Nibb31

After watching the video, these guys were all worked up about making money in space, but not one of them suggested an actual way to make money in space. DeGrasse Tyson seemed skeptical about the whole idea, and rightly so IMO.

One didn't "code" special effects in those days, young padawan.

Debunked plenty of times. Launching an Atlas V to kill a single escaping terrorist would be stupid. At $100 million a pop, it would be massively expensive, even for a prime target like Bin Laden. It takes months to prepare an Atlas V and you would have to launch your X-37 into the correct orbit, let it loiter there for weeks, and wait for the proper reentry window to launch the strike. An ICBM with a conventional warhead would be cheaper and faster. Prepositioning an Ohio-class with Tomahawks is cheaper, quicker, and stealthier. Even sending Navy Seals in speedboats is faster. Satellites can be monitored by amateur astronomers, including the X-37. In fact, it's constantly tracked on Heavens Above: http://heavens-above.com/PassSummary.aspx?satid=39025&lat=0&lng=0&loc=Unspecified&alt=0&tz=UCT Deorbiting over hostile territory would be public knowledge and would give the target 30 minutes to pack up and move. The X-37 would come in hot and on a highly predictable course, so it would be easy to intercept and shoot down. But mostly, if you want to recover it, you're going to need a runway at the end of that reentry trajectory, which means that you already control a runway nearby the target. If you have that sort of capability, then you don't need a "global strike" vehicle in the first place. There is a reason why both the US and the USSR agreed to ban orbital strikes in the 1960's: they had no strategic or tactical value. PS. ULA is a launch provider whose only purpose is to sell rides on rockets provided by Boeing and Lockheed Martin. It doesn't do R&D or innovation. That's not what it's for.

My understanding is that GLONASS sats are at 19000km. GPS sats are at 20000km. GSO is 36000km.

We had a thread a while back about what it might be doing. A weapons platform doesn't make sense - why would you want to bring a weapon back? It's most likely a technology demonstrator to test long-term exposure of materials or microgravity production of materials (growing crystals or semiconductors). Nothing else makes any sense.

You're talking about GPS satellites. Those are way below geostationary orbit and way out of the way of Apophis.

There's what you tell to venture capital investors and then there's reality. Find a single major aerospace project, government or commercial, that cost less than 15 billion dollars.

Because a geosynchronous orbit can only be on the equatorial plane at 36000 km. If you put a satellite anywhere else, it won't be geosynchronous.

GSO sats are on an equatorial inclination, which is 23.4° from the ecliptic plane. I doubt that a random asteroid will be anywhere near that inclination.

The problem with MBTI is that isn't very repeatable. As such it's a poor way to define someone's personality. I've done it several times, and each time I got different results. I found that for most of the questions, I had trouble answering a definitive "yes" or "no". It would rather be "well, it depends...". I also find it hard to believe that there are only 16 kinds of people. I like to believe that humanity is much more diverse than that. It is very popular in corporate HR circles though, mainly because it's easy to understand.

I wouldn't count on a fully reusable F9H any time soon. The F9-R first stage can only be recovered because it's a first stage booster that is jettisoned at a lower altitude than the non-reusable F9. It then uses part of its dV potential to perform the throwback burn, which puts it on an RTLS trajectory. On the heavy, the lateral boosters will probably use a similar profile. But I wouldn't count on ever returning the core stage, because it will be flying much higher and faster. It would need some serious dV to bring it back as well as some kind of TPS. This would all seriously cut into the payload capacity.

The Saturn V wasn't very efficient either. The F-1 engines had an Isp that would be laughable by today's standards. But it was enough to get the Apollo stack into orbit, which is all it was designed for. Energia was designed for side-mounted payloads, which is also inefficient in terms of structural weight, drag and thrust vectoring (you lose considerable amounts of energy counterbalancing your payload instead of thrusting forward). An inline design would be more efficient, which would mean redesigning the entire core stage. The RD-0120 was also discontinued decades ago, so you'd have to pretty much design a whole new rocket.

Yes, but NASA and Boeing or NASA and Lockheed Martin are equally complementary. The only difference is that we don't see many Boeing or LM fanboys.

And what you'd get would be very similar to the F9-R. SpaceX are practically replicating DC-X with their Grasshopper project. Note that Grasshopper has only reached 1/3 of the altitude reached by DC-X. I personally beleive that the DC-X/Delta Clipper was more promising than X-33/VentureStar. It was simpler, cheaper, and it could have been converted to a secondary role as a Moon or Mars lander. But it suffered from "Not Invented Here" syndrome and NASA wanted wings, so there you go.

X-33 was not an SSTO because it was never intended to reach orbit. It was a subscale suborbital demonstrator for the VentureStar concept. Whether VentureStar was viable or not depended on results from the X-33, so I guess we'll never know. I suspect that the main reason for the X-33 to be cancelled was the realization that VentureStar would have such a small payload fraction that it wouldn't be viable.

SpaceX is not a program. It's a commercial launch provider that works for NASA, DoD, and whoever is ready to pay for their services. You don't call Boeing or ULA a "space program", yet they are in exactly the same business. SpaceX is not going anywhere unless if somebody pays for the ticket.

That video is amazing. It looks like the landing leg frame got completely burnt up. If wonder if the actual folding legs burn like that and how that affects the quick turnaround capability. The folding ones would have hydraulics, covers, sensors and hinges that wouldn't really deal well with the heat. It might explain why we didn't get to see any pictures of the CRS-3 first stage. melted landing legs don't make great PR. Also lots of little fires in the grass around the pad. It's not clear whether they were caused during takeoff or started by flaming debris from the legs.

When they have a stratospheric balloon capable of lifting 300 tons of propellant, let me know. Hint: they will need unobtainium to build a structure that big, which puts it way up there with the space elevator and the launch loop in the unrealistic megastructures category.

The airship-to-orbit idea is so flawed it's not even funny. To get buoyancy, you need air. If you have air, you have drag. A balloon big enough to carry enough propellant to accelerate itself from 0 to 27000 km/h is going to have a lot of drag.

Any mixed crew going on a long duration trip (including an official NASA sponsored expedition) would probably be required to use contraceptives or to undergo voluntary sterilization for the first couple of decades. There are simply too many risks involved.

I doubt that was a reason, given that the first US Army astronaut joined NASA in 1978.

No. The problem with H2 is that it's extremely hard to contain. H2 is the smallest molecule, so just about any material is porous to it. it as dense as possible. You need to keep it liquid because as soon as it warms up, it's going to bleed through any container. This is why they use cryogenics and constant topping up of tanks.

Making hydrogen is cheap. Handling and storing it is something else.

When you have a $200 million comsat that you rely on for your business, you don't skimp on the launch price. You just want to be as sure as possible that your bird ends up where you want it, and you are perfectly ready to pay a premium for that.

Well, brace for surprise: Source: http://www.economist.com/blogs/graphicdetail/2014/04/daily-chart-19