Falcon’s flames: SpaceX launches CRS-11 Dragon
KENNEDY SPACE CENTER, Fla. — SpaceX has successfully launched its 11th Dragon (CRS-11) toward the International Space Station (ISS) in support of NASA’s Commercial Resupply Service (CRS) program. The company’s “Full Thrust” Falcon 9 rocket launched the first refurbished Dragon capsule carrying crew supplies and experiments to be used on the orbiting lab.
Liftoff took place at 5:07 p.m. EDT (21:07 GMT) on June 3, 2017, from historic Launch Complex 39A – the same pad that most of NASA’s Space Shuttles, as well as nearly every Saturn V rockets, launched from. In fact, CRS-11 Dragon was the 100th flight to take to the skies from this location.
Colonel Walt Jackim, of the 45th Space Wing at Patrick Air Force Base, Fla., said: “We truly have a tremendous team on the Space Coast and it’s my honor to be a part of this mission delivering supplies, science experiments and equipment to the International Space Station crew and my friend and Air Force classmate, astronaut Col. Jack Fisher.
“Today’s mission is just another example of our unwavering focus on mission success and guaranteeing assured access to space while showcasing why the 45th Space Wing is the Premier Gateway to Space.”
This was the second attempt to get the Falcon 9 off the ground. The previous attempt, on June 1, was called off about 25 minutes before the planned liftoff due to lightning being reported within 10 miles of the pad, less than 30 minutes before launch. Throughout that countdown, rain and clouds continued to propagate around the area.
A new step in reusability
SpaceX is continuing to hone its proficiency in launching Falcon 9 rockets. The California-based company launched another Falcon 9 just over two weeks ago, and another just two weeks before that. The firm hopes to continue this launch cadence through the end of the year with as many as 12 more rockets from various launch pads expected to take to the skies.
For the June 3 countdown, the 45th Weather Squadron predicted only a 60 percent chance of favorable conditions at launch. The primary concerns were the anvil and cumulus clouds, as well as the potential for flight through precipitation. However, by the time the Falcon 9 entered its terminal countdown, the weather had improved.
Just a few seconds before liftoff, there was a crackling roar indicating that the nine first-stage Merlin 1D engines had ignited. Once the countdown reached zero, the engines were at full power and the launch restraints released the rocket, allowing it to rise above the Space Coast and arc out over the Atlantic Ocean.
Just over a minute into flight, the rocket experienced the moment of peak aerodynamic stress, called maximum dynamic pressure or max Q. This is usually reached around the same time that the vehicle accelerates past the speed of sound.
At 2 minutes, 22 seconds into the flight, the first stage throttled down and separated from the second stage. A moment later, the first stage flipped around and began a “boostback burn” to put it on a trajectory for Landing Zone 1 (formerly Launch Complex 13) at Cape Canaveral Air Force Station.
Meanwhile, the second stage’s single Vacuum Merlin 1D engine ignited to propel the CRS-11 Dragon spacecraft toward its designated orbit.
While the second stage continued accelerating, the first stage arced back toward land. At 6 minutes, 10 seconds into the flight, the 140-foot (42.6-meter) first stage began to re-enter the atmosphere.
To ease the rocket back into the atmosphere, the first stage performed an entry burn. Less than 1.5 minutes later, some 7.5 minutes after liftoff, the stage lit its center Merlin 1D engine to soft land on the concrete pad at LZ-1. Overall, it was the 11th successful booster recovery attempt – the fifth to land on terra firma.
Nine minutes, 20 seconds into the mission, the second stage achieved orbit and shut its engine down. One minute later, the CRS-11 Dragon capsule separated and began the process of deploying its solar panels.
The pressure vessel for this Dragon was actually flown before. It first took flight as part of the CRS-4 Dragon in September 2014. The company plans to fly more refurbished pressure vessels as the production line for “Dragon 1” spacecraft winds down and production of “Dragon 2” or Crew Dragon spacecraft gets into full swing. It is unclear when the next refurbished capsule will be flown.
Meanwhile, back on the ground, with another Falcon 9 first stage recovered, the company is starting to collect a number of “flight proven” boosters.
SpaceX first launched one of these recovered boosters back in April 2017 during the SES-10 mission. Since then, the company has announced its next flight, the launch of BulgariaSat-1, will also utilize a previously flown rocket.
The first stage that will be used to send BulgariaSat-1 into space, core 1029, will be the same one that sent 10 Iridium NEXT satellites into orbit in January 2017.
For now, with the CRS-11 Dragon is in space beginning its two-day chase of the International Space Station. It will rendezvous with the outpost the morning of June 5, 2017.
The ISS crew will then use the robotic Canadarm2 to grab Dragon and place it on the Earth-facing port of the Harmony module. There it will remain until early July.
Video courtesy of NASA Kennedy
Bart Leahy is a freelance technical writer living in Orlando, Florida. Leahy's diverse career has included work for The Walt Disney Company, NASA, the Department of Defense, Nissan, a number of commercial space companies, small businesses, nonprofits, as well as the Science Cheerleaders.