69
votes
If human space travel is limited by the G force vulnerability, is there a way to counter G forces?
The problem isn't so much that humans cannot sustain high G forces for any extended length of time: The problem is that rockets cannot. If a rocket could sustain 1 g acceleration for a bit over a day, ...
- 73.2k
60
votes
Could a spacecraft spin so fast that it spontaneously deconstructs?
Did it really happen?
Yes.
The investigation of Japanese Hitomi spacecraft's failure found that it was spinning too fast due to attitude control error. As a result, the spacecraft spun so fast that ...
- 9,041
59
votes
Accepted
Could a spacecraft spin so fast that it spontaneously deconstructs?
To parallel @Heopps answer:
Did it really happen?
Yes.
In spectacular fashion!
In 1965 NASA launched a boilerplate Apollo command module on a Little Joe II rocket to test the Launch Escape System (...
- 18.2k
47
votes
If human space travel is limited by the G force vulnerability, is there a way to counter G forces?
Ignoring the major point that human tolerance of G forces is not the limiting factor on space travel, plenty of thought has been made on how to counteract G forces, not least by 60s sci-fi writers.
...
- 6,418
21
votes
Accepted
How do vibrational isolators reduce the g-forces of a payload on a launch vehicle?
The g-forces from the rocket's acceleration remain unaffected, of course.
What the vibrational isolators do is isolate the payload from vibrations.
Without them, the payload would experience both the ...
19
votes
Accepted
How much acceleration g-force can prevent pilot from moving their arms?
According to the book Human Engineering guide for Equipment Designers, authored by Wesley E. Woodson and Donald W. Conover and published by the University of California Press, suggests the following ...
- 2,127
18
votes
Accepted
Do astronauts wear G-Suits during the launch?
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 ...
- 178k
14
votes
Could a spacecraft spin so fast that it spontaneously deconstructs?
Reaction wheel? No, these are way overpowered in KSP, and don't exert nearly as high torque in real spacecrafts, never mind the issue of saturation (maximum speed of reaction wheel motor).
But ...
- 54.9k
14
votes
Accepted
How much G force is applied when correcting an orbit around Earth?
In practice, the g force applied for orbital corrections is very small. The satellite operator has plenty of time to make the correction, and if you are capable of accelerating the satellite at more ...
- 167k
12
votes
Accepted
Were shuttle seats reconfigured between launch and reentry to account for the different direction of acceleration?
The seats had a back angle adjustment that was changed from the ascent position for entry. Disappointingly, this is not mentioned in the press reference manual (https://science.ksc.nasa.gov/shuttle/...
- 178k
11
votes
Could a spacecraft spin so fast that it spontaneously deconstructs?
Yes, absolutely.
Every part of a spinning, rigid structure is undergoing acceleration towards the center, proportional to the radius from the axis of rotation and to the square of the angular ...
- 167k
9
votes
How do vibrational isolators reduce the g-forces of a payload on a launch vehicle?
The situation is a bit similar to driving up hill on a bumpy road.
The car's suspension definitely transfers the "average force" from the road up to the passengers, but let's talk about what ...
- 149k
8
votes
How do vibrational isolators reduce the g-forces of a payload on a launch vehicle?
Other than the "DC" (or low frequency part) of the g-forces, all the "AC" (or high frequency components) of the g-forces create both positive and negative contribution to velocity ...
- 990
6
votes
Accepted
Is there a G-force curve estimated for a SLS launch?
I haven't seen acceleration-vs-time curves published by NASA.
The SLS Mission Planners Guide has a table of maximum expected acceleration. Looks like it is predicted to max out at 4.1 g.
- 178k
6
votes
Do astronauts wear G-Suits during the launch?
As suggested above, during launch, conventional jet-fighter style G-protection is not used, because a crewmember will typically be positioned laid on their back, typically with the knees and feet up ...
- 69
5
votes
If human space travel is limited by the G force vulnerability, is there a way to counter G forces?
This is way beyond foreseeable economic possibilities, but the physics is sound:
Gravity is a surefire, scalable, elegant way to counteract G forces from acceleration.
A planet-sized spaceship with ...
5
votes
What are the G-forces of Soyuz 3rd stage engine cutoff
3g (image below from this Quora answer), and it appears that the third stage cutoff is not the most intense. That one comes from the first stage cutoff, which is around 4g.
Car crashes can be huge g ...
- 6,250
5
votes
Accepted
What is the constant g-phase in Apollo re-entry, and why does it not show up on the graph?
Constant-g was used in backup manual control modes.
Note your quote says planned - the value of g the crew would fly was read up to them as part of the pad.
See the discussion in your link.
191:58:13 ...
- 178k
5
votes
How much acceleration g-force can prevent pilot from moving their arms?
how much g-force would prevent the pilot from being able to move their limbs in order to control the space craft?
How many times do they have to lift their arms? How much control of the limb do they ...
- 167k
4
votes
Could a spacecraft spin so fast that it spontaneously deconstructs?
Could a spacecraft spin so fast that it deconstructs itself? What force would cause this (if it would) and which parts would be most susceptible to this force?
It's not a matter of a force causing it,...
- 1,639
4
votes
Is it possible, using known acceleration laws, to drastically lower force required to leave Earth's Gravitational pull?
A structure like that would reduce the amount of energy needed to get to orbit. But:
getting a structure up to 17,500 mph would take vast amounts of energy.
transporting the spacecraft from Earth ...
- 126k
4
votes
What G-forces do different launchers cause?
To supplement the other answers (and perhaps of historical interest) here's a Space Shuttle launch acceleration profile.
Segment labels correspond to the following events/phases:
A: liftoff to ...
- 178k
4
votes
g-forces of suborbital versus orbital passenger travel
Back-of-the-envelope:
The Shuttle kept ascent acceleration at or below about 3g - tolerable for most people; other human-rated launches have gone higher. Even under the 3g constraint, burn duration ...
- 17.4k
3
votes
G forces of Starship 1 when leaving Earth orbit?
In vacuum maneuvers will be taking place with the three vacuum Raptors, target hoped for thrust somewhere around 2500 kN each. For a loaded Starship at around 1000 tonnes F/m=a gives 7.5 m/s2 or just ...
- 21.4k
3
votes
Is it possible, using known acceleration laws, to drastically lower force required to leave Earth's Gravitational pull?
Your basic question seems to be whether we can build megastructures that use passive momentum and other orbital characteristics to make entering orbit simpler. We can, but the specific example isn't a ...
- 4,548
3
votes
g-forces of suborbital versus orbital passenger travel
The paper Great Expectations: Assessing the Potential for Suborbital Transportation says
Suborbital tourism operators expect g-forces of +3g at the start of
the ballistic phase and up to +6g ...
- 178k
3
votes
Are Virgin Galactic tourists asked to take a 6 to 8G centrifuge test to qualify, and if so, what's the point?
https://bis-space.com/membership/voyage/VoyageIssue8-Virgin%20Galactic.pdf confirms that:
The Virgin Galactic spaceship is designed
to fly almost anyone to space without the
need for long term ...
- 1,164
2
votes
How much G force is applied when correcting an orbit around Earth?
Using a very strong engine for high accelaration in a very short time requires additional mass for the rocket engine and the structure. Therefore additional fuel is necessary to accelerate the heavy ...
- 48.8k
2
votes
Accepted
Upper G acceleration limit for a small thorium nuclear reactor and electronics
For a nuclear pulse rocket, the peak acceleration is due to the shock of the push provided by each pulse unit. I struggled a bit trying to find a reference for the G-limit of what shocks electronic ...
2
votes
Accepted
G - forces imparted by launchers
The best way to know is to check the payload planning guide for a particular launcher. Many modern launchers throttle down over the course of a flight to limit g-loading, so a simple rated-thrust ...
- 167k
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