Tourist Transportation to GEO Hotel

The vehicle carrying tourits has to be very safe.

SSTT Rocket

The rocket lifts 4,000 Kg to 100 km and 5 km/sec.

Capsule

The tourists will ride in a capsule on top of the rocket. This capsule will weigh about 4,000 Kg. The breakdown of this weight is as follows.

From [Larson, 1999, page 404] we can see that a mission of under 1 day only needs about 1 cubic meter per person. In [ibid, page 403] they have the following formula for estimating the mass of a crewed vehicle in Kg:
592 * (number of crew * mission duration (days) * pressurized volume (m^3)) ^ 0.346
For crew of 11 people and a volume of 11 cubic meters this comes to 3111 Kg.

For a rugged and reusable heat shield (possibly with transpiration) we will add 25% to this amount, or 778 Kg. An ablative heat shield can be done with only 15%.

From [ibid, page For a reusable (and very safe) heat shield it is probably more than 15%, say 25%. Then we are at 3889 Kg. Still enough room for some grapple attachment and keeping under our 4,000 kg design point. They say this does not include a heat shield or any mission specific stuff, just living space and life support. They estimate that an ablative heatshield is 15% additional mass. Also, this is based on historical data. Current tech should be better than historical average really. So we may well get more than 11 people in 4,000 Kg. We feel good saying 10 passengers and 1 employee, but that it has a good chance of being more.

Life Support

On a normal flight the vehicle will need life support sufficient to get tourists from the LEO-tether to the GEO-tether which takes about 5.5 hours. To be safe in the case where the capsule cannot hook up to the GEO-tether it returns to reenter the atmospher, we will want 11 hours worth of life support.

Acceleration

Laying down on their back, people can tolerate about 10 Gs for 10 minutes [ibid, page 116]. A suborbital reentry wi

Reentry

The vehicle will be designed to be reusable when reentering from the LEO-tether and survivable when reentering from the GEO hotel. So if something goes wrong and we can not hook up with the LEO-tether on the way back from the space hotel we may have to write off the vehicle, but we will not lose customers.

Radiation Shielding

The radiation shielding has to be enough to pass through the Van Allen Belts. We expect to have more than 5.5 hours of advanced warning of Solar Flares and would not launch if there was a flare coming. Deadly flares can last more than 24 hours, so people would never be in the capsule for the whole duration of a bad flare. So we do not feel it is necessary to have enough shielding to deal with flares.

If a designer wanted to have enough shielding for flares it would make sense to have the shielding mass transfered from the LEO tether to the capsule after it is picked up and returned to the LEO tether for the next capsule when it is about to reenter. This would require a stronger tether, but not a stronger rocket or more solar power. So it could be done without too much penalty.

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