Passengers board reusable take-off/re-entry (TRC) craft at the point of departure. The TRC blasts off into space and later docks with a large orbiting platform (for lack of the better word).

The platform is of course fully pressurised and equipped and is designed with a concept similar to an airport in mind. It orbits the planet every few minutes or so and regulary shifts latitude via it's own thrusters.

When the platform is close to an arrival destination, passengers for that destination are ordered to board a relevant TRC which is launched from the platform.

The TRC then re-enters the atmosphere, landing at the destination and disgorges it's passengers.

Setup costs would be very high, however long international travel times would be shortened greatly. I believe that this might be a more efficient alternative to the hypersonic space planes currently in development. TRCs would only need to carry enough fuel for blast off and slight manoeuvering.

Plus, you'll get great view of the Earth while waiting in orbit.
-- mrkillboy, Jun 21 2001

Unfortunately, mrkillboy, there is a fatal flaw in your plan. In order to enter orbit, you have to achieve escape velocity, it is not a case of going up - you have to go fast enough to go into free-fall around the earth. You would have to go into orbit to dock with the lounge.
Unfortunately, this means you need way more fuel to do this than you would need to simply get up into space for a bit and cruise along very quickly before re-entery the atmosphere (along the lines of the hypersonic space plane). So not more efficient at all. In fact, many, many times less efficient. Sorry.
-- goff, Jun 21 2001


What [goff] said;

Unless you can somehow trade the kinetic energy you need to gain to get into orbit for the kinetic energy you want to shed to re-enter at the destination.
-- egnor, Jun 21 2001


What's the point of the transfer lounge, incidentally? Since a "few minutes" isn't long enough for the passengers to relax with a scotch or watch a movie or otherwise do any serious lounging, why not just have the ship itself enter orbit, go directly to a suitable point over the surface, and re-enter? And then you just have a space plane which goes all the way into orbit, which goff's egnor-endorsed annotation argues against.
-- Monkfish, Jun 21 2001


The Math...

Escape velocity approx: 11.2 km/s.

The speed needed to gain orbit: 0.71 × escape velocity
-- Reverend D, Jun 21 2001


How about placing the Transfer Lounge in the atmosphere and making it a giant airship instead?
-- Aristotle, Jun 21 2001


small problem - airship can not go above certain height as it floats on atmosphere, higher up = less atmosphere. It would not be high enough for there to be a point to this. No it would need to be in orbit...

The only thing the lounge does is make the TRCs be able to travel with full pasenger loads all the time. People from place A (regardles of where they want to go) are sent up, people going to place B (regardles of where they came from) go back down.
-- RobertKidney, Jun 21 2001


Aristotle, I was thinking that EXACT same idea! But I dumped it because the airship would too big to keep afloat and be too slow to be practical.

Actually this idea evolved from having an perpetually flying aircraft acting in the same role as the space platform, but only in the high atmosphere.
-- mrkillboy, Jun 22 2001


Actually an Airship can penitrate the atmosphere. If it is rising at a high enough speed. And it is practicle with enough hydrogen the airship will begin its rise at such a high speed that once it reaches the edge the momentum will be enough to push it out of the atmosphere and into orbit, (True the envelope would have to be very big and would require a high level strucural integrety, bluntly the veihcle would be bigger than 2 football fields.) But once in orbit it's large size would be irrelevent. Of course a problem is it would also need retro rockets, or someother type of space propulsion. Having engines like this onboard an airship can cause problems, espcially with the density change. The only way to solve this is either having the propulsion relay on solar power, or perfecting a sytem of beaming energy from the ground to the ship. Then also reentry would be complecated but not imposible, An airship is the best way to go.
-- wood2coal, Aug 27 2001, last modified Aug 28 2001


Eek. I don't even want to -think- about how fast that'd have to be...
-- StarChaser, Aug 27 2001


you could have a hypersonic jet in polar orbit say, with "human bombs" inside bombays. then you could have multiple reentry vehicles, one over minneapolis one over Dallas one over Brazil one over buenos aires and also, Jo'burg Cairo, Ankara, Moscow etc. you get the idea. it would orbit once without landing, then pick up everyone in one city and drop them off for reentry at various places on the globe.
-- drpoundsign, Feb 23 2004



random, halfbakery