| Event | Time (seconds) | Mass (tons) | Acceleration (m/s2) |
| Light up | 0 | 54026.2 | 0.14 |
| First Tank drop | 2.1570E+07 | 38205.9 | 0.197 |
| Second Tank drop | 4.3140E+07 | 22355.5 | 0.337 |
| Third Tank depletion | 6.4700E+07 | 6795.2 | 1.109 |
| Second stage | 6.4700E+07 | 5098.2 | 0.13 |
| First Tank drop | 9.2450E+07 | 3014.8 | 0.22 |
| Second Tank drop | 1.2030E+08 | 981.6 | 0.676 |
| Manoeuvre begins | 0.0000E+00 | 931.5 | 0.712 |
| Manoeuvre ends | 5.5500E+05 | 656.5 | 1.01 |
Takes a bit of explaining, but the table is really in two parts. When the probe is nearing its target it manoeuvres around to place its sub-probes for the best fly-bys of interesting targets in the system, spreading them around far and wide. Each sub-probe has a dust-bug to put out a protective dust-cloud to ionise any meteoroids that might otherwise ram into it – something virtually certain as Daedalus plows through interplanetary space at 12.2 % of lightspeed.
Adam, at 12.2 percent light speed Daedalus should light up the sky in interesting ways as it streaks through the Barnard’s Star system. Even with the elaborate shielding mechanisms the Daedalus planners envisioned, it seems unlikely to me that the craft would survive the encounter. Would be interested in hearing your thoughts on this.
Hi Paul
Welcome to my little blog
Saw your book in “Borders” (yes they’re here in Oz too, just like “Starbucks” etc ad nauseum) and was in instant lust, tho they want $50 for the privilege of buying through them *sigh*
I was at “Project Rho” having a read of Jim Powell & Charles Pellegrino’s “Valkyrie” design which was supposed to cruise at 0.92 c. It uses a ‘droplet shield’ plus a multi-layer Whipple shield to take out sand-grains and the like. I really don’t know what the dust size-spectrum is supposed to be in our system, or Barnard’s. If we assume “Daedalus’s” flight-path through the danger zone of the system is about 100 AU and it’s 50 metres wide, then the volume traversed is 1.5E+13 m x 1964 m^2 = 29.5E+6 km^3… which seems like a few “dust bugs” will get chewed up by interplanetary dust, in my mind.
But then I’m not sure what the odds of crashing into something more substantial will be. Consider the extreme situation of grinding up all the terrestrial planets (12E+24 kg) into 1 mm sized sand grains (2E-6 kg each). In a Sun-centred volume 100 AU in radius there’s 1.4E+31 km^3 of volume. Thus 6E+30 sand grains fit into 2.35 km^3 each.
Now in the real solar system there’s not that much dust and Barnard’s shows no sign of being dustier than our Sun – though Tau Ceti or Epsilon Eridani might be – so a few thousand sand grains might be encountered during a fly-by of a system. How many would it take to wipe out the precursor dust cloud?
An open question.