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Old March 28th 17, 04:56 AM posted to sci.space.policy
William Mook[_2_]
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Default SpaceX announces plan to fly two space tourists around moon

On Sunday, March 26, 2017 at 4:44:42 PM UTC+13, William Mook wrote:
http://rocketbelt.nl/pogos/nasa-lunar-transport

A rocket belt powered by hypergolic fuels has a 3.3 km/sec exhaust velocity in vacuum. To land on the moon from low lunar orbit requires 1.69 km/sec delta vee. To land on the moon and return to lunar orbit, requires 3.4 km/sec delta vee, with a small amount of spare capacity. This requires 64.31% of the take off weight of a rocket be propellant. With a structure fraction of 9.50% this leaves 26.19% of the take off mass as payload.

An A7L spacesuit has a mass of 91 kg when configured for 6.5 hours of lunar surface operations.

Near term biosuits using MEMS based hardware are likely to mass 35 kg and provide for 12.5 hours of surface operations.

https://www.nasa.gov/pdf/617047main_..._spacesuit.pdf

With an 85 kg astronaut, this implies a total payload weight of 120 kg. Dividing this by 0.2619 obtains the weight of the rocket belt required to take an astronaut to the surface of the moon and back.

458.2 kg - take off weight on low lunar orbit.

183.1 kg - landing burn propellant (143 litres) - 10 spherical tanks 12 inches in diameter (half nitric acid, half hydrazine)
109.9 kg - take off burn propellant (85.9 litres) - 6 spherical tanks 12 inches in diameter (half nitric acid, half hydrazine)
45.2 kg - structure - including 8 kg in the form of 0.5 kg spherical tanks. Four columns of four tanks - two columns on each side of the astronaut.
120.0 kg - astronaut & biosuit

So, with 916.4 kg - in a rocket pack - the astronauts can go to the moon and return to lunar orbit - and even recover the rocket packs for reuse.

https://www.linkedin.com/pulse/remem...n-william-mook

https://www.linkedin.com/in/williamm...tivity/shares/

With more advanced systems - using more energetic fuels - and improved spacesuits - much more can be achieved. However, this will certainly make a splash!


At 3.4 km/sec (10,840 fps) we have a range for a ballistic trajectory of 1,111 km (600 nautical miles), flown in 8 minutes.

So, a rocket belt, attached to a light weight space suit, equipped to land on Earth, would permit testing of a rocket belt prior to its use in a moon trip.