In March of 2012, NASA successfully launched five rockets from its Wallops Flight Facility in Virginia. The launch was part of NASA's Anomalous Transport Rocket Experiment, or ATREX, which will help scientists better understand the jet stream. Jack Vieira, range project manager for the ATREX mission, helped to launch five suborbital rockets more than 60 miles above Earth.
NASA Tech Briefs: Jack, let's set the stage here. Can you take us through what happened on Tuesday, the day that the rockets launched? (March 24th)
Jack Vieira: We had a very dynamic operation that night. We knew that we were going to have some difficulties with winds that evening, so we set up a little bit later than we would typically. We had a launch window from midnight until 5 am, and we knew the winds were going to be strong, but hopefully dissipating somewhat as the evening progressed. In anticipation of that, we opened a window at 0200 local, rather than midnight. We still had very strong winds at that time. We were really concerned if we would be able to get the rockets off that evening. Luckily the wind gods were smiling down on us, and at the very end of the window, we did a Hail Mary pass, and we were able to get the rockets off.
NTB: So the wind didn’t affect the rockets?
Vieira: We had two rockets with attitude control systems, but most of the rockets are point-and-shoot type rockets. We have to do wind wading, where we launch a bunch of balloons: a four-and-a-half hour balloon, that goes up to 100,000-plus feet, and then a mid-altitude balloon up to 50,000 feet.
At one hour and 15 minutes, we start launching balloons every 15 minutes. We’re capturing data as it goes up. We have a column of air from the surface all the way up to 100,000 feet, with the definitions, with the velocities, and directions of the winds. With that, we calculate what the azimuth and elevation settings should be, so that we can anticipate how the winds are going to affect the rockets.
For example, if we had strong winds and we were going to launch 100 degrees azimuth at an 87-degree elevation, our wind corrections would change that. We could change that as much as 30 degrees on azimuth to make the corrections, so that it actually flies to 100 degrees.
NTB: What are the goals of the ATREX mission? What are you trying to discover?
Vieira: The PI, Dr. Miguel Larsen from Clemson University, had made a proposal to NASA headquarters, and got it approved. They noticed that way back in the 1960s, and then more recently with the shuttle missions, that in the higher altitudes, the 60-65 mile altitudes, there were extremely high winds (between 200- and 300-mph winds), and they just didn’t understand the dynamics there. Why was that happening?
Then also, there was the fact that those altitudes, some of the communications with satellites and such, were being distorted some, so they were trying to get a better understanding of what happens at those altitudes that create those kinds of winds.
NTB: Why is it so important to learn about this?
Vieira: They want to know what causes those winds. There are no models that show that those winds should be at those velocities at those altitudes, so they’re trying to understand a little bit more so that they can create a better model, which would also affect weather.
NTB: From a technology perspective, how does it work? How will you get what you need for data?
Vieira: We launched, as you mentioned, five rockets, and two of those rockets were mother/daughter payloads. All five of the rockets had trimethyl aluminum (TMA), which is a chemical that once introduced to air, ignites; it’s a spontaneous ignition. The TMA was ejected out of the payloads, and brought into the atmosphere, and the winds would then carry that iridescent cloud that was formed. They had 3 different camera sites — one of them in New Jersey, one here at Wallops, and one in North Carolina. With those three locations, they were able to observe the TMA clouds and watch how the winds pushed it away. What they were actually doing was coloring the winds, so they could see what the winds were actually doing. The daughter portion of the two mother/daughters had some instruments, so they were measuring pressures, and densities, and temperatures.
NTB: What kinds of tools measured and analyzed the wind? You mentioned the mother portion.
Vieira: They had some cold cathodes that they were actually using for measuring all of the data at those altitudes.
NTB: Can you take us through the five rockets and their functions?
Vieira: All five rockets were two-stage vehicles. We had one Terrier Oriole, two Terrier Malamutes, and two Terrier Orions. All of the rocket motors, with the exception of Oriole, are DoD rocket motors that have expired in their time with the military. It gives us a cheap method to get into space with those rocket motors from DoD. The Oriole motor is a commercially bought rocket motor. The highest rocket went to an altitude of 403 kilometers.
NTB: How do the rockets needed for ATREX compare with other rockets? How are these built differently? What are the different functions?
Vieira: These rockets were specifically built for the chemical releases. We’ve launched rockets with TMA in the past at different locations from here at Wallops to Poker Flat, Alaska, where we do a lot of our rocket launches, and also the White Sands Missile Range down in New Mexico. They’re not really that different than the other rockets. We launched mother/daughter scenarios in the past, but they’re not as typical as your single-payload types. They’re basic for us.
NTB: On the day of the launch you could actually see the clouds created by TMA, right?
Vieira: Absolutely. Within a 250-mile radius of Wallops, you could see those clouds. We were getting beautiful pictures from New Jersey. When we actually launched, a host of aircraft airliners reported in, saying how beautiful the skies were looking.
NTB: So the defining characteristic of trimethyl aluminum is that it’s able to color the wind?
Vieira: Correct. It instantaneously combusts with the introduction of oxygen, so it burns and the residue from that burn is an iridescent cloud.
NTB: What is the timeline for this project? How long will this take? When do we get the data?
Vieira: We launched it on the 27th, and I was talking with the PI yesterday, and the data has already been collected. They’re doing the analysis now, so I would say within a couple of months they would have their findings. I was given this project about seven months ago, and we were doing all the payload buildup, the testing, and getting the range in a state of readiness for this mission. It was a fairly quick mission, which is the kind I like the most.
NTB: What were your biggest technical challenges in getting these rockets off the ground?
Vieira: There are different aspects of challenges. One of them was building the payloads. This mission was Ok’d by NASA headquarters, and we immediately went into fabrication. So we built these from nothing. Just the fabrication was quite a challenge. After fabrication, we had to put them through tests and evaluations. Obviously this isn’t the only mission that we’re doing. There are a lot of missions going on through the pipeline, and we were very, very concerned about being able to do this one without affecting the other missions as well. There was a lot of work getting those built and fabricated.
From a range perspective, one of the biggest concerns I had was we had seven telemetry downlinks, and that was going to be challenging to the range. I was very happy to see that it went off like clockwork with those guys. They were able to receive all the telemetry links, and there were no hitches at all. It was perfect.
NTB: What was your specific work with the mission, as range project manager?
Vieira: It’s kind of hard to describe what a project manager is, but I guess the best analogy for me is that I’m the orchestra leader. The band is the one that actually creates the beautiful music. I’m just lucky enough to be the one leading that effort. We had a great team.
Basically, we have a mission initiation conference, or MIC, where the project investigator would come in and say “Hey, this is what I want to do, and these are the requirements that I believe we have to have.” Then we come back with a design review, which we then present back to the PI saying “Hey, we heard what you want, and this is how we plan to incorporate your requirements. Is this correct? Did we capture it properly?” And once that’s been ironed out, there are several reviews that have to go on: mission readiness reviews, range readiness reviews, and then all of the documentation. Nothing gets done without paperwork. I have a project plan that needs to be written, and then [a meeting with] the missions operations director, and then the countdown. With 6 and 7 months to do all this, it was pretty heavy-duty.
NTB: How big of a team was working on this? And how were the work and the responsibilities divided up?
Vieira: From the range, which is what I represent, my primary point of contact with the instrumentation folks is a range support manager. And then underneath that person are a radar lead, a telemetry lead, a communications lead, and a photo lead. It flows down like that, and then it comes back up through the same chain.
NTB: How would you define a successful mission?
Vieira: A successful mission is one, first and foremost, that doesn’t hurt anybody. Thankfully, in my career, we’ve never hurt anybody, and hopefully we’ll maintain that 100-percent success rate. Secondly, of course, we have to make sure that the PI is happy when he leaves, that he receives all of the data that he was expecting, that we captured all the telemetry, that we tracked it with radars properly, so that he knows exactly where the TMA releases were ejected.
NTB: What is your favorite part of the job?
Vieira: By far: sitting in the control center, watching things unfold, hopefully the way that you expected it to. This countdown was over 400 items long, which is a pretty lengthy countdown. The best part of it is to see it take off as you’d expect, and have all the players ready to make the calls for each of the steps —just sitting back and looking at it and being proud of the team.
NTB: What are some of the specific points in this 400-item-long countdown?
Vieira: Right at the very beginning, you have to arm the rockets. Then you have to remove the shelters. We built Styrofoam boxes around each of the vehicles, and we were pumping in heated air, conditioned air, because the payloads, at launch time, couldn’t be less than 60 °F.
That’s one of the things that we were so very concerned with on launch day, was removing the shelters. We removed the shelters late in the countdown, because we were so concerned that the winds could tear those Styrofoam boxes apart. Of course, that’s not what we wanted to do. We wanted to launch the vehicles through the boxes. You had the removal of the launchers, elevating them, and doing a vertical check, and making sure the systems are working properly. Then it was getting the wind waders to give us the data so that we could point the rockets into the right direction.
A challenge always here is making sure that we have a safe hazard area, so that there are no boats in the area. We live right on the coast here. Our neighbors are fishermen. We’re very lucky to have a good working relationship with our neighbors, and they understand that when we’re trying to launch a rocket, they try to stay out of our way. We had to make sure that [hazard areas were clear].
Another big aspect of it was the FAA, because we were launching five rockets, and were launching from close in shore for impacts all the way out to 550 kilometers. We were taking up almost all of the airspace, so we were affecting international traffic and they didn’t really appreciate that too much. They were asking us to not launch before midnight, so of course that’s what we did. We didn’t open a window until after midnight, so then we weren’t affecting nearly as many aircraft as we would typically from 10 pm to midnight, which is a high-volume time for international traffic.