Science Fact vs. Science Fiction

by

Many critics have sought to discredit the launch vehicle architecture NASA is building to enable our nation to return to the Moon and eventually journey beyond in our exploration of space. As the prime contractor for Ares 1 first stage, I would like to separate the fiction from the facts, and set the record straight on some outright false information reported on this program.

The Ares design has focused foremost on delivering breakthrough advances in reliability and crew safety, with the achievable goal of more than 10 times the safety levels of the space shuttle. The fiction reported in many press articles only serves to detract from this all-important objective, and does a disservice to the great men and women at NASA who are delivering on the safety requirement for our new vehicle put forth by the Columbia Accident Investigation Board.

Fiction: Ares 1 first stage is behind schedule and overrunning the budget.

Fact: Ares 1 first stage is tracking right on schedule. We have successfully completed numerous tests of all first stage subsystems, on the first attempt with every test. The first full-scale Ares 1 rocket will be ground tested this month. The Ares 1-X prototype flight test follows in October. The Ares first stage program has executed within the program budget for the past four years.

Fiction: It has been reported that vibrations from Ares 1 first stage will harm the crew.

Fact: Thrust oscillation (vibration) is common to all launch vehicles, solid- and liquid-propelled. For Ares 1, we have no fewer than four engineered solutions to eliminate these effects. It is possible no modifications will be required once the Ares/Orion design is finalized, since the “stiffness” of the final vehicle structures is what will determine the need. This will be a non-issue for Ares just like we made it a non-issue for Apollo and space shuttle. Here’s why: During Apollo’s second test flight, its liquid-engine oscillations nearly caused vehicle failure. Subsequently, a dampening system was installed that solved the problem. The engineering knowledge gained in the 1960s gives us decades of understanding what to do today. In the shuttle era, what we learned about the solid booster tells us Ares might experience some vibration in the last 10 seconds of first stage burn. The planned Ares 1-X and Ares 1-Y tests will tell us which of our four engineering solutions, if any, are needed to ensure the crew doesn’t have trouble reading the flight displays in those last 10 seconds.

NASA developed a simulator for the astronauts to evaluate potential vibration effects. I had the opportunity to fly this simulator. The experience was highly reminiscent of my four launches; it felt like first stage in the shuttle. The simulator further showed how Ares might differ in those last 10 seconds, but frankly, even though the difference was noticeable, it was quite manageable. Some press accounts describing it as “harmful” are a real overstatement. In the end thrust oscillation will be solved for Ares 1, and the crew is likely to experience a smoother ride than they ever have before.

Fiction: The crew of Ares 1 will not survive an explosion of the Ares 1 rocket within the first minute of launch.

Fact: This is incorrect; the Ares design supports safe aborts. The Air Force 45th Space Wing at Patrick Air Force Base, responsible for launch range operations in Florida, has approved Ares 1 for launch on the Eastern Range — a major milestone for the program. In the meantime NASA, its contractors and the Air Force are optimizing Ares and Orion launch procedures to maximize flight safety. Through this process, the 45th Space Wing issued a preliminary report questioning Orion abort survivability based on a 1998 unmanned Titan 4 launch failure. Ground controllers had to send a destruct signal to stop the vehicle from flying off range.

But the Titan 4 differs significantly from Ares 1. Unlike the single-rocket-motor Ares 1, Titan 4 had two solid-rocket motors strapped onto the side of a large liquid-fuel tank. The debris from Titan was therefore significantly greater than is physically possible for Ares 1. The study also erroneously assumed the Orion parachutes open three seconds after abort, when in fact the Orion abort motor is still thrusting the crew to safety for five seconds. Orion parachute deployment actually occurs 20 to 35 seconds after flight termination, when the crew will be much further away from any abort debris. So, although the Titan failure is instructive, we have already performed much analysis on the real Ares 1 that demonstrates a very high probability of success for crew survival during first-stage abort scenarios.

In summary, many misconceptions have been reported regarding the Ares 1 first stage. The real facts are the program is on schedule and budget, meeting all technical requirements, and there are no showstoppers. The in-line configuration and launch abort systems provide the crew the highest safety achievable of any launch vehicle. Ares 1 will provide the nation our safest, most reliable and cost-effective option to leave low Earth orbit on our journey into the next era of space exploration.

 

Charlie Precourt, a retired U.S. Air Force colonel and former astronaut, is vice president and general manager of ATK Space Launch Systems.  Precourt, a veteran shuttle commander, spent  15 years with NASA, during which he served as deputy program manager for the international space station, chief of the Astronaut Corps and director of operations for NASA at the Gagarin Cosmonaut Training Center in Star City, Russia.