Featured Research

from universities, journals, and other organizations

Centrifugally Launched Ball Bearings Could Propel Spacecraft

Date:
August 7, 1998
Source:
University Of Illinois At Urbana-Champaign
Summary:
Small ball bearings, slung from orbiting centrifuges, could one day be used to boost satellites into higher orbits, launch spacecraft to distant planets, or slow satellites and returning space probes for safe re-entry into the atmosphere, say researchers at the University of Illinois.

CHAMPAIGN, Ill. -- Small ball bearings, slung from orbiting centrifuges, could one day be used to boost satellites into higher orbits, launch spacecraft to distant planets, or slow satellites and returning space probes for safe re-entry into the atmosphere, say researchers at the University of Illinois.

"Centrifugal relays are rotors that progressively accelerate reaction mass to higher velocities," said Clifford Singer, professor of nuclear engineering and director of the university's Program in Arms Control, Disarmament and International Security. "In this case, the reaction mass consists of thousands of reusable ball bearings. This avoids the use of bulky on-board engines and massive fuel storage."

In operation, ferromagnetic balls would be thrown from the primary centrifuge and caught by a second centrifuge mounted on the payload. Coils would adjust the velocity of the balls, which would transfer momentum to the payload while being reflected back to the rotor. To further increase the velocity, additional relays could be inserted between the primary launcher and the payload.

"Using centrifugal relays to accelerate payloads at high velocity is becoming an attractive alternative to chemical propulsion systems," Singer said. "With chemical propulsion, the reaction mass increases exponentially with the final velocity. With centrifugally launched ball bearings, however, all the reaction mass is recovered, thereby avoiding this exponential growth."

Singer, aeronautical and astronautical engineering professor Lawrence Bergman and graduate student Malika Ouzidane recently studied the system kinetics and dynamics of centrifugal relays. They also devised a guidance system that meets the demanding accuracy constraints such a spaceborne launch system would require.

"Accurately aiming and tracking the miniature projectiles over a launch path extending up to 10 kilometers will be difficult, but not impossible," Singer said. "We have to monitor and control both the velocity and the direction of the rapidly moving balls so they encounter the appropriate guide tracks on the spinning rotors at just the right time and location."

Precise position and timing measurements could be obtained as the balls interrupt two sets of laser beams directed upon fine-scale photodiode arrays, Singer said. Accurate aiming could be accomplished by energizing electromagnetic deflection coils, which would adjust the speed and direction of the balls.

"What really matters is not the absolute aiming of the projectile stream, but the dispersion in projectile velocities," Singer said. "Controlling the dispersion is a much more manageable task than the actual aiming of the projectile stream."

The centrifugal relay concept is unique in that all components of the system would operate at ambient temperature without any chemically reactive or corrosive materials, Singer said. "This could make it particularly attractive in the long run for reusable spaceborne transportation systems."

The researchers described their centrifugal relay system in the July issue of Acta Astronautica.


Story Source:

The above story is based on materials provided by University Of Illinois At Urbana-Champaign. Note: Materials may be edited for content and length.


Cite This Page:

University Of Illinois At Urbana-Champaign. "Centrifugally Launched Ball Bearings Could Propel Spacecraft." ScienceDaily. ScienceDaily, 7 August 1998. <www.sciencedaily.com/releases/1998/08/980807105147.htm>.
University Of Illinois At Urbana-Champaign. (1998, August 7). Centrifugally Launched Ball Bearings Could Propel Spacecraft. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/1998/08/980807105147.htm
University Of Illinois At Urbana-Champaign. "Centrifugally Launched Ball Bearings Could Propel Spacecraft." ScienceDaily. www.sciencedaily.com/releases/1998/08/980807105147.htm (accessed July 31, 2014).

Share This




More Space & Time News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Supply Ship Takes Off for International Space Station

Supply Ship Takes Off for International Space Station

AFP (July 30, 2014) The European Space Agency's fifth Automated Transfer Vehicle (ATV-5) is takes off to the International Space Station on an Ariane 5 rocket from French Guiana. Duration: 00:34 Video provided by AFP
Powered by NewsLook.com
Raw: Rocket Launches Into Space With Cargo Ship

Raw: Rocket Launches Into Space With Cargo Ship

AP (July 30, 2014) Arianespace launched a rocket Tuesday from French Guiana carrying a robotic cargo ship to deliver provisions to the International Space Station. (July 30) Video provided by AP
Powered by NewsLook.com
In Virginia, the Rise of a New Space Coast

In Virginia, the Rise of a New Space Coast

AP (July 30, 2014) Every summer, tourists make the pilgrimage to Chincoteague Island, Va. to see wild ponies cross the Assateague Channel. But, it's the rockets sending to supplies to the International Space Station that are making this a year-round destination. (July 30) Video provided by AP
Powered by NewsLook.com
Russia Saves Gecko Sex Satellite, Media Has Some Fun With It

Russia Saves Gecko Sex Satellite, Media Has Some Fun With It

Newsy (July 27, 2014) The satellite is back under ground control after a tense few days, but with a gecko sex experiment on board, the media just couldn't help themselves. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins