Nasa reveals its Orion capsule
Taking man to Mars: Nasa reveals the technology behind its Orion capsule and the preparation for its first journey
- Orion could take explorers further into space than anyone has ever gone
- Will be blasted out of Earth’s atmosphere using the Space Launch System
- In September, Orion’s heat shield will be tested in space for the first time
- Orion will be launched for a second time in 2017 to the moon and back
- This will be first time SLS, most powerful rocket ever created, are tested
- Astronauts will get their chance turn to ride the Orion/SLS combination in 2021 on a lunar orbit. After that, destinations are still being debated
By Dr Stuart Clark, Science Uncovered
For the first time in a generation, Nasa is building a new astronaut-carrying spacecraft.
Called Orion, this capsule is designed to take explorers further into space than we’ve ever gone before. Eventually, journeys to Mars itself are being imagined.
The challenge of a journey to Mars must never be underestimated. It is unlike anything the world’s space agencies have tried before – it makes the Apollo Moon landings of the 1960s and ’70s look like child’s play.
Instead of a few weeks in space, a voyage to the red planet and back would take a few years, and this dramatically increases the difficulty.
There are no shortcuts home if something goes wrong. Malfunctions will have to be fixed on the fly – and that includes human malfunctions such as injury or illness.
Appendicitis en route could be a death sentence. Then there are the psychological stresses of living and working in a confined space, isolated from one’s home planet for years.
Nevertheless, Nasa and other space agencies around the world are positioning themselves to take this leap.
The most visible element of this effort is Nasa’s Orion capsule and the Space Launch System (SLS), a grand-sounding name for the most powerful rocket ever developed.
Orion is currently being bolted together and later this year, in September, it will be put through its paces in space for the first time.
‘Orion, along with SLS, is the future of human space exploration,’ says Brandi Dean, Nasa’s spokesperson for Orion. ‘It’s the vehicle we are building to allow us to send humans farther than we’ve ever been able to go before.’
Orion is the first step. It is modelled on the Apollo capsules, and the key component that sets it apart is its heat shield.
To break from Earth orbit requires more speed than simply getting into orbit. On its return, the craft will re-enter our atmosphere with that extra speed, meaning the shield will have a lot of work to do.
The heat tiles of the Space Shuttle will simply not cut it, so Nasa has been developing a new, heavy-duty shield for Orion. The first one was shipped to Kennedy Space Center in December 2013, where it’s currently being attached to Orion.
It is a five-metre-wide structure consisting of a titanium skeleton and carbon fibre skin that support a honeycomb of 320,000 cells. Each one of these was filled by hand with a special material called Avcoat. This proved to be the most effective of the samples that Nasa tested.
Avcoat will flake away during the fiery re-entry, carrying away heat energy and slowing down the spacecraft. Each cell has been X-rayed to check it for perfection.
The titanium skeleton will then provide the strength to withstand the final splashdown in the Pacific Ocean.
The shield will be tried out in this September’s test, when Orion will be lofted into space atop a Delta IV Heavy Lift rocket and sent on a couple of high elliptical orbits.
This will ensure that the capsule hits the atmosphere faster than the Space Shuttle, providing a real test for its shield.
Assuming all of that goes well, Orion will be launched for a second time in 2017. This flight will be to the moon and back, but there will not be a crew onboard and no landing will be attempted.
‘We don’t generally put people on the first launch of a new rocket,’ says Mr Dean.
This flight to the moon will also be significant for other reasons. Namely, it will be the first flight of the Space Launch System. ‘SLS is a game-changer,’ says Kimberly Henry of Nasa’s Marshall Space.
Flight Center, where SLS is being developed. ‘It will be the most powerful rocket [ever], with the most capacity that we have ever had to take humans and equipment further into our Solar System.’
Astronauts will get their chance turn to ride the Orion/SLS combination in 2021. This too will be to lunar orbit. After that, destinations are still being debated.
Orion itself is not capable of going to Mars alone. ‘It’s designed for missions of up to 21 days,’ says Mr Dean.
This means that a return to the surface of the Moon is possible with the development of a lunar lander. But to go further – to rendezvous with an asteroid or to visit Mars – would require a transfer vehicle that the astronauts can live in for months at a time.
Going to the red planet would essentially require a small space station in order to hold enough supplies for the journey.
There are some designs. The Boeing Corporation, best known as the maker of the jumbo jet, has been outlining possible hardware for Martian missions that uses technology being developed now.
One such concept is the expandable space module being designed by Bigelow Aerospace. This could be launched in a compact form and then inflated with air once in orbit to provide a roomy habitat for astronauts.
In December 2012, Nasa signed a $17.8 million (£10.7 million) contract with the company to produce a test module.
Known as the Bigelow Expandable Activity Module (Beam), it is scheduled for a launch in 2015. It will be connected to the International Space Station and monitored for atmospheric leakage, radiation resistance and temperature fluctuations for two years.
Radiation is a key threat to astronauts going to Mars. Just as mariners from the past faced unpredictable, life-threatening storms on Earth’s oceans, so too will the astronauts face dangerous ‘space weather’. The Sun gives out a constant ‘wind’ of radiation.
Other radiation comes into the Solar System from beyond. These ‘cosmic rays’ were monitored on the Curiosity rover during its cruise to Mars in 2012 to get an idea of what astronauts would experience. Unfortunately, the results did not make for happy reading.
Between December 2011 and July 2012, a Mars-bound astronaut would have clocked up the same radiation dose in a day that the average American receives in a year.
If you exclude medical dosages, it would be 10 times more than the average yearly dose for an American. If this is typical, and there is no reason to assume that it is not, the radiation from a 500-day round trip to Mars would exceed NASA’s current safety guidelines.
Making matters worse is the fact that gigantic explosions occasionally take place on the sun, which create storms of radiation that are highly dangerous to humans in space.
Having to survive such storms is almost inevitable on a Mars mission, and despite many ideas, there is not yet any technology that has been tested to do this.
And then there is the problem of microgravity. Without the Earth’s pull to work against, our muscles begin to decrease in mass, and other parts of the body deteriorate as well.
Astronauts’ spines lengthen, causing pain and raising the possibility of slipped discs when they return to a gravity environment, as would be the case if they landed on Mars, where gravity is 38 per cent of that on Earth.
When European Space Agency (Esa) astronaut Andreas Mogensenconducts his mission to the International Space Station in 2015, he will wear a tight-fitting skinsuit that Esa hopes 0will prevent some of microgravity’s effects on the body.
If this is shown to be effective, it could help astronauts arrive on Mars in better condition so they can begin work straight away without having to go through any rehabilitation.
No one yet knows the name of the person who will be the first to set foot on Mars – but Mr Dean knows this much: ‘The people who will go to Mars are certainly alive today. I would not be surprised if astronauts in the corps currently are included on the mission.’
‘Mission to Mars’ appears in issue five of Science Uncovered, on sale now.
20 Mar, 2014
Nasa reveals its Orion capsule
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