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107 votes
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Why do most space probes survive for far longer than they were designed for?

Very good question! The answer boils down to statistics of failure. Some aspects involve the statistics of "random" failures—for some reason some critical component just bites the dust—and some ...
Tom Spilker's user avatar
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70 votes

Have we attempted to experimentally confirm gravitational time dilation?

You don't need a space probe. Or an aircraft. Or even a car. NIST has measured the predicted general relativity time dilation due to a change in altitude on Earth of one foot!
Mark Adler's user avatar
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55 votes

Why do most space probes survive for far longer than they were designed for?

There are a lot of generic answers here about spacecraft. I will try to answer the question specifically for Spirit and Opportunity. 90 sols was deemed sufficient to conduct the primary mission of ...
Mark Adler's user avatar
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55 votes
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Why is tantalum being used for the Hayabusa bullets?

The main reason for using tantalum is the fact that it is a rare element. When they capture the debris thrown up by the bullet, the fact that the bullet itself is tantalum makes it easy to distinguish ...
hdhondt's user avatar
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52 votes

Have we attempted to experimentally confirm gravitational time dilation?

In addition to specific probes like the one mentioned by called2voyage, the effect is significant enough that it affects everyday operations. For example, the GPS constellation needs regular clock ...
Bear's user avatar
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50 votes
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How does a space probe maintain its trajectory while passing through the extreme gravitational field of the gas giants of our solar system?

The trajectory was not only "unhindered" - it was enhanced! Knowing mass of the planet you can calculate very precisely how the trajectory of a probe flying by will be affected. You modify the ...
SF.'s user avatar
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50 votes
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Why are probes that tend to explore outer system always launched to go outwards instead of straight upwards or downwards?

Starting out from Earth, you have the free 30 km/s from Earth's movement around the Sun, which is in the plane of the ecliptic. To get far out of the plane you either have to boost a similar amount "...
Steve Linton's user avatar
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48 votes
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How much more expensive are scientific instruments for space use?

Preface: I am far, far from an expert in space electronics; I don't think I can weigh in on how much these sensors actually are, which is the title question; all I can offer is an uneducated inane ...
0xDBFB7's user avatar
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48 votes
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What are the teeth on the edge of Venera 13 and 14?

The teeth served an aerodynamic function. ...metal teeth were added to the periphery of the impact ring in an effort to reduce the spin and oscillation during the descent and prevent the rough ...
Organic Marble's user avatar
47 votes
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When will we send floating probes to Venus?

When will we send? We already did. In 1985 and 1986 the Soviet Union sent two Vega probes to Venus. Both included a robotic balloon (usually called aerobots). The two balloon aerobots were ...
Ginasius's user avatar
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40 votes

Have we attempted to experimentally confirm gravitational time dilation?

Yes, time dilation was experimentally confirmed by Gravity Probe A, launched by NASA on June 18, 1976. The clock rates of two masers (one on the probe and one on Earth) were compared, and it was ...
called2voyage's user avatar
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39 votes

Why are probes that tend to explore outer system always launched to go outwards instead of straight upwards or downwards?

We've had 5 flyby missions to the outer solar system so far. All of them had primary missions at one or more planets. That set the main constraints for their trajectories. Anything after the last ...
Hobbes's user avatar
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38 votes

Is it possible to create a relativistic space probe going at least 0.1c with present day technology?

I'm showing the calculations for Russell Borogove's excellent answer. You've asked to accelerate an object to 0.1 times the speed of light. Mathematically, $$\left( \frac{\Delta v}{c} \right) = 0.1$$...
DrSheldon's user avatar
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37 votes

Could one of the interstellar probes discover Planet IX by accident?

Any hypothetical planet (or other object) even further out would be very dark, so few photos are taken for any reason other than to look inward. (And in any case, the cameras on the Voyagers are shut ...
GremlinWranger's user avatar
35 votes

When will we send floating probes to Venus?

Why are people so fascinated about Mars and not about Venus at all? The trivial answer - Mars is moderate place. A human could easily get around with a spacesuit, and it is trivial for robots and ...
Fattie's user avatar
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35 votes
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Is it possible to create a relativistic space probe going at least 0.1c with present day technology?

No. 10% of the speed of light is about 30,000,000 m/s. Our fastest space probe to date, New Horizons, left Earth at less than 1/1000 of that speed. With a large propellant tank and a high-efficiency ...
Russell Borogove's user avatar
35 votes

How do space probes find their way and how much fuel do they use to travel?

As to whether space probes are controlled, or follow a predefined program, it's yes to both. One way to think about trajectory planning is that space probes are like billiard balls. By being very ...
SE - stop firing the good guys's user avatar
34 votes

Has any object launched from Earth gone into the Sun?

No, not yet. The Parker Solar Probe became the closest ever artificial object to the sun on October 29th, 2018, surpassing Helios 2 which held the record since 1975 [1]. No other human-made object ...
Polygnome's user avatar
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29 votes

How much more expensive are scientific instruments for space use?

I'll chime in with the other two well-stated answers. In addition to all the testing, there is the issue of "What do you do when the instrument fails a test?" Most COTS (Commercial Off-The-Shelf) ...
Tom Spilker's user avatar
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29 votes

Why are probes that tend to explore outer system always launched to go outwards instead of straight upwards or downwards?

It is important to realize that space probes aren't really useful for finding objects in deep space. Space is so empty that a probe sent in a random "exploratory" direction would have a negligible ...
Mark Foskey's user avatar
28 votes

Is it possible to create a relativistic space probe going at least 0.1c with present day technology?

Breakthrough Starshot claims to be capable of attaining 0.15c to 0.2c. But, the concept is based on a swarm of tiny probes (centimeter scale). They would be propelled by a "ground-based" laser; no on-...
Anthony X's user avatar
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28 votes
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Do exploration spacecraft enter Mars atmosphere against Mars rotation, or on the same direction?

There is always a benefit to entering a planet's atmosphere with matching rotation. In the case of Earth, the difference is a rather huge 920m/s effective airspeed between reentering prograde or ...
CuteKItty_pleaseStopBArking's user avatar
27 votes

What is the rarest launch window?

Comet West with its unpredictable but estimated at 558 000 years period is a good contender. Since launch windows can aim for the alignment of N objects, the answer obviously tend to infinity. You ...
Antzi's user avatar
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27 votes
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Why don't we build standardized space probes?

There already is some economy of scale in the space industry which I describe a bit more below. When it comes to interplanetary missions however, there is a significant limitation on the destination ...
ChrisR's user avatar
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25 votes

How does a space probe maintain its trajectory while passing through the extreme gravitational field of the gas giants of our solar system?

They did not ! This is the trajectory of Voyager 1 at Jupiter. credits wikipedia
Antzi's user avatar
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25 votes
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Why didn't the Pioneer probes maintain communications with Earth as long as the Voyagers have?

Why the Pioneers didn't last as long: The Pioneers were a low-budget mission just to test if flying to the outer planets was feasible They used a smaller radio transmitter (8 W vs. 23 W) and antenna ...
Hobbes's user avatar
  • 128k
25 votes

A balloon in the Venus atmosphere?

The Soviet Union actually deployed balloons on Venus, so I assume they studied them before that. https://en.wikipedia.org/wiki/Vega_program#Balloon
Organic Marble's user avatar
24 votes

Could one of the interstellar probes discover Planet IX by accident?

There are five probes leaving the Solar System. Pioneer 10 and 11 are no longer functioning. Voyager 1 and 2 are functioning but their cameras have not been used since the early 1990s, and it is ...
Andrew is gone's user avatar
23 votes
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What is the general shape and size of a space probe, and how are they launched?

I assume you're talking about space probes that go to other planets. There have been quite a few of those, and they all look different. So I'm going to give an example: Voyager. Voyager's shape is ...
Hobbes's user avatar
  • 128k
23 votes

How come there are so few TNOs the Voyager probes and New Horizons can visit?

It's a small matter of propulsion, or rather a matter of small propulsion. Pluto orbits just over 5 billion kilometers from the sun, if you look at the volume of the space between 5 billion km and 8 ...
GdD's user avatar
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