Alternate BFR (Big Falcon Rocket)

Void · 2018-01-07 14:31:00

BFR Alternates:

I am going to play with the SpaceX BFR. Do strange things with it.
You won't see formula's, calculations of numbers in this. This is a very coarse speculative sugestion of proposals for alternative BFR's based on the currently revealed BFR from SpaceX.
My licence to do so is that you did not stop me which indicates that you either did not want to or could not.
The subtopics are: (Many)
Anyway to review. The BFR revealed involves two robotic landings on Mars, and then two personed landings on Mars.
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Alright, my alternates:
First of all, there is the issue of international insistance and commitment to the protection of presumed outerspace life. To be sure I have a deep suspicion that this was implemented as a ploy to hobble the Western Space Efforts. Politicians in the west went for it because they were concerned for immendiate survival issues. I can understand that. But, can we find a way to elude our capture by our enemies and to prevail? In other words can we work within this hobbling and pick the locks and get what we want? We should if we could!
Aerocapture:
This to my knowledge has not been done. The closest to it is modifying orbits of orbital probes around planets, by dipping into the atmosphere's.
So the current proposal to use BFR for Moon access, is to top off it's fuel in an excentric orbit. Having done that it should be able to go to the Moon, land on the Moon, launch from the Moon and then land on Earth. (If I understand properly what was described).
But, what if instead, you refueled from a less excentric orbit, then did the Moon, and then did an Aerocapture to orbit of the Earth? This is a skill that is needed anyway. The point is then with refueling, the BFR could then exit orbit and land. It is an alternative which is less desired for the specific desire to access the Moon, but it is an alternative which could open up several other locations in the solar system, including orbital Mars, the outer solar system, and Venus. So, being too specific too soon, is in my opinion a behavior to avoid unless you are under extreme duress to get a specific task done.
A Mars centic view will say that if you do in fact establish a Colony/Settlement on Mars, it should eventually be able to refuel BFR's in the Mars orbit, for missions to an asteroid in the asteroid belt, or a NMO (Near Mars Orbit) asteroid. (Sorry for the new acronym)
There is another reason for BFR aerocapture:
Mars access can be divided into three catagries in my opinion:

1) Exploration. (This also is a concern for E.T. life exploration).
2) Robotic Cargo Delivery.
3) Human Access.
*In my opinion, the use of expendable components for #1 is likely to be OK in many situations. We would prefer hardware re-usability for #2 and #3 where possible.
So, I have mentioned altering the capabilities of BFR with aerocapture capabilities.
What about auxiliary fuel/Oxydizer propulsion outside of the craft itself?
Space Shuttle:
This was an abomination that we should love anyway.
https://en.wikipedia.org/wiki/Space_Shuttle
They made it do something within the constraints of the insanity of government, and the cruelty of physical facts. It did cost a bundle. We don't want any part of that, without sufficient reward.
I see two components of interest.
1) Solid Rocket boosters.
2) External Fuel Tank.
Both were forced stupid adaptations because of the constraints which were imposed at the time. It was do that or do nothing.
The insanity of it was to try to get off the surface of the Earth with them and to punch through the Earth's atmosphere with them. But they did the insane and made it work, with the price of money and lifes. This is how we live. Because of the imposible nature of humans, the price of money and blood must be paid from time to time.
Of options #1 and #2, I favor #2, the "External Expendable Fuel Tank", to expand the capabilities of BFR.
#1 is a waste of rocket engines, and the thing is a bomb that vibrates and would likely cause all kinds of trouble for that reason.
I don't think that an external fuel tank in orbit, in a vacuum should be considered an abomination for the purpose of exploration. Ice chunks should not hit it, as there should be none in the vacuum of space, except if you throw frozen poop and pee at it. If you are that stupid, you should be invited to leave the gene pool in my opinion.
It should provide an extention of a rather smooth thrust process.
Granted you would have to modify BFR for porting the fuel and Oxydizer into the engines of BFR. Everything has a price. The question is, "Is the price worth the results?".
Another alternative for Exploration and Cargo delivery is Balistic Capture instead of Hohmann transfer.
I now understand why Hohmann transfer is the desired method to deliver humans to Mars. Radiation and Zero Gee illnesses need to be avoided as much as possible, so for human deliveries so far the Hohmann transfer seems to be the way to go. Time in peril is of a great concern for human transfers between planets.
However balistic capture offers more flexability and in some cases fuel savings. So for Exploration and Cargo Deliveries I choose balistic capture.
https://en.wikipedia.org/wiki/Ballistic_capture
OK, well this whole ballistic capture thing sort of makes sense, but sometimes, I read that the capture is done by coming in behind the planet, or in the above case in front of the planet.
Capture can lead to a orbit of the planet or a insertion to atmosphere for aeroburn.
The main advantage apparently is to not be locked into a 26 month permission period for the Hohmann transfer. It is suggested that you can do it anytime. So, if you have BFR's available you could do Balistic transfers, to do Exploration and Cargo delivery. And for some situations, there could be fuel savings.
Balistic transfers just might allow for a small crew to travel. With a small crew, you would devote more mass to their health. Radiation protection, and zero gee compensations. Only if the payoff was worth the risk to their health however.
One device for this I would reccommend would be Pariffin wax armored suits. For additional radiation protection. Looking silly, somewhat like Starwars SciFi armor.
While BFR appears to be highly automated, it may be worth also including a few humans on early missions in some cases, provided a resonable risk/reward ratio exists for those particular missions.
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So now BFR can be expanded with:
-Aeroburns to orbit.
-External fuel tanks.
-Balistic capture (In some cases for exploration and cargo transfers).
WHY?
What is the objective? Pick the locks of previous human borowing from our future. Not be immoral. Make it happen.
Morality here is the suggestion that we must protect the possible existance of interplanetary life established by international protocols.
My own take is that there are indeed selfish and unselfish reasons to do so. However, I believe that the encombering process of legal impediment is mostly established by those who hope to hold humans as captive property. That would be old world thinking for the most part in my opinion. Slavery and such. Been there had that.
I would like to get around all of that bullshit if it is possible.
So, how do we pick the locks take the prise, and still be moral?
Morality which has been estabilisted against us by the international comunity, is that they may impost diffaulty upon us. In the process of us accessing non-Earth objects. They may extract a price for us doing so in the claim that they wish to protect presumed E.T. life.
While the morality of it is significant. The reality of the imposition is naked agressive rape. The intention is to keep us as their servants. Don't be foolish and suppose that they can be trusted at their word.
Still, lets pick the locks, get the prise, be moral, and make them regret messing with us.
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This is what I propose. I won't cry if it does not happen.
I suggest this.
Get BFR into Martian Orbit by aeroburn. Sponsor that posibility by any method possible including external tanks, and Lunar Gravity assist.
During the Aeroburn, try to capture Martian atmosphere. Maybe you will be lucky and get some dust as well. Further I might hope that somehow it might scout low lattitude ice deposites with radar while being so potentially close to future landing areas. Radar I presume.
So, then BFR is in Martian orbit, what shall else shall it do, and how might it get back to Earth?
What else is that it should land on Phobos and/or Demos, take a core sample and ideally bring it back to Earth orbit by aeroburn. Bigger legs would be great for landing on small moons/asteroids.
So, if BFR lands on Phobos/Demos, it might drill a sample, and also radar scan the interior of such an object, and perhaps even do sonar with its legs contacting the surface.
How to get back to Earth Orbit? Well, I suggested Aeroburns, and External tanks, and Ballistic capture methods.
Why?
Because samples of the atmospere of Mars, and drill samples of Phobos/Demos may define the likelyhood of life on Mar. It is said to be likely that fragments of Mars will be found on Phobos and Demos. Fragments that would have come there from impactors hitting Mars.

I do not rule out humans for such missions, but only if the risk/rewards are favorable.
End.

Have a nice day. My existence should not be such a problem. This is just conversation.

Last edited by Void (2018-01-07 15:09:24)

SpaceNut · 2018-01-07 15:44:56

We have been discussing the size of the BFR and the need for something in between it and the Falcon Heavy as a means to continue to boost larger payloads. As you meantion a variety of cargo on top of the first stage is the key but as I have been reading the stage can only boost a much small payload if we use it as an expendable. So it also means several second stages as well. These second stages also play into destination architecture, refuelling on orbit and anything else that we can think of..

The current methane engine still not in production is still being tweeked and has led to an increase with payloads. This cuts down on the engine count for a given payload to orbit.

louis · 2018-01-07 16:34:41

I strongly oppose your suggestions Void.

I think the BFR/Mars Mission architecture is near-perfect, not least because Space X are spreading BFR development costs across at least five areas: satellite launches, orbital tourism, lunar tourism, E2E transport and the Mars Mission itself (which I have argued elsewhere will in any case be super-profitable). At some point NASA will have to pull the plug on the SLS and use BFR which is going to cost probably a fifth of SLS.

You are right to point out there is an anti-exploration lobby at work and that is something I hope Space X are counter-lobbying. I believe that earth microbes have been taken to Mars with every mission. But they would be unlikely to thrive on Mars.

I imagine the Space X BFR cargo landings will include robot diggers to establish the presence of permafrost ice in the first base zone. That will be the green light for the human mission to take off.

Void · 2018-01-07 16:44:30

Noted Spacenut.

Louis. I agree it looks pretty good. Still, this is only conversation. Could we say, a sanity check? Make sure we didn't leave something worthwhile behind?

So, I will explain more of what I am after.

First of all the notion of doing a aerocapture into Martian orbit would be a rehearsal for a landing. Not entirely a worthless concept. If it is possible to get an air sample from the BFR, during that event then great. If you could somehow radar sound a potential landing site for ice from a rather low altitude then fine.

If that can't work out, the an alternative would be to push a probe out of the cargo bay at some point, probably before the aerocapture burn. The probe would likely have to have it's own heat shield which may not have to be separated. It would have radar which would work for the short duration of the downside trip. No parachute. No retrothrusters. Likely small thrusters to keep it oriented. So Radar probing all the way down with camera views, and then a crash impact to penetrate the ground. Of course this would have to be sterilized reasonably well to follow the rules.

However the radar and camera views and the impact results would give some important information.

As for drilling Phobos or Demos, it is speculated that Martian fragments will be found in that sample. And further, by sounding the interior of a Martian moon important scientific data would be accumulated, and also information possibly important to asteroid mining. Even possibly information having to do with the usefulness of insitu materials from that moon.

And I believe that the best part would be that the international community might finance that mission in part, if they were able to claim some of the glory, and some of the sample.

And the data may shed light on the likelihood of life on Mars. As well as the data from the aeroburn/Impactor.

So, I am offering an opportunity to usurp the power of the opposition by playing by their rules, and to perhaps even collect financial support by that method.

And I will make it plain that I am not into the "Mars or bust hail Mary move". I think we can get the whole solar system if we play it right.

But Mars appears to be the golden piece. We want it real fast if we can get it.

The above is an additional incentive for NASA to throw in with BFR, because it would be playing by the rules, be able to get international participation, and return needed information, and samples from Phobos and or Demos, and the atmosphere of Mars.

Last edited by Void (2018-01-07 17:04:54)

Void · 2018-01-07 17:06:43

My next game would be to land on top of Olympus Mons. Yes I understand you don't like that, and it is likely not a good place to get insitu propellants. However, I have already explained some methods to compensate for that in previous posts. Yes it may very possibly be a no go plan. But this is conversation. I want it to run it's course. Not to be pointlessly be cut off short on some small detail.

While the target is a hard one. It is likely the next move that will be internationally approved if samples from the atmosphere of Mars and from the sample from a moon of Mars tell something about life on Mars, suggest that there is no life on Mars.

Landing on the highest volcano in the solar system is not a small thing

I think it is the least likely place for Martian life to exist, except if there might be active vents. (I don't think that likely). So, yes, an international team, financial sponsors international. Perhaps a combined square dance, and flag propping. And the place should be relatively similar to the Moon which it appears will be visited before a Martian trip.

Really, if there is life on Mars, the wind blown dust should have evidence of some kind. At the same time the situation on the top of Olympus Mons should be so harsh that any Earth life transferred has little chance to make it.

And although I am not good at rocket math, I have to speculate that launching from Olympus Mons would be just a bit easier than from elsewhere, if you have the means to launch to orbit.

And this leads to another idea. If NASA or someone else(s) makes a small lander, then why not carry it in BFR's cargo bay, and then aerocapture BFR to Martian orbit, and then do a small personal visit to some point on the surface of Mars? (Olympus Mons for instance).

Get some good looks are surface reality before committing BFR to the surface of Mars.

Last edited by Void (2018-01-07 17:28:33)

SpaceNut · 2018-01-07 17:07:29

Nasa's current orion deep space gateway is to make use of a Phobos or Demos mission before going to the mars surface sort of a trial run.

Void · 2018-01-07 17:17:56

It would be nice to roll the SpaceX money, NASA money, and international money into one bundle.

Easier to do it if we follow the yellow brick road. (Then pick the locks, take the prise, and share).

You didn't think about bringing a small lander along did you? I don't like the name Red Dragon though. It has evil references in the book of Revelations. The Eagle has positive connotations.

Lets have an Eagle please.

Last edited by Void (2018-01-07 17:37:45)

louis · 2018-01-07 18:46:34

I can't think of anything worse, Void! For every dollar Space X put in they would find it was worth 30 cents within six months.

Space X are doing brilliantly, way ahead of NASA, ESA, the Russians and the Chinese. A lot of comment is predicated on the idea that Space X are going to bankrupt themselves with a Mars mission. I don't see it that way. As soon as they demonstrate the BFR for real, the money for the Mars mission will start rolling in - billions per annum from a variety of sources (Coca Cola, Nike, Adidas, Ford, Toyota, various space agencies, universities, TV networks, Netflix). What TV station, soda drinks company, trainer shoe maker, auto maker etc wants to be the one that isn't involved with the Mars mission?

We don't need to land on Olympus Mons...that's poor PR anyway. Better to land a 1000 miles away and then have an expedition to it...that's much better TV.

Void wrote:

It would be nice to roll the SpaceX money, NASA money, and international money into one bundle.
Easier to do it if we follow the yellow brick road. (Then pick the locks, take the prise, and share).
You didn't think about bringing a small lander along did you? I don't like the name Red Dragon though. It has evil references in the book of Revelations. The Eagle has positive connotations.
Lets have an Eagle please.

RobertDyck · 2018-01-07 19:22:03

Void wrote:

The Eagle has positive connotations.

Benjamin Franklin's letter to his daughter

"For my own part I wish the Bald Eagle had not been chosen the Representative of our Country. He is a Bird of bad moral Character. He does not get his Living honestly. You may have seen him perched on some dead Tree near the River, where, too lazy to fish for himself, he watches the Labour of the Fishing Hawk; and when that diligent Bird has at length taken a Fish, and is bearing it to his Nest for the Support of his Mate and young Ones, the Bald Eagle pursues him and takes it from him.
"With all this Injustice, he is never in good Case but like those among Men who live by Sharping & Robbing he is generally poor and often very lousy. Besides he is a rank Coward: The little King Bird not bigger than a Sparrow attacks him boldly and drives him out of the District. He is therefore by no means a proper Emblem for the brave and honest Cincinnati of America who have driven all the King birds from our Country...
"I am on this account not displeased that the Figure is not known as a Bald Eagle, but looks more like a Turkey. For the Truth the Turkey is in Comparison a much more respectable Bird, and withal a true original Native of America... He is besides, though a little vain & silly, a Bird of Courage, and would not hesitate to attack a Grenadier of the British Guards who should presume to invade his Farm Yard with a red Coat on."

I post this because a spacecraft called "Eagle" already landed: Apollo 11 LM. Time for a new name.

louis · 2018-01-07 19:35:49

Our Golden Eagle in the UK is a lot more merit-worthy.

I've never liked the student-style joke of the Falcon rocket but it's Musk's company so who am I to complain?

I think Pioneer is a nice name but that has already been used for previous space missions.

Let me propose Point 2 for the first Mars Mission. As in "this is human civilisation Point 2". Our latest try...must be an improvement on the previous iteration.

Musk hasn't yet announced a name for the Mission has he?

RobertDyck wrote:

Void wrote:
The Eagle has positive connotations.
Benjamin Franklin's letter to his daughter
"For my own part I wish the Bald Eagle had not been chosen the Representative of our Country. He is a Bird of bad moral Character. He does not get his Living honestly. You may have seen him perched on some dead Tree near the River, where, too lazy to fish for himself, he watches the Labour of the Fishing Hawk; and when that diligent Bird has at length taken a Fish, and is bearing it to his Nest for the Support of his Mate and young Ones, the Bald Eagle pursues him and takes it from him.
"With all this Injustice, he is never in good Case but like those among Men who live by Sharping & Robbing he is generally poor and often very lousy. Besides he is a rank Coward: The little King Bird not bigger than a Sparrow attacks him boldly and drives him out of the District. He is therefore by no means a proper Emblem for the brave and honest Cincinnati of America who have driven all the King birds from our Country...
"I am on this account not displeased that the Figure is not known as a Bald Eagle, but looks more like a Turkey. For the Truth the Turkey is in Comparison a much more respectable Bird, and withal a true original Native of America... He is besides, though a little vain & silly, a Bird of Courage, and would not hesitate to attack a Grenadier of the British Guards who should presume to invade his Farm Yard with a red Coat on."
I post this because a spacecraft called "Eagle" already landed: Apollo 11 LM. Time for a new name.

Oldfart1939 · 2018-01-07 19:44:41

Rob-

In the place of the Eagle, I now propose the Osprey--the true fish hawk.

louis · 2018-01-07 19:49:28

In these enlightened times I think we ought to have regard to how easy it is to pronounce around the world. I think "Osprey" is going to be tricky for 2/3 of humanity. Apollo probably wasn't that easy either, I'll admit. But "Point 2" will be widely recognised because nearly the whole world is familiar with IT terminology now.

Oldfart1939 wrote:

Rob-
In the place of the Eagle, I now propose the Osprey--the true fish hawk.

Oldfart1939 · 2018-01-07 19:55:32

Regarding space vehicle architecture, I now propose a fully fueled "propulsion module." This is a simple fully fueled module which can be in-orbit mated to the earth departure vehicle, the fully fueled Mars lander. It simply provides enough fuel for a propulsion module consisting of an engine array plus some fuel for Earth departure of the fully fueled Mars lander. This takes us to Mars orbit, where the descent stage separates and descend to Mars landing. We fire another fully fueled "propulsion module: into Mars orbit for the return Hohmann transfer mission of the descent/ascent stage.. Trying to prepare massive amounts of LOX and liq. CH4 seems at this point to be unlikely. Just manufacture enough of the needed propellants to get back to mars orbit. The propulsion modules should be powered by UDMH/NTO for long-term stability on storage orbits.

Twenty five years ago when Zubrin first proposed Mars direct, orbital assembly was just science fiction. Now it's reality, so let's just get our shit together and GO TO MARS!

louis · 2018-01-07 20:16:59

Well I was always a fan of orbital assembly and it was hardly ever "sci-fi" since we had space docking from the mid 60s I believe.

However, I just feel we are way beyond that now. We have the Space X BFR Mission architecture which makes complete sense as long as they can build the BFR. I can't see any reason in principle they can't build the BFR so for me that is the way to go and it is pretty pointless trying to second guess the outfit that is probably ten years ahead of all other players.

Oldfart1939 wrote:

Regarding space vehicle architecture, I now propose a fully fueled "propulsion module." This is a simple fully fueled module which can be in-orbit mated to the earth departure vehicle, the fully fueled Mars lander. It simply provides enough fuel for a propulsion module consisting of an engine array plus some fuel for Earth departure of the fully fueled Mars lander. This takes us to Mars orbit, where the descent stage separates and descend to Mars landing. We fire another fully fueled "propulsion module: into Mars orbit for the return Hohmann transfer mission of the descent/ascent stage.. Trying to prepare massive amounts of LOX and liq. CH4 seems at this point to be unlikely. Just manufacture enough of the needed propellants to get back to mars orbit. The propulsion modules should be powered by UDMH/NTO for long-term stability on storage orbits.
Twenty five years ago when Zubrin first proposed Mars direct, orbital assembly was just science fiction. Now it's reality, so let's just get our shit together and GO TO MARS!

Oldfart1939 · 2018-01-07 21:11:53

No, Louis-

It really depends on whether we can ever refuel the BFR on Mars for the return flight back to Earth. The mission architecture I suggested earlier is a way in which we don't send anyone on a one way suicide mission.

louis · 2018-01-07 21:28:40

Well yes, but Apollo 11 depended on a lot of critiical requirements. I am sure you are not the type to say we shouldn't attempt something because there is a one in 100 chance of failure. Well - why not come clean...what is your risk threshold? Personally I'd be happy with 1 in 10 if all the participants were happy with that but I really don't think it will come to that with the Space X mission - that will be more like 1 in 1000 I think.

Oldfart1939 wrote:

No, Louis-
It really depends on whether we can ever refuel the BFR on Mars for the return flight back to Earth. The mission architecture I suggested earlier is a way in which we don't send anyone on a one way suicide mission.

SpaceNut · 2018-01-07 21:32:57

In a way having a fuel source and return ship in orbit is not all that bad if we land in a Red dragon vehicle but what would it take to build a first stage to be able to get back to orbit by recycling an engine from the BFR or to build a solid booster from insitu resources or to sent the sections for later use.

We could also send the BFR via ION drive since we are not looking to use them until man can gets there so all the fuels onboard would need active cooling but would leave some remaining for a crew to use once transfered to the ascent vehcile of choice to make use of....

SpaceNut · 2018-01-07 21:58:07

This is not just a BFR or SLS mission http://www.nss.org/settlement/mars/AccessToMars.pdf

Space Transport and Logistics Issues Covered
• Types and Purposes of Mars Expeditions
• Major Decisions and Alternatives for Earth to Mars Transit Systems.
• Getting Mars Equipment into Low Earth Orbit – Connecting HLV design to Mars Missions.
• Types of Mars Transit vehicles
• Near-Earth Space Infrastructure Needed.
• Getting to and into Low Mars Orbit and back
• Low Mars Orbit Base & Needed Infrastructure.
• Down-select of choices for a re-usable system
Types of Mars Expeditions
• Flyby of Mars only.
• Mars Orbit and Phobos with Tele-operation of surface robotics and base equipment.
• Flags and Footprints (a few trips only) using expendable booster and in-space vehicles.
• Antarctic Style Scientific Bases (semi-permanent & open-ended) – with reusable vehicles & ISRU.
• Permanent Scientific Bases - major ISRU.
• Base with commerce to support government.
• Bases and Settlement(s) with commerce. Rational for avoiding “Flags and Footprints” Missions
• F&F is a dead end road. If you build a "flags and footprints" (non-re-usable) architecture, then all you will get is a short series of flags and footprints missions Period. This path is not sustainable due to the continuing high cost of building replacement vehicles.
• There could be a very long gap afterward before Human Mars exploration is resumed, just like the one after Apollo.
• This creates a risk of loss of public interest and support similar to the post-Apollo period.
• It creates no Mars infrastructure usable for future missions.
• It is inefficient and produces relatively few scientific results for the money spent.
• (The most important Mars Direct Concepts – such as equipment pre-positioning and using local materials - are very useful for many kinds of missions).

elderflower · 2018-01-08 05:52:51

An orbital rendezvous from the surface could be done with a CO/LOX powered first stage rocket with a capsule on top. So that could be shipped in an empty state and its tanks charged using atmospheric CO2 and quite a bit of power. In that case we need only land the NTO and Hydrazine derivatives for the capsule engines.

Oldfart1939 · 2018-01-08 10:02:33

My suggestion for the Mars lander involves manufacture of only LOX on the Mars surface. I really would prefer a UDMH fuel in the lander with just LOX replenishment. Having a fully fueled ERV in orbit makes most sense to me--for the first few missions until we get better experience with ISRU for production of propellants. The first few landings will need to be pioneering missions, not the whole hog, full bore BFR deals.

Void · 2018-01-08 11:15:28

I like your thinking. I have been pondering it a bit more, and think automation is the way to go to scout the surface, at least at first. All we really want is to look for signs of life, and to assess what the resources are.

Of course my choice of the Caldera of Olympus Mons is really a bit of silly romance, but it or places like it would be a good test start of automated reconnaissance of various places. I do believe that the planetary protection conventions should be "Reasonably" observed. Landing on Olympus Mons, would in my opinion free much of the cost of sterilization. I would think that coating the parts when possible with substances toxic to microbes would be sufficient.

I would want a rover, seismometers, and a sample return to orbit rocket. If LOX could be taken from the atmosphere as you suggest, that would be a good test. Robots are already so good, and will be better. It would make no sense to put a human down I think until BFR is ready to pick a spot and land.

A sample return of Martian dust to the orbital BFR might go a long way to defining the reality of possible Martian life.

Last edited by Void (2018-01-08 11:18:45)

elderflower · 2018-01-08 17:19:28

Any Mars orbit base proposal needs to address the gravity question. As far as I can see the changes to human physiology over a 34-36 month ( or more) mission in weightlessness are going to be so debilitating that even the fittest astronaut would be unlikely to survive earth re-entry, if they get that far through the mission. Artificial gravity through rotation of the ship, or landing for long periods on the surface seem likely to be the only ways to keep the crew healthy.

Void · 2018-01-08 17:50:13

Good Question. Unfortunate one as well. I am not strongly equipped to help in that area, but I will offer such tricks as I can think of.

First of all, I would think that a fully automated scouting mission would be preferred. I not sure that is possible yet though, if the notion is to distribute probes to the surface, and to drill one of the Moons.

So if you are going to send a crew, then I would think you would prefer to spend perhaps a Month around Mars, and use a Hohmann transfer one way, and a ballistic capture the other way. Whichever is the most convenient. That might cut the total time duration very sharply. Avoiding your concerning 34-36 Month mission. I could hope for perhaps a year or a little more. Maybe I will get a beating for that notion. I think If I understand what is available for travel times, is it about 3-6 Months.

https://www.cnbc.com/2017/11/29/what-it … eship.html

So supposing Hohmann transfer of 3-6 Months to go there. 1 Month to be there, and a Ballistic return to Earth. Which likely will take longer than 3-6 months. So, could we hope for a year duration +/- several months?

For a scouting mission I would not expect a large crew. Just a skeleton crew (Hopefully not to be real skeletons).

This is "Alternate BFR", so I am just trying to craft an alternative which is not the same as the current stated plan for BFR.

For the radiation concern, I offer this additional plan:
https://en.wikipedia.org/wiki/Stormtrooper_(Star_Wars)

No, not starwars or the force
Really I have already mentioned personal radiation armor which would be composed of something like Paraffin wax, with a cloth surface I suppose. Hopefully it would not look as stupid as a storm trooper from star wars, but still the image sort of is an approximation. I don't know how much help that will be.

I would imagine it would be kept on if you are not doing a task where it would get in the way. It would be an annoyance I should think, but perhaps helpful.

That in addition to the bulk of the ship may help. Under alternate BFR, the ships fuel tanks would be much more full most of the time that under normal BFR. That might help.

The ship is also supposed to have a "Storm Shelter" for really bad patches.

There are exercise machines to try combat bone and muscle loss. I would presume they would be on the ship.

The only other thing I could think of would be a spring loaded cage you would stand in and be able to walk with, which would apply pressure from your above body, head, shoulders, hips, to pin you against the floor.

Maybe some type of centrifuge even. If the crew is small, having one or two small centrifuges might help.

But microgravity will take a toll in any case. Having a shorter duration trip would be a big item. So, not to use Hohmann both to go to Mars and to come back.

That's all I have. Maybe it is not enough. I feel it might be.

Last edited by Void (2018-01-08 18:23:20)

louis · 2018-01-08 17:53:19

Yes, this was the problem with the Boeing (?) proposal to do short duration hops down to the surface from orbit... your body would be wasting away over that timeframe.

elderflower wrote:

Any Mars orbit base proposal needs to address the gravity question. As far as I can see the changes to human physiology over a 34-36 month ( or more) mission in weightlessness are going to be so debilitating that even the fittest astronaut would be unlikely to survive earth re-entry, if they get that far through the mission. Artificial gravity through rotation of the ship, or landing for long periods on the surface seem likely to be the only ways to keep the crew healthy.

Last edited by louis (2018-01-08 17:53:51)

SpaceNut · 2018-01-08 19:00:59

Nasa indicates that to land 88,200 lbs of payload, the throw to mars is in mass range of 176,400 -242,500 lbs would be required in Mars orbit prior to EDL. So even Nasa is looking at half that of the BFR for a mars mission to the surface.

Void the mission stay time of 30 days on the surface would require a duration from launch to splash down of 500 days. With the long stay on the surface is a duration of 900 days. The outbound and return trip times unless we used a lot more fuel on either end is in the 6 to 9 month travel times each way without dropping payload mass to mars.

My question is what are we delivering to mars that needs to have such a high mass level.....to the surface...

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