On 25 May 2016 at 10:11, Craig Berry wrote:

>
> At Traveller accelerations, you don't need anything close to two weeks
> of acceleration to put something on a minimum-energy transfer orbit.
> Those have delta vees in the 10s of km/sec. At 1g (which we'll round
> to 10 m/s2), and assuming a required dv of 10 m/s:
>
> v = at
> t = v/a
>   = 10000 m/s / 10 m/s2
>   = 1000 s
>
> Or a bit less than three hours.
>
> So the tugs spend three hours or so boosting a cargo onto a Hohmann
> transfer orbit, then another six boosting back roughly the opposite
> way to intercept an incoming shipment and decelerate it into orbit at
> the destination. Tug pilots would get home in time for a late dinner.
> :)

Again, not in the same direction. the incoming and outgoing vectors
are *very* different.

Remember, the outgoing cargo is aimed for were the planet *will be*
when it gets there in weeks to months.

The incoming cargo is coming from where the planet *was* when it was
launched.

Pretty much *opposite* vectors. Incoming will be "catching up" with
the planet from "behind" as it orbits.

Outgoing cargos will be launched "ahead" of the planet.

--
Leonard Erickson (aka shadow)
shadow at shadowgard dot com