Jupiter/Saturn Mission Concepts

[TMac3000]

EDIT: This thread is now open for discussion of other concepts for exploration of Jupiter and Saturn, as well as ASM.

The Uranus/Neptune concept threads got me inspired, so here's yet another idea for a gas-giant science mission.

This is a three-part mission.

A pair of probes would be sent to Saturn:
1) Arroway: Named for Jodie Foster's character in the movie "Contact". Arroway would aerocapture into a polar orbit around Saturn, and dive into the planet's atmosphere through the famous hexagonal storm at the north pole. It would deploy a balloon, send back live video and take as many atmospheric chemical composition and weather readings as possible before it folds.

2) Sharapova: An Iapetus lander. Because of the moon's tennis-ball-like appearance, this probe is named to honor one of the game's greatest (and as beautiful as Saturn is:thumbup. This vehicle would land in the "dark" area Cassini Regio, near the equatorial ridge. No specific landing site has yet been chosen. It would take crust samples and send back pictures of the surrounding terrain.

The third part is the most ambitious: MINOTAUR--Manned Iapetus eNvironment Observation, Terrain Assessment, Utility and Ranging. This is a manned mission to Iapetus, to be constructed and launched during Arroway/Sharapova's Saturn transit. A team of four will land in Ronceveaux Terra--again, exact landing site to be determined--build a small base, and explore the local terrain. They will also take crust samples to determine more about this world's composition.

S/A would be launched at the next Saturn window, from Wideawake using a Jarvis. MINTOAUR would be assembled in LEO during the transit, and hopefully can reach Saturn at the window after that, but no later.

 

[Nicholander]

Interesting! By the way, what time period is this supposed to be in? (Like, 2040s or something)

Also, I think you mean aerocapture, not aerobrake in Arroway's plan. Aerocapture is going from escape velocity to orbital velocity using a planet's atmosphere to slow you down, while aerobraking is decreasing your orbital speed to slow down while already IN orbit, such as decreasing your apoapsis height.

 

[TMac3000]

Right you are. I synonomize a little too easily

Anyway, I want to design the MINOTAUR first, and the math is turning out really interesting so far...

Here's what I've got:

NASA recommends 0.8 kg of oxygen per astronaut per day. Compressed to LOX, this is only .0007 cu m/person/day. I want a crew of 4. Saturn is...let's call it 2250 days by Hohmann orbit. Now, this is a round trip with a good amount of time on site, so I'll triple that to 6750 days. .0007*4*6750 is 18.9 cu m. Volume of a sphere is V=4/3 pi r^3, so solving for r and skipping some steps, we get an O2 tank diameter of 3.305 m, or about 12 feet.

But you don't use pure oxygen unless you want another Apollo 1, so we have to figure the nitrogen in too. I want a 70/30 atmo at three-quarters of a bar, so I need a...:uhh:about 5-foot LN2 tank to supply that.

Do I have this right so far?

 

[dgatsoulis]

Here is a little bit of theory.

These calculators might help (scroll down to mission calculator for consumables).

 

[Topper]

You forgot Enceladus!
I also started thinking regarding a Saturn mission...
In the last week, I read in the news that there could be live conditions in an ocean under the ice tank of Enceladus. Fountains may blow the frozen microorganisms into space

So the spaceship just needs to collect some frozen samples in space and return them to earth...
Without drilling, digging and / or melting...

Maybe it's possible to do that without entering into an Orbit around Saturn (Similar to Stardust etc.).
But if you want to have an orbiter, this could be a second part of the probe...


Alternately to a sample return mission, the samples could be studied inside the orbiter itself or it can carry a little lander which can collect the falling snow and study some fresh samples directly on the surface...
But a lander should have a big under surface (maybe an air cushion) that it does not sink into the snow.
The good point is that gravity is very low so it does not need to be very stable...

Also a Titan rover/baloon/ship could be cool which could be another part of the mission...
I know all together might be to heavy...

http://www.spacedaily.com/reports/R...umes_from_Saturns_icy_moon_Enceladus_999.html

 

[K_Jameson]

Interesting mission but, for me, realistically speaking, a manned interplanetary spacecraft, if will ever made, will be sent to other targets first. Centuries will pass before a man will leave a footprint on Iapetus.

The unmanned part is also interesting. But Enceladus and Titan have definitively the crown and every flagship-class mission to the Saturnian system must be absolutely directed on these two targets well before Iapetus, IMHO.

 

[TMac3000]

You guys are probably right. But still, Iapetus is a really cool-looking moon that no one talks about much, and I wanted to come up with something zany and original. I haven't forgotten Enceladus and Titan--they are hugely important! I'm merely leaving them to other Orbinauts to explore.

And Nicholander, I apologize for not getting to your question of a launch date. I have not yet had the opportunity to look for Saturn windows, and may not for a couple of days yet due to work.

Besides, I don't even want to think about picking a date until this thing is at least finished on the drawing board. I made the mistake with the Deep Six Project of picking a launch window too early, when we already had the Iron Hill Project underway. We ended up with too much stuff going at once, and D6 got shelved pretty much indefinitely I may pick it back up some day.

All I can say for now is that I want A/S to go on one window, and MINOTAUR to go on the next window.

---------- Post added 03-17-15 at 08:34 AM ---------- Previous post was 03-16-15 at 06:35 PM ----------

Okay, here are some rough figures for liquid consumables tanks:

Volumes (4-man crew, 6,000-day mission, based on info found via this thread)

O2: 16.8 cu m
N2: 7.2 cu m (for 70/30 atmosphere at 1 bar)
H2O: 720 cu m

This gives the following tank diameters:
O2: 3.1 m (10 ft 2 in)
N2: 2.4 m (7 ft 2.5 in)
H2O: 11.12 m (36 ft 5.7 in)

Propellant tank info will have to wait, as I would need to determine my exact details on launch window and mission profile before I can figure out how much gas I'm gonna need I'm considering a gas-core NTR.

Do these figures look right?

 

[K_Jameson]

Another note: Sharapova is a beauty, but isn't exactly a good name for a serious space science mission... OK OK we have even spacecrafts named after Hatsune Miku... forget my post... :rofl: ;-)

 

[Pipcard]

Yeah, naming a spacecraft "Hatsune" doesn't sound very serious, but the difference is that Miku has been directly associated with space and rocketry by some people in real life. Maria Sharapova has not.

But you don't have to change the name if you don't want to.

 

[Urwumpe]

The difference is.... we will run out of names if we just use the space-related ones.

 

[K_Jameson]

Yeah, naming a spacecraft "Hatsune" doesn't sound very serious, but the difference is that Miku has been directly associated with space and rocketry by some people in real life. Maria Sharapova has not.

But you don't have to change the name if you don't want to.

I was kidding... love your Miku-related addons. Very original and funny.:thumbup:

---------- Post added at 03:47 PM ---------- Previous post was at 03:45 PM ----------

But you don't have to change the name if you don't want to.

Surely! :thumbup:

 

[TMac3000]

Thanks, guys

Can you provide some feedback on the estimations I have so far? Do these numbers make sense?

 

[Urwumpe]

Thanks, guys

Can you provide some feedback on the estimations I have so far? Do these numbers make sense?

So far yes, but I am not sure if you can reduce the oxygen requirement further by using regenerative systems - same for the water. Those are still experimental in spaceflight, but already in flight testing on the ISS.

Food is another factor there - you can't grow everything in a greenhouse.

Essentially, you will launch with a huge trunk of MREs ... and maybe discard parts of the trunk as you approach Saturn.

Maybe you can use the low gravity of Iapetus for some reuse of the now empty cargo modules for extending the base...

 

[TMac3000]

I am not sure if you can reduce the oxygen requirement further by using regenerative systems - same for the water.

Ah, yes...I actually discussed this with my mom the other day (she knows I'm into space flight, but we have only very short and vague conversations about it--she's more of a tatting fan:lol--you can crack the CO2 that you exhale back into oxygen for breathing, and the waste carbon can be mixed with other chemicals to make more fuel. Recycling water seems a bit gross, but there is no technical or sanitary danger in it.

Food is another factor there - you can't grow everything in a greenhouse.

I know...a big trunk of MREs is exactly what I plan. Liquid consumables (water, LOX, LN2, propellant) would be stored in those big tanks I was talking about, positioned along the centerline of the ship...food would be kept in a separate storage module along with all the other daily solid supplies people are going to need for 15-20 years (clothing, scientific equipment, soap, tampons, stuff like that) But that will be a separate part of the ship.

The tanking arrangement is what I'm looking at first. I was thinking of a fore-to-aft arrangement of equally-sized sphericial tanks. But then I realized the water tank (and probably the propellant tank) would be four to five times the size of the LOX and LN2 tanks. That creates possible center-of-gravity and balance issues.

So, maybe cylindrical tanks of some kind? Laid end-to-end, fore to aft?

Maybe you can use the low gravity of Iapetus for some reuse of the now empty cargo modules for extending the base...

Now THAT is a good idea--kind of reminds of the "wet workshop idea" from Apollo Applications

 

[dgatsoulis]

projectrho's mission calc gives these numbers:

And here is a volume visualization (in cubes)

 

[TMac3000]

Thanks, dgatsoulis. But I can't see them on my work computer...so I'll check them out this evening and get back to you

---------- Post added 03-18-15 at 05:38 AM ---------- Previous post was 03-17-15 at 01:37 PM ----------

Hey, that's really interesting! It makes me think the tankage could be inside the ship, so I would not have to worry about meshing and designing it...

---------- Post added at 07:34 AM ---------- Previous post was at 05:38 AM ----------

Just a thought--if I used a Venus-Earth-Jupiter-Saturn trajectory, it would save dV, but doesn't the time added to the mission mean the extra consumable mass would out-weigh the fuel-mass savings?

 

[Urwumpe]

Just a thought--if I used a Venus-Earth-Jupiter-Saturn trajectory, it would save dV, but doesn't the time added to the mission mean the extra consumable mass would out-weigh the fuel-mass savings?

Is a optimization problem. But 6000 days are already a dwarf below 20 years - that's a lot of dedication for an astronaut, so a few years more will very likely be no problem for the already convinced.

But then... 20 years also mean a lot of time for illnesses, accidents, warfare, zombie attacks....

 

[kamaz]

tampons

Either send an all-male crew, or have women undergo hysterectomy. You're not going to send anyone below 30 (training!), and with a 16-year trip it means they will be at least 46 at return -- that's generally past the child-bearing age, plus the radiation damage to ovaries is going to be considerable.

---------- Post added at 02:22 PM ---------- Previous post was at 02:17 PM ----------

NASA recommends 0.8 kg of oxygen per astronaut per day.

This is with breaking down CO2, or without?

to figure the nitrogen in too. I want a 70/30 atmo at three-quarters of a bar, so I need a...:uhh:about 5-foot LN2 tank to supply that.

N2 is not consumed by humans You may however want to have enough of both O2 and N2 to repressurize the entire ship, possibly several times (in case of decompression).

Also, you want to keep that in several tanks, placed in different parts of the ship.

 

[fsci123]

Why did you choose just Iapetus... Assuming one could travel to the Saturn system, they would probably also have the ability to visit multiple moons in the system.

 

[Urwumpe]

N2 is not consumed by humans You may however want to have enough of both O2 and N2 to repressurize the entire ship, possibly several times (in case of decompression).

Also, you want to keep that in several tanks, placed in different parts of the ship.

In reality, you also have to include leakage, since there is no perfect seal in the world.

But that's some unknown variable, because we have no real idea how the leakage will develop from launch to EOM.