# Tag Info

56

Yes, you could go "over" or "under" the asteroid belt. However, plane changes are expensive, and as pointed out in the comments, the asteroid belt is not very dense (average distance of 600,000 miles [1 million kilometers] between objects) so there isn't much to avoid.

28

No spacecraft has been yet lost to the asteroid belt. In fact, we have the opposite example of missing an asteroid when it was even targeted, like was the case with MINERVA lander of the JAXA's Hayabusa deep space probe, missing the 25143 Itokawa asteroid. Why haven't we lost any spacecraft due to collision with asteroids in the asteroid belt is also pretty ...

25

Dawn has several mission objectives, including to continue testing the Ion Thruster. But why Ceres? Ceres and Vesta were chosen, because they have contrasting content, one icy and one rocky. Also, they are among the protoplanets that remain intact since formation, which (hopefully) leads to a better understanding of the formation of our solar system, ...

18

Here's how you can work it out. First, thrust in kilo-Newtons (kN) divided by mass in metric tons yields acceleration in meters-per-second-per-second. Divide by 10 to get acceleration in approximate Earth surface gravities (9.81 is the real factor). Dawn uses its thrusters only one at a time (they aren't pointed the same direction), and a single NSTAR ...

17

I just want to add that a lot of work goes into predictions of abundance, for objects including those we have not detected so far. There is some similarity to exoplanets - where we know that a method has a detection bias. If you can quantify the detection bias perfectly, then you can get the total abundance for different sizes. One source gives a pretty ...

11

Very little upside, lots of downside. It's colder out there, which means that keeping your IR sensors cool is a bit easier. The orbit is wider, so you get more parallax, but the orbit is slower, so you have to wait longer to get the results. The sun is smaller and dimmer, so the area of the sky that you have to avoid (as it is too close to the sun) is ...

11

Dawn uses an ion drive which is very efficient but does still require xenon as a reaction mass. Dawn started with 425kg of xenon and used about 275kg to get to Vesta and will use about 110kg to get to Ceres. The remaining 40kg is for stationkeeping and margin. Dawn does not, nor was it planned to have, enough xenon left after arriving at Ceres to depart ...

11

This question is similar to: Do the planets, asteroid belt, kuiper belt, and scattered disk lie on the same plane? Earth is on the ecliptic plane, Jupiter is 1.305° inclined relative to the ecliptic, so not quite coplanar but pretty close. The asteroid belt, being made up of a diverse set of rocks, is all over the place (from here): The description of ...

9

Purely propulsive plane changes are expensive, but a much smaller adjustment followed by a swing-by maneuver over the pole of a planet a bit like Voyager 1 did at Saturn, (which in this case I guess would have to be Venus, Earth or Mars), might be much less expensive. Or you could just leave Earth orbit in a direction that doesn't happen to be in the ...

9

It is highly likely it was known that the upper stage would could be overshot into the asteroid belt, but it may be within the upper-bounds of expectations. The reason for this is that Elon commented in the Falcon Heavy post-launch press conference that the propellant left in the upper stage was "within 0.3% of expected values". This means they knew how ...

8

This answer and question on physics cover a similar topic, I will link to it here and block quote the most relevant parts. The most notable part of this answer is most likely going to be: Asteroids are not distributed uniformly in the asteroid belt, but could be approximated to be evenly spaced in a region from 2.2 AU (1 AU is 93 million miles, or the ...

7

tl;dr: There's a fair bit of wiggle room in density estimates, macroporosity is a thing to consider, you could still feasibly find a lot of material on this rock I first want to clarify that asteroids are typed according to their spectral properties. In the case of 129 Antigone (at least according to the paper linked in the Wikipedia reference section), its ...

6

Is Starman/Roadster in any danger of asteroid belt? Honestly? No. The Asteroid belt does contain lots of asteroids. But this is deep space. These things are not close together in any sense. Think of it this way: If Starman had been set adrift on the Pacific Ocean, how likely would he be to collide with another ship? Pretty low? The ships on the ocean are ...

5

To plug the numbers given into a simple calculation: The asteroid belt has a volume of 4,35E25 km^3. If we assume for a moment that the asteroids are evenly spaced, and there are 15 billion asteroids (estimate given above for sizes 0,1km+), we arrive at roughly 180km distance from asteroid to asteroid. 3 Orders of magnitude in the number of asteroids give us ...

4

Those charts don't tell the whole story. Keep in mind that inclination, eccentricity, and SMA are only three of six orbital elements that define the position of an orbiting body. Two bodies in the exact same orbital path (inclination, eccentricity, SMA, argument of periapsis, and LAN) could be in different positions on that orbit, on opposite sides of the ...

4

NASA doesn't seem1 to currently have any plans for an extended mission so far. See this screenshot from this page: Also from Wikipedia: An extended mission following the completion of the Ceres study is also possible, although unlikely, as greater scientific returns may be attained by spending more time at Vesta and Ceres. Although 2 Pallas would ...

4

The total mass of the asteroid belt can be estimated from the effect the belt has on the major planets. The total mass is estimated to be $2.8×10^{21}$ to $3.2×10^{21}$ kilograms. About 1/3 of this is concentrated in Ceres alone. From Hidden Mass in the Asteroid Belt (2002): These results make it possible to predict the total number of minor planets ...

4

I cannot give you a valid answer for later Missions, but here something about Pioneer and Voyager: As Scientists discover there is a very rare planet constellation in the 70/80ies allowing to pass all large outer planets with one mission, they had been very keen in doing this mission (Voyager). BUT: In fact they have not known if it is possible to cross the ...

3

Individual asteroids in the belt orbit the sun, each on a slightly different path. The positions of the asteroids relative to one another is continuously shifting, because the further out an orbit is, the slower it is. The main population of the asteroid belt orbits between about 2.1 and 3.3 AU from the sun. The inner asteroids of that region orbit the sun ...

3

It would be a bit like sailing your ship from Spain around the cape of Africa rather than through the Mediterranean sea to get to Egypt just because you were worried you may hit off Malta or Sicily. There would be significantly more to avoid within a significantly smaller space in low earth orbit than out in the asteroid belt which is extremely empty ...

3

Apart from the points were an actual asteroid is, the density is very low. "Contrary to popular imagery, the asteroid belt is mostly empty. The asteroids are spread over such a large volume that it would be improbable to reach an asteroid without aiming carefully." (source) Furthermore the distribution of the asteroids is not uniform, thus the mean density ...

2

CASTAway (PDF) is a mission proposed for ESA that would flyby 10 asteroids in the Main Belt and observe tens thousands telescopically to determine their composition.

2

Yes, the asteroid belt does indeed orbit the sun. Not quite sure how the asteroids would stay out there if they were not in orbit. Some individual asteroids are not in the belt however. From http://www.astro.cornell.edu/~randerson/Inreach%20Web%20Page/inreach/asteroids.html: Most asteroids in the Asteroid Belt have an orbital period of about 3-6 Earth ...

2

There is no way to power any 'prospecting equipment'. The batteries on the stage are dead already, and there are no solar panels on board. Also, no equipment is visible in the prelaunch photos. The batteries on the stage were made to power the stage for the ~6 hours it needs to work. The stage has to be standard for the flight to be valuable as a ...

2

I've used the plotting of the Horizons projection described in this answer to show the distance between the Roadster and Mars out to 2030. The projection is likely to be slightly revised as future optical detections described here come in. There is also more to read in this answer. There is quite a close approach between the Roadster and Mars predicted in ...

2

The orbital speed of Mars is about 24 km/sec or ~ 2 million km/day, and so relative velocity to an asteroid could be fairly slow for one in a similar orbit, or easily 1 million km/day or more for one in a weird orbit. Optical (Visual, thermal IR) You could set up several optical (visible or thermal IR) survey telescopes around Mars, and try to vigilantly ...

1

I don't see the down sides to be anywhere nearly as strong as @JamesK's answer suggests! Some space telescopes use several kW of power but one of them is 500 W and these are all circa 1 AU where power is plentiful so there was no need to lower it. In deep space if you really need to just collect CCD images in cold space and process them with processors ...

1

To melt your asteroid you need heat. A lot of heat. But the sun is very hot (1.57×10^7 Kelvin, according to wikipedia); the sun is also roundish, so you can't really focus all of that heat, but it's probably more than hot enough. So the question then is how big a lenses can you make? If you can make a big enough lens, and keep it pointing the right ...

1

The asteroid belt ranges from 2.2 to 3.2 astronomical units (AU) from the Sun and is 1 AU thick, see. So it is a very long way to go over it and too much fuel would be necessary. All the very sucessful spacecrafts to the outer solar system would have been impossible if they had to use a trajectory over the belt.

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