The Ares rockets and Orion crew module are supposed to eventually replace the Space Shuttle in NASA’s inventory of craft to ferry astronauts to and from space. The Ares has been the target of quite a lot of criticism, too. There are calls for the project to be scrapped. However, most of those calling for scrapping the Ares project are outside of the space community, and almost all are outside of the field of aviation and rocketry. The most common complaint is, “Why can’t we just use one of the other big rockets that already exist?” Well, the reason is that those rockets are not designed for manned missions. In order to carry humans, rockets and aircraft have to go through a rigorous test procedure, and each and every part has to be separately certified as compliant with those tests. Going back and doing that for an existing rocket would be at least as expensive as building a new one from already certified parts. That is what the Ares is: a rocket built mostly from already certified parts. So, I am not convinced that it would really save money to scrap Ares, and it might even cost more money and more time in the end. Already, we are facing a period of time in which NASA will have no vehicle capable of getting astronauts to and from space. We’ll have to either purchase flights from other nations (Russia) or hope that private companies come up with a space taxi of some sort to get to and from the space station. That is why Ares is important. I only wish that the Constellation Program (the overall program that includes Ares, Orion, the Altair lunar lander, and more) had more money and resources to develop the program faster.
Two Ares rockets are planned. The smaller rocket (and even it is huge!) is the Ares I. The Ares V rocket will be taller, but also much wider. If built, it will be the largest operational rocket ever constructed. The Ares I will stand over 300 feet high. The Ares 1-X currently sitting at Launch Pad 39B at the Kennedy Space Center is 327 feet high. That makes it the tallest rocket launched from the Cape since the early 1970s, when the last Saturn V rocket launched. Incidentally, the last Saturn V rocket was launched in May 1973 from Launch Pad 39A. Over a week later, a Saturn I-B rocket lifted off from Launch Pad 39B with a crew of three astronauts to man the space station. I think that may have been the last time that two different rockets sat at the launch pads at Launch Complex 39 (Kennedy Space Center). Now, over 36 years later, two different rockets are sitting at launch pads at Launch Complex 39 once again: Ares I-X at Launch Pad 39B and the Space Shuttle Atlantis on Launch Pad 39A for the STS-129 mission. The following photograph catches this historic moment. Click on the photo to get a larger version.
The Ares I-X is the first test flight of the Ares configuration. The first stage of the Ares uses the same type of solid rocket motors that the Space Shuttle uses for its Solid Rocket Boosters. The Space Shuttle uses a stack of 4 solid rocket segments. The Ares uses a stack of 5 solid rocket segments. The second stage uses a J-2X engine, derived from the famous J-2 engines used on the upper stages of the Saturn V rockets. The body of the upper stage is derived from the Space Shuttle external tank. This is a new stage, and though it is derived from existing technology, there are modifications that need to be make, so it is not simply a matter of sticking an engine onto the end of a shuttle external tank. Atop the second stage would be the completely new components: the Orion Crew Exploration Vehicle and its service module and the new Launch Abort System, designed to pull the crew capsule away from the rocket in the event of a catastrophic failure of the rocket. These upper stages are not yet ready for flight.
So, why is the rocket flying on Tuesday if the upper stages are not ready? This first developmental flight of the Ares stack is primarily a test of the first stage and the design of the stack. Remember, the first stage is derived from the shuttle’s solid rocket boosters. These rockets are strapped onto the side of the shuttle’s external tanks. They were not originally designed to fly alone. So, one of the goals of this rocket flight is to test the solid rocket first stage of the stack. Also, the shuttle’s solid rockets only have a nose cone on them. The first stage of the Ares has another rocket on top of it (the second stage) and even more hardware on top of that! So, there is a very real engineering concern here. There should be no serious problem. The rocket should be easy to control, and the rocket segments should have the strength to hold all of this extra weight. Remember, the shuttle’s rockets have helped lift the much heavier Space Shuttle into orbit, and that was strapped to the side of the rockets (an even tougher problem from the point of view of engineering). Still, the rockets have not flown in this configuration before, and so there is always the potential for unforeseen problems. That is why we need this test.
For the Ares I-X flight, the first stage will be a bit scaled down from the full five segment first stage of later Ares flights. This will be essentially a four stage rocket that is a modified shuttle solid rocket booster with an inert fifth segment. The upper stages will consist of dummy stages (though there will be active guidance and thrusters on the dummy second stage). The rocket will take off, reach an altitude of about 130,000 feet and the second stage will deploy as if on an actual orbital mission. Since the second stage rocket will not fire, the stage will then fall into the Atlantic Ocean. After stage separation, momentum will carry the rocket about another 20,000 feet higher before it falls back to Earth. Parachutes will deploy, and the first stage will splash down into the Atlantic Ocean, where a surface ship will retrieve it. There will be sensors on the rocket recording every facet of the rocket operation. The Ares developmental flights will have far more sensors than will fly on the operational missions. Data collected on the flight (upper stage sensors as well as first stage sensors) will then be studied over the next couple of years. With any new engineering design, even a modification of an existing design, there will almost always be something unexpected to turn up. Having the first operational test so early in the project (the full unmanned test stack won’t likely fly for at least five years) allows engineers to study the data from the launch in order to modify the upper stages as needed before they are finished being built. That is the smart way of doing things: test out each part as it is ready. The next Ares launch, the Ares I-Y, is expected in four years, around November of 2013. The Ares I-Y will test the high altitude emergency Launch Abort System. In the mean time, there will be separate tests of the upper components, just not on an Ares stack. A full blown Ares/Orion launch, called the Orion 1 mission, may launch sometime early 2014. That would be the first test including a fully functioning (but unmanned) Orion capsule atop the stack.
Though there will be only a four segment first stage in the Ares I-X flight, the experience for those of us watching the launch should be the same as for a full five segment first stage. The biggest difference will be in how far and high the vehicle flies. I am hoping that everything goes well. I will be leaving for the Cape in a few hours. The rocket has passed its test review, and everything seems go for launch so far from the engineering aspect. Weather, though, may be a problem. The forecast is for clouds. Since this is a test flight, they must have clear weather to observe all aspects of the mission. However, they only need about 15 minutes of clear weather, so there is a decent change of getting that. Yesterday, the mission team estimated Tuesday’s weather as only 40% go. However, Tuesday is still several days away, and things might look up. As I look at the weather, it looks like it may be a bit better, perhaps 50%, but I am not the one making the call. Still, I’ll be there Tuesday and Wednesday to see the launch.
Images courtesy NASA