Surrey Space Centre aims to enable extremely low-altitude spacecraft orbits in the upper atmosphere, thanks to funding from the UK Space Agency.
Satellites in orbit use rocket propulsion to maintain their altitude. These engines require fuel to power their chemical or ion engines but when the fuel runs out, the orbit slowly erodes with the satellite re-entering the atmosphere. A new type of electrical propulsion has been developed that has no need for onboard fuel. Instead it syphons air particles out of the atmosphere and accelerates them to provide thrust. Much like an ion engine but this time, the fuel source is air making it ideal for low Earth orbits.
There can’t be many ideas that beat the crazy yet ingenious idea of a rocket engine that uses part of the fuselage for fuel! Typically a rocket will utilise multiple stages so that excess weight can be jettisoned allowing the rocket to be as efficient as possible. Now a team in Scotland is working on a rocket engine that consumes part of its body to use as fuel, reducing weight and providing even more thrust so that greater payloads can be used.
Artist depiction of future lunar astronauts. (Credit: NASA)
When astronauts return to the Moon in the next few years, the plan is to have them stay for good while establishing a permanent outpost on Earth’s nearest celestial neighbor. Like all space missions, a lunar outpost will require fuel for long-term sustainability, but would it be better to mine fuel on the Moon or get fuel resupply from the Earth? This is what a team of researchers led by Bocconi University in Italy hope to address as they addressed the best option in terms of deriving fuel from either the Earth or the Moon.
There are many types of rocket fuel. Some are more useful on a particular planet. And some can be created by bacteria. A team from Georgia Tech has found a rocket fuel with an interesting mix of those characteristics that might be a focal point of in-situ resource utilization – on Mars.
he launch of the Phoenix spacecraft on a Delta II rocket in 2007. NASA is looking for alternatives to hydrazine monopropellant, used en route by Phoenix's navigational thrusters Image credit: NASA/Sandra Joseph and John Kechele
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NASA announced yesterday that it’s looking for new technology proposals using environmentally friendly fuels to launch payload. The space agency is hoping to move away from hydrazine, the fuel that currently launches anything that travels beyond the atmosphere from commercial satellites to private spaceflight and exploration probes.
As a rocket propellant, hydrazine is great. It’s incredibly efficient, can be stored for long periods of time, has excellent handling characteristics, is stable up to 250 degrees Celsius (482 Fahrenheit) under normal conditions, and decomposes cleanly.
It also happens to be extremely toxic.
Shifting away from hydrazine would be a shift away from known environmental hazards and pollutants. There would be fewer operational hazards for those dealing with fueled rockets before launch. The change could also simplify the complexity of the rockets’ systems and, possibly, increase overall propellant performance.
The ALICE powered rocket before launch. Image credit: Dr. Steven F. Son, Purdue University
The benefits don’t stop there. Advantages on every level trickle down. “High performance green propulsion has the potential to significantly change how we travel in space,” said Michael Gazarik, director of NASA’s Space Technology Program at the agency’s headquarters in Washington. “By reducing the hazards of handling fuel, we can reduce ground processing time and lower costs for rocket launches, allowing a greater community of researchers and technologists access to the high frontier.”
Developing green propellants won’t be quick or easy. It will be a major challenge for NASA, particularly from a cost, schedule, and risk perspective. The agency has established the Technology Demonstration Missions Program at the Marshall Spaceflight Centre in Huntsville, Alabama to oversee the green fuel program. It will act as a bridge between laboratory confirmation of a technology and its use on a mission.
This isn’t the first time NASA has tried to develop green fuel. In 2009, the space agency and the US Air Force successfully launched a 9-foot rocket 1,300 vertical feet using a mixture of aluminum powder and water ice. The mixture, called ALICE, has been studied since the 1960s as an alternative propellant. The reaction between substances produces a large amount of energy during combustion and green exhaust products.
Environmental impact aside, fuels like ALICE could be manufactured on the Moon or Mars, negating the cost of sending propellants along as cargo on long-duration missions. This would be when designing long-term missions.
The winning aircraft - Pipistrel-USA, Taurus G4 - during its flight as part of the miles per gallon flight. (NASA/Bill Ingalls)
Aviation, too has been an outlet for NASA’s green fuel initiatives in the past. 2011’s CAFE Green Flight Challenge, sponsored by Google, had competitors in general aviation design aircraft capable of flying 200 miles in less than two hours and use less than one gallon of fuel per passenger. The first place winner of $1.35 million was the team Pipistrel-USA.com of State College, Pennsylvania used an electric aircraft that achieved twice the fuel efficiency required by the competition — they flew 200 miles on the equivalent of a half-gallon of fuel per passenger.
With this shift to green fuels, NASA hopes to partner with American companies to usher in a new environmentally friendly era of open access to space. The agency is planing to make multiple contract awards for green technologies with no single away exceeding $50 million.
