How to build a starship

Date:24 April 2013 Tags:, ,

PM designs a craft that can deliver passengers to a distant star. Launch date: 2112. By Michael Belfiore

In late 2012, scientists, researchers and optimists gathered in Houston for the second annual 100 Year Starship Symposium, a Pentagonand Nasa-supported project to promote the technology needed to construct an interstellar spaceship. Inspired by the audacious enterprise, PM envisioned a space-craft ready to take 200 people on a 90-year trip to Proxima Centauri, a red dwarf star 4,24 light-years away. Astronomers are finding more potentially habitable planets in the Universe – humanity just has to figure out how to get to them.

Create an ecosystem
Interstellar missions require a revolution in food production. One thing missing in deep space: sunlight. Scientists at Kennedy Space Centre are tailoring the wavelengths of LEDs to grow specific crops. Space farming also demands a deeper understanding of micro-organisms that support plants.

“How do you renew soil?” asks Mae Jemison, a former Nasa astronaut whose foundation is leading the US government’s 100 Year Starship project. To find out, astronauts are using a chamber on the International Space Station to determine the healthiest conditions for plants, micro-organisms and insects. “All the knowledge that we need to mount a mission to another star, we need to know to survive on our planet,” she says.

The Trip

Choose a destination: 

Epic journeys start with a destination. Astronomers using advanced space telescopes are finding hundreds of planets every year – researchers estimate that 50 per cent of the 150 000 stars analysed by the Kepler space telescope have planets the size of Earth or slightly bigger.

But scientists don’t yet know if there are any planets orbiting red dwarf Proxima Centauri, the closest star to our solar system. Nasa’s James Webb space telescope, due to launch in 2018, may be able to pick out the subtle changes in starlight that indicate if planets are present.

What to wear:

Even mundane tasks become make-or-break challenges on a starship. Karl Aspelund, an assistant professor at the University of Rhode Island and a speaker at the 100YSS Symposium, is focusing on the question of laundry during a deep-space mission. “On the space station, they just throw away clothes. You can’t do that on a long mission,” he says. “Maybe we need to rethink what it means to be covered or clothed. Are we coated somehow, instead of wearing pieces of fabric? That could get really weird, but maybe that’s what needs to happen if civilisation is going to move off the planet.”

Stay safe:

The biggest danger to the starship’s crew is decades of exposure to cosmic radiation, which can sicken passengers and put their offspring at risk by damaging DNA. Any ideal design would avoid adding the extra mass of physical shielding; advances in force-field technology might provide the solution.

Advanced Magnet Lab, a Florida-based company that makes medical and military imaging equipment, is working under a multi-year Nasa grant to study the use of magnetic fields to repel these dangerous particles. The reduced gravity on board a spaceship interferes with the human body’s flow of cells and fluids, which impedes healing.

Ronke Olabisi, Rutgers University biomedical engineering professor and 100YSS science board member, is developing an injectable goo that speeds the repair of wounds, bone fractures and internal organs. The system encapsulates proteins that spur bone and tissue growth in microspheres that don’t trigger an attack by the patient’s immune system. “The outcome of this project won’t just benefit astronauts,” Olabisi says. “Each year billions of dollars are spent treating over 2,8 million chronic wound patients in the US.”

Landing on an alien planet :

The starship crew deploys small, speedy probes to confirm details about Proxima Centauri’s planets. The probes communicate their findings via lasers operating at visible-light frequencies. One key question: is there life in that alien solar system?

Scientists have long believed that red dwarf stars were unsuitable hosts for habitable planets, since they eject deadly, atmosphere-erasing X-rays. However, the European-run HARPS spectrograph in Chile in 2012 sampled 102 red dwarfs and estimated that 41 per cent might be hiding habitable planets.

Researchers have also recently argued that the moons of planets that orbit red dwarfs could be large enough to hold atmospheres. No one knows what we’ll find. But humans will, for the first time, no longer be doomed to extinction when our sun’s fuel runs out. We’ll have the chance to be permanent residents of the Universe.

Timeline:

Year one:

The Hof, only 5.5 light-hours away from the Sun, passes Pluto. The vessel is still years away from reaching maximum speed.

Year two:

The edge of our solar system is called the heliopause, where our sun’s solar wind dies away. It is estimated to be about 28,3 billion km away.

Year ten:

The Oort cloud, a massive region of icy comets, is the last pitstop to restock water and raw materials. Robot miners do the collecting so the ship doesn’t have to slow.

Year 25:

The first infants born in interstellar space graduate. They are trained to be crew—and perhaps colonists.

90 Years out

After several years of deceleration, the Hófvarpnir reaches a new solar system, Proxima Centauri, 4,24 light-years from the Sun.

Propulsion: 

The Hof has a plasma engine powered by a fission nuclear reactor. Plasma engines show great promise: last year, the Texas company Ad Astra signed an agreement with Nasa to test a solar-powered version in space – possibly on the ISS – in 2015. In the future, fusion power may be realised; if it is, we can incorporate it into PM’s proposed spacecraft.

How a fusion plasma engine would work:

Microwaves heat hydrogen isotopes to 600 million degrees Kelvin, creating plasma.

Powerful magnets contain the superhot plasma and push the material together so that the isotopes fuse. This fusion creates a huge amount of energy.

Magnetic fields guide the plasma out of the magnetic nozzle, propelling the ship at an incredible 12 per cent light speed.