On: Ion engines could take us to the solar gravitation...

[JumpCrisscross]

1 kW/kg is an ideal power plant. Does the paper define a minimally-viable one?

If we beef up the chemical stage, e.g. by launching on Starship and re-fuelling in LEO, can we make do with 100 or even 10 kW/kg?

(Also, to put 550 AU in perspective, Voyager 1 is 165 AU out [1]. At 38,000 mph Voyager 1 [2] travels about 3.6 AU/year [a]. Going straight out, it would reach the Solar gravitational lens in 2131 [b].

[1] https://science.nasa.gov/mission/voyager/where-are-voyager-1...

[2] https://en.m.wikipedia.org/wiki/Astronomical_unit

[a] (38026.77 x 24 x 365) / (9.2956 x 10^7)

[b] 2024 + (550 - 165) / a

[perihelions → JumpCrisscross]

550 au in 13 years is a mean of 200 km/s—chemical rockets are nothing compared to that.

[JumpCrisscross → perihelions]

And that is for a flyby.

We’re not getting to 550 AU with chemical rockets alone. Nuclear, ion and/or solar sails will be needed.

[zardo → JumpCrisscross]

The focal "point" extends indefinitely, there's no need to slow down once you get there.