, MCP).

We both want to go, and we're coming up with the same ideas. Our differences are few. So yea. But now the question is what is Congress willing to pay for.

Last edited by RobertDyck (2016-01-31 20:48:26)

GW Johnson · 2016-01-31 15:43:01

KDB512 and RobertDyck:

You two are talking about variations on the same basic mission design. I think you both already know that. And I think you both have gone way further than Zubrin ever did with his 1990-vintage Mars Direct scheme. Zubrin is smart, but he is not god. I would caution about thrusting maneuvers on a spinning tethered design. That's a development item. A rigid spinning baton design is far less of a development item.

As for NASA, its troubles are both technical and management, but the management is by far the dominant problem. It traces directly to the "corporate welfare state" problem that I despise so much, and have railed against in these forums. The only thing holding Musk back is not totally embarrassing his biggest customer (the US government/its various agencies).

That being the case, I'd be less interested in what Congress is willing to pay for, and a whole lot more in what Musk (and some others) are willing to pay for when the government will not. That's what sets when men finally go to Mars. Not NASA or any other government agency.

GW

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