Thursday, December 17, 2015

Open Letter: NASA needs to change

This is an open letter directed towards the Office of the Administrator of Nasa,

Their should not be any ambiguity of the primary goal of Nasa in the 21st century. That goal is to put humans on Mars, and jumpstart a new age of human deep space exploration. Nasa has accomplished incredible things that only a century ago would have seemed to be impossible. The idea of an affordable and common solution to deep travel is not nearly as much of a fantasy as the a trip to the Moon was in the years before the Moon Landings. The fact is that, most of the technology needed to make humanity a space-faring civilization already exists. It is simply a matter of accepting the challenge that stands between humanity and the distant planets. Unfortunately, despite the announcements of NASA that Mars exploration is indeed the goal of the program, I don't believe that Nasa currently has the correct philosophy when it comes to designing spacecraft.

Everyone in the aerospace industry is aware that the goals of SpaceX could be a complete game changer for the future of access to space. Their goal is reusability as the path to Mars. Elon Musk and other entrepreneurs have realized that rockets cannot continue to be a multi-year projects that cost billions of dollars, they must be a vehicle that can be flown and returned to earth safely for reuse. I understand that Nasa has considered reusability of rocket parts, but it is not beneficial to the current financial model of the agency. As a government agency, Nasa must serve a role that benefits the constituency of politicians which involves keeping long established aerospace-contractors employed within many states. Building single-use, multi-billion dollar rockets fits that model because it makes sub-contactors money. The problem is that this will not lead to new innovation in access to space. By maintaining the same facilities and technology's that were used in the shuttle era, Nasa is not looking toward the future. Im afraid that even if Nasa does accomplish a Mars landing, on the back of the SLS launcher, the program may be become irrelevant quickly.

I believe the solution is for NASA to make a preliminary Mars mission with the SLS, but quickly transition to a new model shortly thereafter which is capable of more than single missions at the expense of an expendable heavy lift launcher. 

Wednesday, December 9, 2015

The Mars Transit Vehicle

An artists depiction of what a joint SpaceX/Bigelow aerospace transit vehicle might look like. (Source: http://img03.deviantart.net/039d/i/2015/208/1/4/spacex_mars_transporter_by_euandesign-d930lb3.jpg}
The first spacecraft habitat's that go to mars will have to be a remarkable achievement in efficient use of space. The more crew compartments and services provided to the astronauts, the heavier the craft will end up being. So a long duration spacecraft, needs to be small and pragmatic enough to be affordable, yet large enough to accommodate as many of the needs of the crew as possible. The study, "Minimum Acceptable Net Habitable Volume for Long-Duration Exploration Missions" published by NASA, establishes the minimum requirements of volume for the crew of a Mars transit vehicle. Ultimately, I believe these findings will become very important in the eventual design of the spacecraft.

One of the greatest challenges to overcome will be negating the health effects of microgravity on astronauts while they are in transit. Astronauts aboard the ISS must devote a large amount of their time to exercise to avoid muscular dystrophy and deterioration of bone marrow. They regularly run on a treadmill and use resistance bands to simulate gravity. The study, assumes that the exercise equipment will be smaller than what is currently being used on the ISS. A Mars transit will be at least six months so this equipment will inevitably add volume and mass to the Mars spacecraft. Another approach is to design the spacecraft to incorporate a centrifuge, a spinning section that simulates gravity using centrifugal force. This sort of architecture would most likely increase the overall cost and size of the vehicle and it may be more efficient to simply use exercise equipment to simulate gravity.

Another important aspect of the spacecraft will be the psychological influence it will have on the astronauts. Unavoidably, being in a highly confined space for long periods of time will take a toll on the mental health of the astronauts. Everyone has experienced the feeling of confinement during long road or airplane trips. It can quickly result in frustration and an uncomfortable feeling of confinement, These limits have been pushed in space before by cosmonaut Valeri Polyakov who holds the record for continuous time spent in space at 14 months without any drastic changes in his mental health. It is vital that the astronauts have a communal area for dining and other activities in order to assure that the spacecraft is not mentally damaging. A specified work space will also have to be a requirement, allowing for a separation between the recreational and working activities of the crew.

SpaceX testing a reusable booster stage
One aspect of the vehicles design that is not analyzed in the study, is it's capacity for reusability. There are two distinct approaches to designing a deep space craft. It can be built with the same design philosophy as the Saturn V, where most of the vehicle never returns to the earth in an effort to save mass at the expense of losing hardware. Alternatively, the design can make an attempt to salvage a portion of the hardware used in the vehicle for later missions like the Space Shuttle. The current model of NASA does not currently embrace reusability. Every component of the SLS rocket, the main fuel tanks, solid rocket boosters, and second stage will drop into the ocean after launch, and those components will have to be constructed again for the next launch. This makes the cost of flying multiple missions extremely high, because each SLS will take large amounts or resources to complete. So how do you reuse a rocket stage? You either have to attach parachutes to the stage for a soft ocean landing or land the rocket propulsively on land. Led by Elon Musk, SpaceX, a private space company who was recently granted a contract to bring crew to the ISS in 2017, has been been developing rockets that have a full recoverable first stage that can boost back towards the launch site and land with a high level of accuracy. This is an extremely difficult maneuver to pull off, and SpaceX has failed to accomplish it twice. Nonetheless, SpaceX has long-term plans to build a Mars vehicle capable of being fully reusable. This would dramatically reduce the cost of traveling to mars to a fraction of the cost that NASA has proposed.

Of course this would bring new challenges to designing a habitat, because in NASA's model, the transit vehicle does not need to be brought to the surface of Mars or the Earth, with only the Orion capsule serving as the lifeboat that return the crew to the surface of Earth. Ultimately, if SpaceX achieves it's goal of building a fully reusable mars vehicle, I believe this will be a much greater accomplishment towards the future of space travel than a single expendable Mars mission.

Citation:

Whitmire, Alexandra. "Minimum Acceptable Net Habitable Volume for Long-Duration Exploration Missions." (2015). Print. 

Wednesday, December 2, 2015

The Journey to Mars

(Source: nasa.gov)

Above is a recently released infographic laying out NASA's plan to get humans to Mars. It is a sign that NASA has been slightly ramping up its PR efforts to get the public interested in a human mission to Mars. This image emphasizes the "flexible" approach of the SLS program while emphasizing that eventually goal is in fact Mars. Based on this graphic NASA's approach is a long multi-step process. Rather than focusing on building a spacecraft with the sole purpose of a manned mission to Mars, they are developing the different components necessary to get us to that point over the years. In the meantime, those components can be used for less costly missions like an asteroid redirect mission and a trip back to the Moon. First, they want to build a heavy lift launcher, the SLS which is already underway. At the moment this is where most of NASA funding and effort is being channeled. Without an adequate launcher none of the other crew-transport vehicles necessary will be useful. Next, is the testing of the Orion capsule, the vehicle that will ride atop the SLS into orbit. While NASA likes to emphasize the importance of the Orion capsule in its mission to Mars, it is important to note that the Orion is not an adequate spacecraft for transporting crew to Mars. While it is the largest capsule Nasa has ever built, it is still relatively small; just over 5 meters in diameter, meaning that astronauts could not live in it for more that a few weeks at most. NASA is taking this indirect approach  to best make use of it's limiting 18 billion dollar budget. Next, the picture lists a "In-space habitat/Mars transport spacecraft". For me this is the most interesting feature of the graphic, because it represents the missing piece in NASA's venture to Mars. Until this transport spacecraft is assembled and testing there is no guarantee that NASA has the capability of getting humans to Mars. This is mainly because Nasa is still considering options when it comes to designing this spacecraft. Bigelow Aerospace is a private company who has designed inflatable habitats for use as a space habitat. These habitats have the benefit of being both expandable and lighter than a conventional habitat module. This module will be launched and docked with the space station January 2016 to test it's capabilities. While it's not certain wether NASA will use the module in it's eventual Mars mission, this suggests that NASA is willing to incorporate modules designed and built by private space companies into it's Mars transit habitat. NASA has awarded four companies; Boeing, Orbital ATK, Lockheed Martin, and Boeing, contracts to develop transit habitats. The rise of the commercial aerospace industry could be the key in breaking the cycle of Mars program's being cancelled. By developing technology through these established companies, NASA does not have to pay out of pocket for all the expenses of the spacecraft development. In my next post I'll write more about the development of transit habitats, and the way that SpaceX hopes to take a much different approach to space transit by making their architecture fully reusable.


References:
Gebhardt, Chris. "NASA Reviews Progress of Habitat Development for Deep-space Exploration." NASA Reviews Progress of Habitat Development for Deep-space Exploration. Web. 2 Dec. 2015.

Tuesday, December 1, 2015

Developing a 21st Century Spacecraft


A mission to Mars is currently virtually impossible because there isn't an existing spacecraft capable of getting humans there. Over the last few decades, NASA has successfully landed rovers and probes to the surface of Mars, but sending humans to another planet is an entirely different challenge. Unlike robots, humans have biological needs. In order to stay healthy for a months long trip in space, they need enough air to breath, water to drink, food to eat, and room to freely move around in. In addition, astronauts need protection from the harsh environment of space, which is constantly bombarded by radiation and temperatures that can kill astronauts almost instantly. All these requirements mean that the first Mars spaceship will have to be larger and heavier than any spacecraft built before. A large spacecraft requires a huge rocket to get it to Earth orbit and beyond. Huge rockets cost huge amounts of money and years to build, making a deep manned space mission difficult to accomplish in any short period of time. The way the first Mars missions are designed is incredibly important because it will ultimately determine the likelihood of humanity establishing a permanent foothold on Mars, because the sustainability of the program will ultimately influence the way spacecraft are built in the future. The Apollo missions were huge accomplishments, but were ultimately unsustainable due to their cost, and as a result, astronauts haven't visited the moon in over 40 years. A Mars mission should be about designing a dependable deep space craft that will revolutionize space travel technology and begin an new era of manned space exploration.

After the Apollo program reached the Moon within a decade of it's inception, it seemed inevitable that humans would be exploring the surface of Mars before the end of the 20th century. As the Cold War space rivalry between the US and the Soviet union dissipated, it became clear that there was not enough political pressure to mount a manned Mars mission. NASA's funding shrank to a small fraction of the size that it was during the Apollo era and the maintenance and construction of the International Space Station (ISS) became the primary function of NASA's manned space program. A human Mars mission was no longer an inevitability, only a long-term goal. The Space Shuttle long outlasted its intended 15 year lifetime, flying 135 missions over forty years, allowing astronauts to visit the ISS regularly (Duggins 32). The Space Shuttle was never designed to leave the orbit of Earth because it was not designed to undertake a journey to Mars, let alone land and return astronauts from its surface. In 2011, the retirement of the Space Shuttle has finally freed up the NASA budget to focus on Mars. With the loss of the shuttle, the Unites States lost it's ability to send astronauts to the ISS, and now depends on Russia to use the Soyuz rocket for manned missions. This is an awkward arrangement because it gives Russia control over the cost and maintenance of the manned space program and if there to be an international disagreement with the Russians they would have the power to suspend flights to the ISS. In order to restore manned spaceflight to the ISS, NASA turned to the private sector, offering contracts to companies if they could design and launch their own human-rated spacecraft. As of 2015, SpaceX and Boeing are the two companies who have won these contracts by designing human-rated capsules. Each capsule is capable of transporting 7 astronauts to the ISS. By allocating the development of these spacecraft to private companies, NASA has been able to dedicate the majority of Mars funds towards the SLS. In order to get to Mars, with current technology, you need a huge rocket.
“What NASA will do or has done historically for, say, a new vehicle design is they’ll come up with the overall design and then they will have various government contractors build the elements of that design, usually Boeing or Lockheed Martin or that kind of thing. And then those government contractors will subcontract to smaller companies, and those smaller companies will subcontract to still smaller companies. And so by the time you actually get to somebody who’s doing something useful, like actually cutting metal, you have profit and overhead to the fourth or fifth power. And it’s really, really expensive, and it’s kind of inefficient.” - Elon Musk

NASA's proposed SLS rocket expected to launch in 2018 (Source: Jason Rhian)

Many who follow space exploration, view the NASA's planned launch date of the mid to late 2030's for a manned Mars mission as too little, too late. By designing SLS to be a "flexible" program, the government has essentially made it easy for the SLS program to be cancelled altogether or repurposed, and never used for a Mars mission. While the SLS program has support from congress, it is likely that NASA could be cut even further in an effort to reduce government spending. It has happened twice before, NASA first planned a manned mars mission in the 80's called the Ares program, but this was cut. In the 2000's the Constellation program was planned. It would be a massive deep-space exploration program that would start a Moon base and eventually take men to Mars. This program was also cut due to a lack of funding and concerns over the long-term viability of the program. Due to the unreliable nature of funding for NASA's programs, some argue that NASA should abandon SLS before it is too late and hand over the development of a heavy-lift launcher to private company's like United Launch Alliance and SpaceX. (Wilson)

References:
  • The Rise and Fall of the Space Shuttle, Book Review: Final Countdown: NASA and the End of the Space Shuttle Program by Pat Duggins, American Scientist, 2008, Vol. 96, No. 5
  • "NASA commits to $7 billion mega rocket, 2018 debut"CBS News. August 27, 2014
  • Wilson, Peter. "Kill the Space Launch System to Save Human Spaceflight." RAND.org. Web. 1 Dec. 2015.

Thursday, November 19, 2015

A New World Next Door


"We're the kind of species that needs a frontier — for fundamental biological reasons. Every time humanity stretches itself and turns a new corner, it receives a jolt of productive vitality that can carry it for centuries. There is a new world next door. And we know how to get there."   - Carl Sagan 

The idea that one day astronauts might step into a tiny tin can and soar into the untouched vastness of space once again, inspires me in a way that no other idea can. It makes me think about what it means to be human, and question what our true limitations as a species are. There is a transcendent quality about the challenge of reaching Mars, a quality that borders on the realm of myth and legend. And yet, Mars still floats untouched, a crimson beacon in the sky, beckoning for us to reach higher if we dare. 

Ever since the Apollo program's Moon landings set a stirring precedent for the possibilities of human spaceflight decades ago, a manned mission to Mars has remained only a dream. Over the years, in the hopes of reaching Mars once and for all, NASA has drawn up several ambitious mission proposals to get us there, but budget shortfalls and a lack of political will, have doomed them all to be cancelled. As of 2015, NASA's plan is to continue to building a powerful rocket capable of bringing a spacecraft to Mars, named the Space Launch System (SLS). Unfortunately, due to the unpredictable nature of American politics and the constraints of NASA's budget, there is no guarantee that the SLS program won't be cut before it launches humans for the first time 2021. In an attempt to free up more money, NASA has depended on the Russian Soyuz rocket for transport of astronauts to the International Space Station (ISS), and is now awarding contracts to private aerospace companies like Boeing and SpaceX to develop an American spacecraft capable of reaching the ISS. Frustration with NASA's Mars program, has led private companies like SpaceX, to announce their own ambitions of exploring Mars. In this blog, I'll be discussing how a Mars mission can be planned and the technological and political challenges that must be overcome before astronauts can ever plant their boots on Martian soil.