Past Entries
Part 1: (The Basics of) Rocketry and Spaceflight
Part 2: Disasters and Anomalies
Part 3: Reusability and SpaceX
Introduction
In the aftermath of the Soviet launch of Sputnik, the National Aeronautics and Space Administration was formed in 1958 to help the US compete in the Space Race. Within just 11 years, NASA created all of the technologies they needed to accomplish their crowning achievement: the Moon landing. To this day, this is considered the crown jewel of the American space program.
For those who expected that this would soon be followed by bigger, better achievements, they would soon be in for a rude awakening. The influx of cash that allowed NASA to land a man on the Moon quickly dried up, in favor of a political leadership far less invested in such massive, expensive undertakings.
It is, of course, important to note that NASA isn't all about launching rockets. Much of its work is far less visible - aeronautics research, propulsion systems for jets, Earth science, various science projects in space, and so on. The scope of that research is vast and not to be dismissed. But ultimately, what has always inspired people about NASA is indeed those crowning achievements - such as launching the Apollo 11 lunar landing mission on top of the massive Saturn V rocket. And that is, of course, what we will be focusing on today.
Of course, we know the story since then. NASA began the Space Shuttle program, which promised cheap access to space with reusable rockets and delivered nothing of the sort. That program ran from 1981 to 2011 - far longer than it should have given its significant bloat - and was used to service the International Space Station and to conduct various science missions. At the turn of the millennium, in 2005, the Constellation program was proposed - a three-step plan of building a rocket to get into low-Earth orbit, to the Moon, and finally to Mars. In early 2010, after concluding that the program would be far too expensive and would not deliver anywhere near on time, it was unceremoniously - and rather controversially - cancelled by President Obama, leaving NASA with something of a loss as to its direction for the future.
So what followed? A right mess. While NASA does still have two key vehicles in development - the Orion capsule for deep space travel, and the Space Launch System (SLS) as a massive rocket to lift people that far - it wouldn't be unjustified to note that neither of these programs is particularly well-liked by the public. The craft are fine, but the lack of direction within NASA is rightfully seen as troubling.
So where does NASA stand right now? In addition to its science work, which will mostly be set aside for the sake of this post, the main projects of NASA could be divided into three major areas: the ISS, the SLS, and Orion. We will discuss those three here.
International Space Station
Billed as an orbiting science laboratory, the ISS is a cooperative venture between the US, Russia, and other partners, which is used for a wide range of scientific work in low-Earth orbit. NASA is one of the most important stewards of this station.
A many-billion-dollar space project (costing at least $100 billion to build and operate), the station takes a lot of work to keep running. The station has a crew of six, which has to be supplied well for their life on the station, and repairs frequently have to be made to a rather hefty piece of engineering (the station itself). Russia and the US shoulder much of the responsibility for keeping the station alive - each sending both people and supplies up - and NASA of course holds the responsibility from the US side of taking care of these matters.
In the aftermath of the end of the Shuttle program, though, there was a hitch: the Shuttle was NASA's main transport to the station and now they were out of a means by which to launch to the station. On the cargo end, they managed to work out a decent solution - the Commercial Resupply Services contract, awarded to SpaceX and Orbital Sciences (later Orbital ATK), to launch unmanned missions to deliver supplies to the station. Though neither is at the pinnacle of reliability, they are both quite cheap by rocket launch standards, so this actually worked out fairly well. The real snag, however, came with the loss of ability to launch manned missions.
As of now, there is only one rocket in the world that can regularly launch manned missions to the ISS: the Russian Soyuz-FG. Since the end of the Shuttle program, NASA has bought seats from Russia to send astronauts to the ISS, at a price that has steadily risen from $50 million a seat to $80 million over the years. Though even at this monopolistic price, it isn't that expensive, from a political standpoint it is a national embarrassment that the US has to pay Russia to launch astronauts because it can no longer do so itself. NASA's current plan to end reliance on Russia is the Commercial Crew program - for which two American companies (SpaceX and Boeing) are developing manned launch capabilities. These are both scheduled to be finished by 2018 - although given their somewhat sluggish progress towards completion and the consistent slip in schedule (it was originally expected to be done by 2014), it's very likely that 2019 or later is a better bet.
In recent times, Russia has shown an interest in ending the station (for reasons I will cover in a different entry) - and after negotiations, has agreed to keep it running until only 2024. Although it might be possible to extend its life a few years past that, in all likelihood the station's years in orbit are not many. Despite the insistence of other partners to the contrary, it would be very difficult to imagine a successful ISS if Russia were to pull out of the project - and within about a decade that will happen. And when it does, it will be yet another conundrum for NASA and its commercial infrastructure. Will the Commercial Crew/Resupply services be needed without the ISS? Will there be a new space station? Would it be worth trying to keep the project running as Russia pulls out? Unfortunately, at the moment we have only difficult questions, not so much in the way of answers.
Space Launch System and Orion
The SLS and Orion make up the infrastructure of NASA's future manned space plans - whatever those will be. In truth, that's one of the major problems with NASA as of now: they are making a super-heavy lift rocket (the SLS) in the same weight class as the Moon-landing Saturn V, and a capsule capable of withstanding long space journeys (Orion), but it's not clear that they even have a plan as to what to do with them. Go back to the Moon? Build a Moon base? Land on an asteroid? Go to Mars? All of this depends on what the political sphere says, and it's not clear that the politicians know what they are seeking to invest into.
The Space Launch System, or SLS, is a rocket that is meant to provide the kind of lift capability that is needed to launch to those far-reaching targets beyond low-Earth orbit. It is based on the Space Shuttle, abandoning the ideas of using an Orbiter and of reusability, but otherwise keeping much of the same technology.
If you are familiar with the Shuttle - which, if you read my previous entries, by this point you should be - it is clear that this vehicle basically turned the external tank into a rocket in its own right, tossed the Orbiter aside, and left the solid rocket boosters as-is. The desire was to reduce the development work by recycling an old design and old technologies - an understandable, if controversial, choice.
The cynic's view on this design is that it is a pork project, meant to give business to all the Shuttle companies that were to be out of a job with the retirement of the Shuttle. It's very hard to deny that that was an important factor - some of the design choices in the Shuttle were questionable, and the cost of the Shuttle program was very questionable - but the cynicism is not fully warranted. Although the rocket was partially designed by politics, and will definitely be more expensive than it needed to be, the Shuttle technologies are well-understood, reliable, and easy to retool for this purpose.
While it would still probably make more sense to design an all-new system that is created by engineers rather than politicians with pet interests, this was the rocket that could be built, it does have the capabilities that are necessary for manned missions far beyond Earth, and it has the political support to receive stable funding. And yet, it is understandable why people are less-than-enamored with this project, one that they see as pork without a purpose. It is no surprise that the message of SpaceX, among others - that NASA is wasting a lot of money, and that private enterprises should take up more responsibilities in space exploration - resonates with many.
My opinion on the SLS is as follows. It's definitely not the rocket that I, as an engineer, would have designed. If building a rocket from the ground up, many of the design choices were the wrong ones. But we always have to deal with those kinds of substandard choices, and we cannot always rebuild everything from the ground up, because we live in a world of budgets, politics, and deadlines. The Space Shuttle was not a perfect program, but its technologies are still intact, and it's not a bad idea to leverage that for reasons of politics and expediency. It is no surprise that none of this is popular - the Apollo program was not particularly popular in its own time - because such massive endeavors only become popular once people start to forget how much we had to spend to get there. I strongly believe that the SLS is no exception.
The other part of NASA's grand project is the Orion, the last surviving relic of Constellation, a spacecraft for carrying up to four people into space, to low-Earth orbit and well beyond.
I must admit that I am no expert in the field of manned spaceflight, simply because I haven't worked much with that and there is a lot more to the topic than most would realize. It is, however, no surprise that this craft is one of the most expensive pieces of equipment that NASA is working on. While cargo is perfectly content to sit inside a capsule, restrained and bundled tight, humans are far more fussy about that, requiring everything from food, oxygen, and water to, for longer missions, comforts beyond those of sitting in a tiny, cramped space for months. Humans die much more easily than satellites break, and they cannot live very long when stuffed into a tiny box - insanity will quickly set in.
For low-Earth missions to the ISS, this is difficult enough to manage - you have to keep people alive for a period of time that ranges from a couple of hours to a few days. A well-disciplined person with air and water could easily bear a few hours inside a cramped box, but all bets are off with anything much longer than that. Comforts such as free movement, hygiene, and exercise become a necessity - and each aspect of that takes a fair bit of work to arrange.
If you want some background as to the complexities that go into that job, this paper is a good place to start, as it covers many important aspects of that journey. One that is of particular interest to me, that I will briefly cover, is the service module of the craft.
This module is quite a large part of the craft - and among other things, functions as the propulsion and the life support of the craft. It generates oxygen and water from the fuel (incidentally, a very big advantage of hydrogen for manned deep space missions is that hydrogen + oxygen = water) and powers any number of other systems necessary to ensure that the crew survives and the craft can get where it needs to go. It goes without saying that the more complex the mission, the more advanced the module will have to be. Concerns such as this make Orion as expensive as it is.
Conclusion
The ISS is the bread and butter of NASA's current space operations, and its days are numbered. Its rocket for its deeper space missions, the Space Launch System, is largely perceived to be little more than a pork project. Naturally, being tied to an unpopular project makes Orion about as popular as SLS - that is, not at all. And yet, there is one thing about it that should be appreciated: it does provide a genuine path forward from which these ambitious missions could be achieved.
Let's just hope NASA figures out one of these days what that mission will be. We have the tools - now we just need to figure out what we intend to do with them.