Nasa has selected a variety of companies to work on projects to create advanced space technologies, including faster methods of propulsion.

Other projects to be worked on include improved habitats for humans, and small satellites to explore deep space.

And one of the companies in the 12 Next Space Technologies for Exploration Partnerships (NextStep) says they have an engine that could get humans to Mars in just 39 days.

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Nasa has selected a variety of companies to work on projects to create advanced space technologies, including a faster method of propulsion known as Vasimr (illustrated), which could apparently get to Mars in a matter of weeks, not months

The Vasimr engine - which uses plasma as a propellant - is being developed by the Ad Astra Rocket company in Texas.

Their engine shot to fame a few years ago when it was revealed that it could drastically reduce the journey time to Mars from months to weeks - although it may require a nuclear power source.

And following the successful test of a prototype in 2013, it seems Nasa is now considering it for use on a future mission to Mars.

WHAT IS THE VASIMR ENGINE? Short for Variable Specific Impulse Magnetoplasma Rocket, Vasimr works with plasma, an electrically charged gas that can be heated to extreme temperatures by radio waves and controlled and guided by strong magnetic fields. The magnetic field also insulates nearby structures so exhaust temperatures well beyond the melting point of materials can be achieved. In rocket propulsion, the higher the temperature of the exhaust gases, the higher their velocity and the higher the fuel efficiency. Plasma rockets feature exhaust velocities far above those achievable by their chemical cousins, so their fuel consumption is extremely low. Advertisement

‘We are thrilled by this announcement and proud to be joining forces with Nasa in the final steps of the technology maturation,’ said Dr Franklin Chang Diaz, Ad Astra’s Chairman and CEO, in a statement.

‘We look forward to a very successful partnership as we jointly advance the technology to flight readiness.’

Over three years, Nasa will give the company about £6.8 million ($10 million) to get the engine almost ready to fly in space.

This will be achieved with a demonstration of their new prototype, the VX-200-SS, which will be able to fire continuously for more than 100 hours.

A previous test in 2013 saw Ad Astra complete 10,000 successful high power firings of a Vasimr prototype.

However, this involved short duration bursts for less than a minute. Proving the engine works for more than 100 hours will be key to it one day being used on a spacecraft.

The Vasimr engine is seen here being tested. Short for Variable Specific Impulse Magnetoplasma Rocket, Vasimr works with plasma, an electrically charged gas that can be heated to extreme temperatures by radio waves and controlled and guided by strong magnetic fields

In rocket propulsion, the higher the temperature of the exhaust gases, the higher their velocity and the higher the fuel efficiency. Plasma rockets like Vasimr (illustrated) feature exhaust velocities far above those achievable by their chemical cousins, so their fuel consumption is extremely low

The Vasimr engine could be part of the entire spacecraft that will ultimately take astronauts to Mars. The rocket that will send them on their way will be the Space Launch System, illustrated, which will complete an unmanned flight in 2019 - and it will have room for some secondary payloads to go to deep space

HOW LONG WOULD A MANNED MARS MISSION TAKE? Owing to the orbits of Earth and Mars, there are specific windows of opportunity when a mission can take place. Our planets come as close to each other as 33.9 million miles (54.6 million km), but can be as distant as 250 million miles (400 million km). For this reason spacecraft to Mars, such as the Curiosity rover, have to launch in certain windows when the planets are aligned. The next window is open from January 2016 to April 2016, and will see the launch of two more missions to the red planet. For a future manned mission, they will need to launch out in one of the windows and return in another. Just getting there will take up to nine months. The astronauts will then be there waiting for a year until they can come back, again taking up to nine months - a total of around three years. Whether an engine such as Vasimr could shorten the time it would take to cover the distance, though, remains to be seen. Advertisement

With this and other technologies, Nasa said in a statement they want to develop exploration capabilities around the moon, and at Mars.

‘Commercial partners were selected for their technical ability to mature key technologies and their commitment to the potential applications both for government and private sector uses,’ said William Gerstenmaier, associate administrator for Human Exploration and Operations at Nasa Headquarters.

‘This work ultimately will inform the strategy to move human presence further into the solar system.’

Three advanced electric propulsion projects, including Vasimr, will develop engines that operate in the 50 to 300 kilowatt range.

By comparison, current electric propulsion used by Nasa - such as the ion engine on the Dawn spacecraft - operates at less than five kilowatts.

Meanwhile, seven companies have been picked to work on the habitats that will house astronauts as they make their way to Mars in the 2030s.

While the Orion capsule will take astronauts to and from Earth, it can only sustain a crew of four for 21 days.

To make the journey to Mars, expected to last anywhere from several months to three years, astronauts will need to live in some other structure.

Nasa will be hoping one of the projects it is funding will find a way to house the astronauts for the grueling journey to and from the red planet.

While the Orion capsule (shown after test flight in December 2014) will take astronauts to and from Earth, it can only sustain a crew of four for 21 days. To make the journey to Mars, expected to last anywhere from several months to three years, astronauts will need to live in some other structure

Previously, Boeing outlined the six steps needed to land and return on Mars (illustrated). Two are already in production - the Orion spacecraft and SLS rocket. The other four things needed are a large 'tug' spacecraft, a habitat, lander and an ascent vehicle - all of which Nasa is hoping to develop in the next decade or so

Nasa is also asking companies to development capabilities to sustain a crew of four for 60 days in cis-lunar space - between Earth and the moon - with the ability to scale up to Mars missions.

The companies selected include Bigelow Aerospace, who are creating an inflatable habitation module - a prototype of which will be attached to the ISS in 2018.

And finally, two companies have been selected to develop small satellites - CubeSats - to launch as secondary paylods on the first flight of Nasa’s huge Space Launch System rocket in 2019.

As the rocket is so powerful, it will give these CubeSats a rare opportunity to explore deep space, as opposed to remaining in Earth orbit.