The fellow flier with whom Mitt Romney had a physical alteration on an airplane turns out to be a hip hop star – and he claims in the 2008 GOP presidential hopeful got physical first.

“He grabbed my shoulder, and I was like boom get off of me,” the artist says. “The man assaulted me. I was protecting myself."

Romney and his wife, Ann, were heading to Los Angeles on Monday - and flying economy class - after attending the Olympic Games in Vancouver when they encountered the musician.

According to Romney spokesman Eric Fehrnstrom, the artist "became physically violent" when Romney asked him to move his seat upright before takeoff.

"Gov. Romney did not retaliate but instead let the airline crew respond to the incident," Fehrnstrom said.

Neither Romney nor his wife was hurt.

A spokesman for the Royal Canadian Mounted Police said Air Canada Flight AC552 was returned to the gate and Sky Blu was taken into custody. He claims he wasn’t arrested.

"The alleged victim did not wish to press charges," said Cpl. Jennifer Pound of the mounted police. "The male that was arrested and released caught a later flight."

“I have no hard feelings toward him, Sky Blu said in the video. “I’m sure he’s a good dude. It was just an unfortunate situation”

A Nasa satellite designed to uncover hidden cosmic objects has been blasted off from California.

The Wide-field Infrared Survey Explorer blasted off from Vandenberg Air Force Base on a Delta II rocket just after 1409 GMT.

It will pick up the glow of hundreds of millions of astronomical bodies.

The probe is expected to uncover objects that have never seen before, including some of the coolest stars and the most luminous galaxies.

It will do this by scanning the entire sky in infrared light with a sensitivity hundreds of times greater than ever before.

Viewing the sky with "infrared glasses" can lift a veil on many objects that are not visible to the naked eye.

Sky scanner

The satellite will also have a role in planetary protection: Wise will be able to detect some of the darkest near-Earth asteroids and comets.

This would help efforts to determine whether any of these objects could strike Earth in the near future.

Wise joins two other infrared missions in space: Nasa's Spitzer Space Telescope and the European Space Agency's Herschel Space Observatory.

This mission is different from those others in that it will survey the entire sky.

It is designed to cast a wide net to catch a variety of objects of interest.

Wise will target dim objects called brown dwarfs. These are effectively failed stars, having not gathered up enough mass to ignite.

Brown dwarfs are cool and faint, and nearly impossible to see in visible light. Mission scientists expect the spacecraft to uncover many hundreds.

This could double or triple the number of star-like objects known within 25 light-years of Earth.

The spacecraft will spend a month checking out its instruments.

The $320m project is managed by Nasa's Jet Propulsion Laboratory in California.