55

The planned test was a centrifuge test. They were going to take the entry vehicle up past the 10-g mark and back down. According to the JPL Mission Manager, who was my boss at the time, the g-switch was supposed to come off the peg at 3 g's, saturate at 10 g's which told the deployment controller to enable the deployment sequence start (i.e., to "arm&...


35

The Space Shuttle used liquid hydrogen, contained in the external tank along with liquid oxygen. While the Falcon rockets do use liquid oxygen, they do not use liquid hydrogen. Keeping the liquid hydrogen cool was the primary driver for the foam. The Orbiter was mounted alongside and below the the top of the external tank. The Falcon payload is mounted at ...


25

I had the same question. Elon Musk confirmed the "engines did great!" There's also some discussion over here where the prevailing opinion is that the shutdowns were intentional. Just before the engine on the left of the screen goes out, you see all three of them gimbal. The one being shut down moved out of the way, and the others took up a ...


19

SE won't let me comment under or upvote rkagerer's comment. Yes engine shutdowns intentional due to the flight profile. Key points IMO: given the minimum raptor thrust is around 40% or ~90 tonnes (https://twitter.com/elonmusk/status/1295553672454311941?lang=en), even at minimum throttle SN8 will still be accelerating upwards SN8 must stop upward ...


18

The problem is not the foam breaking off per se, but the fact that the orbiter was below the fuel tank and got hit by the falling foam. The Dragon capsule is on top of the stack, it can't be hit by a piece of foam that comes off the booster.


16

It was not a thermal image at all. It is an optical image that has been captured by Orbiter of the lander spot and not thermal image as reported by others media houses. OHRC is same like our human eye. Since it consists of only one spectral band in visible region, so Image will be of gray scale, Not color image. https://twitter.com/Madrassan_Pinky/...


12

Do all chemically-fueled rockets need foam insulation? Not all, but some do. Generally the small subset of ones that utilize hydrogen fuel. The hydrogen-fueled Delta IV uses essentially the same insulating foam as shuttle did. Photo from clickorlando.com The hydrogen-fueled SLS uses a similar foam. Photo credit NASA This question Insulation on rockets--...


12

Apparently the battery is only prone to explode while used. So when turning the satellite off, the risk appears to be mitigated sufficiently (I expect the battery to be discharged. A battery storing no energy can't cause an explosion, as an explosion is simply the uncontrolled and rather sudden release of said energy). This means the main risk of a GEO ...


9

It was Voyager 2 (launched before Voyager 1). Technical details on Voyagers are surprisingly hard to find. The most detailed account I found was in Voyage to Jupiter, the official NASA history of the project. During the first minutes of flight, there seemed to be two difficulties with the AACS.The first was a problem with one ...


8

The Federal Aviation Administration is the United States' Federal Government organization responsible for every US vehicle that flies. The Electron flies, and it is launched by a US company, hence, it falls under the jurisdiction of the FAA, more precisely under the jurisdiction of the FAA's Office of Commercial Space Transportation. This is based on ...


7

As a rule of thumb, no rocket fuel (or oxidizer) will ever be able to detonate on its own. For the simple reason that the maximum flame front propagation through it needs to be slower than the fluid speed through the injectors, otherwise the flame would propagate back into the tanks. NO, no-one has ever managed to pump flammable fluids faster than their ...


6

National Geographic reports that the 2014 Antares explosion carrying a Cygnus v4 for the Cygnus CRS Orb-3 mission "knocked two spectators off the bed of their pickup truck and another off her dock. The blast broke windows and imploded doors in buildings close to the launch site", which both shows that something did indeed knocked over and windows got blown ...


6

Thanks to @jkavalik for the informative answer and helpful links! As is pointed out there, there seems to be an abundance of false social media accounts claiming to be K. Silvan. From today's Sep 09, 2019 post: Regarding Social Media Accounts in the name of Kailasavadivoo Sivan, Chairman ISRO: It has been noted that social media accounts in the name of ...


6

Vostok flight computer had a number of preset programs that could be activated by receiving the appropriate command from Earth. The COMSAT receiver was based on an older military system that was originally designed to remotely detonate explosives. Soviets widely used radio-controlled mines (called F-10) in WW2 to destroy strategic targets left after troops ...


6

Or perhaps was it found again much later? It appears to have been found. According to Wikipedia, Satcom 3 is COSPAR ID 1979-101A; Celestrak has a current TLE for it. SATCOM 3 1 11635U 79101A 20165.54218687 -.00000091 00000-0 00000-0 0 9990 2 11635 9.1831 306.7881 4819048 43.5856 92.1293 1.82528373183904 That's an eccentricity of ...


5

There is a famous incident with a V-2 (or V-2 derivative) from White Sands landing near Juarez Mexico. From the El Paso Times It was May 29, 1947. Here is the El Paso Times report: El Paso and Juarez were rocked Thursday night when a runaway German V-2 rocket fired from the White Sands Proving Ground in New Mexico crashed and exploded on top of a rocky ...


5

Oscar-7's designed lifetime was three years. But it did work from 1974 to 1981 (in its first period), about the double designed lifetime. Oscar-7 was reliably used by the amateur radio community all over the world from just after launch until June 1981 when its batteries likely shorted. This in turn short-circuited the entire power system, just like ...


5

There is no* safe condition used by Ariane 5. It is not common to use Launch Escape Systems for UNmanned flights. Actually the hardware of a spacecraft is not as costly as you may think, the development itself is driving the costs. So usually there are Flight Spare Units (Wikipedia Flight Spare) of the spacecraft, sometimes even (nearly) assembled. If a ...


5

It's worth noting that at this time, there isn't enough details on Artemis to know for certain. The program is only a bit of a concept at this time, with the hope to have it more fully fleshed out soon. Still, anything very specific, like backup procedures, probably has many possible options. Presumably this will be similar to the Apollo system, have a ...


5

Using Wikipedia: The hydrazine tank of New Horizon has an elastomeric diaphragm separating the liquid from the pressurizing gas helium within zero gravity. There are 16 thrusters with redundant plumbing to the tank. The diaphragm prevents helium entering the plumbing, so all hydrazine within the tubes is trapped. If the elastic diaphragm does not fully ...


4

Proton is Russian, and of course has failed, and badly recently. They skipped Ariane which had some early launch failures. India and Japan had lost vehicles as well. Everyone has launch failures at some point. (A more interesting question might be, is there a booster without a launch failure, defined as loss of mission/payload? Saturn V, Falcon Heavy come ...


4

Is Perseverance still in Safe Mode? Not any more: NASA's Mars rover Perseverance is fine and out of 'safe mode' as of July 31, 2020.


3

It was as of the latest update, but they were working on recovering it. They have full communication with the spacecraft as of now. The press release, issued on July 30, stated the following: Right now, the Mars 2020 mission is completing a full health assessment on the spacecraft and is working to return the spacecraft to a nominal configuration for its ...


3

Humanity hasn't yet reached a consensus. Return samples obtained from a Category V body must be curated at facilities rated Biosafety level-4 (BSL-4). Because the existing BSL-4 facilities ... do not have the complex requirements to ensure the preservation and protection of Earth and the sample simultaneously, there are currently at least two proposals to ...


3

During the moon race, a soviet N-1 rocket exploded seconds after liftoff. This is ranked as one of the largest conventional explosions with an approximate yield of 1 kt of TNT. Upon impact of the base of the N1 with the pad, the vehicle exploded, destroying launch pad 110 east, which would take over 18 months to repair. [...] At T+23 seconds ...


3

Some rockets (especially hybrids) use nitrous oxide oxidizer, which exothermically decomposes into nitrogen and oxygen and is capable of detonation. This is not just a theoretical hazard, Virgin Galactic experienced an explosion during a cold-flow injector test in 2007 that killed 3 people and injured 3 more. Acetylene is typically handled as a solution in ...


2

Accident with Cosmos-57 https://www.kik-sssr.ru/Evolution_of_KRL.htm The test of the gateway was successful and the Post-2D station NIP-6 (Yelizovo) issued a command to transfer air to the gateway, and the Post-2D station of the neighboring NIP-7 (Kluchi) duplicated it. As a result of adding two identical commands, another command was formed. This was ...


2

I don't have a source sorry, but I suspect the reason for having insulation is to prevent formation of liquid oxygen on the out side of hydrogen tanks. Hydrogen is so cold that it can cause the Oxygen (and Nitrogen) in the the air to condense. Liquid Oxygen just dribbling onto the launch pad and rocket would be a bad thing. Steel burns in liquid oxygen. ...


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