[pavel_lishin]

Not just identifying them, but also being able to catch them in time. They're coming in at solar escape velocities, and going out with same - and the odds of everything being aligned in such a way that we can take several years to do gravity assists are incredibly low.

[adolph]

> odds of everything being aligned in such a way that we can take several years to do gravity assists are incredibly low.

Project Lyra develops concepts for reaching interstellar objects such as 1I / 'Oumuamua and 2I / Borisov with a spacecraft, based on near-term technologies. [0]

Several technology options are outlined, ranging from a close solar Oberth Maneuver using chemical propulsion, and the more advanced options of solar and laser sails. [1]

0. https://i4is.org/what-we-do/technical/project-lyra/

1. https://arxiv.org/abs/1711.03155

[XorNot]

It occurs to me since survivability isn't a problem for an unmanned probe, that a "cold" nuclear thermal engine vehicle could be used as a loitering interceptor: get it a solar orbit, and leave it till you see a target, then accelerate up to extra-solar escape velocity.

It solves the disposal problem neatly, since the probe and reactor are both leaving the solar system forever afterwards.

[mathsmath]

I wonder if a one-way trip with an impactor would be useful. It would at least be easier than a roundtrip journey to and from solar escape velocity.

Also, it seems like the space base weapons treaty is being ignored now (https://spacenews.com/russia-vetoes-u-n-resolution-on-nuclea..., https://www.npr.org/2024/05/30/nx-s1-4975741/what-to-know-ru...). I wonder if there is an opportunity to do some science with space-based lasers and spectroscopy. The energy would be small, but then again we can learn a lot just from the off-gassing created by the sun’s photons as well.

[pavel_lishin]

Oh yeah, I don't think we're anywhere near "sample return" capability for an extra-solar object.

I doubt we're even near "impactor" capability, tbh. I think our best bet might be "catch up with something in the Oort somewhere around 2070, if we see something coming a decade ahead of time".

[mathsmath]

Never underestimate the ability of humans to throw something really hard ;)

I actually think if the object was on the right trajectory and we had enough time, that you could pretty much park an impactor in its path. You could probably do a lot of science based on the spectra of the resulting cloud.

I agree that gently landing and return a sample with that much delta V is out of our reach at this point. Maybe with enough shielding, you could park a second sample return vehicle in the path of debris.