26
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Will the duration of traveling to Ceres using the same tech developed for going to Mars be proportional to the distance to go to Mars or not?
Planning travel within the solar system doesn't work quite like you assume. A spacecraft typically uses its rockets for a few minutes at the start and end of the journey and coasts the rest of the way,...
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18
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How unreachable are Jupiter's moons from Mars with the technology developed for going to Mars?
Let's go back our old friend the Pork chop plotter. Earth to Jupiter using minimum fuel takes around 2 years and you get one opportunity per year, more or less, to get there. You can shorten the ...
- 19.4k
17
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Is going to Ceres "as easy as going to Mars" like this aerospace engineer says?
This hinges as bit on what "as easy as" means. We clearly can't go to Mars today because we don't have the technology. We do have all the bits and pieces in theory, but we haven't build anything that ...
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16
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Would it be possible to get a modified SprHvy booster to orbit, then send a full stack with Starship on a "standard" config, then mate them in orbit?
An earth to orbit rocket is not automatically a good choice for flying interplanetary.
The major problem is that thrust to weight ratio has to be higher than one to take off, but often departure ...
- 21.4k
13
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Accurate map of Ceres
NASA has produced a topographical features map of Ceres, with names for some craters. The map was produced in 2015.
This one has few more details,
- 13k
12
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How unreachable are Jupiter's moons from Mars with the technology developed for going to Mars?
I whomped up a spreadsheet to compare scenarios like this: Hohmann.xls.
Typing Earth into departure planet cell and Mars into destination planet I get
Launch windows open each 2.14 years (synodic ...
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11
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Why was Dawn placed into an orbit that would only be stable for "decades"
Why was Dawn placed into an orbit that would only be stable for “decades”
In order to simultaneously obey the rules and maximize science.
Maximizing science means staying at Ceres and collecting data ...
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10
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Is going to Ceres "as easy as going to Mars" like this aerospace engineer says?
Well, I'd say that "We can go to Ceres as easily as Mars" isn't quite true, but it's really a matter of perspective.
On the one hand, measuring by fuel expenditure, specifically rocket delta-v, a ...
- 18.1k
8
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Accurate map of Ceres
The USGS Astrogeology Science Center's Astropedia is an excellent source for derived mapping data products (though only 7 Ceres products).
Here is a "Ceres Nomenclature" data product:
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7
votes
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Would a sniper bullet fired on Ceres reach orbital or even escape velocity?
Indeed, you are correct, it could reach escape velocity. The M110 can reach speeds of over 700 m/s, which is well above the escape velocity. Most guns actually don't need oxygen to work either, as the ...
- 121k
7
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Terraform via moving Ceres To Mars orbit, using ion drive
We're a long way away from being able to do this.
Is it theoretically possible? Let's see if we have enough delta-V:
Mass is 1021 kg, with 1/3 available as propellant.
Using the Rocket Equation:
...
- 126k
6
votes
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Manned exploration or Colonization of Ceres -- Any studies
There is a lack of solid, science-based study into realistic colonisation options because until Dawn arrived very little was known for certain. Much more is known now but even so, we know probable ...
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6
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Xenon vs Hydrazine, "Should I Stay or Should I go?" Dawn mission decisions
There is one wheel still operable (at least it was operable the last time they operated it), but Dawn no longer uses it. The third wheel failure was in April of this year (2017 for those reading this ...
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6
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Would it be possible to get a modified SprHvy booster to orbit, then send a full stack with Starship on a "standard" config, then mate them in orbit?
It might be just barely feasible, …
… given a generous dose of handwavery and wishful thinking.
SpaceX can't be bothered to release detailed design docs, so we will have to resort to rough ...
- 1,565
6
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Will the duration of traveling to Ceres using the same tech developed for going to Mars be proportional to the distance to go to Mars or not?
In addition to Steve Linton's excellent answer there's a simple pattern:
To get somewhere for the minimum fuel generally takes one half the orbital period of the slower of the launch and target ...
- 11.5k
5
votes
Asteroid Mining on Ceres
Ceres has a surface gravity on of 0.029G and an escape velocity of 500ms. So there would be a down, standing up would be possible and it would be impossible to accidentally escape into orbit. Falling ...
- 21.4k
5
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Is Dawn's upcoming low periapsis orbit for XMO7 "resonant"?
This is not a complete answer but I can offer an example of an orbit being in resonance with the rotation rate of a central body.
Astrophysicists indeed sometimes use the word "resonant" to describe ...
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5
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Those bright spots on Ceres — are scientists still "scratching their heads"?
Wikipedia has a decent summary of the current state of thinking on the bright spots in Occator crater:
on 29 June 2016, scientists reported the bright spot to be mostly sodium carbonate (Na2CO3), ...
- 126k
5
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How can I verify my reconstructed gravity field of Ceres from spherical harmonics?
Formulation
Brandon A. Jones wrote an excellent summary of the different formulations and methods to compute spherical harmonics in his 2010 PhD thesis available here. Chapter 2 is especially of ...
- 6,200
4
votes
Accepted
Ceres gravity from spherical harmonics from Dawn, how to get the coefficients, definitions and potential?
What you're missing is the descriptions of the contents of that file. That's in another file, right next to the one you found. The data for the Ceres gravity model are in JGDWN_CER18C_SHA.TAB and the ...
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3
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How unreachable are Jupiter's moons from Mars with the technology developed for going to Mars?
Using @HopDavid's excellent spreadsheet, we get a delta-V of about 6.9 km/s for a 3 year mission from highly elliptical Mars orbit to Callisto, the only one of the large moons where the radiation ...
- 19.4k
3
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Could a Human reach escape velocity by jumping from the surface of Ceres (a dwarf planet)?
Surface gravity gives no information about escape velocity. Saturn for example has a surface gravity comparable to Earth, but an escape velocity three times higher. Similarly, if the Moon had a 10% ...
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How to achieve escape velocity from Ceres?
A hydrazine monopropellant rocket would have a specific impulse of around 230-240 seconds and so an exhaust velocity around 2000 m/s. The rocket equation then tells us that for a delta-V of 262 m/s ...
- 19.4k
2
votes
Terraform via moving Ceres To Mars orbit, using ion drive
Ceres orbital speed is 17km/sec
To make it intercept, you need to do a 5km/sec burn according to http://www.projectrho.com/public_html/rocket/appmissiontable.php
Ceres is 9x1020 kg
In other words you ...
- 12.6k
2
votes
Terraform via moving Ceres To Mars orbit, using ion drive
For example, from the Moon, the characteristic time of the atmosphere loss would be some ten millions of years*. Mars is further from the Sun, and has a higher gravity. This would be enough for us. ...
- 3,276
2
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Xenon vs Hydrazine, "Should I Stay or Should I go?" Dawn mission decisions
To answer the question about staying at Ceres or going somewhere else:
Dawn does not have enough Xenon propellant left to enter orbit around another asteroid. It can leave Ceres, but can only do a ...
- 126k
2
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Xenon vs Hydrazine, "Should I Stay or Should I go?" Dawn mission decisions
I think that your guess addressing the decreasing with the orbital radius $(1/r)^n$, $n=3...\infty$ of the non spherical terms for the gravity potential are probably the clue to the problem. This ...
- 1,772
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Could a Human reach escape velocity by jumping from the surface of Ceres (a dwarf planet)?
Folks here are assuming that a human cannot run 265 m/s. But it seems to me that such a speed would be attainable on Ceres, especially if you allow me to build a track and ride a bicycle. On Earth ...
- 21
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Thermal management of manned craft at Ceres
In short: the answer is yes to all of the above and the amount of each depends on details.
Thermal design of spacecraft usually starts out with assumptions regarding the size, total heat loads, and ...
- 463
1
vote
Accepted
Would a space rocket launching from Ceres in a path to Jupiter be faster relatively to the sun than one launching from Earth?
On the down side, at 2.77 times the distance from the Sun as Earth, the orbital speed of Ceres is $\sqrt{1 / 2.77} = 0.6$ of Earth's orbital speed.
But on the up side, it's also starting higher up ...
- 148k
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