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67 votes

Why did the Chinese send flies and plants to the far side of the moon?

Right now, almost 100% of existing research on growth in gravity fields is basically at 0g (ISS/Mir/Skylab/whatever) or 1g. There are a lot of questions of what happens at 1/6g or 2/3g? No good ...
geoffc's user avatar
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44 votes
Accepted

How did humans grow plants on the Moon despite the harsh conditions?

While it's still cool, it's not as tricky as it may sound at first: The seeds, including water, are stored in a sealed, heated and shielded container. The container also includes fruit flies and ...
DarkDust's user avatar
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32 votes

Why aren't there any robotic missions on Europa or Enceladus?

There are probably many answers, but for guesstimating hypothetical missions a look at delta-V/subway maps like this are highly informative in terms of problem scale. Working from that getting into ...
GremlinWranger's user avatar
27 votes

Is there any demonstrated or even proposed technology that can sterilize a spacecraft with 100% certainty and yet leave it electronically functional?

Absolute 100% sterilization is impossible. There's always a tiny chance that some microbe lands on a component during manufacturing, gets entombed inside the packaging, and therefore is unreachable ...
DrSheldon's user avatar
  • 48k
23 votes

Why is Curiosity not heading for Peace Vallis?

It is actually too likely to find water there. There are 3 categories of Planetary Protection missions for a mission to Mars, IVa, IVb, and IVc. Curiosity meets the IVa criteria, a mission not ...
PearsonArtPhoto's user avatar
  • 121k
23 votes
Accepted

Why aren't there any robotic missions on Europa or Enceladus?

@GremlinWrangler's answer sums up several important points; Getting a low mass rover from Earth all the way to landing on the surface of one of those Moons requires much much more rocketry (delta-v) ...
uhoh's user avatar
  • 149k
22 votes

Can a launch of a rocket or ship from Earth go so badly that it damages the Solar System?

No. Look at the numbers: ...
Antzi's user avatar
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22 votes
Accepted

Are there free insects in the ISS?

Jared Olson, robotics instructor and flight controller at Johnson Space Center, claims not, and as an entomologist I think that's actually plausible. It sounds like there are extensive quarantine and ...
tardigrade's user avatar
21 votes
Accepted

Did Streptococcus mitis survive 950 days in the lunar environment?

Yes, viable Streptococcus mitis was found on the Surveyor 3 camera returned by Apollo 12. This is described in the report Analysis of Surveyor 3 materials and photographs returned by Apollo 12 (25 Mb,...
DrSheldon's user avatar
  • 48k
17 votes
Accepted

Have there been experiments in space to determine how plants grow without any gravitational or light cues for direction?

Seeds include a plant embryo with a root and a shoot already developed. When the seed germinates, the root and the shoot each elongate through tissue growth at the tip (meristem). Without ...
DrSheldon's user avatar
  • 48k
17 votes

Is there any demonstrated or even proposed technology that can sterilize a spacecraft with 100% certainty and yet leave it electronically functional?

No, it is not possible to make it 100% sterile. Especially if you consider self-replication as only requirement to classify something as life (It's complicated. See obligatory xkcd reference) Few ...
Matija Nalis's user avatar
16 votes
Accepted

Can a launch of a rocket or ship from Earth go so badly that it damages the Solar System?

First, some perspective. The impact of a single fragment of the Shoemaker-Levy comet on Jupiter released an estimated energy equivalent of six million megatons of TNT (approximately 600 times the ...
John Bode's user avatar
  • 2,300
15 votes
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Have water bears ever been studied on the ISS or in Space?

They have been flown on the FOTON-M3 mission... In 2007, three projects were conducted during the FOTON-M3 mission studies. The Tardigrade Resistance to Space Effects (TARSE) Project was the ...
Organic Marble's user avatar
14 votes

What is the maximum atmospheric pressure a human can tolerate?

The answers are found in the SCUBA diving world. Diving is interesting in this sense in that 10m is roughly an increase in pressure of 1atm. In general, you wont see humans doing well above 30atm. ...
Cort Ammon's user avatar
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14 votes
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How certain are we that we have not accidentally sent life to other planets/moons?

First of all, rocks from Earth are probably just about everywhere in the Solar System. One simple example is this rock found on the Moon. A number of pieces of Mars have been found on Earth, and if ...
PearsonArtPhoto's user avatar
  • 121k
13 votes
Accepted

Can (human) gas propel someone in a contained space station?

I'll try. Please don't judge. Say, 5 liters of carbon dioxide (a guesstimate of about how much of bowel volume could be occupied by a single pocket of gas; may not be average or maximum, but is ...
SF.'s user avatar
  • 55k
13 votes

Agriculture on an exoplanet

Ignoring the infrared radiation aspect of your question, what you are describing is a situation not too dissimilar to what exists in many parts of Australia. The extreme degree of weathering that has ...
Fred's user avatar
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12 votes
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Largest inhabitable volume in space

So far (2016) the biggest "room" in orbit was the Orbital Workshop of Skylab. Here's a video showing astronauts moving in the largest part of Skylab. You never get to see the "floor&...
DarkDust's user avatar
  • 12.5k
12 votes

Does SpaceX plan to enhance/change the genome of space colonists to speed up the adaptation process to the living conditions on Mars?

No. SpaceX is a space launch company, not a genetic engineering company. That branch of science lies completely outside their research. Never mind the ethical aspect: the astronauts are volunteers, ...
SF.'s user avatar
  • 55k
11 votes
Accepted

Melanized fungi on the ISS - are they 'enjoying' the elevated radiation levels there?

The experiment Growth and Survival of Colored Fungi in Space (CFS-A) - 12.07.16 showed that: fungi can grow inside the space station and could decompose food and other organic materials in humid ...
called2voyage's user avatar
  • 23.7k
11 votes
Accepted

Could a molecular cloud be breathable?

Not a chance. Those "clouds" are a vacuum, but just a vacuum that has a few more particles than outside those "clouds". The density of those "clouds" around 1–100 particles per cm³. You can't ...
gerrit's user avatar
  • 11.7k
11 votes
Accepted

Can centrifugal force actually overcome the health problems of microgravity?

First, I want to get out of the way that the equivalence principle, which is well supported by experiment, contends that gravity and acceleration are one in the same: "pseudo"-gravity caused by ...
WaterMolecule's user avatar
11 votes

Why did the Chinese send flies and plants to the far side of the moon?

They did it for propaganda or pride mostly. What sprouted quickly died because it froze. They did not have a method to protect the biosphere from the temperature swings. This is what they expected ...
Diznaster's user avatar
  • 111
10 votes

Can a launch of a rocket or ship from Earth go so badly that it damages the Solar System?

Not in terms of physical damage, no. Rockets and spaceships and all the energy they contain is just so very, very, very, very small compared to everything. There is one possibility for large scale ...
Innovine's user avatar
  • 4,625
10 votes
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Life on Mars: How do we know it is not from Earth?

One tool in the astrobiology toolbox is chirality, the property that many chemical compounds exist as "left-handed" and "right-handed" mirror images. These have the exact same ...
SE - stop firing the good guys's user avatar
8 votes

Could a spacecraft be made out of wood?

Yes, and it has been used in the past (See: NASA - balsawood). It was not a significant portion of the spacecraft but it has occurred. You can, in theory, use any material to build a space vehicle, ...
Inti's user avatar
  • 336
8 votes

Is child birth possible in lower gravity?

Mammal experiments have shown that zero gravity does not affect fetuses in the late stage of gestation. http://curious.astro.cornell.edu/physics/153-people-in-astronomy/space-exploration-and-...
Foo Bar's user avatar
  • 300
8 votes

Can a flock of birds crash a rocket?

As noted in Johnny Robinson's answer, there has been at least one recorded incidence of bird strike during launch. This was STS-114, the first Shuttle launch after the fateful STS-107 mission. That ...
David Hammen's user avatar
8 votes

Why aren't there any robotic missions on Europa or Enceladus?

The motive for the exploration of Enceladus and Europa is different from that of Mars. The primary motive for exploration of the two moons is the possibility of finding an independent instance of ...
Vince 49's user avatar
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