29
votes
Accepted
Is water on Mars the same as Earth water?
Fundamentally, water is water. In its purest form, it is the same anywhere, except perhaps for the isotopes. However, one of the wonderful things about water is the fact that it's a good solvent, and ...
- 121k
26
votes
Accepted
What was this Ziploc bag used for on an Apollo 14 moonwalk?
That's not a Ziploc bag, but the retroreflector's dust cover. Here is a larger image of it removed:
And here's an image with the cover still attached to the retroreflector:
...
- 76.5k
12
votes
Accepted
Choosing a specific region to live on Mars, how important will the degree of dust there be, compared with the availability of water?
Water is extremely useful on Mars. You can use it to generate oxygen directly via electrolysis and the hydrogen byproduct can be reacted with carbon dioxide to make even more water. We drink water. ...
- 1,082
12
votes
What was this Ziploc bag used for on an Apollo 14 moonwalk?
To answer the last part of your question: yes, it was normal to throw away stuff that was no longer needed. On Apollo 11 alone, the astronauts left behind more than 100 items, including
four urine ...
- 126k
11
votes
Accepted
Decision Factors for using 100% $ O_2 $ cabin atmosphere in early US space program
Despite a higher risk of a fire, pure oxygen also has some advantages.
First, the internal pressure of the vessel is only a fifth of a normal breathing mix, allowing less structural load on the hull ...
10
votes
Can fish really live in microgravity without water?
Gills aren't purely for respiration. Fish constantly excrete ammonia and urea from their gills and without sufficient water to wash the waste away this would soon cause death, much like how too small ...
- 111
7
votes
Will suits worn on Mars lose kilograms of "expendable water" each time they are used?
Since Steve just contributed an answer to this...well, so will I. There's no need to consume and eject mass for heat control. Mars is cold.
See, for example, this Science article.
Although wind ...
- 10.1k
7
votes
Accepted
What kind of lighting does the ISS use?
Feng Shui is not used. The ISS is a science lab and Feng Shui is not scientific.
Currently, fluorescent lighting is used. A study is underway to replace this with LED lighting.
The Testing Solid ...
- 126k
7
votes
Accepted
How cryogenic oxygen was heated up for CM cabin repressurization?
Unsurprisingly, it worked exactly like it did in shuttle.
To assure uniform flow, the capillary restrictors are coiled around a
warm water-glycol line to increase the oxygen temperature.
Page 2....
- 178k
7
votes
Accepted
When was an operational satellite accidentally damaged by another man-made object in space?
I think that there must be many such collisions that occurred without even the satellite operators noticing, and certainly not reporting them. There were also intentional collisions with anti-...
- 6,667
6
votes
Accepted
How to make a camera survive in (near) space?
I've used a stock GoPro on a high altitude balloon that made it to 40 km, it recorded the whole way up and down (on external power). So depending on your mass and financial budget you could use this ...
6
votes
Accepted
What happens in to the fuel in fuel-rich Lox-Kerosene?
TLDR: The combination burning of hot kerosene and sun-driven decomposition of any remainder gets rid of it quite quickly.
From an environmental point of view, this is the bottom line:
It is ...
- 12.6k
6
votes
Temperatures in "near" space compared to LEO
A vacuum is a pretty good insulator, much better than the air at the altitudes balloons operate at.
- 126k
6
votes
Why is there no concerted effort to collect solar energy on a global scale?
The scale needed to address human energy requirements in the near future and the scale of things like Dyson spheres are completely different. Human energy usage at present is about 18TW Assuming 20% ...
- 19.3k
5
votes
Accepted
Determine envelopes for the payloads?
For STS payload induced enviroments, grab yourself a copy of the Space Shuttle User's Handbook and you will find plenty of data starting on page 31 of the pdf.
Vibration, noise, thermal, pressure (...
- 178k
5
votes
Will suits worn on Mars lose kilograms of "expendable water" each time they are used?
As far as I know, no Mars suit has been finalized yet. The Apollo A7L suit is really heavy (91 kg), which was acceptable in the Moon's lower gravity. On Mars it'd get uncomfortable pretty soon, so I ...
- 126k
5
votes
Will suits worn on Mars lose kilograms of "expendable water" each time they are used?
Well, of course we don't know what our engineers will choose but:
Mars has an atmosphere so traditional earth cooling/heating is possible.
Think about a fancy heatsink running in your MarsSuit.
- 12.6k
4
votes
Accepted
Which computer monitors will work on Mars?
I think LCDs are going to be just fine on Mars. We have LCD displays meant to withstand temperatures as low as -50°C here on earth. Usually the displays do not work at such temperatures, though, so a ...
- 855
3
votes
Temperatures in "near" space compared to LEO
Heat transfers in one of three ways: convection, conduction, and/or radiation.
In the vacuum of space, radiation is the primary mechanism of heat leaving a spacecraft. Radiation is slow acting and ...
- 2,275
3
votes
Does a LEO mission to study the marine debris exist or is at least planned?
It seems the European Space Agency is planning to do it, see this recent article (19 March 2018):
https://www.esa.int/Our_Activities/Preparing_for_the_Future/Discovery/...
- 2,113
3
votes
Is water on Mars the same as Earth water?
This discussion on quora talks about deuterium abundance on Mars:
Deuterium occurs naturally on Earth in water as 1 in 6,400 hydrogen atoms or 1 part in 3,200 by weight. On Mars it is one deuterium ...
- 19.3k
3
votes
Decision Factors for using 100% $ O_2 $ cabin atmosphere in early US space program
It is very difficult to make a soft or hybrid space suit manouverable with higher pressure (over 5 or 6 psi for example), because they are effectively just big balloons which just get stiffer and ...
- 855
3
votes
Will suits worn on Mars lose kilograms of "expendable water" each time they are used?
It seems plausible to me that a CO2 sublimation system is an option. Perhaps instead of water, a pressurized tank of liquid CO2 is expended.
The advantage would be that a station based compressor ...
- 31
3
votes
Will suits worn on Mars lose kilograms of "expendable water" each time they are used?
Let's take @Uwe's number of 500W from body heat and the functioning of the suit. This needs to be removed from the suit one way or another.
Passive conduction isn't really an option on Mars, the air ...
- 19.3k
3
votes
How bright would Earthlight be from the surface of the Moon? Can you read under the light of the Earth?
The OP links to the Forbes Mar 18, 2017 article Ask Ethan: How Bright Is The Earth As Seen From The Moon? and @PM2Ring comments
FWIW, Dr Ethan Siegel is a qualified astrophysicist and an excellent ...
- 149k
2
votes
Will suits worn on Mars lose kilograms of "expendable water" each time they are used?
UPDATE: "Ice batteries" are already starting to be commercialized, currently as larger scale devices for homes or buildings. With experienced gained here, a miniatureized version may be ...
- 149k
2
votes
How big of a problem is the Lunar eclipse in April 2014 for LADEE?
How big of a problem is the Lunar eclipse in April 2014 for LADEE?
8.5 years later, we know the answer. From Wikipedia's LADEE; End of mission:
The probe then dealt with the April 2014 lunar eclipse ...
- 149k
2
votes
Vehicle liquids freeze on the Moon -- how has this problem been solved?
Supplementary answer:
Vehicle liquids freeze on the Moon -- how has this problem been solved?
There's an example where liquid/solid transitions really are a feature, not a bug.
How much wax is on ...
- 149k
2
votes
Why are the EVA suits in the suitport (concept) exposed to the environment?
The "Suitport" images you have seen are conceptual. They serve to illustrate the concept and capture people's imaginations, and showing any additional structure would be counter to that purpose. If we ...
- 1,738
2
votes
What would it take to collect methane from the atmosphere and use it as rocket fuel?
Energy. Air liquefaction requires a lot of energy. As noted in the comment by @CallMeTom to collect enough methane you have to liquefy huge amounts of air just to get some methane. However air ...
- 191
Only top scored, non community-wiki answers of a minimum length are eligible