Space elevatorto boldly go . . .

Christoph Weinsheimer

PhD Coffee

27-JAN-2015

A very old desire

I Gen. 9, 1-9:Tower of Babel

I 1895: Konstantin TsiolkosvkyI Inspired by the Eiffel TowerI First idea of 36000 km high tower

Christoph Weinsheimer Space elevator 2/11

A more ambitious approach

I Problem: No existing materialstanding those high compressionforces

I . . . , many more

I Solution: Start it from the roofI Bring a long cable to

geostationary orbitI Start lowering cable to earth

while extending it into space

Christoph Weinsheimer Space elevator 3/11

A more ambitious approach

a = −G ·Mr2

+ ω2 · r

I Can use counterweight instead of long extensionand to compensate decreasing gravity

I Keep center-of-mass well above geostationaryorbit (GSO)

I Stress at GSO at maximum⇒ use tapered cable

Christoph Weinsheimer Space elevator 4/11

A more ambitious approach

But still . . .I Conventional cable material would be . . .

I . . .way too heavy. > 1000 space flights necessary to bring cable to GSOI . . . too weak. Need to stand its weight below a given point

Christoph Weinsheimer Space elevator 5/11

The messiah of materials

Carbon Nanotubes

I rolled-up graphene sheets

I Tensile stress of 200 GPa(≈ 100 times stronger than steel)

I Very leightweight(order of 101 t)

Christoph Weinsheimer Space elevator 6/11

Other conceptual issues

Basestation:

I Modern designs use mobileseabased anchor platforms

+ compensate for high winds

+ compensate for incidents of spacejunk

- higher cost compared tolandbased solutions

- starting from sea-level, inopposite to a mountain top

Christoph Weinsheimer Space elevator 7/11

Other conceptual issues

Climber:

I Climber design crucially dependson the cable design

I Coriolis forces appear duringaccent/decent

I limiting climbing speedI 300km/h ⇒ 5d climb time

I energy transfer during climbI most promising: free laserI through cable, nuclear power,

solar panels are other options

Christoph Weinsheimer Space elevator 8/11

Other conceptual issues

Counterweight:

I Heavy captured asteroid(http://science.nasa.gov/science-news/science-at-nasa/2000/ast07sep_1/)

I Space station above GSO

I More climbing cable extended into space

Christoph Weinsheimer Space elevator 9/11

Let’s put some money in

Annual competitions for climbers, power supplies andcables (2005-2009)

Partnership with Elevator2010 increasing the pricemoney to 400000$

Development of massive nanotube manufacturingcapabilities

Announced the launch of an carbon nanotubes basedspace elevator in 2050

Considered in 2014 to design a space elevator, but didnot started it

Christoph Weinsheimer Space elevator 10/11

Outlook

I Carbon nanotubes are promising candidate for cable material

I Currently many projects and companies actively developing technology

I Once deployed, the elevator make on-earth rocket launches needless

I Could enable building space ships off-earth

I Could enable deep-space exploration

Christoph Weinsheimer Space elevator 11/11