Questions tagged [safety]

Questions regarding space exploration safety issues and procedures.

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2answers
132 views

Is a low-altitude, stable glide really absolutely needed to bail out of the space shuttle?

After the Challenger disaster, the Space Shuttle astronauts were outfitted with pilot spacesuits equipped with parachutes and internal emergency oxygen supplies, and the space shuttle was equipped ...
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How dangerous are RCS thrusters?

How dangerous are RCS thrusters, in a vacuum, to A. other spacecraft, especially when docking, and B. astronauts in EVA suits? How far away do you have to be to be safe / do RCS thrusters need to be ...
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Is present-day plumbing technology enough to make refueling of hypergol rockets safe? What about only in space?

Sadly, all of the currently commonly used chemical rocket fuels that are either hypergolic or storable are horribly toxic/corrosive/explosive. RP-1 is so safe you can pour it out of a gas can, but ...
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216 views

Do all dangerous asteroids first pass through keyholes?

Scitech Daily's MIT Engineers Devise the Best Way to Deflect an Incoming Planet-Killer Asteroid Now MIT researchers have devised a framework for deciding which type of mission would be most ...
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1answer
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Loose items in Apollo CM during reentry?

Would there have been any danger to the astronauts or the equipment if a soft item, like a crumpled up napkin or tissue, was loose during the Apollo CM reentry, or did everything have to be secured?
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Was there any risk of the Gemini hatches blowing open?

The Gemini hatches open outward, as can be seen in this EVA image. I know this was required for the ejection seats to work, but wouldn't this also pose a risk of depressurization if the latch ...
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1answer
183 views

Does the Artemis III mission have a backup plan if the astronauts are unable to ascent from the Moon?

For the unlikely scenario where the Artemis III astronauts having landed on the Moon press the ascent button and nothing happens, will NASA have a backup or rescue contingency plan? If so, what ...
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1answer
123 views

How will space suit computers likely be radiation hardened?

Writing this comment inspired the following question: Space suits are critical to life, so if there's a solar storm and the astronaut has received a less-than-lethal dose of radiation, they'll be ...
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Did the Apollo missions fly “over the top” of the Van Allen radiation belts?

In the video The Moon Trees That Flew To The Moon On Apollo 14 after about 08:47 Scott Manley says that Apollo 14 "flew up over the top" of the Van Allen radiation ...
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1answer
120 views

How do we use Fire Extinguishers to Control Fire in the Space Station?

In this NASA Webpage for Fire Prevention in Space, it is given that If a fire were to occur on the ISS, the astronauts would become firemen and follow a three-step response system. First, they ...
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Best (least worst) conditions to “store” an astronaut in a suit for six days?

@GremlinWrangler's answer to How can an Astronaut survive for six days inside a Spacesuit? includes the following: make sure the suit can provide air and water, and adjust the temperature to ...
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Aerosol products in space

I am assuming aerosol products are not used inside the living environment of a spacecraft while it is microgravity. Is that correct, or are there examples of such products being used while an ...
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What is the furthest distance Apollo astronauts can be from each other during a Lunar EVA?

I'm assuming there has to be a limit set by NASA of how far astronauts can be from each other for their safety. If something happens to an astronaut's EVA suit, the second astronaut can use the "buddy ...
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1answer
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Was this a rapid SCHEDULED disassembly? How was it done?

The new Curious Droid video Apollo's Forgotten Computer - The LVDC discussed the Saturn V flight computer that's also discussed in answers to Is this really the Saturn V computer only, or are there ...
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Has one satellite's outgassing ever affected another satellite in the same fairing? Documented examples?

At about 01:31 in Scott Manley's new video RocketLab & Reusable Rockets - Plasma Knifes, Ballutes, Helicopters and... Elephants he says: This occurs during a ...
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Is the EU really banning “toxic propellants” in 2020? How is that going to work?

This comment links to an archived presentation by Tesseract "The space transportation company offering revolutionary propulsion" says on slide 8: Timing is right Small satellite ...
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What is Tesseract's “secret sauce”? (green propellant)

TechCrunch's Tesseract makes spacecraft propulsion smaller, greener, stronger tells us to "ditch the hazmat suits" and https://www.tesseract.space/products-and-services lists the Lyra 22 (i.e. 22 ...
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Why would the Apollo Lunar Module pressure dump (to space?) valve have a bacterial filter?

This answer to Why did they bother closing the hatch on the LM while doing EVA? links to a transcript of Apollo 11 which contains the following (find it there by searching for "radiative"): 109:41:...
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880 views

How long were the Apollo astronauts allowed to breathe 100% oxygen at 1 atmosphere continuously?

This answer explains that from the time they suited up "in the Suit Lab before launch" until the time the capsule started depressurizing during ascent, the Apollo astronauts were breathing 100% oxygen ...
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1answer
78 views

What scenario would require the closeout crew to use their light sticks?

The light sticks are intended as an aid in case of an emergency, and are colored orange to identify the astronaut crew, while technicians in the close-out crew carry green ones. https://en....
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2answers
120 views

Does landing a Falcon 9 first stage affect the allowable launch azimuths?

The rationale for limiting the allowable launch azimuths for many launch sites usually includes "dropping booster stages on population". With SpaceX (and maybe Blue Origin in the future) returning ...
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How did sloshing prevent the Apollo Service Module from moving safely away from the Command Module and how was this fixed?

The Insider.com article 'We could have lost the Apollo 11 crew:' A once-classified anomaly nearly killed NASA's first moon astronauts, a new book reveals describes a problem during reentry of several ...
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What makes Ada the language of choice for the ISS's safety-critical systems?

We have it on good authority that Ada is widely used for "safety critical software" on at least the US side of the International Space Station. Of all the possible languages to choose from, what are ...
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What were the Top 10 Shuttle Risks in John Young's “famous letter”?

Whilst reading A Technical History of the External Tank I ran across this comment: Although the problem has not recurred, John Young, in his famous top ten Shuttle risk letter ...
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1answer
900 views

What exactly is a “Green Run test” for SLS that NASA is considering skipping?

The Ars Technica article Rocket Report: A new Delta 2, Blue Origin inks with NASA, a fiery Falcon Heavy says: Boeing seeks to ship SLS core stage by the end of 2019. With a renewed emphasis from ...
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1answer
154 views

Going to the Lunar gateway during the upcoming solar maximum! What will the radiation environment be like?

EarthSky.org's What will the sun do next? says: On December 6, 2018, the Center of Excellence in Space Sciences India (CESSI) reported that two of its scientists have made a prediction for the ...
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What is the minimal distance of clearance in the direction of flight path for a rocket?

Usually the rocket launch sites are placed on a coast or a place where there's basically no civilian buildings in the direction of flight path. Is there a standard/regulation on the minimal ...
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1answer
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How are airborne particulates monitored on the ISS? Are they distinguished at all by size and/or type?

The question What kinds of activities, experiment and, procedures done on the ISS must be done in chambers vented to space? links to and quotes from this answer to the 3D Printing SE question How is ...
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What kinds of activities experiment and procedures done on the ISS must be done in chambers vented to space?

This answer to the question in 3D Printing SE How is 3D printing done in space? says The first big space-specific issue is actually air quality. You can't just open a window to air out the molten-...
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1answer
254 views

Why didn’t the space shuttle external tank have pressure-relief vents?

During a space shuttle abort, it would have been vitally important not to allow the vehicle to droop below 265 kilofeet during powered flight, as excessive aerodynamic heating below 265 kft would have ...
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How do HMX-fuelled rockets launch without exploding?

Unlike most civilian solid-fuel rockets, which use ammonium perchlorate/aluminium fuels with a rubber binder (known in the industry as ammonium perchlorate composite propellant, or APCP for short), ...
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1answer
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How close did Apollo 16 astronaut Charles M. Duke Jr. get to the edge of Plum crater?

The New York Times article What Happened to Earth’s Ancient Craters? Scientists Seek Clues on the Moon’s Pocked Surface includes a NASA photo with the caption: Astronaut Charles M. Duke Jr., of the ...
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1answer
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Why not turn off the main engines while using the launch escape system on liquid fuelled engines?

I've seen a couple of launch escape systems firing and the rockets main engines are on, isn't it more safe if you turn off the engines? Edit: i agree that the engines turning off might be not so ...
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1answer
904 views

Why are lightning towers at launch pads topped with big hollow tubes with spiral windings and not “lightning rod-shaped” lightning rods?

https://xkcd.com/2107/ Why are the lightning towers around launch pads topped with big hollow tubes with spiral windings? Why not conventional lightning rods - big metal rods with pointy things at ...
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1answer
243 views

How are SRBs and solid rocket motors transported safely? Do they ever end up on trucks driven down public highways?

The BBC News article The Rocket Scientists Mixing Up a Giant Firework begins with: In a remote corner of tropical South American jungle, French scientists are mixing a ‘cake’ with a difference – a ...
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“Prolonged exposure to microgravity … makes facial hair flammable”?

TheWeek recently published an article titled "The Colonization of Space", which contained the following sentence (emphasis added): Prolonged exposure to microgravity weakens bones, atrophies ...
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How are the liquid propellant umbilical cord protected from the exhaust?

The launch pad umbilical cords supply propellant to the rocket, and will definitely have some remaining at the time of liftoff. I remember the Saturn V footage wherein a heavy protection door slams ...
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1answer
217 views

How common is the ability to compensate for a lost engine through gimbaling?

Discussing a system of regulating thrust through lighting/extinguishing engine pairs, I was met with a reply: Really there is no need to treat engines as a pair in this context. In fact, ...
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What do you need to do legally to have an object in orbit?

Hello fellow explorers, I've been looking into amateur satellite and rocket launches. Now, I'm by no means saying I'm an expert and have all my plans ready for launch. However, hypothetically if I ...
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3answers
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August 30th 2018 Soyuz leak, any dangers for re-entry?

On August 30th 2018, Soyuz MS-09 had a leak that was fixed by the ISS crew (source). Does the leak/fix have any consequences on using the Soyuz for returning to Earth? Would the fix hold the stress ...
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What is the primary reason for SpaceX motion to have astronauts board Dragon before fueling up the rocket?

News piece: NASA supports SpaceX plan to fuel rockets with astronauts on board. The move is criticized by many as unnecessarily dangerous. From what I understand though, it shouldn't be necessary - ...
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1answer
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High velocity particle impact on humans in outer space

The Earth is constantly bombarded by matter from space. Is there any risk of high velocity dust particle/micro-object (cosmic garbage e.g.) impact on astronauts while in outer space? What chance is ...
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CubeSat Design Requirements and Safety Restrictions?

I was reading XKCD, and came across this beautifully designed CubeSat: It is dubbed SafetySat: "During launch, in the event of an unexpected sensor reading, SafetySat will extend prongs in all ...
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How would the antenna on a spacecraft in GEO be provided an electrical ground?

I would like to understand better what specifications or guidelines address the electrical grounding/Earthing a parabolic reflector Antenna in GEO to minimize the potential difference with respect to ...
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1answer
244 views

What data was used to estimate accumulated radiation dose for the Apollo astronauts?

Half-year, and occasional one-year stints aboard the ISS, and especially lifetime totals nearing 2.5 years are possible ethically because these missions take place within the Earth's magnetosphere ...
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422 views

Safety regulations for storing, handling, and using rocket fuels?

How does a company with no experience in space (like SpaceX or Blue Origin) find out how to safely handle hazardous and flammable fuels? Are there safety regulations for how to store, handle, and ...
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1answer
445 views

How much jerk do astronauts experience? Is there a safety limit?

From Wikipedia: In physics, jerk is the rate of change of acceleration; that is, the derivative of acceleration with respect to time, and as such the second derivative of velocity, or the third ...
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1answer
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Where does space travel rank in per-passenger-mile safety?

Air travel is the safest method of transportation, with 0.07 deaths every billion passenger-miles. While space travel certainly has a higher fatality rate per-space-traveller (~3%)1, 2, where does it ...
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Are there rules, policies, or guidelines regarding spacewalking soon after launch?

In light of this answer, where except for a few cases, space walks from the ISS are usually performed starting about a month after arrival at the ISS, are there any rules, policies, or guidelines that ...
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Earthing system in space?

On Earth, we have a good reason to deploy electric devices with an "Earthing system": this helps to avoid dangerous leak currents on surfaces. Now how is this solved on a spacecraft?