&gt; Spacecraft from gram level complete spacecraft on a wafer (“wafer sats”) that reach more than 1&#x2F;4 c  and reach the nearest star in 20 years to spacecraft with masses more than 10^5 kg (100 tons) that can reach speeds of greater than 1000 km&#x2F;s<p>Picking a nit: don&#x27;t do this, don&#x27;t mix units when making a comparison. They both should have been fractions of c, or km&#x2F;s, and it would have been nice to see how long the heavier vehicle takes to make the nearest start. But don&#x27;t mix units in comparisons.<p>And yes, of course I can figure it out, but it destroys the flow of reading.