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, ...
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69
votes
Accepted
How (the heck) did Lunokhod 2 drive, navigate and survive a ~40 kilometer drive over four months on the Moon using 1970's technology?
A few interesting videos about the lunokhod rovers:
Tank on the Moon
The Lunokhod Rovers - It Happened in Space #7
Secret Soviet Lunar Rovers and Extra Terrestrial Cars - Lunokhod,
Mars Rovers
The ...
- 13k
54
votes
Why are the recent flights of two billionaires discussed in terms of space travel?
Did they reach space?
Branson: yes
The Virgin Galactic SpaceShipTwo class craft "VS Unity" flew Branson up to 53.5 miles (86 kilometres). This altitude is considered "space" by the ...
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.
...
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40
votes
Accepted
What are some of the obsolete technologies that space agencies used in day-to-day work during the 1960s?
Everything has changed in the last 50+ years.
Every group working on space exploration had secretaries, lots and lots of secretaries, about one for every four to ten technical employees, plus many ...
- 73.2k
36
votes
Could a helicopter fly on Mars?
There's nothing like seeing it flying in a Mars-density chamber to answer your question:
Crazy Engineering: Mars Helicopter
I have a really nice video of it in controlled flight in the chamber, but ...
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36
votes
Accepted
Why doesn't the USA use structurally stronger rockets for the more important launches?
I think you got it wrong: R-7 launches sometimes are also postponed due to weather. Just to name few examples: 18 December 2018, 9 March 2018, 22 April 2016 - Kouru; March 22, 2016 - Baikonur, 2 ...
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34
votes
Accepted
Could a helicopter fly on Mars?
Gravity is about a third of Earth's and competitive aerobation helicopter models have a truly excessive power surplus. Just look at this.
There won't be any manned helicopter flight. The helicopter ...
- 54.9k
28
votes
Why doesn't the USA use structurally stronger rockets for the more important launches?
This question is based on several serious misconceptions.
R-7 launches never get postponed due to weather.
Actually, they do. "The launch of the Soyuz 2-1A modernized carrier rocket, scheduled for ...
- 178k
23
votes
Accepted
Has any piston machine been used on a space mission?
Apparently JWT uses piston pumps in its Cryocooler system:
The only moving parts in the cryocooler are the two 2-cylinder
horizontally opposed piston pumps in the CCA, and by having
horizontally-...
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22
votes
Accepted
Technology: How would a state-of-the-art space shuttle be built?
This could go many ways, depending on whether you mean a clean sheet design or incremental updates to STS. I'll assume the latter, in a parallel universe where the STS-107 accident never happened and ...
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22
votes
Do 3D printers in space stations mean a significant cost reduction?
A 3D printer on station isn't likely to lead to direct cost savings; the range of items it can replace are limited, and it has to be supplied with feedstock mass in any case; it won't allow for ...
- 167k
22
votes
What are some of the obsolete technologies that space agencies used in day-to-day work during the 1960s?
I would say Core Rope Memory
The Apollo Guidance Computer was one of the first computers to made use of integrated circuits. It was light and small enough (roughly 70 pounds) to fit in the CM. One of ...
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19
votes
Do 3D printers in space stations mean a significant cost reduction?
The 3-D printer on the ISS is more for testing purposes than anything. The idea is that for really long duration missions, a 3-D printer will allow them to make something in case something breaks, or ...
- 121k
18
votes
Is there any reason that NASA's launched space probes and MERs usually operate decades longer than expected?
The idea that NASA would intentionally under-represent the lifetimes of those (cherry-picked) missions implies that somehow they knew those lifetimes before launch. Nothing could be farther from the ...
- 58.5k
18
votes
Has any piston machine been used on a space mission?
Not sure that this is exactly what you seek, but the main pumps in the Space Shuttle hydraulic systems were "reciprocating piston variable displacement pumps". This type of pump was not ...
- 178k
15
votes
Accepted
How do we create a zero gravity environment on Earth?
There are two methods which are used:
Aircraft can fly on a trajectory that will simulate zero gravity for a few seconds, usually around 30. This is used for most short term zero gravity tests. It is ...
- 121k
13
votes
Can spacecraft be made invisible to stations on Earth?
The key is that you don't need to make a satellite impossible to see (e.g. cooling it down to 20 Kelvin); You just need to make it harder to see.
"Misty" is supposedly the codename of a stealth ...
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13
votes
What are some of the obsolete technologies that space agencies used in day-to-day work during the 1960s?
Sending interdepartmental messages by pneumatic tube.
Image Credit - NASA
More info here.
If an individual flight controller wanted a paper printout of one of his console displays, like a SMEK-...
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12
votes
Why doesn't the USA use structurally stronger rockets for the more important launches?
Structural strength is not the only factor in rockets dealing with weather, they are already designed to withstand many Gs of acceleration carrying tons of explosive fuel. Flying through a cloud isn't ...
- 19.9k
12
votes
What are some of the obsolete technologies that space agencies used in day-to-day work during the 1960s?
Here's a few.
Mechanical calculators for better precision than a slide rule.
Planimeter for determining moments of inertia. Used this at solid rocket manufacturer on military missile designs.
Pen ...
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11
votes
Accepted
How do they conduct electrolysis in zero gravity?
I guess the generic answer for any mass separation system would be that you spin it, but mass separation isn't really effective for electrolysis since that requires larger separation between anode and ...
- 76.5k
11
votes
How to move in space with just solar panels or without them?
Partial answer based on the constraints the question appears to have. Some solutions would not be considered practical by today's standards, but this doesn't appear to be asking for only practical ...
- 149k
10
votes
Accepted
Were Nixie tubes used by a space program?
According to Apollo Experience Report: Crew Station Displays and Controls, NASA Tech Note D-7919, the only Nixie intended for use in Apollo was cancelled:
The first change involved the nucleonics ...
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9
votes
Could a helicopter fly on Mars?
You can calculate the hover power required out of ground effect by using the following formulas:
Given $m$, the mass of the helicopter, the required lift force is $L = g_{Mars}\cdot m$
The required ...
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9
votes
How was Enterprise held/released from the carrier 747 for the Shuttle approach and landing tests?
The mount on the top of the 747 (the Shuttle Carrier Aircraft) for the drop tests was very similar to the one used throughout the program for ferry flight. The major difference was that the legs on ...
- 178k
8
votes
Accepted
Why have space stations become less volume-efficient despite technological progression?
The International Space Station is a far more capable vehicle than any of its predecessors. This comes at a cost, and that cost is mass. There's a problem here: Doubling the electrical power more than ...
- 73.2k
8
votes
Accepted
What are the differences in technology between OSIRIS-REx and Hayabusa missions?
Here's a quick comparison of the two missions. Differences to follow.
OSIRIS-REx
Name: Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer
Lead Institution(s): ...
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8
votes
Could a 21 meter space telescope detect the nearest exoplanets?
As of 2017, 22 exoplanets have been imaged directly. The most distant of those is 1200 ly away.
This shows 4 of them orbiting HR 8799, which is 128 ly away:
These observations are good enough to ...
- 125k
8
votes
Accepted
What is the preferred technology for bulk data storage on a modern space probe?
The Voyagers used tape because that was the state of the art in the 1970s. Rotating harddrives were available, but are less robust than tape drives (and would act like a gyroscope, complicating ...
- 125k
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