Wall Panels

Wall panels are used to present large concepts or to interpret artifacts, photos, dioramas, etc.  Generally speaking, wall panels are large, professionally designed, and incorporate a variety of images as well as copy.  Wall panels may be used in conjunction with other types of exhibit interpretation, or on their own.  I have developed wall panels for virtually all of my exhibit clients.  

I worked with Chief Astronomer Derrick Pitts at The Franklin Institute to develop these wall panels for FutureSpace, an exhibit that was mounted in the museum's Futures Center wing.  The exhibit was on display for several years between 1990 and 1995.  Of course, some of the information presented is now out of date!

FutureSpace at The Franklin Institute

BUT SCOTTY -- THERE'S NO SUCH THING AS "WARP DRIVE"!   

Space is so vast that science fiction writers invented faster-than-light propulsion systems to get their heroes to the heart of the action.  The Starship Enterprise needs its superfast Warp Drive to hunt down the evil Romulans.  But this physically-impossible speed may not be enough.  Even at light speed (186,000 miles per second), it would take 4 years to reach the closest star, and 2,000,000 years to visit the next galaxy.  Today's fastest spacecraft poke along at a mere 60,000 miles per hour (1/10,000 the speed of light).

 TRIED AND TRUE  

All of today's rockets use chemical propulsion systems. 

Chemical rockets burn a mixture of fuel and oxygen.  The Saturn V rocket, sent to the moon, used kerosene as the fuel.  The kerosene was mixed with liquid oxygen to make it burn efficiently.

Rocket launches obey Newton's third law of motion: to every action there is an equal and opposite reaction.  The rocket does not push against the Earth.  [graphic]  The action of the propulsion system is the expansion of hot gases in every direction within the combustion chamber.   

[graphic] This action creates a reaction: the motion of the ship away from the expanding gases escaping through the rocket's exhaust nozzle. 

[graphic] This system works in the same way in space: the ship does not need anything to push against to make it move. 

[photo of 51J rocket lifting off w/ caption: 

The chemical reaction within the combustion chamber causes expanding gases to push against its walls.  A vent on one side of the chamber allows expanding gases to escape.  The expanding gases push against the closed side of the chamber with equal force.  These actions push the rocket upward.]

Spacecraft using chemical propulsion systems must carry their own heavy fuel.  It's terribly expensive to carry enough fuel to travel beyond the moon and return to Earth.  [graphic: lbs. of fuel/rockets]  There are no filling stations in space.

 GETTING AWAY FROM IT ALL

 Gravity keeps us from floating off the surface of the Earth.  The greater the mass of an object, the more powerful its gravitational pull. 

A rocket leaving the Earth must fight Earth's gravitational pull.  To reach Low Earth Orbit (between 160 and 22,300 miles from Earth), Space Shuttle must generate enough thrust to accelerate to at least 17,000 miles per hour.  To reach the moon or Mars, a spacecraft must travel even faster.

 ON BEYOND PLUTO?

 Today's goals in space include manned lunar and unmanned planetary exploration.  These goals are easily served by today's cheap, reliable rocket technology because:

           -- destinations such as the moon, Venus, and Mars are right next door in the cosmic scheme of things. 

            -- all exploratory missions (except those to the moon or Mars) are unmanned.  With no humans on board, there's no need to hurry!

            -- chemical propulsion systems are presently available, tested, widely used, and reliable. 

But to travel beyond our solar system we will need new space craft technologies and propulsion systems that can gather fuel as they go.  If we travel at Voyager speed (only 36,000 miles per hour), it will take us 8,000 years to reach Alpha Centauri, our closest neighbor star!

 What improvements are needed?

             -- Rocket technology that will carry an extremely compact fuel or collect fuel from space as it travels;              -- Accelerate to 200,880,000 miles per hour -- 30% of the speed of light;
             --  A ship that can accommodate and protect a crew of at least 40 people for 120 years. 

 SHIPYARDS IN SPACE

In the next two decades, NASA plans to construct spacecraft in orbit or on the moon.  Shipyards in space will give us greater flexibility in the size, shape, and structure of future spacecraft. Here's why:

 A spacecraft launched from Earth must ride on a launch vehicle.  Launch vehicles must be streamlined to cut through a thick atmosphere, and must carry sufficient fuel to lift the spacecraft into orbit.  The spacecraft itself must be small enough to be carried by the launch vehicle.  This "piggyback" system is very expensive, partly because the launcher must be discarded after a single use.

 But in orbit or on the moon, the effects of both the gravity and atmosphere of Earth will be either reduced or eliminated.   We won't need a launch vehicle, only a propulsion system.  The spacecraft can be built in any shape, and can be much larger than Earthbased ships.  With the ability to construct ships in space, we can develop cost-effective programs for expeditions to Mars or beyond.

 FUTURE SPACESHIPS

All of the following ideas for future propulsion systems are theoretically possible.  None of them are presently in use.

Solar Sailships -- are easy to build, and may actually be in use by the next century.  Their ultra-thin aluminum foil sails, miles wide on each side, would be pushed by solar particles (photons).  Solar sailships may build up speeds as high as 20,000,000 miles per hour.

The fusion-powered Daedulus -- would use a series of miniature nuclear explosions to build up speeds of up to 6.2 miles per second.

RamScoop technology -- would use a powerful electromagnet to gather positively-charged sub-atomic particles (ions) in space.  These ions would react with hydrogen in the ship's interior, moving the ship along at about 1 mile per second.

Ion Engines -- would carry its own super-dense propellant made from mercury and cesium gases.  These gases would be bombarded by  electrons to create positively charged ions.  These ions would then be attracted to a negatively charged grid at such speed that their exhaust velocity would create forward thrust of ___ mph

STAR TRAVEL, WARP DRIVE, AND HYPERSPACE

Could the future hold faster-than-light travel?  Could we make "hyperspace" leaps to other star systems?

No!  Not according to the laws of physics as we know them.  This is why:   

The closer you get to the speed of light, the greater your mass becomes.  At the speed of light, your mass becomes infinitely great.  An infinitely great mass requires an infinite amount of energy to move.  Since an infinite amount of energy is not available, a light-speed spacecraft is unlikely given our present understanding of how things work.

 If we really hope to reach other star systems, we will probably have to rely on multigenerational space voyages, lasting hundreds of years.