Nibb31

The F9 second stage has been pretty reliable until now, and although the MVac engine has a lot of differences with the stage 1 Merlins, there are some serious economies of scale. Centaur and Minotaur are pretty expensive. Regarding the first failure, material and supplier selection is their fault. Cutting corners by going for the cheaper supplier who sells non-aerospace grade parts has a cost. As for "suspicious", I don't even want to try to figure out what you meant.

We don't know yet. It could still be a problem with the ground equipment or a procedural error.

LC-40 is going to need serious reconstruction work, putting it out of service for months (maybe a year). Assuming there is nothing wrong with the launcher and they can resume F9 flights ASAP, they are going to have to expedite LC-39A operations and the delays are going to increase their backlog even more. If there is any redesign work, that will mean more delays before RTF, that will mean more backlog and they will absolutely need both pads. This probably means that FH will be postponed again, which is also likely to push back the 2018 Mars launch target (which was overly optimistic anyway) to at least 2020. It also means that the big September MCT reveal probably isn't going to happen. They will delay it at least until they get back on track with a successful F9 flight and recovery. You don't announce Big F. Plans when you have just destroyed a customer's payload.

A launch isn't just a rocket (which is also why the cost of a launch isn't just the rocket hardware). Pre and post-launch operations, including payload and pre-launch testing are all part of the launch campaign. So this should certainly be counted as a launch failure. Both the vehicle and the payload were destroyed, as well as a large part of the pad. Whether it happened on the pad or 10 meters above the pad is irrelevant, it's still a LOM.

LC-39A is leased to SpaceX for F9 and FH launches. LC-39B is being prepared for SLS.

You won't see any benefit at all. But you will screw up the O2 sensor's readings, which might cause the ECU to run the engine extremely lean. This might reduce fuel consumption to an extent, but it will also cause detonation, valve damage, and increase NO2 emissions.

It's the famous "Pantone" scam, invented by Paul Pantone, who ended up in jail for fraud and then pleaded mental issues to end up in a psychiatric hospital instead. The only folks who promote this are either people selling "kits" to convert your car or conspiracists. Believe me, if this worked, car manufacturers would be the first to fit it on every car they make instead of spending billions on R&D for cleaner engines.

I don't see why not. There are dozens of air and space museums around the World with much more obscure pieces of aerospace history than this. Where I live, there's a space museum with a mockup of Mir used for ground-training and couple of Soyuz DMs. There's also an air museum where people pay to see a Concorde and a Super Guppy. These places would both love to have a Buran. The problem is actually buying it and transporting it. The buying part is the hardest, because after the fall of the Soviet Union, the actual ownership of the assets is probably a bit obscure. There are several entities that can claim ownership, including Roskosmos, the Russian Air Force, the Republic of Kazakhstan, etc... and within those entities, I don't think anybody wants to be the person who sold off an item of national pride like the a Buran orbiter.

For thermal reasons. White reflects, black absorbs. Depending on what you want to achieve, black or white are the most efficient. Contrary to what some people believe, spacecraft are designed for efficiency, not to look sleek. One of the fundamental flaws with the Space Shuttle was NASA's obsession with wings. Remove that component, and we might have ended up with a proper VTVL like the old ROMBUS, SASSTO designs, or DC-X or Falcon 9. But we all know what they say about hindsight. You can't blame the engineers of the 70's with designing it the way they did. The intention of the Shuttle was to become the DC-3 of space, a single vehicle for all US launch needs. Apollo was considered too expensive, so NASA needed to come up with something more economical. It had to fly often to be economical, which means that it had to be used for everything, which means that it had to be multi-purpose. It made sense in the day. It really should have been a smaller experimental vehicle, like X-33 or DC-X) rather than a operational fleet. I'm certain that after a few years of flying an "X" Space Shuttle, they could have come up with a much more mature, safer, and more serviceable design.

I have no doubt that it can't be done. It's just that it hasn't been developed or proven, along with the ISRU and refueling. There is a lot of engineering and testing to do before it can be used on a manned spacecraft. And SpaceX's "trial and error" development methods don't lend themselves well to the realities of the 2 year synod.

It's Isp that matters. Raptor is a bigger engine, so it has more thrust, which means that you need less engines. It's supposed to use liquid methane, which is less dense, which means you need more tankage. Long duration cryo storage and transfer is another unproven technology that needs to be added to the list.

Current LEO spacecraft like Dragon or the latest Soyuz already use GPS for navigation, so yes it is possible.

If the orbital refueling architecture proves correct, the BFS isn't going anywhere until they have at least 2 vehicles. To demonstrate Mars return, they need at least 3: one for the journey, one to refuel in LEO, and one to refuel in LMO. The return trip is only possible if the ISRU works well enough to produce enough propellant for 4 launches, 450x9 = 2700 tons of propellant in 2 years. That's a lot to expect from an autonomous system, and you'll need some huge storage tanks too.

It was a totally different landing method. Powered landing of a manned 150 ton vehicle is whole different matter. All of the points tater pointed out are true. As I said above, there is a huge difference between a concept that works on paper, and actual engineering. And with a launch window every two years, maturing technology through iterative development is going to take time.

No it hasn't. There is a difference between "This might work on paper" and "We have the technology". The difference is called engineering, and it's subject to all sorts of real-life practicality roadblocks such as cost, regulations, environmental impact, politics, materials, supply chain, safety, etc... Now it would be great if this thread didn't turn into yet another "If only had built Orion" discussion. We had them all before. kthxbye.

Red Dragon will not be manned. They will be using it for collecting data, development and prototyping. When it comes to sending humans, concerns about contamination fly out of the window.

Actually, size does matter when it comes to optics. There's no substitute for a big lense or a big mirror and these things are hard to fold. A couple of years ago, I wouldn't have be surprised if there was a hidden CIA/NRO agenda behind the SLS program, because it doesn't make any sense to develop such a vehicle with no real purpose, and Congress seemed to have a weird fixation on the 130mt payload capacity. However, you can't keep an SLS launch secret and we would probably be seeing a military payload in the manifest at this stage. After all, never attribute to malice what can be explained by stupidity. (I also wouldn't be surprised if Stratolaunch is a modern-day equivalent of the Glomar Explorer...)

One way to work out the minimum requirement for the BFS, you need to look for the dV requirements for each leg of the journey. Assuming it uses for the BFR and its own propellant load to get into LEO, the other minimum requirements are: LEO to Mars intercept and LMO to Earth intercept = 4260m/s Mars surface to LMO =3800m/s So assuming that the BFS is refueled in LEO and LMO by another BFS, and assuming it needs a few hundred m/s for propulsive landing and manoeuvering, the BFS needs to have at least 5000 m/s of dV with a payload of 80 metric tons. In order to support 100 tons after landing, the dry mass of the vehicle will have to be at least 40 tons, including landing gear, structure, life support, heatshield, etc... (I think that's optimistic). So when you plug this data into the rocket equation with an average Isp of 320s, you get a total mass of 591 mt. Which is about the weight of a fully loaded A380. To get the BFS to LEO; the BFR first stage is going to need to spend 4000 m/s and land. The Falcon 9 separates at Mach 10, which is 3430m/s, so it might be possible to push the envelope a bit more, but this means that the tanks of the BFS are empty when they reach orbit with its 80 ton payload. If you want to go anywhere, you need to fill it up. We've calculated that the BFS tanks are going to need to carry approximately 450 tons of propellant, and since the BFS has a 80 ton payload, you are going to need 6 BFS tanker flights to LEO and 6 to LMO to fill it up for each trip. As for plugging the requirements of the BFR into the rocket equation, to get 4000m/s out of a 150-ton single stage with a 591-ton payload, you're rocket is going to weigh 2650 metric tons fully loaded. And that's without counting drag and gravity losses. Basically, that puts you in the Saturn V size category, with a BFR equivalent to the S-IC and S-II, and a BFS equivalent to the S-IVB and CSM/LM stack. The trick is in making the BFR and BFS reusable, which makes orbital refueling feasible. Of course, to make this scheme work, SpaceX has yet to demonstrate: 1st stage reusability Powered landing from orbit Orbital spacecraft reusability Orbital refueling and propellant storage Fast turnaround of the above Long duration life support Mars reentry Mars powered landing Automated ISRU and ground refueling Mars launch Reentry from Mars That really is an awful lot of technology to be developed by a single company.

You can't just divert government funds to a private corporation legally.

How so? Most of his achievements were strongly subsidized by the US government and had a clearly defined customer base and business plan. Mars is nothing like that. As I mentioned above, there is a lot of tech that needs to be developed and much of the tech that they do have doesn't apply. For example, most of their precision landing experience doesn't apply to Mars because those systems are based on GPS. They can't build their own GPS network on Mars (GPS sats are freaking expensive) so they will need to develop a whole new system based on optical recognition, prelanded nav beacons, or some other tech that doesn't exist yet. As RedKraken said, their iterative development method won't work too well with launch windows every 24 months. They won't be able to afford rapid prototyping and crashing stuff to see if it works the way they usually do. Certifying a man-rated life support system and life-dependent reliable ISRU and refueling techniques is going to need many development flights before they can risk human lives on those technologies, and debugging is hard in these conditions.

I think it will probably be two vehicles: - BFR: A huge reusable first stage. - BFS: An oversized Dragon. It will work as an upper-stage for getting to LEO, then it can be refueled by a couple of other BFS. So basically, you need at least 2 BFS. One carries cargo to Mars. The other is used for refueling the first in LEO. You might need to wait for 2 or 3 refueling flights before you perform the Mars transfer burn. You will need some sort of ISRU to get back, so the first cargo flight is going to need to carry an ISRU propellant plant. Of course, this is a lot of technology to develop: HLV, ISRU, refueling, life support, interplanetary heavy propulsive landing, etc... SpaceX can't realistically develop all of that in-house in less than a decade or two.

There will be more gravity pulling the front of the car than the back, so there is a force acting to stop the rotation. They will eventually crash into each other and stop any relative movement. Unless a third object appears.

No, the car would just move front first and the rest will follow behind. No rotation.

A research paper, to be accepted, must be peer-reviewed and published. A research paper that is kept secret isn't a paper. Any of these published paper have been freely accessible by any library, and probably most of them were already in various NASA servers. If you are qualified enough to be able to read and understand science papers, then surely you have access to a library. What this news seems to be about is an online search engine, which is certainly a good thing, not releasing previously unreleased content. This is like the "news" a couple of months back of NASA releasing "unpublished photos" of Apollo on Flickr, when those photos had been available in the Apollo Archives at nasa.gov since the 1990's. For some people, if something isn't on a flashy website, then it doesn't exist.