# Tag Info

0

Based on this similar question provided asking about meteors, I suspect the answer is that no, you could not safely assume that satellites would fully disintegrate. If your concern is the threat to astronauts on the surface though, that chance is very, very minimal.

3

More of a comment, but I need the space. Firstly, are you sure about the temperature of the ice being minus 5° C? That's just below freezing temperature and very close to melting temperature. Using the assumption that the ice would be a crystalline solid analogous to a crystalline rock such as basalt, it would be best to keep the size of the openings within ...

3

Since you already have a comet available near Mars, I would propose landing it it on Mars instead. Soft-landing it is only an optional feature and not a hard requirement. You will get all the volatiles (and non-volatiles as well) on Mars. Quite possible that you'll create a hydrosphere at the same time. You will make quite a strong dust storm, but Mars is ...

-1

To add to the "yes, but we'd need a lot of fuel" answers, nuclear pulse propulsion could do it. This system involves chucking nukes out the back of your spaceship, so for safety's sake I'd prefer that you used chemical rockets to get to the other side of the Moon first. You'd also need to overcome some engineering problems, and the nuclear test-ban ...

-2

Misc.: If you were to start from space, like the L5 point, you need less fuel to escape Earth. Fuel needs to be sent to L5, of course. We might be able to make it on the moon! Another issue is if part of the vehicle returns to Earth/L5; only part (the payload) needs to decelerate at Mars. You might harness solar winds to drive you there, and loop the ...

1

The original OP's question Could meteorites prevent Mars exploration? has been transformed into another question that was answered, though partially, into energetic calculations and probabilistic calculations. I will try to answer the original question. First, how can a meteorite prevent colonization of a planet? You must accept that when people take all ...

1

Uhoh's answer neatly covers the damage a given meteorite would have upon impact. I'll add to that approach the likelihood that a meteorite even strikes Mars or Earth. A Martian year is 1.6 times longer than an Earth year (686.96 days versus 365.25). At first approximation, on average, a planet is just as likely to be hit by a meteorite at any point in its ...

2

This is an interesting question! Partial answer! I don't know about the frequency of Martian meteorites, but for a given one we can estimate its terminal velocity (if it reaches it) and kinetic energy. If it doesn't reach terminal velocity, then it's going to be going a heck of a lot faster and have a heck of a lot squared more kinetic energy. A 1 cm radius ...

2

There are a lot of variables in this question concerning exactly when an abort is required and what has caused the abort. Some Mars mission profiles can use a free return trajectory. If this is used and for whatever reason it becomes necessary to abort, it is relatively easy to return to Earth by applying a small course correction. This will allow the ...

0

We only need to generate electricity. You can calculate the amount of energy and change the amount of displacement per cylinder. But generating electricity would be more beneficial than direct drive systems. If solar and wind go down, use the "gas" generator as backup...

3

As in the other answers, your ideas won't save fuel and time, but they may in the future vastly improve likelihood of mission success and crew safety, at the cost of more fuel and time. An unpeopled lander, or a sequence of unpeopled landers could, for instance, establish a fuel depot on Mars to allow for a lighter craft to land, and then refuel with the ...

12

The group picture was taken by a wireless camera that had been released by the rover on the ground, from its bottom side. See this article in Chinese: http://www.cnsa.gov.cn/n6758823/n6758838/c6812123/content.html and use the Automatic Translator. I believe the explanation in Chinese reads: "The picture of the "touring group" was taken after ...

5

Taking the current location of the Zhurong rover, 25.1° N and 109.7° E, as a guide to location of the region in question the Mars Global Surveyor took this photograph in 2004, It shows "whale" like features on the surface of Mars, similar to the ones in your question. The location of these features is the Isidis Planitia 8.6° N, 268.2° W, which is ...

6

Rather than having fuel tanks you meet on the way the better way would be preposition fuel tankers at the start and end of the trip i.e Earth and Mars orbit. You put fuel tankers in Earth's orbit as its the easiest place to refuel (in this scenario) and means you can make use of small rocket launches (crew, ship, and fuel separately) instead of needing one ...

18

If you think less about fuel and more about the other amenities for a long distance mission, you are awfully close to the concept of a cycler. The basic idea is that you take a big vessel, on which astronauts can live for a long time and accelerate it on a trajectory that regularly passes by the places you want to travel in between. You do this without a ...

16

The real problem is that, in space travel, your speed determines your trajectory, and therefore two objects can't follow the same trajectory at different velocities. Precisely, a faster interplanetary trajectory will give you a more elliptic, elongated orbit around the sun, while a slower one will be more round (and I don't even consider the case of gravity ...

3

NASA Moves Longest-Serving Mars Spacecraft for New Observations from February 2014 mentions Odyssey's battery: Odyssey flies in an orbit nearly over the poles and synchronized with the sun. For most of its first six years at Mars, the orbit was set at about 5 o'clock, local solar time. At every spot Odyssey flew over as it made its dozen daily passes from ...

4

The NASA Odyssey Launch Press Kit has a bunch of info, including the electrical power system. It seems to have a nickel-hydrogen battery. Nickel-Hydrogen Batteries have the "distinctive virtue ... [of a] long life", but a cursory search of NASA's Open Data Portal doesn't seem to show anything relevant to Odyssey's current battery status.

30

Unfortunately sending propellant ahead to pick up on route will not help. The same amount of propellant will be needed regardless if both are accelerated together or separately. Also if launched separately it adds to the complexity of the mission as a docking will be required. Any type of docking requires both ship and propellant store to be traveling on the ...

3

There are no risks, only benefits, but the laws of physics dictate that this won't happen for a loooooong time, even with the first couple generations of nuclear rockets, whenever that happens. Earth has a minimum escape velocity, irrespective of mass and currently all space-craft just reach it and coast until they get to their destination and then burn the ...

4

tl;dr: The slow sublimation rate over 4 days rules out CO2 as the primary component (which would have sublimated much more quickly when exposed to the warm-ish atmosphere and sunlight), and careful measurement of the strong downward slope in reflectivity in the near infrared at about 1 micron from hyperspectral imaging demonstrates ~99% water ice for at ...

13

The limitations, as we know it: Fuel. The infamous rocket equation means we get roughly a few times more fuel for every km/s delta-v budget. #1 is why we avoid braking by rocket engines. When we reach Mars, we need to be almost at the speed of Mars and then brake in its atmosphere. If we go faster, Mars' tiny atmosphere cannot brake us enough. And even if ...

2

The question is vague about what it means by "Earth-like". Let's look at some increasingly Earth-like scenarios on the second planet (which I shall call "Terra"). Same gravity as Earth (probably the same mass and diameter as Earth), but none of the other resources described below. You would need to build and launch everything from ...

48

The biggest risk on a flight to Mars is cumulative exposure to radiation, so a 1-2 month flight would actually be much healthier for a crew than a 7-8 month flight. I don't know of any risks that would be increased by a shorter flight. The limitation to making a faster spacecraft is fuel. In order to go a little bit faster, you need to fire your rocket ...

3

Breaking News! (01:24 UTC June 8, 2021) China releases new Mars image taken by Tianwen-1 probe, CCTV (English) Article shows before and after picture of the landing and associated debris: ...taken by a high-resolution camera installed on the orbiter of Tianwen-1 at 6 p.m. on June 2 (Beijing Time) Now to feature map this with HiRISE data for some more ...

22

It turns out there is a paper that discusses this exact ice patch: it's water ice, and they're referring to the white section at the top. (The small granules in the lower left may also be water ice, but they don't discuss that specifically. It certainly looks like small ice chips). Cull et al (2010) "Compositions of Subsurface Ices at the Mars Phoenix ...

5

Basically none, because you're not going outside without a pressure suit. Mars's atmosphere is completely unbreathable. Not only is it completely lacking in oxygen, but it's so thin that humans wouldn't be able to survive breathing it even if it was 100% oxygen. If you go outside without a pressure suit and an oxygen mask, you'll promptly suffocate. As a ...

25

tl;dr: The UV index is primarily concerned with the level of UV-A that can cause sunburn and, potentially, skin cancer. The actual UV-A flux at Mars is not dramatically different from that at Earth (less because of distance, more because of no attenuation). *But the big difference is the unattenuated UV-C and UV-B! The total solar constant at the Earth is ...

8

On Mars, Curiosity has a diffractometer so in principle it should be able to measure the Bragg diffraction that is used to detect quasicrystals. However, such analysis may not have been done yet.

5

From the abstract, it appears the proposed mechanism is not to extremely slowly build an entire atmosphere at 0.1kg/second. That would make little sense, at it merely reduces a loss mechanism, not adding back lost material. Instead, they say that: The Martian atmosphere is currently in an equilibrium, where surface outgassing and solar wind atmosphere loss ...

5

By exhaustive listing: Sojurner: Mission lasted 83 sols, so the entire distance travelled is eligible. 104 meters. Spirit: at least ~500 m, from maps. (I know a distance-per-day table exists, I just couldn't find it now) Opportunity: at least ~600 m, from another map. Perserverance: ~345 m (though that number is from 20th of May, a few weeks off). Curiosity:...

2

Just build for the structural needs of your Mars vehicle, the atmosphere there is thin enough that none of the standard Vacuum nozzles will be overexpanded, and for a rocket operating at the surface, the mechanical size limits will be much more stringent. If anyone want to provide a more comprehensive answer, please do so. The true answer is a ridiculously ...

3

I dug out The Case For Mars (1997) and while it gives some very basic outlines of this, it does not go into any great detail. From Chapter 9: The industrial effort associated with such a power level would be substantial, producing about a trainload of refined material every day and requiring the support of several thousand workers on the Martian surface. ...

2

The paper in question has this to say: After correcting for instrument response, these three transits all have a clear signal with an acceleration amplitude of ~$50\text{ nm/s}^{−2}$and a duration of ∼$100 \text{ s}$. Rotation into a ZNE coordinate system shows afirst pulse of positivepolarity on both horizontal components with a duration of $30 \text{s}$, ...

0

The sky of Mars is blue like the one of Earth. The ESA picture you can admire below the text shows unequivocally that the sky of the Red Planet is much like the one above the Sahara desert. Mars' thin atmosphere. (ESA/DLR/FU Berlin/J. Cowart/CC BY-SA 3.0 IGO)

0

Why wouldn't the sky appear that way? The sky color has little to do with the color of the land. It is to do with scattering of light by particles in the air as we are looking away from the planet. Think about it, why isn't the Earth's sky green here in the Northwest where there is endless forest? Read the NASA article below for why the sky is "blue&...

3

There are many rovers/landers that have taken pictures of the martian sky before. Generally, as raw images, the color of the sky is a dusty caramel color, as shown here. Here is one from the InSight lander as well, which shows more of a gradient. I predict the sky's color would look something like the second picture, depending on how it's calibrated.

2

Supplementary answer, which is also somewhat complementary to both @Hobbes's extensive/exhaustive answer and @LouisvanRijn's intriguing answer and shows that their answers were spot-on! From Forbes.com's Mars Opportunity And Spirit Rovers Could Have Lived Practically Forever With One Tiny Change: One option would be to install some mechanism such as wiper ...

1

Unfortunately Insight's subsurface thermal probe is not in place so we don't have data from Mars, but what it would look like is at say 50 or 100 cm below the surface the temperature was constant, but closer, within say a few centimeters of the top, the surface temperature would drop every night and rise every day. Rock and especially loose soil is a lousy ...

Top 50 recent answers are included