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It has been almost 50 years since the last time mankind truly escaped the bounds of Earth orbit and ventured out to the last destination reached beyond that point – the Moon. This was accomplished during successful landing and return of Apollo 17 to and from the Moon in 1972. That journey, made by three U.S. astronauts, represents the final time both man and machine were tested by the rigors of spaceflight beyond where Earth’s own gravity was the dominant force.
In the near five decades since, massive advancements have been made in the fields of space exploration – in terms of both the technology used to explore it, and the ways the human body and mind are being trained to prepare for it. These advancements have been so profound, so radical, that when the time came for plans to be made for mankind to make that journey beyond Earth once again, the planning called for something rather different from the amalgamation of aluminium and plastic that made up the command and lunar modules of Apollo 17.
This was to be a 21st century craft for 21st century flight – a craft capable of sending up to six travelers to the Moon…and possibly, one day, to Mars. And based on that singular vision, what has arisen is what NASA believes to be the next stage in human space exploration.
The Orion Multi-Purpose Crew Vehicle, better known simply as the Orion. A craft capable of sending mankind to Mars and returning, again and again.
But…how exactly is such a craft prepared to deal with the rigors of a spaceflight so much longer and further than any before in human history?
An earlier article spoke of the training the human body and mind has to receive for such an undertaking. This one, the first of two covering the Orion craft, shall continue that discussion. We will establish the history of how such a craft came about, outline the preparation the machine, like its human controllers, must undergo before the mission can go ahead, and describe how every part of the craft is conditioned for survival and optimal performance in the most exacting of environments over a long period of time.
Before looking at how the Orion module is set up to get to Mars, we will take a look at its history, which will cover the first key areas. The other areas will be covered in later articles.
History: How Orion Came To Be
History is littered with plans for spacecraft designed to go to Earth orbit and beyond. However, many never made it past the planning stage, due either to lack of feasibility, money, or often both. One example is the ambitious Mars Design Reference Mission conceived by NASA in the 1980s, or the Soviet Heavy Interplanetary Spacecraft design of the 1970s. However, it was reasonably clear from the start that Orion was not to be one of these – it was thought of at a time where the desire for a new kind of spacecraft was paired with the political will to make it happen.
For the longest time, NASA had been looking for a capable vehicle to replace the aging Space Shuttle fleet, especially in the aftermath of the dreadful loss of the astronauts and the shuttle Columbia in 2003. It was decided that the new craft was to be one that would fit as many requirements as possible – to be as capable of going into orbit and resupplying the International Space Station in the fashion of the Shuttle as it would be capable of returning to the Moon…or further afield.
To this end, the Orion was conceived as part of the Constellation Program put into motion by President G.W. Bush, and was shortly announced thereafter in 2004. It would be designed to fulfill both crew and cargo lift requirements to the ISS, as well as be capable of taking a crew of up to six beyond Earth orbit and return them safely. This would be coupled with a new generation of heavy lift rockets capable of sending it into orbit and beyond.
However, in 2010 a government inspection found the Constellation Program to be underfunded, behind schedule, and lacking in several key areas of development. As a result of this, almost all of the project was scrapped, including the heavy lifters…but the Orion survived the cuts, instead being re-conceived as the Orion Multi-Purpose Crew Vehicle. It would no longer use a specifically designed rocket, but instead would rely on the existing Delta IV Heavy rockets used by NASA, but the purpose remains the same as it ever had been – to follow in the steps of the Apollo missions and go even further.
Orion to Mars
Though modern technology may have changed a great deal from the heady days of the Apollo Program, some key design aspects of Orion would remain much the same – the basic composition, a crew module being attached to a command module, and the shape of the crew module itself. Re-entry dynamics being very much unchanging, the pioneers of the Apollo Program had the ablative flat surface for re-entry into Earth’s atmosphere pretty much down-pat half a century ago. In light of that, a general shape rather similar to the Apollo module was called for.
However, that is where the similarities end.
The Orion crew module is designed to be bigger in terms of volume and mass than the Apollo equivalent – two and a half times the volume and around one and a half times the mass. This increase is offset some by the attached service module which contains essential equipment and more that is much lighter than its Apollo equivalent. This increase in volume means much more room for the apparatus needed to support the crew, which boosts the capacity from the Apollo-era three to a possible six member crew in the module.
Other improvements in the name of modern technology include a digital control system similar to the “glass cockpit” systems on the most modern airliners, a system designed to achieve docking with another spacecraft automatically rather than manually (a first for a U.S. spacecraft), vastly improved computer systems, and, possibly the most significant development, heat shield ablation technology designed to not only achieve a safe re-entry, but to make the module entirely reusable after more than one journey back to Earth. Such an advancement will save vast amounts of time and money in the future. To allow for further developments in technology over the next couple of decades, the components of the Orion are also designed to be as generic and as adaptable as possible for new parts to be integrated into the module once they are developed.
All in all, the Orion is designed to combine the vehicle style and shape of the Apollo-era command module with the very latest in technology to carry it to the Moon and Mars – and safely back again.
However, it might now be asked…what about the specific systems? What exactly makes them capable of taking the long trip to Mars and back – possibly multiple times – safely and successfully?
Keeping Them Alive – Life Support
The core of the Orion is the crew module. And the core element of the crew module is, of course, the system designed to keep crew members alive and healthy through a journey that could last a matter of years before completion. Of course, the basic requirements for such a system – maintaining food, oxygen and potable water, eliminating waste, and preventing possible hazards to the life of the crew – have been the same ever since the very first human missions into space, but the advancements of technology in that time have made it easier to meet such requirements and lower the risks associated with spaceflight.
The basic life support requirements for the Orion are eightfold, but can be summed up as being able to support a full crew (either four or six) in a “shirtsleeve” – that is to say no spacesuits – environment for a full Lunar or ISS mission. Furthermore, it must be able to operate for six months in an inactive mode either attached to the ISS or in Lunar orbit, tolerate failure of more than one essential system, and satisfy the various dimension and mass limits that were part of the Orion design.
With all of that in mind, the Orion crew module life support system meets these needs and uses new, modern technologies to do so, some of which include:
- advanced carbon filters that recycle the air that astronauts would need (and, yes, no square scrubbers in round holes this time)
- a Halon gas fire extinguisher system as well as hand-held fire extinguishers for the crew
- a comprehensive temperature control that is both active (can be controlled by the crew) and passive (happens all the time regardless of crew involvement)
- waste and water management systems that eliminate potentially harmful waste while recycling where they can
All of this accounted for, the Orion is perfectly capable of taking a crew of six to the ISS or a crew of four to the Moon.
But what about Mars?
Though the Orion crew module is capable of supporting astronauts for a reasonable amount of time, the lack of space for food and other supplies mean that more room is needed should it be required to take on the many-years venture of a Mars mission. To that end, a Deep Space Habitat (DSH) covering exercise, training, recreation, and supply space is envisioned, which will be covered in greater detail in the future.
Gotta Be Tough – Structure
As has been covered in previous articles, the rigors of spaceflight place as much stress on machine as they do to man. From the initial g-forces of liftoff to the various heat and gravitational stresses that happen upon re-entry, every aspect is designed to test the limitations of the technology placed up there…with the penalty for failure being severe. And with spacecraft, the first point of possible failure is the outside structure of the vehicle itself.
So, having considered this, the outer hull of the Orion has to be designed to resist everything that launch, a long period of spaceflight, and the rigors of not one but multiple re-entries can throw at it – and more. And as was mentioned earlier, though the general shape of the crew module hasn’t changed since the days of the very first human spaceflight – re-entry dynamics haven’t either, after all – the materials used to build and coat it have.
Firstly, the Orion crew module is fitted with possibly the most comprehensive abort system ever designed for a human spacecraft. Should a failure happen on the launchpad or ascent that might endanger the lives of the astronauts involved (and tragically both of these things have happened in U.S. missions in the past), then the abort system would fire, throwing the capsule and its occupants away from the failure and to a safe landing with immediate effect.
Once in space, the capsule defends against the various rigors of spaceflight in a variety of ways. The structure is designed to defend against micro-meteor strikes, which on any long mission would become a significant hazard. The capsule also utilizes a form of welding named friction-stir welding (FSW) in its construction, which vastly reduces the possibility of leaks in the structure, and strengthens the hull while reducing its overall weight – always a plus in space operations.
Finally, for re-entry, the module has been fitted with the Avcoat ablator system – a system that shows the advantages of revisiting the old days, seeing as a similar system was used to outfit the Apollo crew modules. Facing the extreme conditions of temperatures of over 5,000 degrees Fahrenheit, the Avcoat material heat shield, made from a combination of silica fibres, epoxy resin and fibreglass, is fitted directly to the bottom of the crew module. When returning from the ISS or the Moon or even from Mars, the ablator will absorb all of the friction heat buildup caused by the spacecraft coming into the atmosphere at several thousand meters per second, directing it away from any weaker parts of the structure. Additionally, the ablator is designed so that upon recovery of the module, it can be detached from the crew module and a new one put in place – thus making the module reusable as many times as is deemed safe. This will be a great help both in terms of time between launches to prepare, and the overall costs of the missions themselves.
A long time in space provides an exacting test for both man and machine. With the measures put in place described here, the structure of the Orion demonstrates – as it did during its first test flight in 2014 – that it is as up to the task as its occupants will be.
Since its inception, the Orion has been, through a combination of some old reliable technology and most cutting edge new technology, NASA’s vision of a spacecraft that can go forth far into the 21st century. It will be all things for all occasions, as comfortable on a cargo run to the ISS as touching down on the Martian surface. In this article, the history and a few of the systems of this remarkable vehicle were covered, and in the next, the remainder will be detailed, giving a better idea of what makes this spacecraft truly special. And it will reveal that why, in come a couple of decades time, this craft could indeed be taking people to one of our nearest planetary neighbors for the very first time.
More from Ross:
Ross Wakefield is a freelance science writer, communicator and consultant, with specialized expertise in the field of current and historical space developments. Ross has a Bachelors degree in Physics with Astrophysics from the University of Leicester and a CMCU in Astronautics and Space Engineering from Cranfield University and is a member of the Institute of Physics and British Mensa. Ross is currently beginning a series of articles with The Mars Generation on various space-related topics. When he’s not glued to a computer screen, he enjoys playing and watching sport, reading various books and trying to find where the nearest good pool table is in the United States. Find Ross on his Twitter.