Piecing together NASA's Ares I rocket

CNET News' Daniel Terdiman is the first reporter to see the completed solid rocket booster designed for future missions to the moon, and maybe Mars.

Daniel Terdiman Former Senior Writer / News
Daniel Terdiman is a senior writer at CNET News covering Twitter, Net culture, and everything in between.
Daniel Terdiman
6 min read

The rear section of the first-ever completed Ares I solid rocket booster, which will be test-fired on Aug. 25. This signifies a major milestone for NASA's Constellation program, which will replace the Space Shuttle program, and which is intended to send humans back to the moon. Daniel Terdiman/CNET

PROMONTORY, Utah--"This is the world's biggest solid rocket motor."

Those eight words, with which Kevin Rees described the Ares 1 rocket to me on Monday, are at once entirely understated, and hugely consequential. Rees is the director of test services for ATK, the primary rocket contractor on NASA's Constellation program.

Since 1981, the Space Shuttle has been NASA's main program. But now, with just a few more Shuttle launches left, the space agency--and the huge ecosystem of contractors who support it--are seriously turning their attention to Constellation, the next program. Constellation is expected to take Americans back to the moon, and may someday take them to Mars. And like the Apollo and Mercury programs in the 1960s and '70s, Constellation is designed with a crew capsule that will be placed on top of a giant rocket--in this case, the Ares I.

And here before me, in what can be described as essentially a huge shed at ATK's massive complex about two hours north of Salt Lake City, the first of those rockets is resting on its side, awaiting its first moment of glory, a planned August 25 test-firing.

Though the Ares I has been on the drawing board for some time, and many people have seen imagery of it, no reporter has ever seen one fully assembled. As part of my Road Trip 2009 project, I had the honor of being the first, and of sharing the first pictures with you.

Photos: Ares I five-stage solid rocket booster

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The Ares I rocket is a five-segment behemoth, fully 154 feet long. By comparison, the Space Shuttle used two four-segment rockets, each of which was 126 feet long. But lest you think that an entirely new program means entirely new equipment, think again.

I was told throughout my visit to ATK that every effort is being made to reuse components from the Space Shuttle program. And that's why every single 12.2-foot-wide cylinder used to make this first Ares rocket--known as DM 1, or developmental motor 1--has been recycled from previous Shuttle missions. Indeed, the various components that make up DM 1 have been used in 48 different Shuttle launches.

Still, it's not as if the pieces are just picked up out of the ocean and thrown back into the rotation. Rather, they are painstakingly reconditioned and made ready for reuse, as they have been throughout the Shuttle program. That's one way NASA has kept costs down during the program, and how it intends to do so going forward into Constellation.

The reason it's possible for ATK to reuse segments from Shuttle launches in the Ares program is that Ares rockets have a lot in common with those used in the Shuttle program. To be sure, the Shuttle used two boosters, and didn't have a capsule installed on top, while Constellation will comprise a single booster with an Orion crew capsule on top. But the boosters will be very similar, beginning with their exact same width and segment dimensions.

There will be some differences, however.

For example, the insulation on the interior of the cylinders is different on the Ares segments than it was with the Shuttle, and one big reason is an effort to be better stewards of the environment than in the past. For instance, the insulation of the Shuttle segments used asbestos, while the Ares segments have done away with that poisonous material.

'A little bit of melancholy'
But as demonstrated by the fact that the segments in DM 1 have been into space so many times as part of the Shuttle program, there is a heavy emphasis on reuse. Even the ATK professionals couldn't always tell right away whether a segment that was being worked on was for the Shuttle or for Ares.

At one point in my visit, we passed by a spot where sections were being put together to make segments for what, apparently, will be the very last Shuttle mission. While nothing around the work there signaled this momentous detail, it's clear that the folks at ATK are well aware of it.

Ares I rocket
Artist's rendering of the Ares I crew launch vehicle during ascent. NASA/MSFC

"There's a little bit of melancholy" about it, said one of my hosts, Gregg Kotter, program director for the Ares I First Stage Five-step motor program. Still, whatever sadness the people here feel seems more than offset by the excitement at being part of what NASA clearly hopes will be its standard-bearing program for another 30 years or so.

Yet the Shuttle work is still very much in evidence. One stop on my ATK tour was to the propellant mixing facilities where it was explained to me how the crews here make the solid fuel that is used to light the Shuttle--and soon, the Ares--rockets.

We weren't able to go inside the facility to see the systems because it was a Monday, and on Mondays they are mixing propellant. From a safety standpoint, I can see why they don't want visitors in a facility where someone is actively mixing a fuel that can launch a Space Shuttle.

But again, given that ATK here is working simultaneously on both Shuttle and Ares, my hosts had no way to know which program was getting the propellant being worked on while we were there.

And when asked which program the fuel was for, a technician gave about as simple an answer as he could: "Shuttle."

We did get to talk a fair bit about how the propellant mixing is done, and one thing was clear: It takes a whole lot of fuel to get a giant rocket off the ground. Each segment of the rocket requires 40 giant (600-gallon) mixing bowls full of propellant, which is made up of a binding agent polymer; iron oxide, a burn catalyst; aluminum powder, the fuel source; an epoxy bonding and curing agent; and ammonium perchlorate.

When mixed, it becomes a true solid. I'd heard the term "solid fuel" before, but had never really understood what it meant. In fact, it's just what it sounds like: A fuel that, as I saw inside a small device called an igniter--which is placed at the top of the rocket--looks like plastic, and which is very much a solid. In fact, it's brown, flexible and cool to the touch.

Once mixed, the propellant is cured for 44 hours, and then applied to the interior surface of the rocket segments, where it is then cured for another 52 hours.

After the rocket segments are fully assembled and filled with propellant, they are then put through an X-ray and ultrasonic inspection to make sure they don't have any bubbles in them. If they do, Kotter told me, they can either be rejected altogether--which is an extremely unpopular option--or technicians can try to assess the problem and see if it can be fixed. It wasn't clear how often this happens.

Gentlemen, start your engine
For the teams getting ready for the August 25 Ares I test-fire, it has been a long time coming. Some members, Rees said, have been working on this for more than two years.

Once everything is in place, the ignition of the rocket--which will be laid flat on its side and will shoot its massive blasts of fire back into a giant pit of sand and rock--is an extremely fast process. First, a pellet is dropped into the igniter--a small device that is larger than the tactical motor on a lot of rockets, and which has 300 pounds of propellant inside--which will then set off the main rocket bore. From zero to full thrust takes 600 milliseconds.

Assuming the test goes well, it will only be a matter of time before ATK starts shipping rocket segments, one at a time, to NASA's Kennedy Space Center in Florida, where they will eventually be assembled into a rocket that the space agency will launch into space. Those segments will be put on trains that will take ten days or so to cross the country before they reach Kennedy.

And if you were to see one of them on the road, you wouldn't be able to tell if they were for the Shuttle or for Ares. But if you happened to have a chance to ask someone in the know which they were for, there's a good possibility they'd give you a one-word answer: "Shuttle" or "Ares."

For the next several weeks, Geek Gestalt will be on Road Trip 2009. After driving more than 12,000 miles in the Pacific Northwest, the Southwest and the Southeast over the last three years, I'll be writing about and photographing the best in technology, science, military, nature, aviation and more in Idaho, Wyoming, Montana, South Dakota and Colorado. If you have a suggestion for someplace to visit, drop me a line. And in the meantime, join the Road Trip 2009 Facebook page and follow my Twitter feed.