A time-lapse photo of a rocket launch powered by new aluminum-ice propellant. Credit: Purdue University

Last week researchers from Purdue and Penn State University launched a rocket that uses an unconventional propellant: aluminum-ice. The fuel mix, dubbed ALICE, is made of nano-aluminum powder and frozen water, and gets its thrust from the chemical reaction between the ingredients. The propellant is environmentally friendly, and it could perhaps allow spacecraft to refuel at locations like the moon, where water has been discovered.

Using aluminum for fuel is not completely new--the space shuttle's solid rocket boosters use a small amount of the metal, as will NASA's Ares rocket. But the new work involves making aluminum one of the key ingredients by using nanoscale particles. These tiny particles, when ignited, combust more rapidly than larger particles, forcing more exhaust gases out of the metal and giving the rocket the necessary kick.

The oxygen and hydrogen in water molecules enhance the combustion of the aluminum. Freezing the propellant keeps it intact, avoiding any premature reactions.

The propellant was able to lift a rocket 396 meters during an August flight test, which was funded by NASA and the Air Force Office of Scientific Research. Now, for even better performance, the researchers are working on adjusting the ratios of different ingredients and possibly mixing the nano-aluminum with larger aluminum particles.

A water-based propellant might one day mean that spacecraft could carry less fuel when traveling to distant locations like the moon or even mars. But it would also be nice to have a "greener" fuel for rocket launches back on Earth.

Ares I-X sits on launch pad 39B. Credit: NASA

At 8:00 a.m.* EDT tomorrow, October 27, NASA will launch a test rocket called Ares I-X from Kennedy Space Center in Florida. The rocket is the first new launch vehicle to be tested in nearly four decades and the test will gather data critical to the design and development of Ares I--NASA's new rocket designed to replace the aging space shuttles and take humans to the moon, and possibly to Mars and beyond as part of the Constellation program.

Last week it took engineers almost seven hours to roll Ares I-X to launch pad 39B where it completed its flight readiness review. Now NASA's biggest concern for lift off is the weather. The agency has a four hour launch window, and while it only needs 10 minutes of clear skies for a "go", the forecasters are calling for 60 percent chance of clouds. If the launch is scrubbed, engineers will try again on Wednesday.

The test flight comes at a trying time for NASA, after its plan for the future of human exploration underwent an independent review and the outcome did not favor the Ares I. Despite these findings, NASA officials support the test flight, saying the data gathered will be useful for the design of any future rocket.

"This is the first time in more than 30 years that NASA has built a vehicle in a new configuration so this has been a valuable learning experience," said Doug Cooke, associate administrator for NASA Exploration Systems Mission Directorate in a press release."This test will yield important data to support the nation's next steps in exploration. There is no substitute for hard data--flight testing clarifies the distinction between imagined outcomes and real flight experience."

Follow the launch on Twitter, and the Ares I-X blog, then return to Delta-V for a post-flight analysis.

*Update 8:49 a.m, 10/27.: The launch has been delayed, scheduled for 9:24 a.m.. A rain shower is expected to pass over the launch pad at 9:50 a.m., which could cause further delays if not launched as currrently scheduled.

*Update 9:39 a.m.: There is a cargo ship in the Atlantic Ocean "danger zone", so launch is now scheduled for 9:49 a.m.

*Update 9:54 a.m.: NASA is now waiting for a break in the clouds for flight. The weather aircraft is making its flight and NASA will announce a new launch time in 5 minutes.

*Update 10:35 a.m.: New launch time is 10:54 a.m., but weather forecasters not so confident the skies will hold.

*Update 11:26 a.m.: Today's launch attempt has been scrubbed due to weather. NASA will try again tomorrow, October 28, starting at 8:00 a.m. EDT.

Engineers at NASA have created a prototype of an electromagnetic propulsion system that would use a linear motor and ramjet engine boost system--instead of an all rocket propulsion system--to fling a vehicle into space. It is the first system that would operate beyond the sound barrier using the combination of an air-breathing ramjet engine and an electromagnetic catapult. The work was presented this week at the Space 2009 Conference in Pasadena, CA.

The system is an alternative to traditionally-used chemical propulsion, which requires large amounts of fuel that limits cargo capacity. It is also a zero-emission, reusable system. The idea of electromagnetic launch using linear motors has been around since 1946, but it was not until the late 1990s that NASA started seriously investigating the idea.

The electromagnetic system works by tethering a spacecraft to a rail or track and using a linear motor to accelerate it to supersonic speeds.

"Linear motors are basically electric motors unwound," says Kurt Kloesel, an engineer in aeronautics and propulsion and lead researcher of the system at Dryden Flight Research Center, in Edwards, CA. "There are two groups of coils and an aluminum plate goes inside the gap [between the coils], when you hit the juice you are energizing the coils and the inductive reaction of that throws the aluminum plate out of this motor. "

"You are essentially propelling this vehicle along a track up to the point is disengages from the track and takes off," says Michael Wright, flight systems integration and test manager of exploration systems and co-principal investigator of the system at Goddard Space Flight Center, in Greenbelt, MD.

Kloesel explains that, as a vehicle starts to pick up speed, it incurs drag: "As you go faster and faster, getting towards the speed of sound, the drag goes up significantly, creating this shock wave structure on the vehicle. And once you pass the supersonic barrier the drag goes down again."

So what the researchers are proposing, says Kloesel, is using the electromagnetic system to get past the supersonic barrier. Then, the air-breathing ramjet engine--which feeds on incoming air at very high speed--would take the vehicle out of Earth's atmosphere. The ramjet engine would not be on the rail, but part of the vehicle itself.

The researchers have tested the concept in lab experiments with "bench top models", which have reached approximately 156 miles per hour. Wright says the technology might even be used someday on highway vehicles and airplanes.