Wednesday, August 15, 2012

How large payload orbiters could fly from commercial airports

This is more like a 3rd generation passenger carrying system, one that's built on an established market (a 747, not a DC3).

Previously I've advocated Aerial Propellant Transfer as a form of Assisted Single Stage To Orbit, now, if commerce and travel between Earth and space colonies were to grow to a similar scale to that which we see between cities today, the volume of traffic would require orbital craft as large as todays largest passenger jets.

It would be convenient if the arrival and departure facilities for such spacecraft were integrated into the existing passenger system.

Because of the cost of increasing runway length and width, the growth in aircraft size is now being restricted, if that situation continues, even many decades from now commercial aircraft could be no larger than todays aircraft.

Using APT, an orbiter the physical size of a modern jumbo would require thousands of tonnes of fuel, so while the orbiter could fly from todays airports, the tanker aircraft could not.

Rather than building super runways to accommodate such giants, perhaps flying them from convenient lakes, far from populated areas, will be the solution.

The orbiter and tanker get airborne at about the same time, the former from an airport, the latter from a body of water perhaps hundreds of km distant, they rendezvous at altitude, thousands of tonnes of propellant are transfered, the orbiter carries on to orbit, the tanker returns to its base to be refueled for the next orbiter.

The tanker:
(a) Not being a passenger carrying aircraft,
(b) operating away from populated centers
(c) flying from bodies of water tens of km long
(d) only required to fly for an hour or so to altitude and then return,

could be a relatively simple wing design, not especially refined for fuel economy etc, mounted over a pair of pontoons.