2I/Borisov, the First Interstellar Comet to Have Visited Our Solar System

That is how progress works. Lots of things were researched or invented before progress in other areas (materials, economics, society, other scientific finds...) made these findings useful or even feasible. You never know when and why you will need this, the only thing you know - it will be used eventually. Maybe this will give some important clues into the future interstellar travel, maybe the tricks and technologies invented for this mission will be used elsewhere, maybe sample will give important clues into the origins and probability of life.

Regarding Omouamoua, we just observed for the first time in human history, a cylinder or plate shaped object from another star flying through our solar system with questionable orbital velocities (we are not quite sure how to explain a small acceleration it had). A cylinder/plate is not a low energy geometry (things like to turn into spherical type objects over time), it's from another solar system, we don't know very much about it. How could you not want to visit it?

It's an opportunity to pull off a speed and distance record, visit something from another solar system, resolve big research questions about its shape, composition, origin and rule out any theories of its possible intelligent origin. They are also pursuing it to showcase the benefits of nuclear heat for space.

Because oumuamua had aspect ratio 10:1

Dont underplay the “coolness factor.” The moon landing was pretty cool. Not practical, but freaking cool.

We need more coolness in public policy.

Let's see..

Search for evidence of life outside the solar system. Unless you're planning a trip to another star system this is all we've got in our lifetimes.

Hitching a fast ride to the outer edges of the solar system since it's on a hyperbolic trajectory.

What is the asteroid made of? That shape of asteroid is not normal. Usually they're rubble piles, these were different. Is there formation methods we don't yet know? Were they fragments of a planet's destruction?

On an engineering level, we've never had to rendezvous with something on this trajectory before. Can we?

It would be absolutely helpful to astronomy and planetary science research. We have never in history looked at extrasolar material up close.

And if it is indeed relatively cheap, it doesn't need to be "fundamental".

People often claim commerce and free markets are the driver of innovation. That's true, but they're not the only driver. Industry and national "moonshots" play off each other very well.

if it's what i think they are, they are essentially batteries with a radioactive source. It relies on the gradual decay of the source to create energy which is somehow harnessed and used as a power source. I have learnt here on HN that they last many years, are used on space projects such as the voyager probes, and more recently, the mars rover. They are impractical for other uses, such as powering your fridge and home. And their price is.... astronomical.

The typical radioisotope generator is a Plutonium-238 source like the MMRTG on the Mars rovers. The Plutonium decays by alpha emission with a half life of 80+ years. The problem is there is a very limited supply of Plutonium-238 - we use the entire supply for Mars Rover - and it's very controlled material.

The CAB starts with a non-radioactive material like Cobalt-59 spheres placed in a ceramic matrix. It is then put into a nuclear reactor where it turns into Cobalt-60, which releases energy by beta and gamma emission with a half life of 5 years. This charging can be done every couple years to generate more Cobalt-60 inside the device. Such a power source is something like 40x as power dense as the Pu-238 source and since it's made of high temperature ceramics, it can go to very high temperatures which is very useful for space generators where you have to reject heat using blackbody radiators.

There isn’t a way to use solar power for propulsion energy. The issue isn’t an electrical source, the problem is emitting mass.

Byebye Americas cup and f1, hello solar drag racing

I could swear I have seen a video on building a test chamber with an intense light source to test a heat shield similar to the parker solar probe but with hydrogen or helium piped through it for a solar thermal thruster. But I can't find it now.

Despite reading quite a lot about astronomy, comets and asteroids and the history of all of the three, I didn't get the distinction between asteroids and comets yet. I understand the composition makes the difference, but I didn't get why we expect exactly two (!) distinct categories of intersolar/interstellar objects, and giving them exactly two distinct names. Why not more, or less (i.e. no distinction at all, just a summary of the probable composition)?

Why is this so? Is there a fundamental reason to make this special distinction, or is it just "tradition"?