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I've always been curious about how a manned expedition to Callisto with a landing there and telerobotic exploration of the remainder of the Jupiter system would shape up.
I assume nuclear electric propulsion would be ready by the time we went to Jupiter meaning a one way trip of 2.2 years.
How long would the total mission last? 5 & 1/2 years or so?
And what about a similiar mission to Titan?
I've always assumed that in exploring Jupiter or Saturn that we would send crews of at least 12 to each.
I'm still hoping the U.S. sends missions that far during my lifetime (I'm 37).
Any thoughts? And yeah, I know this forum is about Mars, but we shouldn't be limited in the discussion to one planet.
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Jupiter is the next stop after Mars, but we'll need a pretty highly advanced electric engine or somthing even more exotic to go that far in a reasonable time frame.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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Jupiter is the next stop after Mars, but we'll need a pretty highly advanced electric engine or somthing even more exotic to go that far in a reasonable time frame.
NEO, venus and maybe murcury
Dig into the [url=http://child-civilization.blogspot.com/2006/12/political-grab-bag.html]political grab bag[/url] at [url=http://child-civilization.blogspot.com/]Child Civilization[/url]
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Jupiter is the next stop after Mars, but we'll need a pretty highly advanced electric engine or somthing even more exotic to go that far in a reasonable time frame.
NEO, venus and maybe murcury
Lack of resources to utilize in situ on an NEO or Mercury.
We won't land a manned mission on the Venusian surface until we have armored exoskeletons to help protect astronauts.
Callisto has ice. So we can easily get hydrogen, oxygen, and of course water. Reduces the mission logistics tail.
I suspect that JIMO and a Europa probe will be the last of the unmanned Jovian missions.
Titan is arguably, the most hospitable place in the solar system aside from Earth.
Surface conditions and available resources will determine our destinations alot more than time and distance.
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Near Earth asteroids are the easiest targets. In fact, they are much easier than Mars and arguably easier than the Moon. We could even see a trip to one before astronauts go to Mars. However, all of these would be short Apollo style missions and I don't see any asteroid bases or colonies happening any time soon.
For Venus, the pressures, temperatures, and chemistry should be enough to keep humans away for a very long time.
Mercury is much easier than Venus, but it is still not really very hospitable and the solar flares will be pretty nasty that close to the sun. It will get a low priority.
Jupiter's icy moons are the next easiest targets. With a Hohman transfer orbit, it would take 2.8 years to get to Jupiter. It will be a long mission, but it should be doable without any major technological advances.
Titan comes after Jupiter's moons. A Hohman transfer orbit would take 6 years to get to Saturn, and there would be almost no sunlight. It does have the advantage of an atmosphere that is 1.6 times as thick as Earth's, but you would still need oxygen and it would be extremely cold. Overall, I think that it would be significantly less hospitable than Mars, and it will defiantly require some advanced space nuclear reactors.
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I think a concurrent program targeting all potential system resources makes the most sence. There is no reason to say well, Mars is done, what's next? In this way I disagree with Mars Direct. After you have done the hard work of developing a HLLV to get stuff off of earth, it makes no sence to exclude the moon as a target for you missions. Not that a mars mission should be dependant upon the moon, but both could certianly proceded at the same time.
Likewise, the next generation of mission, brought on by NTR and NEP should target the resources of the outersytem as well. However, I would be warry of missions to Jupiter. The planets gravity well is immense, and a mission inside it could have a very hard time getting back out.
Titan however is a dream come true. I would start sending missions as soon as it becomes possible.
He who refuses to do arithmetic is doomed to talk nonsense.
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The first destination after Mars I'd consider is Venus orbit. If we could place a large enough hab in orbit--say, 100 square meters per person, probably made up of a series of inflatables with redundant life support, two or more of which have radiation shielding--we could install a permanent station in orbit there, from which robotic atmospheric and surface exploration could be run real-time. I'd put the station in an elliptical orbit, periapsis perhaps 500 kilometers up, apoapsis about 30,000 kilometers, giving the station a roughly 1-day orbit around the planet. From such an orbit the delta-v back to Earth would be about 1 kilometer per second, and it would be easy to send probes to the surface. You'd also need a network of communications satellites and a small ion tug for hauling surface samples from a low Venus orbit up to a high orbit (assuming you could get the samples into orbit at all!).
I wouldn't rule out Mercury, either. We'll need engines of considerable power to get there, just like a Jupiter mission. But Mercury is closer and easier to visit, and faster. It might make a good Jupiter precursor mission. There is almost certainly ice at its poles, a good source for return fuel, and by then if there's ice at the lunar poles we'll have developed a technology, adaptable for use on Mercury, to use it.
I am more pessimistic about manned bases on Titan because of the immense cold and the low light levels. The base could indeed operate at normal Titan atmospheric pressure; that would help. But you'd be running your base essentially inside a cryogenic fuel tank. The thick atmosphere will be a constant heat sink; methane rain will make it even worse. The ground would be a huge heat sink as well. You'd need a lot of power to keep yourself warm. You might have problems of ground instability under the base as well because of heating (rather like permafrost problems on Earth).
The cold will mean the base may not have any windows. Besides, Titan's day is two weeks or so long, which means a week of dingy orange-gray is followed by a week of pitch blackness, occasionally punctuated by a bit of hazy Saturn light. The sun provides only 1% as much light at Saturn's distance and the clouds absorb probably close to 90% of it, so the surface lighting is about 1/1000 as much as Earth. Depressing.
It might be easier, initially, to set up a base on one of Saturn's airless moons, where the vacuum provides excelent cold insulation and the sunlight is brighter to the eye.
On the other hand, Titan is such a big and fascinating world, it might be worth it.
-- RobS
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Say you wanted to deliver a 100 ton spacecraft to Callisto.
Assume you use water on Callisto to produce both return fuel and for personal use.
Assume you have nuclear rocket engines of the type we could reasonably expect to build within the next 20 years.
How much mass would you initially start with from LEO?
Note: Assume crew of twelve.
And what would the total mission duration likely be?
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Twelve might be pushing it crew wise.
With a Gas Core NTR rocket, the mass wouldn't be too outlandish.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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Twelve might be pushing it crew wise.
With a Gas Core NTR rocket, the mass wouldn't be too outlandish.
What do you think the mass leaving LEO would be?
And what would total mission duration be probably?
I thought five and a half years with about a 4.4 years total transit time and 1.2 years there.
But I could be wrong.
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Someone will need to come up with a delta-v, for starters. A Hohmann transfer orbit takes 2.7 years each way; rather slow. The delta v from a 400 km orbit is 6.3 km/sec and the delta-v to go into an orbit around Jupiter at Callisto's distance is 5.5 km/sec. I wonder what the delta-v would be for a flight out of closer to 1 year.
-- RobS
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What distance must you get from the sun that radiation hazards from solar flares diminish considerably?
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I consider Callisto or Ganymede as the new challenge when Mars is reached. We can't stop :band:
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I consider Callisto or Ganymede as the new challenge when Mars is reached. We can't stop
All explorers won't stop at Mars, but the marsians will. Given their more accessible resources, exploration of the outer solar system may become as much their decision as it is Earth's.
"We go big, or we don't go." - GCNRevenger
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In terms of distance Ceres in the asteroid belt is 2.8 AU from the Sun but has very low gravity, Venus is 0.7 but nothing that lands survives on the surface for long and its harder to fall inward in the Solar System which leads to the idea of exploration by way of robot balloons, there are Earth trojans but probably with few resources. I have always said the Moon should come after Mars and that probably other things that are not man, Cyborgs, extreme forms of bred animal and plantlife and Artificial Intelligence Machines might colonize and set up farms before man arrives, Jupiter is 5.2 astronomical units with extremes of radiation.
There were reports China had an interstellar voyager type probe planned or Neptune mission or Planned a 2-in-1 Mission to Jupiter and Uranus. The Tianwen-4 mission would attempt to launch aboard the same rocket and then embark on separate trips to the outer solar system.
Gan De: Science Objectives and Mission Scenarios For China’s Mission to the Jupiter System
https://docslib.org/doc/8023577/gan-de- … for-chinas
Jupiter Mission by China Could Include Callisto Landing
https://www.planetary.org/articles/jupi … to-landing
Callisto geodesy: A simulation study to support further space missions to the Jovian system
https://app.dimensions.ai/details/grant/grant.8968494
Europe's JUICE Jupiter spacecraft arrives at spaceport ahead of April launch
https://www.space.com/juice-jupiter-mis … -spaceport
At Jupiter, JUICE and Clipper Will Work Together in Hunt for Life
https://www.scientificamerican.com/arti … -for-life/
The concept that would ultimately become JUICE emerged in 2008, as part of a joint venture with NASA dubbed the Europa Jupiter System Mission (EJSM).
Last edited by Mars_B4_Moon (2023-02-22 07:32:20)
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Robert Zubrin has explored many of these possibilities in print. But I'm really happy to see these older topics revived and discussed actively,
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Yes, old is the new and with that we need nuclear that is safe to provide the energy that we would require to go beyond Mars as that is man space exploring fate.
It's also good to see you are well and back to post once more.
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NASA's Dragonfly on Titan.
Twitter social media talk
As he kicks off the Goddard Memorial Symposium this afternoon, JHUAPL's Bobby Braun mentions that the Dragonfly mission led by APL passed its preliminary design review last week.
https://twitter.com/jeff_foust/status/1 … 4500801536
China Callisto rumors or gossip?
Two competing mission profiles the 'Jupiter Callisto Orbiter' (JCO) and the 'Jupiter System Observer'
Goals of Tianwen-4 Jupiter mission were detailed in an article published in a Chinese academic journal, they include the following: study of the interaction between magnetic fields and plasma present in the Jovian system, examination of the compositional variations in the Jovian atmosphere, exploration of the internal structures and surface characteristics of either Ganymede or Callisto.
https://web.archive.org/web/20230119011648/http://epizodsspace.airbase.ru/bibl/inostr-yazyki/Chinese_Journal_of_Space_Science/2018/5/Xu_et_al_China's_Planning_---_before_2030_Chin_J_Space_Sci_38_(2018).pdf
The goals include: to study magnetic fields and plasmas of the Jupiter system and their interactions; to detect the variations of the composition and structure of Jupiter’s atmosphere; and to detect the space environment, surface characteristics and internal structure of Galileo satellites (Callisto or Ganymede)
The original name referenced the fourth century BCE Chinese astronomer Gan De, who made early planetary observations and reputedly first observed the Galilean moons with the unaided eye
Noted scientist provides update on NASA missions at FSU
https://www.dailyamerican.com/story/lif … 945981007/
In several ways, however, Titan’s environment resembles the early days of planet Earth. In the distant past, our own atmosphere was largely composed of nitrogen and methane. Titan’s atmosphere and surface also contains a large volume of organic compounds which are essential to life as we know it. Surprisingly, beneath an icy surface shell, Titan appears to have a global subsurface ocean composed of liquid water and ammonia. For these reasons, scientists have chosen Titan as a prime target for an upcoming space mission to search for the origins of life and the search for life beyond Earth.
Last edited by Mars_B4_Moon (2023-03-09 09:37:45)
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The Favorite Solar System Moons of Planetary Geologists; An In-Depth Discussion
https://www.universetoday.com/160658/th … iscussion/
The moons of our Solar System have garnered quite a lot of attention in the last few years, especially pertaining to astrobiology and the search for life beyond Earth. From the Galilean moons of Jupiter to the geysers of Enceladus to the methane lakes on Titan, these small worlds continue to humble us with both their awe and mystery. But do the very same scientists who study these mysterious and intriguing worlds have their own favorite moons? As it turns out, seven such planetary geologists were kind enough to share their favorite Solar System moons with Universe Today!
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Of all the moons of planets in our solar system that could potentially be reached in reasonable time frames with current or developing technology, Callisto seems to be the "most hospitable," based on exposure to radiation and availability of essential resources.
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I agree with Oldfart1939. Of Jupiter's moons, Callisto makes the most sense. It's a long way there, even with any imaginable nuclear fission propulsion, though.
Titan at Saturn is just too bloody cold. The other airless moons at Saturn might be candidates, but the travel time is quite long, no matter what kind of propulsion you assume.
The asteroid belt is a lot more reachable, being not all that far past Mars. All of those are airless, and most have almost-negligible surface gravity. That makes missions less expensive, once you pay the price to rendezvous at all. Only the really big ones might have volatiles as recoverable resources, though. The metal ones are quite rare. Not much else is of any known utility to us.
GW
Last edited by GW Johnson (2023-03-25 16:36:59)
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
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There is some good info on the NASA, ESA orbiters in the 'Jupiters Realms' thread, Clipper and Juice
https://web.archive.org/web/20230410113 … nchKit.pdf
Juice will carry ten state-of-the-art instruments, including the most powerful remote sensing, geophysical and in situ payloads ever flown to the outer Solar System. Nine of the instruments are led by European partners, and one by NASA. Juice also includes an experiment called PRIDE, which will perform precise measurements using radio telescopes on Earth.
EUROPA
Surface: young, active
Juice flybys: 2
Juice’s closest approach: 400 km
GANYMEDE
Surface: varying, offering a geological record spanning billions
of years
Juice flybys: 12
Juice’s closest approach: 400 km during flybys, 500 km
whilst in orbit (potentially aiming for 200 km)
CALLISTO
Surface: oldest in Solar System, heavily cratered
and inactive, remnant of the early Jovian system
Juice flybys: 21
Juice’s closest approach: 200 km
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Ganymede may be more "scientifically interesting" than Callisto, due to the presence of a magnetosphere, but is far less hospitable.It would be possible to do some surface exploration of short duration there, but the radiation environment will still subject astronaut-explorers to manageable doses. Most of the time there will be spent below ground in radiation shelters.
Callisto is a better choice of an outpost for further Solar System exploration.
Europa is far to hostile on the planetary surface, w/r radiation.
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a topic which perhaps relates to discussions on ExoMoons
Why Do So Many Moons Have Oceans?
https://nautil.us/why-do-so-many-moons- … ns-302939/
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With all deployments complete, Juice is fully stretched out and ready for cruising to Jupiter
https://twitter.com/ESA_JUICE/status/16 … 2103128065
Our mission will obtain the most detailed pictures ever of Jupiter's moon Europa. The camera that will make it possible has now been integrated onto our spacecraft!
https://twitter.com/EuropaClipper/statu … 4396642306
Radiation Maps of Europa: Key to Future Missions
https://europa.nasa.gov/news/17/radiati … -missions/
In his new paper, Nordheim didn’t stop with a two-dimensional map. He went deeper, gauging how far below the surface the radiation penetrates, and building 3D models of the most intense radiation on Europa. The results tell us how deep scientists need to dig or drill, during a potential future Europa lander mission, to find any biosignatures that might be preserved.
The answer varies, from 4 to 8 inches (10 to 20 centimeters) in the highest-radiation zones – down to less than 0.4 inches (1 centimeter) deep in regions of Europa at middle- and high-latitudes, toward the moon’s poles.
To reach that conclusion, Nordheim tested the effect of radiation on amino acids, basic building blocks for proteins, to figure out how Europa’s radiation would affect potential biosignatures. Amino acids are among the simplest molecules that qualify as a potential biosignature, the paper notes.
“The radiation that bombards Europa’s surface leaves a fingerprint,” said Kevin Hand, co-author of the new research and project scientist for the potential Europa Lander mission. “If we know what that fingerprint looks like, we can better understand the nature of any organics and possible biosignatures that might be detected with future missions, be they spacecraft that fly by or land on Europa.
Europa Clipper’s mission team is examining possible orbit paths, and proposed routes pass over many regions of Europa that experience lower levels of radiation, Hand said. “That’s good news for looking at potentially fresh ocean material that has not been heavily modified by the fingerprint of radiation.”
Last edited by Mars_B4_Moon (2023-06-01 06:53:47)
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