Nibb31

Huh? NASA has always been a government agency.

Not sure about the trunk or upper stage separation events, but the first stage does.

There's no putting down a football in orbit and expecting it to stay exactly where you left it. If the Exoliner is left without attitude control or power, it will just float around, drift, tumble, and you're going to have a hell of a time getting it back. Aha! I didn't spot that in the pictures! Thanks for pointing it out. Well, I guess I'm sold then.

Sure, but then what ? How does the Jupiter remove the new Exoliner and put the old Exoliner on the Centaur when both the Jupiter and the Centaur can only be attached to one Exoliner at a time? Imagine holding two footballs, one in each hand. How do you swap them around without dropping one of the footballs?

I don't get it. How does the Jupiter put the Exoliner back onto the Centaur ? At some point in that mission profile, either it needs to be handling two Exoliners at the same time, or it needs to do several runs between the Centaur and the station. How long does the Centaur have to loiter while the Jupiter does all this shuffling around ? - - - Updated - - - Space and aircraft are totally different divisions.

It looks like yet another desperate attempt to stick wings on something that doesn't need them.

Makes sense. I'm not sure how long a Centaur can stay alive on orbit, but it might need upgraded batteries to wait until the tug arrives. The canister still needs to bring along more propellant than usual though, because the tug needs to deorbit and reboost itself into orbit, which requires more dV than a simple deorbit. Have the SNC and SpaceX proposals been published yet?

The ATV program is finished. No more flights. The current CRS-1 cargo contracts end in 2017. This is for the second round of cargo flights, called CRS-2. LM and Boeing are competing against Dragon and Cygnus. Boeing is offering a stripped-down cargo version of CST-100. Cygnus is probably renewing its current offering. We don't know yet if SpaceX is going to offer Dragon v1 or v2 for CRS-2. IMO, LM's Jupiter has very little chances. It looks very over-engineered for CRS-2 (the robot arm in particular) and NASA doesn't have any plans for using it for other missions.

It's the old (very old) concept of a space tug. The idea makes sense on paper: keep the propulsion module on orbit and only launch dumb canisters. In practice, it's a different story though (like always). In order for the tug to dock with the canister, the canister is going to need some sort of attitude control, which means that it needs avionics, power, and RCS. It needs to carry the propellant to refill the tug for the next mission. After the rendez-vous with the station, the tug needs to deorbit the canister and reboost itself into orbit, which is going to waste a lot of dV, meaning that the canister has to bring along more propellant than if it just had to rendez-vous and deorbit itself. The canister also needs two docking systems instead of one, one to dock with the tug and the other to dock with the target. So in the end, if your cargo canister has a docking system, avionics, RCS and propellant, then it might as well just fly itself to the destination. The tug idea doesn't save a lot in terms of mass, but adds a lot of complexity to the mission because you have an additional docking event and two vehicles to control instead of one.

Yes, real rockets typically use explosive bolts, because they are the less failure-prone method of separating two parts that were previously meant to be firmy attached. Pyros are also used for aircraft ejection seats and cockpit canopies and hatches. Even with explosive bolts, there have been failures. A couple of Soyuz missions have had some hairy re-entrys because 1 or 2 explosive bolts failed to fire, causing the service module to stay attached until the attachment points were ripped off by the aerodynamic load. SpaceX tends to use mechanical latches instead of pyros for obvious reusability reasons.

That's called a bladder tank, and it's already used for space applications, mainly in RCS systems.

Where did you get that this is a habitat module? It's an experimental module without life support that is as big as a cupboard. Its purpose is to test long term exposure of the materials. It will likely be used as storage space, maybe even for trash, and will spend most of its time on orbit with the hatch closed. It most certainly will not be used on a regular basis.

If it's space tourism that you're talking about: - Space tourism will always be uber-expensive, simply because energy is expensive and you need a lot of it to accelerate someone from 0 to 26000km/h. - No space tourists are going to spend more than a few days on orbit. Because it will be expensive, and also because there simply isn't that much to do. - - - Updated - - - On how many occasions have astronaut panic attacks on long duration space flight caused problems ? Long duration isolation experiments have been conducted for decades now and the medical corps knows how to deal with it. People here are speculating about something that isn't even a thing.

Agreed. And space tourists won't be signing up for more than a few days of weightlessness anyway.

And your point is? As I said, the extra space is nice to have, but it is in no way a showstopper for any planned mission. It has never been an issue for the navies around the world that have used submarines for over a century, and it hasn't been an issue for space flight either.

But modern submariners stay for months at sea without surfacing. They don't go crazy. I can understand that having extra space is a nice comfort, but it's not mission-critical in any way.

"On December 20, 2012, NASA awarded Bigelow Aerospace a US$17.8 million contract to construct the Bigelow Expandable Activity Module, under NASA's Advanced Exploration Systems (AES) Program." http://www.nasa.gov/mission_pages/station/news/beam_feature.html There are no new markets. There is government-sponsored research to develop new technology that might or might not be used for commercial purposes. In the end, commercial space only exists because the government is paying for it.

Lifting bodies are less stable than winged vehicles. They have a lower lift/drag ratio, and require flaring manoeuvers to break their speed. Without control surfaces that's not going to happen, and you are going to come in too fast and too steep. Note that capsules are technically lifting bodies, because they are designed to have a positive lift/drag ratio. Yes, they can reenter passively, but without parachutes for the last part of the landing, they're dead too.

A lifting body, just like a spaceplane, requires control surfaces, hydraulics, electronics, and some sort of deployable landing gear. It has a lot more moving/active parts than parachutes or powered landing.

What you are looking for is the functionality of a NAS, so if I were you, I'd just buy a NAS. Remove the drive from the USB enclosure and stick it in the NAS. This is the solution that will get you the best performance and a decent NAS can also act as a home server to run all sorts of useful stuff. Another solution is to buy a router with a USB 3.0 port that supports 3TB drives. Or you could just plug it into your PC and leave it always on.

It Dependsâ„¢

Rubbish. Did Gemini crews go crazy ? Do submarine crew go crazy? Truck drivers? Cubicle workers? Miners? Flight attendants? Nothing to do with space sickness. The size of the ISS is driven by the mission equipment that needs to be on board. There are detrimental effects to large volumes. See Skylab. One of the lessons was that astronauts routinely go stuck in the middle of the volume with nothing to grab on to. ISS modules are designed so that astronauts are always in arm's reach of a wall or a handle of some sort. Likewise, inflatable modules will never be used as large open spaces. They need outfitting with walls and floors. Instead, someone has to inflate the module and then spend quite some time outfitting the interior with everything that couldn't fit inside when the module was deflated. In order to be used, an inflatable shell needs internal walls, floors, wiring, ventilation, and then furniture and equipment. This can represent a lot of expensive on-orbit work and some logisitics flights for the interior equipment. This isn't necessarily cheaper than launching an equal-size volume in two hardshell modules. All paid for by your taxes. You're welcome. I don't see whats so new about the government paying contractors to do stuff.

Even if you're driving off a cliff, it's still worth hitting the brakes. It might give you a bit more time to brace for the impact...

The anthropogenic heat is generated by the greenhouse gasses that are emitted mostly by burning stuff (CO2) and by intensive breeding (Methane), not by radiating heat from power plants. The greenhouse effect has then caused enough warming to start melting tundra areas that contained a lot of methane in the form of permafrost. There are similar effects at play with melting glaciers interfering with warm and cold ocean currents. These are called positive feedback loops and explain why the whole climate is getting out of control. Some of those effects are indeed natural, and much stronger than any man made direct influence, but they were triggered by human activity. Fusion is still science fiction at this point. Even if a working model was invented now, it would still take at least 20 years to start the first production fusion plants, and many more decades before it becomes a significant power source. Nuclear has its own problems, but at least it doesn't produce Methane or CO2. The problem of nuclear waste will have to be dealt with at some point, but the problem of greenhouse gasses has to be dealt with now.

Absolutely. You also need to include the Mission Control Centers (each country has its own), the engineering support, the administrative overhead, the science committees, etc... The main cost is the thousands of people who are involved in all those tasks. - - - Updated - - - No, it's much smaller, but uses the same techniques.