43 Recommendations for Kids Space Books

We are so lucky to have Ross Wakefield join us as a guest writer.

Please visit our “Get Involved” page to learn more about how you can volunteer and/or join The Mars Generation. Let’s go to Mars!

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Photo: NASA

Introduction

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

Overview

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.

Photo: NASA

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:

Photo: NASA

• 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.

Photo: US Navy

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.

Conclusion

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:

The Road To Mars: Our Past and Our Future

Going To Mars, Part 1: The Human Element

Going To Mars, Part 2: The Curiosity Rover, A Martian Marvel

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.

We are so lucky to have Ross Wakefield join us as a guest writer.

Please visit our “Get Involved” page to learn more about how you can volunteer and/or join The Mars Generation. Let’s go to Mars!

*** Please note guest submissions are options of the author and do not necessarily reflect the mission or beliefs of The Mars Generation.

Introduction

For a long time now, Mars has been the object of desire for many missions from a range of different space agencies. Many of them have been very successful (like the incredible story of the NASA rover Opportunity, whose proposed mission life cycle was 90 days yet is still gathering and sending data after 13 years), and some not-quite-so successful (the poor Beagle 2, long believed to have been destroyed upon landing but recently discovered to have been inactive simply because two solar panels failed to deploy, blocking the communications antenna). Though Mars has a reputation for making missions difficult for various reasons (roughly two-thirds of probes sent to Mars have failed before their missions could be completed), at the present time there are no less than eight different active vehicles sent by mankind either in orbit or on the Martian surface itself.

One of these vehicles, the most recent successful arrival on the surface, has given us more data than ever about the Martian environment. It is assessing the climate, analyzing geology, offering possible conclusions on whether or not life of any kind once existed on Mars, and perhaps most importantly, looking to answer a fundamental question:

If we were to visit Mars in the future…how hospitable would it truly be?

In the early 2000s, NASA began work on a project that would eventually become known as the Mars Science Laboratory (MSL) mission. The idea was to determine once and for all the current and past habitability of Mars for organisms both complex and simple.

The centerpiece of this mission was the rover that the MSL carried with it, right down to the Martian surface itself: the vehicle named Curiosity.

The Curiosity Mission, Now and Into the Future

Early Stages to Landing

In 2004, NASA began taking proposals for the various parts that the probe would take to Mars, and within four years most of the instrumentation had been completed and was being tested. Though the project did run over-budget during development and NASA had to simplify many of the instruments in order to make a revised launch date, the rover – given the name Curiosity thanks to sixth-grader Clara Ma from Kansas – took flight from Cape Canaveral in late 2011; the beginning of a ten-month journey to Mars.

The MSL mission had, and still has, several basic objectives – chief among them to identify possible “biosignatures” or features that imply that a biological presence had once been on Mars. The mission also performs detailed geological testing of the area to identify exactly what kind of rocks and soil may be found on the Martian surface. And finally, it records and analyses radiation levels both during the journey to Mars and once on the surface. That data, of course, would be potentially crucial for planning a future human Mars mission – and more on that later.

On August 6th, 2012, Curiosity landed successfully in the Gale Crater, very close to the equator of Mars. After a tense 14 minute wait, news of this reached the waiting mission staff, and very soon after that the world knew that the most complex and elaborate rover yet designed for Mars missions would soon begin its exploration. The choice of Gale Crater had been carefully considered beforehand; the site for the landing had to include both a variety of different materials for geological analysis and also the kind of rocks capable of indicating the evidence of past water and (maybe, just maybe) ancient fossils. From past observations of the surface, that particular location satisfied all these requirements – and its close proximity to the Martian equator would help with communication.

On the Surface

Once on the ground, Curiosity got to work, using a variety of instruments to assess the Martian surface in pursuit of its mission. Though the initial thoughts regarding what the rover could carry had been limited by budget and time constraints, a wide variety of instruments were fitted to the rover for use.

These included:

– a spectrometer designed to assess the chemical makeup of rocks using alpha particle radiation and X-rays, ideal for getting an accurate composition of the sample.

– an X-ray diffraction analyser, designed to target specific minerals within rocks and identify whether or not any particular rock might have had water involved in its creation or its development. Past or present water, is, of course, a key indicator of possible life.

– an instrument for analysing the few gases in the Martian atmosphere, looking in particular for specific oxygen and carbon signatures within carbon dioxide and methane that would tell if those gases were produced chemically or organically.

– a radiation detector, switched on at launch in order to measure the radiation doses given to the mission both by the Sun and by other possible sources.

– a weather package designed to measure wind speed, temperature, humidity and other important values.

– a variety of different cameras – five for imaging the surface and other interests, and 12 for supporting the movement of the rover itself.

With all of this instrumentation on one vehicle, Curiosity is by far the most complex rover ever sent to a body outside of Earth orbit and land successfully.

Within a few months of landing, the rover made a rather spectacular success when it came across what was described as an “ancient stream-bed.” This indicated that there had, at one time, been a wide-flowing and vigorous river system, at least in that area. Though the existence of flowing water in the past had been heavily touted since the Mariner missions of the 1970s, this added further weight to the idea that Mars did, in recent history, contain flowing liquid water – and by extension, possibly life. Further discoveries the following year of abundantly accessible water in soil samples added more credence to this theory.

In early 2013, a sample of rock taken by Curiosity at Gale Crater detected water, carbon dioxide, oxygen, sulphur dioxide and hydrogen sulphide. This is a chemical combination very well-suited for the existence of microbe life, thereby adding further weight to the idea that Mars was, once upon a time, potentially habitable for simple forms of life.

In late 2014, the rover detected a spike in methane levels ten times higher than the baseline value in the Martian atmosphere, as well as other organic compounds within rock samples. While the source of these compounds is debatable, it is entirely possible that they could have been produced by ancient microbial processes.

In late 2015, there was enough data gathered by Curiosity for a conclusion to be made that the landing area of Gale Crater was once either a large lake, or stream, or both, billions of years ago.

Finally, in late 2016, NASA gave a summation of the mission so far, where they confirmed the relative success of at least one objective of the mission. In their opinion, the Gale Crater site once contained an ancient river or lake, with a chemical energy source and all the chemical ingredients needed for life to have once existed there. Their conclusions were definitive – while Mars likely does not have life now and possibly did not in the past, the conditions were extremely favourable for life to have existed there once upon a time.

From the time of its launch, the rover has measured the doses of radiation from galactic cosmic rays as well as energised particles emitted by the Sun. The findings, however, were sobering: the dose that the rover took in the time frame that a human Mars mission would entail (860 days total: 360 days traveling back and forth and 500 days on the surface) was almost twice what NASA deems an unacceptable lifetime limit for its astronauts in orbit around the Earth.

Future of Curiosity

Though the initial plan was for the rover and the mission to be active for just two years, within a few months of landing the mission plan for Curiosity was extended indefinitely. This didn’t come as a surprise to most familiar with the sheer durability and toughness of such rovers: the story of the NASA rover Opportunity, as shown above, pays testament to that.

Presently, Curiosity is to be found exploring the surfaces of Mount Sharp, looking for further clues as to

Martian history and in particular how the planet moved from a relatively habitable abode for simple life to one incapable of supporting it. Still in excellent working order with only a couple of minor technical difficulties to inhibit it, the rover has traveled over 16.5 kilometres from its landing site.

Right now, the key objective that the rover is focusing on as it climbs Mount Sharp is to discover exactly how and when the lakes and rivers upon Mars dried out, thereby giving possible clues as to why it happened.

On its fifth “birthday,” the rover even played a little “Happy Birthday” tune to itself – and with any luck, Curiosity will continue to roll on in the course of its mission for many years to come.

What Does It All Mean For Future Missions?

In the roughly five year timeline since Curiosity first landed on Mars, this probe has given NASA and the world a treasure trove of information regarding surface and atmospheric conditions on Mars, some of which confirmed what previous missions had hinted, and some of which was entirely new. It has, by all accounts, been a remarkable success – and no doubt there is still much more to be found and more information to be sent back by the durable, brilliant rover.

However, the thirst is for more than just robotics to set their wheels on the surface of our nearest planetary neighbour. As has been mentioned in previous entries, more than one organization on Earth has the hunger to put humans on Mars and to do it soon. But to do that, we need a lot of information about conditions there – both for the sake of mission parameters and for the safety of the astronauts that would go.

So, in light of that, what has the Curiosity mission told us about a potential human Mars mission that is noteworthy?

Well, the first discovery is possibly the most difficult factor discovered by the mission, and the one most likely to put serious holes in a lot of Martian ambitions – the high radiation levels.

As was noted earlier, the maximum accepted lifetime dose of radiation by NASA for its low Earth orbit astronauts is one that will give a three percent additional risk of fatal cancer development. The readings from the rover show a total dose of around 1 sievert of radiation during an 860-day Mars mission, which corresponds to a five percent additional risk – almost double what NASA deems acceptable. And this, of course, does not take into account other missions that the astronaut may have been on previously in their lifetime, nor the (likely) vital time in a zero-G environment that they would need for the purposes of training for such a Mars mission. This finding, showing that the total dose was higher than many people expected, indicates that serious consideration is going to have to be given to radiation shielding for any astronauts involved in such a mission.

There are, of course, solutions to this problem – increased radiation shielding for the craft involved, as well as the choice of building a habitat for this purpose (likely essential for long-term habitation of Mars anyway) once on the surface that would be likewise shielded. Such shielding does increase the potential weight of any mission sent, and so increases the cost and possible complexity. Such things will have to be carefully considered in the planning of any future human mission.

The second discovery involves the landing of the rover itself, where a rather unique system was used. Rather than just one system – thrusters, an airbag or parachutes – being used to arrest the fall of the rover to the surface, Curiosity instead used a unique combination. Initially, a heat shield was used to reduce speed during the initial entry into the thin Martian atmosphere. This was followed by a parachute once further down, and thrusters once within around two kilometers of the ground. Finally, and most uniquely, a “sky-crane” system was used, where cables helped lower the rover away from the rest of the descent vehicle until touchdown, at which point the cables separated and the other part of the lander flew away to land elsewhere. Such a system was entirely novel and was deemed one of the few possible ways that a wheeled rover as large as Curiosity could be landed safely – that is, without causing damage to vital systems through impact or the dust cloud generated by such a landing.

The success of this principle demonstrated that heavy yet delicate payloads can be deposited on the Martian surface, and as any human mission is going to require an awful lot of heavy yet delicate equipment, this method is a useful possibility for getting materials down to the surface.

The Curiosity rover has also confirmed beyond reasonable doubt that while organic compounds exist on Mars, organic life likely does not at this point in time, which has connotations for precautions that any crew might have to take if it came to encountering simple life there – such as increased anti-contamination procedures and the like.

All of these, along with various discoveries that have been made regarding chemical and organic findings on Mars by the rover, mean that this mission has been given a wealth of information that will prove useful if and when humanity decides to send some of its own representatives to the Red Planet.

Conclusion

Almost five years after its landing, the Curiosity rover is still almost fully functional, rolling away through the Martian landscape, testing and sampling all the time. A testament to the ingenuity of those who helped place it there as well as the durability of the rover itself, it should continue to supply incredibly useful data for many years to come.

By far the heaviest and most complex vehicle ever to land on the surface of a planet that is not our own, it has spent the last half a decade giving us a wealth of information. Through discoveries made by this one rover, we now have a much better idea of the best method to deliver heavy payloads to the Martian surface, the previous habitability of Mars, and the likely dose of radiation that a human mission to Mars might face, and more. Even now, it seeks to answer another question about Martian history by attempting to discover at least a rough idea of the time at which liquid water there might have vanished.

In the next couple of decades, it is possible that a human Mars mission will finally result in human feet upon that planet. Maybe, just maybe, when they do…

…there will be a tough little rover, battered but still working…rolling up to greet them.

More from Ross:

The Road To Mars: Our Past and Our Future

Going To Mars, Part 1: The Human Element

Going to Mars, Part 3A: Orion, The Next Generation of Travel

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.