virtual Project Mercury

[PB666]

So we have alot of argument on the colonization discussion of Mars and Venus. Now the conversation has drifted to space colonization and gamma rays. All of these are things are equally fanciful, except for the fact not the better of any of our space agencies are capable of doing any of these and now everyone is on a race to land on the Moon (deja-vu) and colonize it. None of these plans, at the moment are credible. Primarily there has to be the drive to do it, and maybe the chinese have that drive.

We need a project of our own, I propose the colonization of Mercury, not because its doable or easy, but because its hard and true kerbanauts are willing to take the risk. THe project is not to get kerbs to Mercury but humans. Each human needs the resources of 8 Kerbanauts. He also needs to eat and breath oxygen (food and mercury have neither)

To start off this project is not going to be an overnight thing. And I think people can participate by designing their own 3D space craft and submitting examples of various landers. I will be submitting from time to time to try to stir the debate. ITs not a project that needs to be done in one step, for instance if a colony needs a solar shield before assembly this can be done. The colony is a one way trip (for relatively obvious reasons), and settlers need to come up with ways to harvest resources. Any and all resources can be used from earth, but only existing technologies. Let us assume that Putin has decided to make the Biggest rocket, but has nothing to launch on it, to you create the payload and he will launch it for you (as well as all future profits of your heirs). The problem is that Russians have no Equitorial launch sites. So you will be launching the mega Rocket from S. Kazakhstan. 45°57′54″N 63°18′18″E

This the way I see it.
Cons.
1. The sun is very hot  and carbonization of human flesh is more than a little painful.
2. Mercury is either very hot (surface tempature) or very cold, there are very few places that are mild. 
3. Mercury only has a transient atmosphere as nominal solar winds pass around its surface and sublimate along its sides.
4. Exposure to ionizing radiation from the sun and solar storms are at their highest.
5. Surface is hard (vulcanized) and lacks subsurface water.
6. Mercury is not strickly tidally locked. and so static sites on the light termination might be perilous.
7. sensitive electronics, kiss them good-bye. All electronics will need to be shielded.
8. Zero warning for solar storms.
9. Certain commonly used metals and plastics used in space become unstable with high levels of irradiance. Even solar panels have to be tilted to prevent over heating.
10. The dV requirements are insane for anything larger than a satellite the launch required is enormous.

Pros
1. You beat out Mexico as the number one sun destination.
2. There is an endless supply of cheap energy for ion drives and habitation.
3. Its easy to land and take off of, and allows precise targeting of landing sites.
4. Nobody else wants to do it, you don't have to compete with hype like "Zubin said" this or "Musk said" that. Everyone will think you are completely insane which means you are free to design and revise in relative peace and quiet.
5. In terms of Hohmann transfer times mercury is close, on average mercury is closer to every planet in the solar system relative to all other planets.
6. Along the termination water and other less volatile gases sublimate.
7. There is more elemental hydrogen in Mercurys very thin surface hugging atmosphere than any other rocky planet in the solar system. Oxygen is also present (both are at very low levels but pockets of these still exist). Mercury is a great place to harvest solar winds.
8. Mercury has the highest differential between daytime and night time temperatures in the solar system, this might be useful.
9. Its a great place to drop dreamy-eyed martian colonist!

 

 

 

 

[DAL59]

48 minutes ago, PB666 said:

Its easy to land and take off of

It has almost the same gravity as Mars, but no atmosphere to help slow down.  

Also, its very uneconomical to ship products of Mercury.  

Solar power beaming, on the other hand...

(You should rename this thread to avoid confusion with the Mercury Mission VR Experience)

[PB666]

4 hours ago, DAL59 said:

It has almost the same gravity as Mars, but no atmosphere to help slow down.  

Also, its very uneconomical to ship products of Mercury.  

Solar power beaming, on the other hand...

(You should rename this thread to avoid confusion with the Mercury Mission VR Experience)

Uneconomical is an understatement, the issue is hows of uneconomical.

Lets do some starters on the problem.
-Its tidally locked but in 3/2 orbit.
-Axial tilt is 2.0' however some estimate to be as low as 0.027 degrees. Its tilt may vary because.
-As the planet turns the tidal effect of the sun is 17 times greater than at on earth. The surface of equitorial Mercury is not static, it moves. 
-In addition the sun stops its flight across the sky close to periapsis, the moves again.

The low axial tilt means that it is possible to land on mercurial poles however how would one practically deduce a good landing spot.
1. Sending many satellites.
2. Sending on satellite and observing the satellite for several mercurial orbits.
3. Send a surveyor that maps the location of ice.
4. Laser spectrometer that can assess the type of ice and its characteristics.
5. Just send a lander and hope you land on a good spot the first time.

Once a good landing spot is obtained then.
A. What about the sun, its going to blast the ship from 360' degrees over the course of a year, how to protect.
B. Mercury has a magnetic field, how effective will this be without an atmosphere.
C. Since there is no atmosphere, the sun's light is unfiltered, even close to termination.
D. What about solar panels, where to place, what specific designs are needed.
E. Will the panels be fixed or should they be mounted to set between the ship and the sun.

These things inform on how to build the lander, and that then tells the magnitude of the economic difficulty.

The point about colonizing Mercury is that it exaggerates the problems of reaching other planets. 

Here's what I would do. First I would send 3 communication satellites. 1 that is in an equitorial orbit and 1 that is has an exactly polar orbit the radial with respect to the sun, the other satellite would be a surveyer also with a polar orbit that crosses the poles.

Second I would send 2 or 3 small probes and landing them at a pole, surveying the water as they approach the surface. Each craft would have surface mounted temperature, radiation and cosmic radiation sensors so the radiation exposure it surveyed over at least 3 years.

 

[PB666]

So how to get a communication satellite to Mercury. There are many options but few are viable. Assuming we have taken off from Earth at the Earth-Sun, Mercury-sun inclination node and have made all the plane changes required in Hyperbolic orbit near the minimum altitude (A big problem to begin with). We have propelled something into a elliptical orbit that crosses the path of Mercury. We will worry about how we created a and e later. The needs of entering orbit around Mercury will dictate all lower stages.

We then have to do at least two burns (one to intercept mercury at PE) and one to circularize once insides Mercuries SOI. This one small sentence creates a world of problems.
1. We either need:
a. two engines and propulsion systems
b. An engine that can  be restarted several times.

Provided that our intercept is close to mercuries periapsis we can estimate the least dV required.
2. We need at least 5581 dV once having left Earths SOI. Because we will have to spend some dV correcting (Another big math problem) the orbit close to Mercuries PE we should plan on bring 6500 dV of thrust.

This then creates the third problem.

3. We can use 475 ISP cryogenic rocket engines but once we get into orbit we do not have a liquid hydrogen storage ability, complicated by proximity of burn points close to the sun. Storage of liquid oxygen is equally problematic close to the sun, if we plan to take liquid oxygen to the sun some of the PL weight must also include oxygen conservation (refridgeration system) which requires additional solar panels, etc. IN addition the RL-10b-2 uses ablative thermoprotective coating on its nozzles to decrease engine weight and gives it a finite duty cycle of 220s at full thrust. This is problematic with regard 6500 dV for optimally power rocket the burn time is significantly longer.
We need a high ISP engine that is light weight, but has enough thrust to inject itself into mercuries SOI.

4. The need is to get 2.5 ton (metric all further usage) (Not including fuel tank or engine) into a circular orbit about Mercury. This weight is based on the https://en.wikipedia.org/wiki/Tracking_and_data_relay_satellite.

Assuming that the antenna itself will be made of highly reflective material capable of withstand the solar temperatures some structure will need to be added to these to protect the electronics and batteries from the deleterious effects of the suns heat.

If the end Transfer stage use 250 ISP monopropellant engines then it will need something like 60 tons (mostly monopropellant tanks). This is an awful lot of fuel for a 2 ton rocket. What are the alternatives?

 

 

[regex]

How often do Venus slingshots to Mercury come up? That would make transit much easier by providing some of the velocity external to the craft.

Steps to Mercury:

1a. Go to asteroid belt (why do I always start there? Oh right, it's easy-mode.)

1m. Send robot miners to Mercury.

2a. Mine asteroid belt.

2m. Have robots dig out some large hab-capable caves on Mercury.

3a. Create Dyson swarm.

3M (HAHAHA). Have robots line hab-capable caves with something other than regolith.

4a. Beam power to Mercury-bound craft.

4m. Colonize the place.

18 hours ago, PB666 said:

4. Nobody else wants to do it, you don't have to compete with hype like "Zubin said" this or "Musk said" that. Everyone will think you are completely insane which means you are free to design and revise in relative peace and quiet.
9. Its a great place to drop dreamy-eyed martian colonist!

#legit

[PB666]

So I created 3 solution space craft.

The first was about 63T and used only monopropellant.

The second weighed 26T and used a massive number of fixed solar panels and ION drives to carry monopropellant to mercury to finish circularization.

The third version was strictly ION drive, has 6700 dV of thrust ISP = 2250 and had alot of solar panels bringing the weight to 9.7 Ton. The burn time was 17 days.
The good about this vessel was there was alot of room to increase fuel. the bad aspect is the burn time. BTW it is balanced. 

Three framed images are the mercurial satellite and of course the forth is from NASA. The illustration is actually a flawed one, NASA reported that relative to the direction of the sun the solar panels needed to be turned about 0-30' eitherwise the solar panels would overheat. IIRC something about decoupling electrons leaving holes that rapidly degraded the solar panels.

The weaknesses of this space craft are:

Solar panels should be retractable (for launch, and frame is to heavy. Solar panel weight should be decreased and more solar panels need to be added. It gets the job done but way too slowly for maximum oberth effects.
If there were more solar panels I could increase the ISP from 2250 to 9000, lower the fuel, This space craft would benefit from 20 fold more solar panel area (ridgid) but no increase in weight or at minum weight in panel gained equals weight in fuel reduced...The basic problem is how also to protect the space craft.

Here is the launch vehical. Notice the non-optimal payload configuration

Launch and Boosters ~ 4 km/s dV  3.2 mT

Third stage - 4.5 km/s dV 0.655 mT

Hohmann transfer start - 8.1 km/s dV 0.197 mt

Hohmann transfer end - 6.5 km/s dv 0.010 mt

There are solutions. Such as increasing the base of the fairing. Ultimately this is only a fix.

For some statistics, The primary launch engines are 68A's. The ION drive is a replica (in function) of the high performance 35KW ION drive tested by NASA with ~90000 Exhaust velocity at 80% efficeincy, the claim was that the thruster can operate over a wide range of ISP, thus I chose ~23000 this particular unit has 6 devices and its never operated at full power (about 40% peak rated power due to the limitation of the panels). Hohmann start transfer is performed by RL10b-2 engine (OP since the engine is only rated for 220 seconds, that's a bit of a cheat). The assumption here is that with a proper fairing base I could go with a wider fuel tank on start transfer stage and then use more of the very light-weight RL10b-2 engines. Thus the size of the fairing base is pretty important for multiple reasons. The struts are variable length gas pressurized pipe section (0.15 m outer diameter 0.1075 m inside diameter).
This piping will in the future be replaced by carbon fiber but with a highly reflective surface coat of metal. The connectors are just to make assembly easier. Solar panels are offset on both sides in order to balance the shielding panels.

There is an alternative on the launch, that being to use no fairing and crawl into a higher elevation of 20,000 meters (64,000 feet between Concorde flight height and SR71 cruising altitude) before beginning a notable gravity then pushing past Mach1. Most of the fuel is wasted but some is saved because subsequent burns closer to the horizon as a consequence of residual vertical momentum. 

 

 

[NSEP]

Interesting. Never thought of colonizing Mercury Before. Well after all, it does not have the flying above literal hell problem or there is not enough atmosphere to land by parachute but enough to heat up your craft during reentry problem. 

Edited November 14, 2017 by NSEP

[PB666]

ITs not so much about solving the living part, its about solving the getting there part and shaping current technologies. We assume that living on Mercury is very dumb; very, very incredibly dumb.

The thing about Mercury is that we do not need to some vapor-ware to do it (like a fusion reactor or cloud cities). We just need an awful lot of existing technologies.

I should make the point that If fusion was a thing, you do not have return windows of very much sooner than those of Venus or Mars. Alternatively one could collect helium gas, or metals for ION drives, provisions of better solar panels.

Without nuclear fusion return from mercury is all but impossible (that part making it dumb).

 

 

[DAL59]

15 minutes ago, PB666 said:

Without nuclear fusion return from mercury is all but impossible

True.  With a solar sail, you might manage a soil sample, but overall, unless there's ice and you do a lot of slingshots, its a one way trip.  

16 minutes ago, PB666 said:

The thing about Mercury is that we do not need to some vapor-ware to do it (like a fusion reactor or cloud cities). We just need an awful lot of existing technologies.

Airships exist...  

[PB666]

3 hours ago, DAL59 said:

True.  With a solar sail, you might manage a soil sample, but overall, unless there's ice and you do a lot of slingshots, its a one way trip.  

Airships exist...  

There is no airship of any produced variety that would survive the atmosphere of Venus.

[DAL59]

It has been studied though.  I also fail to see how Mercury is easier than Mars though.  

[PB666]

19 minutes ago, DAL59 said:

It has been studied though.  I also fail to see how Mercury is easier than Mars though.  

Who said anything about easier. I said the idea is to get there on something that already exists. Venusian balloons do not exist, no-one has tested even a tiny blimp on venus.

The problem with the mars dream is what is being proposed is hype, its vapor-ware. Its proposed in one week and is not-a-thing the next week.
Thing about mercury is we know how to land on a planet without atmosphere (the moon is the same problem), we know how to deal with the sun, we know how to predict where the sun will be catastrophic and where it will be adequate for solar-farming. We know how to build bigger rockets, how to conserve fuel . . . . . . . . .

We don't know how to land on a cloud, we don't know how to get a 350 ton ship to land on its feet after several screwball turns in the atmosphere. We don't know how to deal with Martian dust, or turn vapor-ware into electricity that can be used to pump water below the martian surface that we dont know exists.

If you can break a most hard problem down into a set of accomplishable steps, even the most hard problem can be solved. But if there are steps that are unaccomplishable because of an acute lack on information, then the problem is no longer an engineering problem but a scientific problem. Mercury is an engineering problem, venus is a scientific problem and Mars is an ambition problem. Its ambitious because what they seek to do they do not yet have the resources to do, and what they can do, they do not seek to do. Mars colonization is a suicide mission pretending to be something else. Mercury project is a suicide mission that is not pretending to be anything else.

[DAL59]

7 hours ago, PB666 said:

no-one has tested even a tiny blimp on venus.

Actually, they have.  The russian Vega missions successfully deployed two balloons into the atmosphere. 

[PB666]

1 hour ago, DAL59 said:

Actually, they have.  The russian Vega missions successfully deployed two balloons into the atmosphere. 

Not blimps, there is no internal ballast,  fixed gondola, motors or steering structures  and they lasted 46 hours. " A blimp, or non-rigid airship, is an airship (dirigible) or barrage balloon^[1] without an internal structural framework or a keel. Unlike semi-rigid and rigid airships (e.g. Zeppelins), blimps rely on the pressure of the lifting gas (usually helium, rather than hydrogen) inside the envelope and the strength of the envelope itself to maintain their shape. "

To qualify as a blimp it would need to be able to remain viable for months and they would need to be able to maintain altitude (See below). I should point out that the turbulent forces in the atmosphere of venus are so great that one of the landers thought it had landed 20km above the ground. Violent winds are not a place for blimps. Hot-Air blimps rely on the pressure of hot air to keep the ship alot, if the atmosphere is already hot then the air inside the blimp needs to be hotter still. "At this altitude, pressure and temperature conditions of Venus are similar to those of Earth, though the planet's winds moved at hurricane velocity and the carbon dioxide atmosphere is laced with sulfuric acid, along with smaller concentrations of hydrochloric and hydrofluoric acid. The balloons moved swiftly across the night side of the planet into the light side, where their batteries finally ran down and contact was lost. Tracking indicated that the motion of the balloons included a surprising vertical component, revealing vertical motions of air masses that had not been detected by earlier probe missions."- vega page on wiki

" Volume changes of the lifting gas due to temperature changes or to changes of altitude are compensated for by pumping air into internal ballonets (air bags) to maintain the overpressure. Without sufficient overpressure, the blimp loses its ability to be steered and is slowed due to increased drag and distortion. The propeller air stream can be used to inflate the ballonets and so the hull." blimp- wikipedia.

A example of a test would be to place a space tolerant creature in the B L I M P and have it survive for  a period of time. Anyone who thinks a venusian blimp is a serious proposal in the above context . . . . . . . .

Edited November 15, 2017 by PB666

[kerbiloid]

Spoiler

13 hours ago, DAL59 said:

I also fail to see how Mercury is easier than Mars though.  

On Mars you should deal with atmospheric CO2 pressure, ice caps containing water, maybe some subsurface ice deposits, perchlorates, etc.
You should take them into account, plan your technology and ecology keeping in mind the local resources, analyzie, doubt, calculate and then find errors in your calculations, suffer.

On Mercury things are much easier. There is nothing except the burnt rock, you don't have to deal with local resources for ISRU, you just know: all you need you must bring from the Earth.

 

[DAL59]

7 hours ago, PB666 said:

Not blimps, there is no internal ballast,  fixed gondola, motors or steering structures  and they lasted 46 hours. " A blimp, or non-rigid airship, is an airship (dirigible) or barrage balloon^[1] without an internal structural framework or a keel. Unlike semi-rigid and rigid airships (e.g. Zeppelins), blimps rely on the pressure of the lifting gas (usually helium, rather than hydrogen) inside the envelope and the strength of the envelope itself to maintain their shape. "

To qualify as a blimp it would need to be able to remain viable for months and they would need to be able to maintain altitude (See below). I should point out that the turbulent forces in the atmosphere of venus are so great that one of the landers thought it had landed 20km above the ground. Violent winds are not a place for blimps. Hot-Air blimps rely on the pressure of hot air to keep the ship alot, if the atmosphere is already hot then the air inside the blimp needs to be hotter still. "At this altitude, pressure and temperature conditions of Venus are similar to those of Earth, though the planet's winds moved at hurricane velocity and the carbon dioxide atmosphere is laced with sulfuric acid, along with smaller concentrations of hydrochloric and hydrofluoric acid. The balloons moved swiftly across the night side of the planet into the light side, where their batteries finally ran down and contact was lost. Tracking indicated that the motion of the balloons included a surprising vertical component, revealing vertical motions of air masses that had not been detected by earlier probe missions."- vega page on wiki

" Volume changes of the lifting gas due to temperature changes or to changes of altitude are compensated for by pumping air into internal ballonets (air bags) to maintain the overpressure. Without sufficient overpressure, the blimp loses its ability to be steered and is slowed due to increased drag and distortion. The propeller air stream can be used to inflate the ballonets and so the hull." blimp- wikipedia.

A example of a test would be to place a space tolerant creature in the B L I M P and have it survive for  a period of time. Anyone who thinks a venusian blimp is a serious proposal in the above context . . . . . . . .

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160006329.pdf

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160006580.pdf

[PB666]

3 hours ago, DAL59 said:

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160006329.pdf

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160006580.pdf

HAVOC stands for High Altitude Venus Operational Concept.
Note that the temperature at 50km is 75'C about 5'C hotter than the boiling temperature of alcohol. There is no place in the world where humans can survive for any length of time with temperature above 50'C.

[DAL59]

Then go to 55 km.  

[PB666]

They were trying to match the surface pressure of Earth, for whatever reason.

[kerbiloid]

Someone should mention Petronius.

Spoiler

14 hours ago, PB666 said:

temperature at 50km is 75'C about 5'C hotter than the boiling temperature of alcohol

No way! This is absolutely inappropriate.

12 hours ago, DAL59 said:

Then go to 55 km.  

Yes, good idea. Otherwise the colonists would lynch you.

 

[DAL59]

7 hours ago, kerbiloid said:

Yes, good idea.

At Venus, you also get plenty of gravity unlike Mercury and Mars.  

And plenty of fertilizer chemicals.

And you can aerobrake.

[PB666]

1 hour ago, DAL59 said:

At Venus, you also get plenty of gravity unlike Mercury and Mars.  

And plenty of fertilizer chemicals.

And you can aerobrake.

Humans generate their own fertilizer. Yes you can aerobrake but you cannot land. Venus has less gravity than Earth. In addition your airship, when exposed to unpredictable venusian winds and invert, inverted gravity is not to good on the head.

[PB666]

OK so the next part. The inclination node for Mercury occurs about 48 days after the vernal equinox and on this day one can launch from cape canaveral at about AtP77 and circularize orbit at 145 km. A burn to a velocity at AtP296 centered to about 14800 m/s can create an elliptical that peaks approximate to Mercury's apoapsis and is approximately the same plane. The total amount of DV required is about 16000 to 16500 m/s from launch to first part of Hohmann transfer. As mentioned in the previous post above there are craters with water near the two poles of mercury, as well as water that accumulates transiently. Already we have determined and ION drive system 6500 capable of insertion into Mercury. This creates a required 23000 m/s dV required to reach Mercury.

We have not yet considered the lander and its dV required, this will be part of the orbital payload weight.

[kerbiloid]

About the Venus.
The upper limit of a mountain height for Venus is ~10..12 km.
Carbon nanotubes can be an order of magnitude stronger.

So, do like this and live on top.

Spoiler

55 km high or so.

[PB666]

Sure, why not just bring  a trillion tons of carbon into venusian atmosphere to build the tower of babel, how well will that all go down.