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Spaniard

Member

From: Spain

Registered: 2008-04-18

Posts: 133

Extremely lightweight on orbit mass driver

There will be on near future capability to create extreme large but lightweight structures to build things really big.

http://nextbigfuture.com/2015/02/nasa-n … te-on.html

A mass driver from Earth to Mars will be possible with limited mass. Perhaps a ratio 5:1 with launch spaceship will be possible.
The mass driver between GEO and LEO, enough far from LEO to avoid that each launch change its orbits too much to go inside Earth atmosphere. Later, using efficient ion propulsion, the mass driver recovers the original orbit.

The spaceship will need propulsion in any case. For transfer corrections and to slow down the speed to avoid the need of very high speed reentry on Mars.
Because the launch could be high speed, ion propulsion could be used for the spaceship too.

Advantages.

Near as fast as pure chemical.
Faster than pure ion.
Near as efficient as ion propulsion.
More reusing infrastructure.

Disadvantages.
Orbit align is difficult for reuse... or more fuel will be needed losing the advantage.
No experience with this kind of technology. Unknown problems.

Tom Kalbfus

Banned

Registered: 2006-08-16

Posts: 4,401

Re: Extremely lightweight on orbit mass driver

So mass drivers have been talked about since the 1970s, why hasn't NASA built any? If they were simply impossible, then why did O'Neill mention them?

tahanson43206

Moderator

Registered: 2018-04-27

Posts: 19,218

Re: Extremely lightweight on orbit mass driver

Spaniard has been active in the forum recently (in 2024) so I decided to ask FluxBB if Spaniard had created any topics.

This is an interesting speculative topic, to which Tom Kalbfus replied.

From the vantage point of 2024, I think we can conclude that mass drivers ** are ** extremely difficult to build beyond the laboratory demonstration that O'Neill's students showed at Princeton in the 1980's.  The longest mass driver of any significance in 2024 is the aircraft launch catapults built into the Gerald R. Ford aircraft carrier.

Based upon proven performance to date, i conclude that a structure such as envisioned by Spaniard in 2015 was and remains speculative.

Physics appears to support the concept .... it is engineering that is challenged to produce a working system.

Collapsing stars (and black holes) appear to be able to create mass drivers of some size.  It appears that rotational energy of collapsing matter is able to produce jets of energy and particles that are squeezed out of the collapsing mass in narrow jets.

(th)

Void

Member

Registered: 2011-12-29

Posts: 7,752

Re: Extremely lightweight on orbit mass driver

I also want Spaniards thoughts.

I have pondered something that can have a similar effect.  A tether system to do spin launches from such an orbit as he suggested.  The spin would come from Electric Rockets.

I have seen evidence of patents that have a sort of slide method to launch objects from a spin launch system.  This might accommodate humans.

The use of solar power may be acceptable as the solar power plant does not get launched, instead it is a sort of platform to launch payloads from.

In this device, energy is stored in spin inertia, rather than capacitors as in a mass driver.

Done

Last edited by Void (2024-04-03 10:50:00)

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