New answers tagged

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This is a supplement to the accepted answer from @JohnHoltz to show an example of the maximum solar radiation in Jezero crater (18.38⁰N) throughout a full martian year. Februari 18, 2021 (planned landing date Perseverance): r = 1.57021553, lat.= 2.243093 --------------------> ............................................................717 x 0.773941 ...


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In this question I suggested, that, on the face of it, the SS520-5 sounding rocket could get about 5kg from the surface of Mars onto a trajectory to hit Earth. That rocket (a three stage solid fuel rocket) masses 2.6 tons at liftoff. Let's make the rather large assumption that I haven't missed any problems (someone has already suggested the cold as an issue)....


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Earth Orbit Rendezvous is a method for applying brute force. Mars Orbit Rendezvous actually improves efficiency, potentially by a lot. A Mars sample return (or, for that matter, a straight-up crewed mission to Mars) needs to do the following in order: Launch from Earth (*) Get on transfer orbit to Mars (*) Land on Mars with an ascent vehicle ready Take ...


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I asked one of the copter's engineers, Matt Keennon, what the hole in that one leg's foot was for. He replied that it's only for stowage. ... because of the odd way the copter is held in place under the rover, with all sorts of mechanical constraints from the rover, that one leg could not be held down by a simple lever pressing on the leg strut, so instead ...


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The solar radiation can be calculated knowing the distance from the Sun, the subsolar latitude, and the latitude of the place of interest. Knowing those three values, the calculation would be as follows: $$solar\; radiation = 717\; W/m^2*\left(\frac{1.38138027}{r}\right)^2*cos(latitude-subsolar\; latitude)^0$$ The term $(1.38138027/r)^2$ corrects for the ...


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You obviously could do this, by fudging $\epsilon$ suitably. However this idealised greenhouse model is wrong for Earth and is probably wrong for Mars as well. It's wrong for Earth because the atmosphere is not optically thin for long-wave radiation (infrared), so you simply can't consider the atmosphere as a single layer like this. Instead you have to ...


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Solar Irradiance Mars has seasons, just like Earth. While Mars weather is significantly less interesting than Earth's, due to the thinner atmosphere, the average temperature difference between summer and winter can be more than 50 C. The difference between daytime high and low can be more than 120 C. If we consider the three forms of heat transfer, we can ...


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There is Carnot's theorem for the theoretical maximum efficiency of heat engines. It is valid not only for mechanical engines like steam engines or Stirling engines but also for solid state devices like the thermocouples used in RTGs. The Carnot efficiency depends on the upper and lower working temperature. $$ \eta = 1 - \frac {T_c}{T_h} $$ Tc is the cold ...


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All heat engines, whether mechanical or solid state, produce work based on heat flow across a temperature difference. The maximum efficiency of a heat engine depends on how large that difference is.


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The 3 vacuum engines will be used for Trans Mars Injection (TMI) since they are more efficient in vacuum. While each one is off centered, firing all 3 will make it balanced, so this makes the most sense. For landing, it will be a bit trickier. I haven't seen anything publicly, but I suspect they will use the vacuum engines for part of the time, and the 3 sea ...


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No, Perseverance will not drive for months with the helicopter stowed on its underside. From the Surface Phase of the Mars 2020 Perseverance Launch Press Kit I got the information below. The first 30 sols after landing will be a commissioning phase within which the rover will perform a short drive test. After that Perseverance will need to find a flat area ...


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@JamesK's answer indicates that HiRise is the "highest resolution camera on a Mars orbiter" but it's worth noting that it is also (at least currently) the highest resolution known, human-built camera anywhere in deep space! @Phiteros' answer to What's the largest aperture telescope sent beyond the Earth-Moon system? begins: After looking through ...


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Answering the "what would work?" part of the question: I would use an electret haired brush which barely touches the surface of the solar panels. Electret filters are very effective in collecting fine particles. The brush is mounted on a simple wiper. Once it collected the brown powder it vibrates downstream to shed the dust of, a bit like a dog ...


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The highest resolution images come from the HiRISE camera on the Mars Reconnaissance Orbiter. With an angular resolution of one micro-radian it has a ground resolution of about 0.3 m (12 inches) Here's an image of the Phoenix lander on its parachute, at a resolution of about 30cm taken from https://static.uahirise.org/images/2008/details/cut/...


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Is Perseverance still in Safe Mode? Not any more: NASA's Mars rover Perseverance is fine and out of 'safe mode' as of July 31, 2020.


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It was as of the latest update, but they were working on recovering it. They have full communication with the spacecraft as of now. The press release, issued on July 30, stated the following: Right now, the Mars 2020 mission is completing a full health assessment on the spacecraft and is working to return the spacecraft to a nominal configuration for its ...


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Many sources. (eg this one) mention the samples orbiting Mars in a "basketball-sized" container until collected by the Earth Return Orbiter. I haven't seen any authoritative ones saying it's also shaped like a basketball.


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How about both .since the space station is mainly shielding .fabricate it from materials needed to kick start mars colonization .Resources from the moon probably aluminium maybe water .Most of the other materials from asteroids. Sending platinum group metals etc back to earth .When the second generation of space station has been constructed send first ...


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Why will we go to Mars? It certainly is not ideal to build a colony on Mars. There are many threats to human life there - it is one of the deadliest environments a human could be in. To Elon Musk, inspiration is the key to human progress and motivation - we will go to Mars for the same reason that humans do space exploration at all - it inspires us and we ...


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Partial answer; rather than an areostationary orbit with zero inclination, an inclined areosynchronous orbit (i.e. same period but tilted) would never lose direct line-of-sight to Earth except when it goes behind the Sun. From the surface of Mars it would make a figure-eight in the sky once a day (see this answer for what those look like), but these days ...


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@MarkAdler's answer begins It's not. but I'd refine that and say It's not expected to be. In What precautions are planned to prevent samples returned from Mars crashing and releasing organisms on Earth? I imagine the unlikely event that the returned sample capsule crash lands and opens and then the second unlikely possibility that it contained either ...


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There is a giant committee set up among all the space powers to coordinate this. From the ESA page: http://www.esa.int/esapub/bulletin/bulletin121/bul121e_marelli.pdf "The Space Frequency Coordination Group (SFCG): The SFCG was created 24 years ago as an ESA and NASA initiative. It is an informal group composed of frequency managers from all of the ...


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Much of engineering is about compromises. One can find an ideal solution, like a Hohmann transfer orbit. Yes, that is the most fuel efficient way to get from earth orbit to Mars orbit. It is like the top of a rounded mountain. That is the peak, but there is a lot of ground near the peak that is almost as high. Maybe you are willing to give up a bit of ...


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Answers to Could "live" video be transmitted from Mars? suggest this is theoretically possible. No, they don't. Imagine having 1-3m (or more) parabolic antenna deployed during landing and precisely directed to Earth. An aerodynamic nightmare. Edit: According to https://mars.nasa.gov/mars2020/spacecraft/rover/communications/ there is an "up to ...


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Resources, as Pearson mentioned, are the key; specifically matter. An object in the inner Solar System is emphatically not a closed system, so the second law of thermodynamics does not apply: Any object here is embedded in the Sun's radiation, an inexhaustible source of low-entropy energy. This energy flux enables it to lower its entropy (by radiating even ...


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The thing your're missing is that the Hohmann Transfer orbit takes time, and both Mars and Earth are moving around the sun. For the Hohmann Transfer orbit to work, the position of Mars at arrival has to be opposite the point of of Earth at Departure. The following image depicts Earth's and Mars' orbit as circular, rather than elliptical to simplify ...


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I found this article for the 2012 Curiosity rover launch which stated that NASA Television will be broadcasting live coverage of Curiosity's landing on Aug. 5 beginning at 8 p.m. EDT (I also found this video showing the mission control room during the landing but I don't know if that was shown live) So, I suppose that it is probable that we will see live ...


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The technical reasons for colonizing Mars instead of building space stations are all spurious. So why Mars? An entrepeneur will garner more kudos colonizing Mars than being in the business of space stations. Not unless, the entrepeneurs discover a good money-making reason for building space stations and that a colonized Mars is less profitable. In fact, ...


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Quite possibly Upon learning that Mars did have surface water at some point, you have updated your question to ask if Mars would be a good approximation for Earth if Earth had little to no water, or if the water had been missing for a period of time. Conversely, try looking at areas of the Earth that have had little to no water, or where the water has been ...


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It's motivational. Had JFK given us a more realistic goal than landing a man on the moon by the end of the decade, we would have failed. Such a goal might have been: First, I believe that this nation should commit itself to achieving the goal, before this decade is out, of establishing a permanent outpost in space, in preparation for landing a man on our ...


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There were some instruments attached to the heatshield that took measurements of the atmosphere during the entry, descent, and landing phase. This suite was referred to as MEDLI (MSL EDL Instruments). This was used for gathering data about how the heatshields performed, and what the atmosphere around them was like, during EDL. While instruments measuring how ...


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According to NASA, it is already "almost" arable: [...] the soil on Mars actually does have the nutrients plants would need to survive on Mars! There may not be the right amount of nutrients depending on where astronauts land on the Red Planet, so fertilizers may need to be added to the soil. The perchlorates in the soil would be leached out and ...


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Actually, it's possible to use perfluorocarbons to create the necessary greenhouse effect: https://science.nasa.gov/science-news/science-at-nasa/2001/ast09feb_1. These are much stronger greenhouse gases than CO2 and are also non-toxic. Of course, terraforming would still be an expensive and long-term project, even using these gases.


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It's a bit of a late answer, but most proposals don't actually use increased CO2 to warm up the planet. They use super-greenhouse gases (like perfluorocarbons), or they increase the amount of sunlight hitting Mars. As for a terraforming roadmap, there's one by Robert Zubrin, which proposes that it would take about a thousand years. However, others argue ...


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I think the reasons are psychological - that occupying and building a life on a planet is more comprehensible and appeals better to people, by using the appearance of opportunities that are in a more familiar form. It is easier to popularise and market than promoting the building of space habitats. Any colony attempts will rely heavily on taxpayer funded ...


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Other answers have already mentioned the availability of resources and the ability to endure disasters, which I agree are two key reasons. I have not yet seen anyone mention what I consider the third key reason. Elon Musk does not just want to take us to Mars, he wants to make humanity a multiplanetary species. Sufficiently many people (a commonly ...


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One proposed method for this would be to use silica aerogel: https://www.nature.com/articles/s41550-019-0813-0. This would block UV light and also raise the temperature to above freezing point (via the greenhouse effect). As for the water problem, while there is indeed no liquid water on Mars, there is water chemically bound in minerals like gypsum, which ...


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Are there other good reasons to choose Mars instead of space stations in some orbit? Perhaps the following non-technical but social argument could be a good reason: Much like in the space-race to the Moon, exploring natural solar bodies with actual humans can have profound and inspiring effects on (both/all) colonies of conscious beings. Having a spaceship, ...


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Radiation I think this is actually the biggest concern, IMO. Astronauts aboard the ISS have a measurably increased risk of cancer due to their higher radiation exposure. Putting enough shielding on a space hab to reduce risk to earth surface levels would be unimaginably expensive. On the other hand, Mars has gigatons of surface rock which makes a pretty ...


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The big problem is that space is empty. To build the space station, people need to haul every single gram there. Every single atom on a space station needs to be shipped there at cost--whether it's from an asteroid, planet, or elsewhere. On Mars you have the ability to use local resources. You can easily dig and build using the resources at hand without ...


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The biggest advantage of Mars is there are resources available on that planet. Run out of oxygen? Make your own! Same with water. Set up refining, and you can make your own metal. Large windows are more difficult in no atmosphere than Mars's thin atmosphere, which makes growing crops easier, at least according to The Case for Mars. I believe this is because ...


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HiRise routinely observes at high latitudes. In fact I can quickly find these examples: At $86.8^\circ$: https://hirise.lpl.arizona.edu/ESP_035295_2670 At $82.2^\circ$: https://www.uahirise.org/ESP_027324_2625 At $87.9^\circ$: https://www.uahirise.org/PSP_010623_2680 At $85.8^\circ$: https://www.uahirise.org/PSP_010636_2660 You have a large gallery of high ...


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