Tag Archives: Gravity

All day cruising down the space corridor

light_linesAnother gorgeously science-fictional concept: that of the constantly shifting gravitational corridors in the solar system that will allow for the rapid transit of spacecraft around the Sun:

Scientists in the U.S. and Germany are attempting to map the corridors to allow them to be used by spacecraft exploring the solar system. One of the researchers, Shane D. Ross from the Virginia Polytechnic Institute in the U.S. described the system as a series of low energy corridors that wind between planets and moons. Once a spacecraft entered a corridor it would “fall” along the tube, much as an object falls to Earth.

If and when there is a substantial demand for intra-system space traffic these channels in space will become like the shipping lanes of the oceans of Earth.

[from Physorg][image from TheAlieness GiselaGiardino²³ on flickr]

Streamlined satellite

goceThe European Space Agency’s satellite GOCE (Gravity Field and Steady-State Ocean Circulation Explorer ) has been called the most beautiful satellite to be launched (Monday from Plesetsk Cosmodrome in north-west Russia, if all goes well).

GOCE needs a low orbit to accomplish its mission, which is to map “fantasically small” variations in the Earth’s gravity.

The arrow shape and fins are necessary to keep the spacecraft stable as it flies through the wisps of air still present at an altitude just under 270km. This orbit is much lower than for most Earth observation missions but will be essential if Goce is to sense the very subtle gravity anomalies that exist across the planet.

The satellite will also fine-tune its altitude with an ion engine, which accelerates charged xenon atoms through nozzles at the rear of the craft.

The data will inform a multitude of science disciplines:

  • understanding how the mass of ocean waters circulate, moving heat around the planet, will assist climate prediction
  • a better knowledge of the way mass is distributed inside the Earth will be useful to those who study geo-hazards such as volcanoes and earthquakes
  • and because gravity defines what is meant by “up”, “down” and “level”, the new data can underpin a truly universal system to compare heights the world over

This first of at least six projected  missions is being launched by a modified ICBM. Glad to see one of those things get put to good use.

[Image: NASA]

GOCE lowly, lest ye fall

goce-copyEric Drexler writes about the beautiful Gravity and Steady State Ocean Explorer on his blog:

I’m glad to see that someone finally found an excuse to launch a streamlined spacecraft that will cruise above Earth, steadily firing its engines to keep it moving. (Aristotelian physicists take note.) The European Space Agency will soon launch this sleek piece of hardware on a mission of gravity measurement with unprecedented accuracy: The Gravity Field and Steady-State Ocean Circulation Explorer (GOCE) will carry accelerometers able to sense accelerations as little as 10–13 of what we tolerate on Earth.

Apparently because GOCE will orbit much lower than usual it needs to be streamlined to cope with the thin upper atmosphere and generate thrust to keep itself aloft.

Anyway it’s a very pretty piece of kit: surely the MacBook Air of spacecraft1.

[via Eric Drexler][image from ESA]

1: In that it’s solid-state and sleek.

The LHC may find extra dimensions

xkcd is an absorbing mix of stick figures, physics, programming, math, love and dark humour

One of the main functions of the Large Hadron Collider – the huge supercollider in Geneva, Switzerland – is to find the underlying reasons for why the particles in the universe have mass and how gravity works. My masters project is a simulation of the most simplistic solution, the Standard Model Higgs Boson. If the collider doesn’t find this particle in its simple form, there are number of more complicated theories proposed for how the world works at this tiny level.

One of these theories supposes that for every particle in the universe, there’s a supersymmetric particle balancing it out. Another set of exotic theories that could be proved right at the LHC is Extra Dimensions – is the reason Gravity is so weak compared to the other forces because its power is trapped inside other dimensions we can’t see? This would link into the infamous string theory, which describes all the tiny particles we’re made of as vibrating strings of energy, suggesting six or seven dimension we can’t see that affect everything we do see! The 27km diameter collider will start smashing protons together later this year if all goes to plan and a new era of particle physics will begin.

[link via ScienceDaily, image from the awesome webcomic xkcd]