81

Mars' temperature range is rather large, with temperatures down to -107 °C measured by the Viking landers. This is below rubber's glass transition temperature of -70 °C, below which rubber becomes brittle. So you can't use rubber. A rubber tire is heavy. The tread of a normal road tire is more than 1 cm thick, off-road tires are thicker and heavier. It also ...


61

The problem isn't so much that humans cannot sustain high G forces for any extended length of time: The problem is that rockets cannot. If a rocket could sustain 1 g acceleration for a bit over a day, we could go to Mars in a bit over a day. It instead takes several months to get to Mars because the rockets used to get there only fire for a few minutes. The ...


43

The capsules designed to reenter the atmosphere have to slow down from about 8 km/s to zero by the time they get to the ground. They actually don't use the part that looks like a cone to do that. They all have flat bottoms that they face into the wind to do that. If you compare the Dragon capsule from your link to a Soyuz capsule, the Orion capsule, or the ...


43

Ignoring the major point that human tolerance of G forces is not the limiting factor on space travel, plenty of thought has been made on how to counteract G forces, not least by 60s sci-fi writers. You can find more information than you ever wanted at Projectrho on this topic. The general gist: for lowish accelerations like 2 G, you don't need to do ...


28

Resilience: There is no way that an inflatable tyre of any kind can be used for remote missions, because they are incredibly unreliable. Think about car or bike tyres here on Earth, where we have a fairly small range of temperatures. They puncture easily, they burst, they lose pressure, the rubber degrades etc. When they have a puncture, fixing them is ...


27

Temperature shifts Earth's temperature swings from extreme to extreme is quite moderate. That is, coldest is generally around -40C and warmest is around 40-45C. The Moon has two weeks in blazing hot sunlight, much hotter (depending on your reflectance) but well over 100C, and two weeks of much much colder. Not quite absolute zero (-273C), but pretty ...


27

Yes, definitely. For example: Taurus, now Minotaur-C first stage (US, Orbital Sciences Corporation), based on Peacekeeper ICBM first stage. 9 launches since 1994, out of which 3 failures. Minotaur I (US, Orbital Sciences Corporation), repurposed Minuteman missile with M55A1 first stage and SR19 second stage. 11 launches since 2000, all successful. Minotaur ...


23

There's a Spinoffs from the Space Shuttle Program page hosted on the NASA Marshall Space Flight Center portal. According to it: Jewelry Design — Jewelers no longer have to worry about inhaling dangerous asbestos fibers from the blocks they use as soldering bases. Space Shuttle heat shield tiles offer jewelers a safer soldering base with temperature ...


22

There is one area of exploration on Earth that approximates conditions on Venus, namely that of deep oil and gas mining, and a few additional areas of technology, near avionics engines, and even auto engines. The stated goal for such electronics is to function at 200 C or higher. The most promising technology for surviving high temperatures is Silicon ...


22

A 3D printer on station isn't likely to lead to direct cost savings; the range of items it can replace are limited, and it has to be supplied with feedstock mass in any case; it won't allow for significantly fewer supply launches. The primary benefit is that it can allow for the repair of a system the astronauts would otherwise have to do without until the ...


18

The 3-D printer on the ISS is more for testing purposes than anything. The idea is that for really long duration missions, a 3-D printer will allow them to make something in case something breaks, or they realize they need something that didn't come initially with the ship. So far I can only find a few things that have been made, including a ratchet, several ...


17

Yes, we know of a least one CubeSat that has flown (and is currently flying) with an active propulsion system. Specifically a steam powered warp drive. STRaND-1 (Surrey Training, Research and Nanosatellite Demonstrator 1) was launched aboard PSLV-C20 on February 25, 2013. Developed jointly by the Surrey Space Laboratory and Surrey Satellite Technology Ltd, ...


17

It's fundamentally impossible to measure gravity from an object that is in freefall. This is the first principle of general relativity. What accelerometers will give you is accelerations (linear or rotational) induced by thrusters, atmosperic drag, reaction wheels, etc. vibrations from rotating solar panels, crew-induced forces, etc. The only thing you ...


17

This could go many ways, depending on whether you mean a clean sheet design or incremental updates to STS. I'll assume the latter, in a parallel universe where the STS-107 accident never happened and the program continued on and actually did upgrades. We can look at what was planned for STS: Improved engines: health monitoring, new controller, new nozzle ...


16

Try looking at research done at The Aerospace Corporation, Penn State and Utah State. It turns out that there are very good reasons to print the fuel for hybrids. Adding a third dimension, beyond the images, above, of standard grain shapes can cause increased mixing of oxidizer and fuel, raising Isp. Regression rate was significantly increased in tests at ...


16

According to this statement by the ESA, Rosetta is presently sending signals to the ground stations at about 28 Kbps; Ignacio says that the spacecraft's own telemetry downlink uses about 1 or 2 Kbps of this, so the rest is being used to download science data from Rosetta and lander science and telemetry from the surface. Given that you have 28 kbit/s for ...


15

This latest (second powered) test flight of the SpaceShipTwo was really interesting to watch (YouTube video, the "feathering" aerobraking starts at 2:14 into it), but this currently unique to The Spaceship Company designs (owned by its sister company Virgin Galactic that's itself within the Richard Branson's Virgin Group) approach to aerobraking was actually ...


15

The idea that NASA would intentionally under-represent the lifetimes of those (cherry-picked) missions implies that somehow they knew those lifetimes before launch. Nothing could be farther from the truth. You can't just calculate a lifetime. There is extensive testing and associated analyses performed on the hardware to provide sufficient confidence that ...


14

There are also the Dnepr-1 rockets, made from converted R-36 missiles. One that launched in June 2014 delivered a payload of 37 satellites, making it the current record-holder for most satellites delivered in one launch. Elon Musk likes to tell the story of going to Russia to buy ICBMs when he was first thinking of getting into a space project - that's how ...


14

That blue box is a wired receiver unit for the wireless microphone (they currently use a Sennheiser handheld with SKP-100 wireless transmitter, but they did or still do use also products from other companies, inc. e.g. Shure that I know they flew during some STS missions to the station). The box also hosts its own microphone because the wireless microphone ...


13

Not particularly, at least not long term. Let's take a hypothetical high earth orbit imaging satellite. We want it stealthy. Here are the iterations.... We have to account for the blackbody radiation, which is the infrared light given off by all objects that are above 0 kelvins (-273.15° C). To hide this, we need to exactly match the backdrop. That ...


13

Consider the Earth and moon to start out with. Obviously we can extract energy through tidal power (which is a real thing, although the economic question is non-trivial). This is possible because the Earth is spinning faster than the moon orbits. However, this tidal power is rate-limited. As long as we're using water as the working fluid, the theoretical ...


13

Here are some Apollo specific innovations: microchip, cordless tools, joystick, CAT scans, technology in MRI machines, modern shoe designs, freeze dried food, vacuum sealed packages, dampening material, retro-reflector (detects chemical leaks), water purification, silicon based storage of records, fly-by-wire, ground water cleaning, large fabric roofs used ...


13

Earth Carbon nanotubes might endure the enormous stress of an earth elevator but only short lengths have been manufactured so far. It would be a mega engineering project that would dwarf earlier human endeavors. An earth elevator would need to extend at least to geosynchronous orbit at about 36,000 km altitude. And unless there were a truly enormous ...


13

I would like to firstly echo the suggestion to read Project Rho. Throughout the entire site, there is a tremendous amount of hard science and it is all deeply entertaining. http://www.projectrho.com/public_html/rocket/spacegunexotic.php In short, a space war would look more like the Cold War than any other war we've known. With nuclear ICBMs, we ...


13

At this point in time it seems doubtful that we could intercept and deflect an asteroid large enough to justify being deflected. This is simply a matter of momentum, a large asteroid has a great deal of momentum and the puny little spaceships we can presently intercept an asteroid with can impart only very little momentum. The only way we can substantially ...


12

After days of Googling this, I am going to say that it appears none have. It's worth noting that there are dozens of propulsion systems for cubesats (Google 'cubesat propulsion'), but I was able to turn up nothing referencing any that have actually flown. One would think that if the systems had been used, be it privately or by a university, a result for an ...


12

At the very start of Apollo? Very little, beyond a basic launcher. Everything else was mostly developed on the fly for Apollo. Pretty much all of Gemini was developing ideas to use for Apollo. At the time of the announcement by JFK very little existed in either sides. Basic engine design might have helped, but in the end, the US did a better job at large ...


12

The key is that you don't need to make a satellite impossible to see (e.g. cooling it down to 20 Kelvin); You just need to make it harder to see. "Misty" is supposedly the codename of a stealth satellite project run by the National Reconnaissance Office (NRO). There are at least two suspected Misty satellites in orbit (See the "Misty" article on Wikipedia ...


12

There's no reason a Von Neumann probe could not be built once a civilization reaches the appropriate technology level, it's a matter of desire. When a civilization becomes advanced enough all it needs to build anything is a supply of matter or energy, as the one can be used to make the other. When you say "the absence of Von Neumann probes" I suspect that ...


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