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63

Are there failure modes that cause loss of pressure but not rapid, unplanned disassembly? Yes. The 3-man crew of Soyuz 11 died when a valve was jolted open, venting out all the cabin air supply. Soyuz was redesigned after that accident to carry two crew in pressure suits instead of 3 crew in shirtsleeves. (I believe they now carry three in pressure suits.) ...


62

For the Falcon 9, the worst-case point should be near the end of the second-stage burn, when the mass of Alison Goldfrapp's ex is largest relative to the remaining mass of the rocket, and only a single engine is available to steer, with a relatively short moment arm between the gimbal and the center of gravity. I assume that we are not launching any non-ex-...


53

This is a point worth emphasizing: When you dive off a high dive, or go on a free fall ride at an amusement park, or fly on Virgin Galactic, you are experiencing weightlessness in exactly the same way as the astronauts on the ISS. At the height of the ISS, the earth's gravity is about 90% of what it is at sea level. You could launch a rocket straight up and ...


44

The jacket is to control the Propellant Mean Bulk Temperature, a critical factor in solid rocket motor performance. The silos for the missiles that the launcher was derived from were air-conditioned for this reason. the Minuteman boosters in the Lower Stack were designed to be launch (sic) from a climate controlled silo with virtually no outside weather ...


43

Rockets always seem to launch slower than I expect them for the thrust they can produce. Do they really launch off the pad at maximum thrust? In most cases, yes. For most orbital launchers, over 90% of the mass at liftoff consists of propellant. As the propellant is burned and exhausted, the mass rapidly decreases, and the rate of acceleration increases in ...


38

Because it's required by law (51 USC Ch. 509: Commercial Space Launch Activities) and by FAA regulations (14 CFR Chapter III - Commercial Space Launch Activities, Federal Aviation Administration, Department of Transportation) that implement those laws. Even amateur rockets are subject to some FAA regulations. A rocket going up 10 km is subject to quite a few ...


34

The drop in acceleration around 40s into the flight is the shuttle throttling down to reduce the aerodynamic load on the vehicle. It then accelerates when past this point. The drop in acceleration at 2 mins into the flight is due to the solid rocket boosters running out and being discarded. Acceleration then continues to build, as the thrust from the engines ...


33

Yes, for a few minutes. It is similar to what is done in a zero gravity airplane flight, but a longer period of time. Also, orbital weightlessness is basically the same thing, the spacecraft and you are falling at the same rate.


29

nextspaceflight.com This website is incredibly useful, providing a list of most upcoming launches with links to livestream and information as well as keeping a list of past launches (along with some additional things like Starship info and testing dates) Additionally; spaceflightnow.com/launch-schedule


27

To expand a bit on David Hammen's answer, the reasons for the regulations requiring FAA permits for rocket launches are related to public safety (or sometimes the egos of bureaucrats, but mostly public safety.) There are a couple of particular areas that these fall under: Range Safety Obviously, rockets carry a lot of fuel and often very toxic materials (e.g....


24

Gemini 2 (unmanned) was filmed for 90 seconds (second link) by an F-4


22

For shuttle at least, I believe the longest delay was the torturous launch flow of STS-35. (tl;dr it was delayed six months.) Using the criteria in the Space Shuttle Missions Summary, namely Postponements are defined as launch delays which occurred prior to call-to-stations for OMI S0007 Shuttle Countdown. Scrubs are launch date changes after the start of ...


22

As in many things, shuttle was an exception, the answer for it is No. At liftoff the Space Shuttle Main Engines were running at a throttle setting of 100% of their rated power level. About 4 seconds after liftoff they throttled up to 104.5%. The maximum emergency throttle setting was 109%, but this was never used in flight. Screenshot from a Shuttle Mission ...


21

The maximum percentage wasted to noise is approximately 1%. The acoustic efficiency, defined as the ratio of the sound power to the rocket exhaust's mechanical power, for the majority of these data range between 0.2 and 1 percent...with 0.5% as the most probable value. NASA SP-8072 ACOUSTIC LOADS GENERATED BY THE PROPULSION SYSTEM Using the equation for ...


21

The Automated Ground Umbilical Systems (AGUS) Project contains a good overview of umbilical systems. The fluid lines are separated by "quick disconnects". Here is some information on them from that paper. Quick disconnects (QD) provide fluid servicing either directly to the vehicle or to a mobile facility. Considerable effort has been made in ...


21

At least for some vehicles, "dynamic pressure is closely monitored" is not correct. You need to have an air data probe to actually monitor it, and not all vehicles do. Shuttle: Dynamic pressure was not actually measured1 during ascent so "Max Q" was not either. The magnitude and time of Max Q was predicted by prelaunch simulations, and ...


20

I'm always surprised when I see how slow they seem to budge from the pad. I know they're massive, but still. Remember that when you are in the vehicle, what you feel is acceleration, not speed, but when you are outside looking at it, what you see is mostly speed, not acceleration. Speed obviously starts at 0, and is the the result of the integration of ...


19

Certainly a reasonable question. A possibly useful mental model is to spin a bucket of water in some form. Initially only the surface layers will spin but each layer transfers motion to the next layer in and eventually the entity of the mass is spinning in a steady state. Similarly with the atmosphere over geologic time scales the atmosphere is spinning with ...


18

Very unlikely. The first launch of a satellite in space, Sputnik, was launched without any prior public announcement. The US knew about it 7 months before the launch happened. It is pretty inconceivable that a launch could have happened that we wouldn't have had any knowledge of beforehand. The linked CIA papers even predicted the launch date to within a 2 ...


18

Shuttle crewmembers wore a g-suit, but only for entry. Anti-g Protection Crewmembers wear a g-suit for entry that provides pressure to the lower body separate from the ACES. The applied pressure prevents blood from pooling in the lower extremities upon return to 1-g conditions after two or more days of microgravity. Crewmembers wearing the ACES suit do not ...


18

Of the American companies ULA and SpaceX, the ULA currently maintains the longest "flawless" streak: ULA Launch History SpaceX Launch History Counting the launches: ULA has had ~126 successful launches since 2007 SpaceX has had ~98 successful launches since 2017 Assuming neither company has a failure, SpaceX will soon overtake the ULA, possibly ...


16

The Space Shuttle SRBs had cameras, and after sep a falling SRB can clearly be seen falling with its twin. The way they fall in unison is amazing, note the parallel orientations for most of the fall.


16

Shuttle: tl;dr - Shuttle throttled down based on the sensed acceleration. The "bobbling" about the 3g limit you see is because a proportional-integral control scheme was used and because the rate of change of the throttle command was limited. Details - The throttling algorithm works on an integral and proportional error. This algorithm tends to ...


16

Electrolysis-based propulsion becomes practical only once you've reached orbit, where you can power the electrolysis with solar panels and where you don't need enormous thrust. Whatever you'd use to power electrolysis for a first stage would be much heavier than conventional chemical propulsion.


16

@Russell hit the most important point (cabin decompression), but there are some others: Protection from small fires or chemical fumes. These are irritants to the eyes and respiratory tract, and can hinder an astronaut's ability to function, if not injure or kill. The suits are fire retardant, so they will not burn like some clothing will. They provide ...


16

For shuttle it was commanded by the vehicle computers. At T-31 seconds control of most remaining countdown events was handed over to the vehicle, including SRB ignition and blowing the hold-down post nuts. Source: Countdown See What holds the Space Shuttle orbiter itself stable on the launch pad? for details of the mechanism itself


15

In latter part of the 1960s it would depend on any nation having developed over the horizon radar (OTHR) capabilities that could provide significant coverage of its opponents launch sites. Australian research into HF radar IN the 1960s made some useful discoveries. One was that a rocket departing the atmosphere produced a very large and easily detected ...


14

269 Days, almost 9 Months HETE-2 was attached to its Pegasus launch vehicle in December, 1999, ready for a January launch. But then, NASA got cold feet. On January 14, 2000, they decided to postpone the launch. We had built it in an MIT lab for about 1/3 what the parametrics said it should cost, and that made some people nervous. Even though it was already ...


14

The lower atmosphere must rotate with the earth because of friction---at least the very bottom of it. That is true, but only at the very, very bottom of the Earth's atmosphere, perhaps the last few millimeters. There are winds, after all. The trade winds and the prevailing westerlies (along with the discovery of how to beat against the wind) resulted in the ...


14

For Apollo, the signal came from a small computer room built inside the mobile launch platform. Giant holddown arms, whose name exactly describes their function, are positioned on the launcher surface to support and restrain the Saturn V. These arms hold the rocket during the first 8.9 seconds of ignition of its mighty engines while the computer beneath, ...


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