Nibb31

Why is that obvious?

Ouch! The wrongness, it must hurt! That is not how a hypothetical space elevator works, not on Mars, not on Earth, not anywhere. The whole point of a space elevator is to reach orbit. The end station therefore must be at a geostationary (or areostationary in this case) orbit. If it's any lower, then you don't reach orbit and you fall down when you step off the elevator. A space elevator is built by launching the end station into an equatorial geostationary (areostationary) orbit, and unreeling two tethers: one down to the ground and one away from the ground to act as a counter-weight. The satellite has to, at a minimum, carry both reels of unobtanium tether material that is strong enough to support a climber vehicle, rigid enough to withstand traction over 36000km (or 17000km for Mars), and light enough to be launched. So far we don't have such a material. Without the counter-weight, the CoM moves away from the satellite and your end station is no longer where it should be. How would you build a centrifugal space elevator exactly? How could you assume that it's easier to build one on Mars than on Earth if you don't understand how it's built? The answer is, you can't, because that's not how a space elevator works. If the centrifugal force was that strong, Mars would be ejecting it's own mass rocks and would gradually destroy itself. GEO satellites in Earth orbit require station-keeping because of orbital resonance from the Moon and even from planets and tiny irregularities in Earth's orbit. Phobos and Deimos are smaller satellites, but they will be passing much closer, above and below the elevator CoM station, causing a much stronger disturbance. They *will* influence the orbit of the elevator, at best causing its orbit to "wobble", at worse causing it to fly off course, which will create tension on the tether. Just like any GEO satellite, the station needs station keeping to remain at the exact point over the equator. At one point, because all orbits end up crossing the equator, the orbit of Phobos *will* intersect the elevator. Which makes your argument a non-sequitur. You suggest that the main reason to build a Mars colony is because it's a good place to build a space elevator, but you need a large Mars colony to build a space elevator. If we have a large presence on Mars, then the problem of mass transport to build and support that large presence will already have been solved. The truth is, there is no compelling reason to build a Mars colony in the first place.

You still need to build the massive power station and the infrastructure to produce the materials for the elevator on an alien planet. It's a massive task that requires a massive infrastructure. The inconvenience and complexity of building something like that on Mars outweighs any benefit compared to other launch methods. And you don't address the problem of Phobos and Deimos crossing your path above and below the elevator station. They don't even need to collide, the gravitational pull alone will push your station out of orbit.

You can experience microgravity without going to space by booking a seat on a parabolic flight (there are several aircraft in the world equipped for this, often nicknamed "vomit comet"). You sit in the aircraft while if flies up and down on parabolic trajectory. At the top of each curve, you get a few seconds of microgravity. In fact, you can get the same phenomenon riding an elevator going down, or when you drive over a speed bump. It has nothing to do with altitude, of course. If you fly straight up, as soon as the engine stops, your rocket falls straight down. You will experience microgravity inside the rocket, just like in the elevator, until you hit the ground (ending your day with great unpleasantness). Astronauts start to feel the effects of microgravity in the same way, only as their rocket accelerates toward the horizon, instead of falling straight down, it simply goes fast enough to fall *beyond* the horizon, meaning that the fall never stops. When you are freefalling while moving fast enough to always miss the ground, that's called orbit.

Oh, alright. So this is for a book? Maybe you should have explained this to begin with. I'm not sure what you mean by "salvageable SLS" or what sort of universe this is supposed to be in, but you're not going to launch rockets without some heavy infrastructure, high technology, and industrial capacity. You need power to produce and store cryo fuels. You need the VAB and crawler transporters to lug them to pad 39B (no, there is no way any launch infrastructure will ever exist in the Midwest, or you could even transport the rockets there. The cores are built in Louisiana and have to be transported by barge to KSC). You need the SRBs. You need to test all the valves, pumps, pyros, wiring, etc... You need functional computer guidance systems and people who can configure them for the mission. You need a skilled and trained workforce or hundreds of people to run all those systems. If you want to describe something like pulling the Saturn V out of a museum to make it flightworthy again, it's a stupid idea. Unless of course you want to play it like Star Trek or Armaggedon and just wave stuff away with storytelling magic, in which case anything goes. Olympus Mons might sound like a great place to launch from, but it's a really sucky place to land at. No aerobraking means that landing needs just as much delta-v as launching and you would be exposed to extreme temperatures and cosmic radiation. I'm still not sure what it is you want to do in five years or ten years or whatever. You're not giving us enough context to understand what you really want.

Mars' geostationary (or "areostationary") orbit is 17000km, which is only marginally easier than the 36000km orbit required for an Earth space elevator. However, it would have to carry some heavy station-keeping capability to deal with orbital resonance (and even possible collisions) from Phobos and Deimos, which are much closer to Mars than the Moon is to Earth. You're also assuming that it would be cheaper to build and maintain such an infrastructure on an alien planet than it would to simply extract rocket fuel from ISRU.

Self sufficiency and closed-loop life support are hard. In fact, it's so hard that we haven't even got it to work on Earth. If we can build self-sufficient colonies on Mars, we can build them in the Gobi desert or under the sea for a fraction of the cost. There is no point in going to Mars.

We have a handful of samples of "we don't know". Still not enough to make any meaningful statistics. Rubbish. How many space exploration probes carry instruments whose purpose is to actually "detect life"? At best some are designed to detect some tell-tale molecules, but the main science payloads are to study geological and chemical processes that have nothing to do with the search for extra-terrestrial life.

Man rating, the way I understand it, requires additional hardware for sensors and monitoring, launch abort and recovery systems, more extensive quality standards that ensure failure tolerance, and lots of trade studies going through every failure mode throughout the flight. It is indeed a lot of paperwork and rubber stamping, but also a lot of technical work, testing, monitoring, and validation. And infrastructure and ground systems are fully part of a launch system.

We have a sample base of exactly 1. That's not enough to extrapolate any meaningful statistics. Note that most science payloads on our probes are designed for studying chemical and geological properties. The "search for life" is mostly a media thing to get the public interested that doesn't reflect the actual science that's being done.

Landing is the easy part. It's getting into orbit that's gonna be hard.

If they were bad and if they are old, then they are worthless.

None of that ever mentioned using Ariane as a launcher for DreamChaser. It's about using DreamChaser to launch European missions. That study is moot now anyway, because it was suggesting use of DreamChaser by ESA as a complement to NASA's commercial crew contract. Without NASA funding, there is no DreamChaser. ESA will not subsidize the US space industry.

The agreement that ESA had with SNC was that they would provide ESA's version of the iLIDS docking adapter, presumably in exchange for piggyback seats on DreamChaser/Atlas. That's it. There would never have been any direct funding of DreamChaser by ESA or any of its member states. The barter agreements exist because they provide jobs to member-state companies in exchange for services from other countries. ESA will never directly subsidize or purchase services or products from a US corporation because its primary goal, above any other, is to provide work for the European space industry. There won't be any manned launches out of Kourou, because the infrastructure simply isn't there, and the ESA member-states simply have no interest in developing that capability. An unmanned DreamChaser makes little sense. There are very few (if any) payloads that require DC's low-g reentry. It's much easier to package fragile experiments in such a way that they can withstand a trip on Dragon or CST-100 than it is to design a whole new vehicle.

We can't, at this point, live on Mars (or any other planet) without a supply chain. Since launch windows are every 2 years, maintaining a supply chain is pretty much beyond our capabilities. Infrequent windows mean that you need to compensate with large payloads, which means that you need big expensive rockets, with a heavy infrastructure that is going to cost a lot to maintain for such infrequent launches. There is no point in building a colony if there is no trade, commerce, or logistics chain between the "colony" and the "homeland". We might be able to build a logistics infrastructure between the Earth and the Moon one day, but sustainable regular transit to Mars is going to be extremely hard and expensive for a long while. It's simply not gonna happen soon. Deal with it. The reason why there is scientific interest in Mars is because it's the only other planet that is actually within a reasonable distance and accessible with our technology. Studying the physical and chemical phenomena that occur there gives us more data points and allows us to extrapolate results to broaden our knowledge on a fundamental scale and also applied to our own environment.

When your business model is to make powerpoints and studies to attract venture capital to keep the company afloat to make more powerpoints and studies, and you know damn well that the advertised goal is ludicrously out of reach, well, that's a scam.

No it isn't. Hermes was cancelled in the very early inception phases of Ariane, therefore, although Ariane was originally intended to be a man-rated launcher, none of that requirement made it into the final design. Ariane 5 is reaching its end of life. ESA is gearing up to start work on Ariane 6, which will be a cheaper and smaller launcher designed to be competitive for commercial and institutional payloads. They are not going to invest any more R&D into Ariane 5 at this stage, so man-rating is out of question. ESA simply doesn't have a policy for independent manned spaceflight because the member states have never agreed on it and none of the governments wants to spend more than they already spend on space. ESA has barter agreements with Roskosmos and NASA so that they can exchange seats on existing vehicles in exchange for technology or components. This isn't going to change in the foreseeable future.

I'm not quite sure what you're asking for here? Try writing full sentences with proper verbs instead of asking us to fill in the blanks and try to guess what you're trying to say. The typical launch windows for Mars are approximately every 2 years with a transit time of 6 months. You could launch at other times, but it would need more delta-v and the transit time would be longer.

Yet another thread where you ask stupid questions. Your question assumes that it is common practice to explain physics and evolution with anthromorphism, which simply isn't true. Therefore your question is meaningless.

Which is exactly what I wrote too. Oh well...

11 - 0b00000010 = 9

It seriously took them this long to debunk it. The smart people on this forum debunked Mars One over a year ago.

The hab could be reused, but would you really want to reuse it, after it's been lived in for 2 years? It will be full of trash, all supplies and consumables will be expended, and most of the equipment will be worn out or need refurbishing or repair. To reuse it: - You would first need to brake it into LEO or EML-1. This will need *a lot* of propellant, which you would have to bring all the way to Mars and back. The extra weight means that you need *much more* propellant to send this extra propellant on a mission. This means that the size of your spacecraft on departure increases significantly, maybe twice as big as if it was expendable. - You would need to send up at least several maintenance missions, to replenish supplies and consumables, change filters and seals, repair stuff that's broken, clean everything up, and bring back 2 years of trash. It would likely be cheaper to just send up a new hab for the next mission.

The production cost of the rocket isn't the biggest cost factor in launch prices. The biggest cost factor is the industry is manpower. Even if you reuse the rocket, you still have to pay the highly qualified personnel that does the logistics, payload integration, handling, testing, launching, R&D, administration, maintenance, etc... You still have to pay for the facilities, infrastructure, the consumables. You save on the production cost, but you have an extra handling and refurbishing cost and the actual unit cost of each rocket goes up because your factory produces less of them. There is a point where the curves intersect and above a certain launch volume, you will get savings. However, that doesn't happen at current launch rates and you're not looking at a huge operational cost reduction. So maybe you save two thirds of the cost of the reusable first stage, but even if the cost of the rocket represents a whopping one third of a hypothetical $90 million price tag to launch a Dragon V2, you've only saved $20 million, with a ticket price per passenger of $10 million. That's not a huge game changer that's going to open up the space tourism skies to the masses.

Obviously Branson agrees with you. I don't. I guess only time will tell. Companies like Novespace or Zero-G sell parabolic flights for a couple of thousand dollars. The experience is pretty similar to what Virgin is going to offer, with a few hours of flight and a couple of minutes of weightlessness. The main difference is that they don't get you bragging rights for reaching the Karman line. But these folks aren't exactly swamped with queuing lines in front of their office. No, it depends on what the insurance companies and investment funds would do. I'm pretty sure Virgin would be sued to death (especially as their self-certification process is only going to be 5 flights), and the press will destroy them. *sigh* Reusability only makes sense if there is a huge demand. That demand does not exist at the current price point and with no destination to go to.