More About NASA Rockets

As I mentioned the other day, NASA has decided to put more development into solid stage rockets. The newest solid state rocket is the DM-2. The DM-2 has a solid state motor that is different from other solid state rockets. It has five segments. Its power is incredible, would you believe that it generates 22 million horsepower? If we take a car that had 200 horsepower, it would need 110,000 of them to equal the same horsepower. Rocket motors are measured in pounds of thrust however and this one has 3.8 million pounds of it. As wondrous as this sounds, the Saturn V rocket from the 1960s had a first stage that put out 7,648,000 pounds of thrust. The Saturn V was not a solid fuel rocket but used Liquid Hydrogen and Rocket Propellant-1 a type of kerosene.

So why are we so excited to be developing this new rocket motor, is it really very much different from solid fuel rockets of the past? The answer is that it is similar to the boosters that were used on the space shuttle, but it has been refined somewhat. The company making the DM-2 is ATK Space Systems, a division of Alliant Techsystems of Brigham City, Utah. If we believe what we have been told, this rocket motor is much safer and more reliable. A fifth segment has been added to the motor, along with a modified nozzle and new insulated liner. The motor is called an enhancement to existing technology. I guess improvements to existing engines and ships are necessary, but only if they are true improvements and not just a way for a corporation to drain money from Uncle Sam. I am not saying that is true in this case, I am just making a statement. Interestingly the Russians have a rocket known as the Block DM-2. It is usually used as an upper stage to another rocket, but is powered by a liquid engine.

Ares 1-X
Photo Source: NASA

NASA seems to be testing a lot of space vehicles lately, all of which have some type of rocket propulsion. Toward the end of 2009 NASA was test firing the Ares 1-X rocket. The total fly time was only 6 minutes. This vehicle produced 2.6 million pounds of thrust. The vehicle also used a solid rocket motor of only of 4 segments. The rocket was 327 feet tall, that is only 33 feet shorter than the Saturn V rocket. I am not a rocket scientist, but it seems to me that we are trying to equal the lift of the Saturn V rocket, using solid fuel engines. Should we be looking for other methods to lift huge amounts of cargo and people into space instead of constructing machines that rely on brute force, much as the rockets of the 1960s? Interestingly this rocket was also manufactured by ATK Space Systems, a division of Alliant Techsystems of Brigham City, Utah. The rocket was said to carry a simulated Orion Crew module and other simulated parts.

Maybe I have been around too long and have become suspicious of everything, but when I read about simulated parts, I start to wonder if this is just an excuse for testing secret weapons and such? Of course this doesn't mean that was what happened, it is just that I have seen this so many times that I can't help but think that way. The Ares rocket has had a long history of problems. There was a vibration discovered in 2007 that could shake the entire rocket apart. NASA felt that it could fix this problem due to its extensive experience in launching and testing rockets. When the Ares I-X was tested, NASA stated that the vibrations were within normal parameters, so according to them the problem seems to be solved. While the rocket seems to have performed well, the launch pad became damaged because of a leak in a ground line. The damage was substantial. The parachute for the first stage is also said to have malfunctioned. This caused damage to the first stage of the rocket, after it was jettisoned.

VASIMR Rocket
Photo Source: NASA

I am happy to say that along with all this conventional rocket testing, NASA has decided to center its space going operations around the VASIMR engine. The engine allows us to reach Mars in about 39 days. VASIMR stands for Variable Specific Impulse Magnetoplasma Rocket. In other words it is really a Ion engine. An MIT scientist named Franklin Chang-Diaz designed the engine. It is capable of hitting speeds of 126,000 miles per hour. The inventor of the rocket wants to put it into orbit by 2013 and is working with private companies such as SpaceX and Orbital Science Corporation. Will private companies actually gain an edge in the space race? Will they have the fastest rocket ever made at their disposal? In these times of shrinking budgets, this might be the best thing that could happen. If the companies find a way to make money on this deal, it could advance space travel by leaps and bounds.

As far as the VASIMR craft goes, there are several different types of craft that use elector-magnetic thrusters coming on to the scene. A VASIMR vehicle is a two mode vehicle. It can either function as a high thrust, low specific impulse propulsion system or a low thrust, high specific impulse system. Radio waves are used to ionize and heat the propellant and magnetic fields. This accelerates the plasma that is created for thrust generation. Ion engines usually wear out their electrodes, but this engine design eliminates this problem. The engine has almost no moving parts to wear out and the magnetic field it produces shields all ports from erosion from the ions. It does have its drawbacks as does everything. It produces tremendous heat that has to be channeled away from the engine safely. The huge magnetic fields also can present problems to instruments and interact with the Earth's magnetosphere. This is countered by using two thrusters oriented in opposite directions to create a zero attraction.

Voyager I
Graphic Source: NASA/JPL/Caltech

If we begin to equip our spacecraft with this engine, it will open the door to space travel. The outer planets would still be years away however. It took two years for Pioneer and Voyager to reach Jupiter. Voyager 1 travels at about 35,790 miles per hour. This is about 1/3 the speed of the VASIMR vehicle. That means that instead of two year to reach Jupiter, it could be reached in 8 months. While this is still a long time, it is doable in a long duration vehicle. This means that the vehicle would have to have shielding from radiation, enough room to move around and all the supplies and water that would be need for a trip of this duration.

I am sure that if we do this, that is employ the VASIMR rocket, it will improve as time goes by and also new types of engines will be discovered that also will decrease the travel time required. We are at the point where we could launch an ion powered vehicle and it could pass the Voyager vehicles that are still heading out of the solar system.