Nibb31

It's just a silly strawman argument. If we are clever enough to design interplanetary robotic exploration missions, then surely we are clever enough to design them so that they don't want to destroy us. You don't need AI that can make decisions to wipe out humanity. You only need to make AI that can detect interesting patterns and pre-analyze data so that you can shorten the feedback loop and But this discussion is an exercice in futility. The truth is, we don't know what technology we might or might not have in 50 years when we decide to focus on exploring Jupiter or the Kuiper belt. I'd rather look at goals that are actually reachable.

James Cameron picked up buzzwords. He is a storyteller, not a scientist. There is no science behind it, other than what he picked to make the story work.

None of that stuff exists. In the context of Hollywood movies, they are buzzwords than can easily be replaced with dilithium, kryptonite, warp drive, or magic. Do you really think James Cameron was interested with equations and actual physics when he ripped off the story from Pocahontas? Even the word "unobtanium" was ripped off from an engineering joke.

Do you have any idea of the operations of running something like Curiosity? I wouldn't call those teams "passive" at any rate. Each inch of ground covered by the rover is actively scrutinized and tested. A human simply cannot be as thorough , especially if he also has to concentrate on navigating, avoiding rocks, watching his oxygen and battery levels, checking on his buddy, returning to the base for lunch and a nap, and communicating with the base. And again, what do you really think they might have missed? The power, speed, and sensor limitations of rovers and probes are practically all due to the mass limitations of getting stuff from the Earth to Mars. If you are capable of sending a 100 ton manned expedition, then you could also send one hell of a rover, extra batteries, spare parts, literally tons of sensors and experiments, and even a couple of teleoperated robonauts to do an oil change on the rover every 20000 km. We aren't sending people to Jupiter or the Kuiper belt in this century, so that point is moot. However, if we ever do develop the technology to send people beyond Mars, it's pretty likely that robotics, sensors, AI, and communication bandwidth will also have improved. In fact, I'm willing to believe that those areas will advance much faster than interstellar propulsion and manned spaceflight technology, which will make the decision to send people even harder than it is today.

We have only just scratched the surface of the Moon. Having gone there in the past is irrelevant. Scott and Amundsen reached the South Pole over 100 years ago, yet there is now a thriving permanent base where 50 to 200 scientists are still doing research and returning science all year round. There is a lot of scientific work that can be done on the Moon: astronomy, geology, biology. It's also a great place to test engineering solutions from dust mitigation to radiation shielding, ISRU, closed-loop life support, in vacuum and partial-gravity. As you say yourself, we are not going to Mars in the next decade (and probably not in the next 20 years either). The Moon is far more achievable, only 3 days away. And building an infrastructure that allows (and requires) permanent access to the Moon is a much better way to secure funding and to make it economical than to keep on chasing dreams of Mars or Venus or Europa and not going anywhere for the next 47 years. Building a small semi-permanent outpost on the Moon is something we can realistically achieve. Cloud colonies on Venus or moisture farms on Mars are pipe dreams. I'd rather see us achieve the smaller goals than keep on dreaming about stuff that won't happen.

Graveyard orbits are typically for GEO communication satellites, which constitute the vast majority of the birds up there. GEO is a circular orbit 35,786 km above the equator. At that altitude, it only takes a tiny amount of dV to push the satellite out to a graveyard orbit which is usually 300 km higher, where they will stay basically forever. By comparison, to deorbit these sats, ie. to bring them down from 36000km to the ground, it would take the same amount of dV that it took to put them from LEO to GEO in the first place, which is a job typically done by a specialized upper stage. Graveyard orbits are specifically chosen above GEO so as to not interfere with current or future satellite operations, and there is plenty of space up there. Only the specific GEO and LEO altitudes are used for actual operations, so graveyard orbit space is not 'precious'. (It has nothing to do with nuclear reactors. Very few satellites have radioactive material on them)

The Mercury suborbital flights were to test all the systems for the orbital flights. Getting the first american in space wasn't the goal of the program, it was getting a man into orbit.

I wouldn't be so sure of that. There are multiple teams monitoring a whole slew of camera and sensor feeds transmitted by every camera, over nearly every inch of ground covered by a rover. What do you think they might have missed ? If anything, a single driver who is concentrated on driving over the terrain would be less efficient. Time delay is no big deal if you're going slow, and neither is bandwidth. Time is one resource that unmanned missions have plenty of. Again, there is no hurry, the rocks aren't going anywhere.

A rover doesn't notice anything. The people driving it do. There is no reason the driver inside an SEV would have more awareness than the driver of a robot, given the appropriate sensors. And there are also things that a robot's sensors might detect (especially if it moves at a slower pace) that a human wouldn't.

A manned mission is limited to a small radius around the MAV/base. Astronauts need to be able to either walk back or be rescued by a second vehicle if their SEV is incapacitated. And if you can land a manned SEV that can cover a dozen kilometers per day, there is no reason why you couldn't land an unmanned one, for a fraction of the cost. But again, where is the advantage in going fast? Only a manned mission has a limited time. Unmanned missions can last for a decade or more, and you can send dozens of them for the same cost as a manned mission. And there is really no point in being quicker anyway. Those rocks aren't going anywhere. There is no hurry. The point is, robots don't need to wield tools, weapons, or press buttons. And that is unfortunately the only real, honest, reason for manned spaceflight at this stage. Because it looks cool. Unfortunately, that's not enough to justify the cost. Trying to justify it by higher science returns or some sort of economical return on investment isn't going to work at this stage. The only reason to do it is political prestige.

Why is this technobabble even in the Science Labs forum? It's fiction, guys. They make up the pseudoscience to fit the plot, not the other way round. Unobtanium is just another word for dilithium, warp drive, or magic.

Certainly, but physical presence is not necessary. Teleoperation is a thing, so are drones. No, multiple probes/rovers can cover more ground in several years than humans in a one month expedition. Machines can do that to.

Shuttle Orbiter habitable volume was 65.8 cubic meters. It would be interesting to compare the habitable space per crew member.

Which is why the idea of a manned expedition to Venus seems doubtful too.

No, because the FGB was primarily designed to stay attached to a space station.

I'm afraid another poor example of a "multipurpose exploration vehicle" is Orion. Orion was designed originally with the mission of travelling to the Moon and back. "Apollo on steroids" was the mantra at the time. It is scaled for 21-day missions, supporting 4 crew members, high-speed reentry, contingency EVA, and radiation shielding. And that's it. Other than going to the moon, it isn't really multipurpose, because you can't use it for much else. It's too expensive and over-engineered for LEO sorties. It can't be used for servicing or repair missions because it can't carry cargo or a manipulator arm. For interplanetary missions, it is either too small as a standalone craft or over-engineered as tender for a larger MTV.

Tantares isn't accurate. Kosmos is much better. Once it was spent, it had no use, so you have to choose between a controlled deorbit over the ocean, or you let it decay into an uncontrolled deorbit where it might end up causing damage or the Americans picking it up and analyzing the bits.

Scotty builds super interplanetary transporter and beams R2D2 to the surface of Venus to study the wreck of the Nostromo. Why did you put this in Science Labs ?

It worked pretty much like all the FGB-based modules. In space, nobody cares which end is the back and which is the front. Each end has its own purpose, and once its on orbit, it moves around with thrusters that are at both ends. TKS itself was abandoned but the FGB section (the habitation and service module part) were used in the Salyut program, Mir (Kvant-2, Priroda, Spektr, Kristall) and the ISS (Zarya). The "rear" section of all those FGB modules contains a docking port, habitation, and propulsion. The "front" section of the TKS carried the VA capsule, which had a hatch in its heatshield (just like Gemini-MOL) for crew ingress/egress. Because of this configuration, the VA capsule had most of its systems and propulsion, including a deorbit engine, in its "nose" section that was jettisoned on reentry. It was really a small forward service module. It also had a beefy LAS on top that, which always makes it look a bit disproportionate. Another similarity with Gemini-MOL was that a few VAs were reused, albeit unmanned, for test flights. Also noteworthy is that a couple of test flights were launched with two VA capsules, one above the other, on top of a Proton. These were to test reentry. In the 90's, a company called Excalibur Almaz, based on the Isle of Mann, purchased some of the old VAs and unused FGB shells with the idea of refurbishing them and selling rides for space tourists. The whole thing was part scam, part financial fiasco, and the capsules were recently auctioned off. If you're interested, I strongly suggest that you download the KOSMOS mod for KSP, which has a TKS and VA capsule to play with. That way you can get a feel for how the configuration worked.

SpaceX is a lean machine. They probably employ an order of magnitude less people than Russia and India in their respective space programs, which compensates. The low cost of labor in these countries explains why they are still competitive on the market. On the other hand, Russian low wages are compensated by antiquated hardware and infrastructure, poor quality control, and ancient manufacturing process that are probably costly to maintain. SpaceX has reduced labor cost by streamlined processes and vertical integration, which is smart, and which explains why they are so much cheaper than ULA or Arianespace. It's going to be hard to streamline the company any more than they are, and SpaceX's 3000 highly-qualified employees are still its major operational cost. Agreed. Launch volume is where the savings lie, not in reusing stages. Launch volume translates directly into production volume, lower prices from suppliers, diluted fixed costs, and lower unit costs. Reusability is spectacular and a fantastic technological achievement, but it actually works against those volume savings.

I guess there isn't much of an emergency because there's no indication that we're going anywhere other than our backyard in the next 30 years at least.

Orion can be depressurized for EVAs like Apollo. The commercial crew vehicles don't have that capability.

What counts is what the customer pays to transport his container from A to B (or his satellite from the ground to orbit). The trucking company might be able to get a 50% discount on a new truck, but that won't translate into a 50% lower price for the customer, because the truck is only a small part of that price. Costs also include the salary and expenses of the driver, fuel, parking, loading and unloading the truck, the salaries of the boss and other employees, offices, maintenance, advertising, etc... In the end, the vehicle is only a small portion of what the customer actually pays. The biggest operating cost of most companies is usually the workforce, rarely the equipment. Reusing stages only reduces salaries in the manufacturing sector. The rest of the company still operates with the same workforce and the same infrastructure. Musk's "70%" quote is disingenuous because it maintains the confusion between cost and price. There is no way reusing first stages can cut $40 million off of a $60 million price tag.

They handle microgravity pretty well on the ISS these days. Orbital medicine has made a lot of progress since Polyakov's 14 month stay. 6 month stays on the ISS are routine and most of the effects these days can be compensated nowadays through medication and exercice, and there is more progress to be made. On the other hand, we don't even know what level of artificial gravity would be beneficial, or even if it is detrimental compared to no gravity at all, because no long duration studies have ever been done. So adding artificial gravity as a requirement simply adds significant complexity and risk and pushes any Mars expeditions even further into the future until after we have done the prerequired science to validate the concept. Which is why none of NASA's DRMs use rotating tethers or spinning habitats. Even if it takes a few days for astronauts to readapt to partial gravity on Mars after a 6 month trip, it's not unsurmountable. Most mission profiles consider a stay on the surface of several weeks or months, so it's not like they will need to prepare for an EVA straight after landing like on Apollo 11.

Not really. But immensely complex, risky, and expensive.