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Questions tagged [safety]

Questions regarding space exploration safety issues and procedures.

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

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 the top? Possibly ...
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1answer
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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
129 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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1answer
304 views

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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3answers
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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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117 views

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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3answers
796 views

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
160 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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2answers
226 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
189 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?
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What are some common (but non-obvious) materials that are particularly unsuitable for spaceflight?

If a product was to be made for use in space, there may be certain materials or certain combinations of materials that might work well on Earth, but be particularly unsuitable for spaceflight ...
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1answer
415 views

Historically, how risky are first launches of new rockets?

Apropos of the Falcon Heavy test flight scheduled for February 6, 2018, what is the failure rate of first launches of new orbital rocket designs? How has this rate changed over time since the 1950s? ...
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For a launch, how is safe viewing distance determined?

In determining safe viewing distance, seems to me there are discrete threats to consider: First is the rocket blowing up on the pad, or just above it. That would have no warning. There would be a ...
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2answers
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Was this large pieces of “space junk” just released from the ISS in the “nadir and retrograde” direction?

According to Space.com's 02-Feb-2018 article Cosmonauts Break Russian Spacewalk Record During Space Station Antenna Repair: The cosmonauts spent the day replacing an electronics box for a high-gain ...
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ISS - Tiangong 2 minimum safe distance

Using the SGP4 propagator, I calculated the minimum distance between ISS and Tiangong-2 for this year. I obtained 12.32 km for 2017-09-27 17:29:36.376 UTC (which is the day 270.7289). I used the TLE ...
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2answers
211 views

What is the best position for a human to be in during launch?

We know from the answers to the question If a human is being sent to space in a rocket, does the seating angle matter? that seating position at launch is of less concern than landing. We also learn ...
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6answers
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Is it safe to see the ISS with the naked eye?

As far as I understand, when we view the ISS, it is because the sun rays get reflected from the solar panels of the ISS and reach us at the appropriate angle. So that would be equivalent to viewing ...
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1answer
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What first aid options do astronauts have during an EVA?

If an astronaut gets unconscious or ill I suppose the colleague will help her to the airlock. But are there any other measures that could be taken already outdoors? Do they have duct tape to seal a ...
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Why haven't backup parachutes been used for spacecraft?

Skydivers normally wear a backup parachute. Apollo 15 survived with two out of three parachutes working properly. But wouldn't it be great to have a second deployment option, like skydivers do? The ...
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2answers
697 views

What is KSC's HURCON II?

HURCON II sounds like DEFCON 2, the 2nd highest level of five levels of The DEFense readiness CONdition (DEFCON); an alert state used by the United States Armed ...
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1answer
363 views

Does the ISS have any ability to detect or sense unexpected/unscheduled objects in close proximity?

In a recent science fiction movie there was a space station similar to the ISS, and it had a "proximity alert". This made me wonder; in the real world, does the real ISS have any capability to ...
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4answers
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Why would a box full of 1cm balls released into LEO be so scary to an engineer supporting the ISS? - (Updated)

update March 2018: I just saw this in Buzzfeed (Google sent me there, I don't normally read it): Rich People Will Soon Be Able To Buy Fake Meteor Showers On Demand. It seems this might happen in 2018. ...
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1answer
158 views

How would the Heimlich maneuver or CPR be done in weightlessness?

Abdominal Thrusts (the "Heimlich maneuver") and Cardiopulmonary Resuscitation (CPR) are life-saving first aid procedures that involve carefully targeted manual forcing of a victims body in order to ...
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156 views

Does a safety team get fined if a rocket launch fails due to the safety of the rocket?

I was writing a story and I wanted to write about this topic but I could not find a straight answer from any website. Please help
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1answer
2k views

Can astronauts wear eyeglasses inside their helmets during launches and landings?

Are astronauts allowed to wear their eyeglasses inside their helmets during launches and landings?? Are there any special considerations or rules? During spaceflight (launches and landings) there can ...
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2answers
135 views

How would a landing escape system be designed? [duplicate]

Launch escape systems have been used for half a century and have worked great when tried. But entering Earth's atmosphere from orbit and landing is at least as dangerous to astronauts, and have cause ...
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1answer
738 views

Any potential downside to throwing personal life support out the door on the Moon?

I found this really interesting description of the ALSEP instrumentation placed on the moon during the Apollo 11 landing, written by Hamish Lindsay, (also, author of Tracking Apollo to the Moon). One ...
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1answer
171 views

What support equipment is necessary to maintain a falcon 9 booster during transport after recovery?

This file photo shows a Falcon 9 first stage being transported by truck after landing. There is some equipment at the end of the truck, which includes dials, knobs, and an exhaust stack, which ...
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1answer
2k views

What is the “ISS's Keep Out Sphere” and what is its radius?

The comment: In a similar vein, it would be interesting to know if going around the moon rather than to the ISS removes any legal hurdles. Do we have any questions covering the legal ramifications (...
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Will a computer be allowed to “self-destruct” astronauts (or passengers)?

In the video clip of this interview, captioned: General Wayne Monteith, 45th Space Wing Commander, talks about the Autonomous Flight Safety System, or AFSS -- a new, automated way of having a ...
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1answer
391 views

What are the issues and concerns related to turbopump blade cracks and manned spaceflight?

While the WSJ headline sounds ominous: Congressional Investigators Warn of SpaceX Rocket Defects, Quartz's SpaceX needs to redesign its engine to ensure it is safe for human spaceflight seems to be a ...
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1answer
1k views

Were ejection seats on the Space Shuttle a practical safety system?

The first four STS missions were flown by Columbia with two pilots and had ejection seats as an option. These seats were eventually disabled (by STS 5) and removed (by STS-61-C). They could only be ...
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1answer
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Is 45 km unusually close to pass the ISS and deploy a microsatellite without warning?

Eight years ago, on September 27, 2008, the Shenzhou-7 carying three taikonauts deployed the microsatellite Banxing-1 for testing maneuvers and external imaging. A few hours later at 15:07 UTC the ...
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9answers
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Tiny emergency propulsive device if stuck floating in a large volume in microgravity

The questions here in SXSE Can you swim in space? and in Physics SE How to escape the center of a room without gravity? [closed] both address aspects of how to move if stuck floating in the center of ...
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What systems or technologies are developed to protect ISS from space debris? [duplicate]

What kind of systems or technology is developed for ISS (International Space Station)? There are so many debris at higher orbits than ISS, but many of them has started deorbiting so we have a ...
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1answer
499 views

What is the ortho/para issue with LH2 as a fuel?

I remember reading somewhere that a catalyst was used to change the ratio of ortho- vs para-hydrogen before it is loaded as LH2 propellant on a rocket. What is this exactly, and why is it necessary? ...
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1answer
2k views

What does it mean for a launcher to be 'nuclear-certified'?

This article says NASA has booked a nuclear-certified Atlas 5 for the launch of the Mars 2020 rover, and says this: currently, Atlas 5 is the only launch vehicle that holds a NASA certification ...
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1answer
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How does the launch risk for a plutonium RTG and a uranium fission reactor compare?

I was looking at this answer that talks about how a good alternative to Radioisotope Thermoelectric Generators would be fission reactors. It makes a number of good points, but in the comment thread ...
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1answer
390 views

Why aren't bubble helmets dangerous in direct sunlight?

I've been thinking lately about bubble helmets used by many cosmonauts and astronauts. Almost every space suit I've seen features a curved helmet, even the Gemini astronauts. But a curved piece of ...
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2answers
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Is the overall mortality rate for being in a spacecraft in space or bound for space about 4%?

I just read this answer in astronomy.stackexchange, where a sobering point was made that the overall to-date chance of losing ones life in a spacecraft is about 4%. While I don't want to dwell on ...
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1answer
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Why were ejection seats used in Project Gemini instead of a tower escape system?

In Project Gemini, the Titan II GLV space rocket used as fuel hydrazine and nitrogen tetroxide, so safety concerns over its toxic propellants were present. But along with the special care that was ...
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371 views

When have astronauts been launched without launch escape system (tower)?

The Vostok spacecraft used by Yuri Gagarin seems to have had an "ejection seat". The Soyuz launcher has an escape tower, which at least once saved its crew. The space shuttle of course did not have ...
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Engineering difficulties towards near-perfect rockets?

So in the light of some technical failures last year, I recently had a discussion about engineering endeavours throughout human history. An interesting recent adventure is the revival of rocketry. ...