My idea was to use 2 stages for an interstellar spacecraft (particularly the Orion Drive) and use it in a way similar to Project: Daedalus. Phase 1 would involve accelerating to cruising speed following assembly in orbit, and that cruising speed is 0.04 c, which will then slow down as we approach the Wolf 1061c (the target planet) system in Phase 2. The First Stage is the Earth/Sol Departure Stage and then we have the second stage decelerate in the target system, known as the System Insertion Stage and enter the orbit of the planet. The two will accelerate/decelerate at 1 G/9.81 m/s^2, for 14 days to reach the 0.04 c mark, send a seedship-sleeper ship hybrid and spend the rest of the trip cruising. There is a problem; is this appropriate? If not, what are some issues I need to concern myself with?

EDIT #1: I am also going to provide a link for those of you who do not know what "mission profile" is by giving you a hands-on interplanetary or orbital example. Mission Profile Description, Definition and Example

EDIT #2: And the technology in this setting is very near-term, for the purposes of making a spacecraft with plausible technology. In addition, the purpose is to basically colonise a new planet. However, by the time they arrive.....well, you boys and girls might wish to kiss humanity on Earth goodbye. :P

  • $\begingroup$ Seem fine to me $\endgroup$ Commented Apr 8, 2016 at 16:43
  • $\begingroup$ @BryanMcClure Even with near-term technology? $\endgroup$ Commented Apr 8, 2016 at 16:45
  • $\begingroup$ This is very similar to what you asked over here so my answer is going to be the same (tl;dr: it's too slow and deceleration will be very, very, very expensive). I'd suggest instead of asking "will this solution work" to ask "here's the situation and the goals, how can I make this work". Like, "the Earth will be uninhabitable in 20 years, we think Wolf 1016c is habitable, how can we send an ark?" $\endgroup$
    – Schwern
    Commented Apr 8, 2016 at 16:48
  • $\begingroup$ @Schwern Good idea. :/ $\endgroup$ Commented Apr 8, 2016 at 16:49
  • $\begingroup$ What would you do for mid-course correction and flight profile adjustments? How would you manage heat during deceleration? $\endgroup$
    – lonstar
    Commented Apr 15, 2016 at 10:28

1 Answer 1


It's probably plausible in terms of the physics. Following the Project Daedalus mission plan ensures that. But the economics are a different problem.

We haven't developed laser inertial confinement fusion to a working level yet. That will be expensive. Project Daedalus reckoned mining of gas giant atmospheres was necessary to get the fuel, which means having a lot of complicated industrial infrastructure in places where we can currently send probes weighing a few tons. We're missing the AI tech for the probe to be self-maintaining and self-repairing over decades: our approach with probes is to have very few moving parts, which isn't really viable for this mission.

And then there's the scale problem. The Daedalus probe weighed 54,000 tons, including 500 tons of payload. Let's be generous and assume we can do the colony job with 5,000 tons of payload. Our vessel is now 540,000 tons. And that's got enough delta-V to slow down from cruise, but to boost it to cruise, we need the departure stage. And our cruise stage with fuel is the payload for that. At a mass-ratio of about 1:100. So the complete ship is about 50,000,000 tons.

Fifty million tons. The largest sea ship we have ever built is about 650,000 tons. Building something about 75 times the largest moving object we've ever made, in space for extra difficulty ... has certain near-term plausibility problems.

Interstellar travel actually requires superscience to make it economically viable. There are plenty of conventions for how you do this, but don't try to fool yourself this has real plausibility in the near future.

  • $\begingroup$ Welcome to Worldbuilding John! $\endgroup$
    – fi12
    Commented Jun 23, 2016 at 16:44
  • $\begingroup$ Oh, trust me. This is meant to be our first interstellar mission, so....... :P $\endgroup$ Commented Jul 2, 2016 at 20:43

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