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64

The O-rings and the temperature were only the last in the long chain of blunders, and that had little to nothing in common with reusability. The construction of the SRBs wouldn't be much different with no reusability in mind. Indeed, SRBs of very similar design are to be used in SLS, and they are not intended to be reusable. About the most important factor ...


63

There are many key points to this, probably none on their own sufficient to ditch the parachutes approach (except economics, those are good enough on their own), but together they make for a compelling case against it; Descent control: As already mentioned, there's a significant guidance uncertainty with the use of a parachute system. Some of it comes from ...


61

The purpose of Starship is not merely to put satellites into orbit for cheap. If that were its purpose then you'd be correct; it's way overbuilt for that. Starship wasn't created to put satellites into orbit though, it was created to construct a self-sustaining city on Mars. Achieving that goal will likely require lifting hundreds of megatons of mass to ...


59

The fairings are not boats. While they appear to float (at least for some time), there will also be water on the inside of the fairing. That results in some issues. Inside the fairing, there are electronics and other corrodable materials. Now the fairing is designed to be as light as possible. Therefore, SpaceX probably doesn't want to make the entire ...


57

SpaceX's demonstrated booster-landing ability isn't the result of a breakthrough but rather a bunch of small incremental improvements. The major limitation has been funding and the will to make it happen. In 1966, unmanned spacecraft landed on the Moon under rocket power in the Surveyor program. It used (IIRC) three fixed-position thrusters, pulsed, to ...


51

They're already made, have plenty of usable life left, were stored in a way that facilitates reuse, and apparently cost less than building and certifying brand new ones. https://www.nasa.gov/feature/proposed-station-water-system-looks-to-retired-shuttles In order to reduce the cost and complexity of the proposed system, NASA engineers looked at reusing the ...


48

There is not enough air on Mars. You would need absolutely humongous wings. There is no air at all on the Moon. Surely SpaceX can find a quick and easy way to get Starship vertical and in position for the next launch. Starship is not structurally capable of being in a horizontal position. It will simply crumple and/or break in half. Could you remove an ...


44

It was charred by the center core after separation: (Source: SpaceX FH launch webcast) Looking at it I would expect one side to be charred too but it may not be - the nose cone is afaik composite (same as the interstage) and not metal.


44

You're basically describing the Space Shuttle. The Space Shuttle wasn't even a good solution when it was designed. It had precisely one goal - to look like a plane for the image of the Air Force. As far as engineering goes, the Big Dumb Booster was already well proven, and is what every other solution to space has used. But in order to get Air Force ...


41

Neither has much financial purpose without the other. A BFR cannot perform any useful function without an upper stage, and that is the BFS. Since the whole platform is a major investment in a new architecture, they are starting with the smaller piece - the BFS. Since it uses some of the same engines as the BFR, it can act as a testbed for both BFR and BFS ...


40

In addition to the water damage is the impact damage: the fairings wouldn't "touch" the water they'd hit the water, even with parachute retardation. A net slows deceleration down and spreads it more evenly across the structure, which is a lot friendlier to the materials and the supporting electronics.


40

It would only make sense to keep the fairing attached if the stage it was attached to was going to be recovered. The SpaceX falcon and falcon heavy are multi-stage rockets, only the first stage is reusable. The fairing is jettisoned once the aerodynamic pressure is low enough it isn't needed anymore, which is before orbital velocity is reached. Because it's ...


34

At the moment no one knows, since no one has done quite this task before. SpaceX is learning alot with each recovered core. In this image of three of the recovered cores in the LC-39A HIF building you can see different levels of wear on each stage. You can see that some of the engines have been removed for likely testing on the initial Orbcomm mission ...


34

Earlier on Musk indicated it may be possible to fly a block 3/4 booster more than twice but it would depend on the missions flown, with LEO missions like this Commercial Cargo mission being easier than GTO missions. I suspect this booster and the previous one that did two cargo missions could be reused if SpaceX wanted to but they are choosing to move ...


33

There are many contributing factors to this problem. The Shuttle was designed in the 1970's and technology has matured since then. Additionally, the issues the Shuttle ran into (While in truth may have been predictable at the time) are now more obvious and a new design can try to avoid them. Consider the simple case of the heat shield on the Shuttle. It ...


33

It's easy to see by just looking at photos and videos of launches of re-used boosters that they don't. There are only a very few very small white lines, probably where engineers inspected some weld lines or other specific points on the vehicle. Here is an example of B1061.2 launching the Crew-2 mission. Note that this is only the second launch of this ...


31

That is my estimation of CoG of nearly empty Falcon 9 booster. On the left is GoG with legs opened, on the right with legs retracted. The landed vehicle is pretty stable. It could withstand the winds of 50 m/sec (97 knots!), if sliding is prevented. There are relatively narrow limits on horizontal component of landing speed as well as on rotational velocity ...


31

Elon Musk stated in a news conference after the Falcon Heavy launch that the BFS will be the focus because they think they understand designing booster rockets pretty well, and thus they decided to focus on the more difficult piece first. He answers this in response to a question that starts at 20 minutes 52 seconds here, and speaks specifically to starting ...


30

Nobody knows, but it seems pretty safe to assume, for a while, things will continue as normal. SpaceX will continue launching rockets and attempting to land them. They will take the one they have (and any more they acquire) and analyse them extensively to determine if they are, in fact, flightworthy again and what effects being used has had on their ...


29

A Space Elevator would still be amazingly useful The two factors that come to mind are forms of power and scale: Power With a space elevator connected to the ground, you could use the energy in your power grid to lift everything up. By doing this, we can use green and renewable energies. With rockets, baring any massive advancements, we are restricted to ...


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 ...


27

I bet that's every rookie US Navy pilot's thought too on their first carrier landing approach. Thing is though, that unlike aircraft, Falcon 9 first stage can't really maintain altitude before landing. Even single of its nine Merlin engines throttled all the way down is too powerful for hovering on nearly empty tanks and landing is really going to be more of ...


27

The fairings are detached to prevent carrying their un-necessary mass to orbit. This typically happens during the second stage burn. See this question for information about the timing of fairing jettion: How strong and "hot" is the wind on the payload after the fairing is deployed at ~110km? An image showing the fairing separation during the ...


27

No. According to this article it is not even cleaned: https://www.arstechnica.com/science/2018/12/singed-and-sooty-spacexs-falcon-9-rocket-still-looked-brilliant-monday/


27

We don't know. One thing we do know is that SpaceX launches are fairly cheap compared to their competitors. Whether that is because of reuse, because their rockets are generally cheaper independent of reuse, or they are simply operating at a loss to shock the market, we don't know. As mentioned by geoffc, SpaceX is a private company, not even publicly traded,...


26

Not reusability per se, but design and politics. The competitor to build the SRBs for the Shuttle program was Aerojet, and their design was monolithic. In other words, no segments. Aerojet was actually selected as the winning contractor but the NASA administrator Fletcher overrode this and gave it to Morton Thiokol. Aerojet had already built an awe-...


26

Dumping it into orbit, even retrograde, will still leave objects in orbit, slowly falling down until they burn up. But for that entire period of time, they become possible hazards to anything in that orbit or lower. A launcher with some minor amount of velocity would speed up the deorbiting, but it would still be there. You would probably want it somehow ...


26

The size is mostly based around missions to Mars as opposed to satellite launch. Where satellite launch is almost a side mission. Refueling missions for Mars missions will require 7 launches (1 payload, 6 fueling missions) for each vehicle going to Mars. Lunar missions will need 2 or more (not clear this number is settled) refueling launches. As noted in the ...


25

A payload fairing is separated as soon as possible when the air is so thin that the payload needs no protection anymore. This reduces the weight of the remaining rocket. The fairing is usally separated at a height of about 100 km before the rocket is orbital. Therefore the fairing has a suborbital flight and reenters the athmosphere. Separating the fairing ...


24

                     Key phases in the launch-and-landing plan for SpaceX Falcon 9 rocket. Image credit: Jon Ross, NBC News.com After the first stage main engine cutoff, cold gas N2 thrusters are used to rotate the booster into the direction of flight, they ...


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