Insider Exclusive: Precourt talks boosters, bovines and brilliance
PROMONTORY, Utah — Charlie Precourt has piercing, steely-blue eyes that help cement one’s mental image of a retired U.S. Air Force Colonel and a four-time space shuttle astronaut. Precourt now works for Dulles, Virginia-based Orbital ATK to develop the massive five-segment solid rocket boosters that will be used on the new Space Launch System (SLS). SpaceFlight Insider spoke with Precourt in an exclusive interview about the June 28, 2016, Qualification Motor 2 (QM-2) test fire.
From the outset, Precourt’s calm, reserved demeanor and ready sense of humor were self-evident as he relayed how NASA and Orbital ATK were busy ensuring that the evolved SRB was being prepared to send crews of astronauts to destinations deep in space such as the Moon or Mars.
On June 24, SFI toured T-97 on an exclusive tour guided by Precourt. He detailed how the team at Orbital ATK had worked for more than a month to get the 177-foot (54-meter) long QM-2 solid rocket motor to approximately 40 degrees Fahrenheit (4.4 degrees Celsius).
“You don’t just chill it overnight and expect a million pounds of propellant that otherwise is at 60 degrees to come all the way to 40,” Precourt said.
To be able to set foot inside the T-97 test stand, one has to wear a special blue overcoat and steel-toed shoes. Donning this prerequisite apparel, we first watched as engineers put their skills to the test through a practice test firing. At the end of the dry run, the CO2 quench arm exhaled a plume of carbon dioxide.
According to Precourt, the team working out at Promontory had conducted the test numerous times so as to ensure a successful outcome on the day of the actual test.
“It’s just a matter of everyone getting comfortable and running through this and trying to find things before the actual test that need to be tweaked,” Precourt said.
It’s all fun and games until a cow comes rolling down the hill…
As was the case on test day, not everything follows the script that engineers have laid out. While a glitch with the sequencer computer that helps to orchestrate the chain of events that lead to the solid rocket booster being ignited saw the test pushed back an hour, another, more unusual, event had the team testing the booster scratching their heads as to what to do next.
As is the case with many launches and test sites in the far-flung locales where these events take place, problems one wouldn’t expect—in terms of space exploration—happen.
During one of the prior SRB tests, a cow had wandered up onto a rocky outcrop just above the test stand. Officials with the company were left scratching their heads as to how to get the free-range beef out of a situation that would have likely meant its death. The situation resolved itself when the cow slipped and went tumbling down the hill. Worried that the creature had hurt itself soon faded as the cow got up after its fall and wandered off—leaving the site cleared for the test.
“It’s like looking into a blowtorch”
Trying to explain to someone what one of these tests is like is often times difficult. The sheer fury that is unleashed is hard to relay via words. One of the most often-used phrases is that looking at the flame hurled out the back of these boosters is like staring into a blowtorch. This analogy is fairly accurate, however, it fails to encapsulate the sensory overload, the punch of the shock wave, or the staccato roar of the engine as it burns through its propellant.
While it might be difficult to relay what watching a rocket test or launch might be like, relaying the importance of this test is not. Simply put, NASA has been carving endless circles in the black sky above our home world for more than four decades. The agency is working toward a two-pronged initiative to cede control of sending crew and cargo to the sole low-Earth orbit destination—the International Space Station—to commercial companies, as it proceeds on the second half of this plan, returning to the business of human exploration of the Solar System.
If everything continues to go as advertised, the first flight of the new super-heavy-lift SLS rocket the space agency plans to use to send astronauts to the distant points of light in the night sky will conduct its first flight in 2018. That flight, Exploration Mission 1, will be the maiden flight of the massive rocket and will employ two of the SRBs that were tested last Tuesday.
Video courtesy of SpaceFlight Insider
Jason Rhian spent several years honing his skills with internships at NASA, the National Space Society and other organizations. He has provided content for outlets such as: Aviation Week & Space Technology, Space.com, The Mars Society and Universe Today.
Jason, How come Morton Thiokol/ATK/NASA have never fired/tested the SRBs in the vertical?
Reason for this question is the dynamics are very different when attached to the old Shuttle and now the new SLS; than when strapped down in the Horizontal. We all know the gas flow within the motor housing twists the whole assembly around the section joints- where the original leakage problems occurred and caused various burn-through of the casing joints on numerous assemblies over the years.
Hope the joint problems are really overcome?
Back in the eighties my company I worked for provided all the case prep adhesive and insulation joint filler interface adhesive vacuum mixing systems for Bldg. 52 and I live in NH.
When I raised the question; I was informed was too costly and no facility existed to accommodate the booster in the vertical- even Stennis’s test stands?
I don’t know of a company that tests SRBs of this or similar sizes in the vertical. Given your experience, perhaps you know of one who does?
Most of the points you mention, to my knowledge, were addressed almost 30 years ago and given that NASA flew 110 shuttle missions after STS-51L suggests NASA and Orbital ATK have a handle on any joint issues.
During the post QM-2 press conference NASA and Orbital ATK noted that while the SRBs might look the same from the exterior – they are completely different from those used during the shuttle era (in fact, even the boosters used in the waning years of the Shuttle Program were very different than their predecessors). Much of the heaters, seals, liners, avionics, the nozzle and other components are new designs.
Stennis tests liquid rocket engines – a completely different animal and not comparable to the solid-fueled SRBs. Who did you raise the question to?
Sincerely, Jason Rhian – Editor, SpaceFlight Insider
July 6, 2016
Fearing my answer might have been too general, I wanted to share the following reply from Orbital ATK with you:
“Test firing a 154 foot long, 12 foot diameter rocket booster in the vertical position would provide significant technical challenges for both assembly and data gathering. However, test firing the booster in the horizontal position does achieve motor qualification objectives. The horizontal motor firing allows accurate measurement of motor thrust in six degrees of freedom. Motor deflection is managed in the horizontal test stand with a mid-span support to achieve a flight like motor lateral deflection. Each hardware qualification test, from qualification of an avionics box to qualification of the assembled booster provides critical information to support the SLS vehicle EM-1 test flight, where additional system level data will be gathered to support future missions. The horizontal test position has been used successfully for many years for modeling and validating booster performance of many types of rocket motors, and was the optimum choice for the SLS booster as well.” – Jeremy Redden / Orbital ATK
Sincerely and with kind regards, Jason Rhian – Editor, SpaceFlight Insider