The wait is over. After nine long years, an agonizing 3,236 days, a hiatus in America’s capacity to launch its own astronauts, aboard its own spacecraft, atop its own rockets, and from its own soil, came to a triumphant end at 3:22:45 p.m. EDT Saturday, 30 May, when the Demo-2 Crew Dragon finally took flight from historic Pad 39A at the Kennedy Space Center (KSC) in Florida.
Carrying the dreams of a nation, to say nothing of the men and women who vacated KSC before them, NASA veterans Doug Hurley and Bob Behnken became the first humans to ride a Falcon 9 into space. Within nine minutes, Crew Dragon—which Hurley later named “Endeavour”—had achieved a smooth orbit, preparatory to Sunday’s planned docking with the International Space Station (ISS).
“Today a new era in human spaceflight begins as we once again launched American astronauts on American rockets from American soil on their way to the International Space Station, our national lab orbiting Earth,” said NASA Administrator Jim Bridenstine. “I thank and congratulate Bob Behnken, Doug Hurley, and the SpaceX and NASA teams for this significant achievement for the United States. The launch of this commercial space system designed for humans is a phenomenal demonstration of American excellence and is an important step on our path to expand human exploration to the Moon and Mars.”
“This is a dream come true for me and everyone at SpaceX,” said Elon Musk, chief engineer at SpaceX. “It is the culmination of an incredible amount of work by the SpaceX team, by NASA and by a number of other partners in the process of making this happen. You can look at this as the results of a hundred thousand people roughly when you add up all the suppliers and everyone working incredibly hard to make this day happen.”
As previously reported by AmericaSpace, the intractable Florida weather put paid to Wednesday’s opening launch attempt, although NASA and SpaceX pressed on to T-16 minutes—with Hurley and Behnken aboard the vehicle and well into the process of fueling the Falcon 9—before finally calling a scrub just prior to the onset of loading the second stage with liquid oxygen. It was hoped that the Launch Commit Criteria (LCC) violating constraints associated with the presence of natural lightning, field mills and attached anvil clouds would clear a few minutes after Wednesday’s “instantaneous” 4:33:35 p.m. EDT launch window, but phasing requirements for Demo-2 to reach the ISS offered no such flexibility. After hearing of the scrub over the communications net, Hurley replied that the crew had seen raindrops on Crew Dragon’s windows and appreciated that the weather was a little too close to call that day.
It also afforded the team some additional (if undesired) “training” experience. “Wednesday’s scrub accomplished something new: fueling and de-fueling of a SpaceX Falcon w/humans onboard,” Behnken tweeted after the scrub. “Fitting that our test flight checked that off the list of firsts before Crew-1 climb into their vehicle!”
With four shuttle missions between them, Hurley and Behnken have experienced launch delays associated with both weather and technical troubles earlier in their astronaut careers. None more so, perhaps, than Hurley himself, who sat through no fewer than five scrubbed launch attempts over a month-long period in mid-2009, before finally rocketing into orbit aboard Endeavour for STS-127 in 15 July. “All Launch Commit Criteria is developed way ahead of any attempt,” he tweeted after Wednesday’s scrub. “This makes the correct scrub/launch decision easier in the heat of the moment.”
Behnken, too, succumbed to a weather-related scrub in February 2010, prior to his STS-130 mission, before launching successfully the following day. “Scrubs are part of conducting spaceflight safely and successfully,” he tweeted. “During my last mission to @Space_Station, weather caught us too. There’s a reason the name @NASAPersevere was selected for another of our Agency’s own endeavors.”
“A lot of disappointment today, the weather got us,” said NASA Administrator Jim Bridenstine after Wednesday’s scrub. “Teams worked in an impressive way, great teamwork. There was a bit too much electricity in the air, no lightning around us, but if we launched, we could have triggered a strike. If we are not ready to go, we should not go.”
And whilst the maxim of “good things come to those who wait” remained apt, the wait threatened to be even longer. Demo-2’s next two launch opportunities—at 3:22 p.m. EDT Saturday and 3:00 p.m. EDT Sunday—also looked set to be scuppered by the threat of poor weather. In fact, in its Friday morning briefing, the 45th Weather Squadron indicated only a 50-50 likelihood of acceptable conditions on Saturday, improving slightly to 60-percent-favorable in the event of a move to Sunday.
“A major pattern shift is underway as the pesky upper-level trough mired in the eastern half of the U.S. has begun weakening and moving east,” it was reported. “This will push the associated boundary into the Appalachians and the weather ahead of it into the Atlantic Coast States.” The result was a steady “nudge” of the subtropical ridge axis to the south of the Cape, impeding the inland progression of the East Coast sea breeze and pushing convection towards the Spaceport. Flight Through Precipitation and both Anvil and Cumulus Cloud Rules associated with afternoon convection remained the potential LCC violating factors for Saturday, with added thick cloud complicating the picture still further on Sunday.
A Launch Readiness Review (LRR) concluded Friday with a unanimous “Go” to proceed with Saturday’s launch attempt and NASA noted that SpaceX had requested Tuesday, 2 June, on the Eastern Range as an additional backup day, should this weekend’s attempts come to nought. Tuesday’s forecast is predicted to be markedly better, with a 70-percent chance of acceptable weather conditions.
Despite the poor outlook, early Saturday the decision was made to press ahead with the launch attempt. During the suit-up process, Behnken joked with NASA Administrator Jim Bridenstine that Hurley’s history of launch delays was to blame for Wednesday’s scrub.
The crew departed the Neil Armstrong Operations & Checkout Building around midday EDT to be greeted by well-wishers, including their wives and children. Behnken reminded his son to be good and make life easier for his mom, fellow astronaut Megan McArthur. They then boarded the Tesla Model X—appropriately carrying the license plate ISSBND—for the ride out to Pad 39A. They arrived shortly after 12:20 p.m. EDT and rode the elevator to board their waiting spacecraft.
Communications checks were conducted between the astronauts and the Crew Operations Responsible Engineer (CORE) in Hawthorne, Calif., with Commander Hurley identifying himself by the callsign “CDR” and Pilot Behnken as “PLT”. Shortly before 1 p.m. EDT, their seats were rotated backward to their reclined launch position to place them directly in front of the touchscreen displays and instruments.
With one hour to go, Hurley and Behnken declared their preparedness for launch. At T-45 minutes, with the weather outlook steadily brightening, the “Go/No-Go” poll for fueling produced a unanimous Go to proceed from SpaceX Launch Director Mike Taylor. The 85-foot-long (25-meter) Crew Access Arm (CAA) was retracted, ahead of the onset of rocket-grade kerosene (RP-1) and liquid oxygen loading into the Falcon 9’s B1058 core stage got underway at T-35 minutes. Tanking of the second stage with liquid oxygen kicked off around T-16 minutes.
Entering the final ten minutes, words of thanks and good luck were exchanged between CORE and Commander Hurley. Chilldown of the Merlin 1D+ engines began at T-7 minutes. In the final minute, imagery from inside Crew Dragon revealed a hearty thumbs-up from Hurley and—in a beautiful show of respect to the pre-launch remarks by Alan Shepard, America’s first man in space—the words “Let’s light this candle!”
Liftoff at 3:22:45 p.m. EDT was as perfect as perfect could be, as Hurley and Behnken rose from Earth under 1.7 million pounds (770,000 kg) of propulsive yield from the nine Merlin 1D+ engines of the Falcon 9 first stage. Making its first orbital launch—the first never-before-used Falcon 9 to take flight in 2020—the “B1058” core completed its expected 2.5-minute burn, before separating and executing a perfect bullseye touchdown on the Autonomous Spaceport Drone Ship (ASDS), “Of Course I Still Love You”, some nine minutes into flight.
A smooth six-minute burn by the Merlin 1D+ Vacuum engine of the second stage then got underway to boost Hurley and Behnken smoothly into orbit. Impressive imagery revealed Crew Dragon separating from the last edifice of the Falcon 9 at just under 12 minutes into flight and a busy few hours lay ahead for the crew. A few seconds after separation from the second stage, the spacecraft’s nose cone opened to reveal the navigational sensors and docking mechanism. Although Crew Dragon was designed with autonomy in mind, right from the outset it was intended that the astronauts would execute a series of manual flight tests: one in free-flight (known as “far field”) and another in closer proximity to the ISS.
Crew Dragon’s thrusters ignited at 4:09 p.m. EDT and fired for seven minutes in the first of five “burns” to raise its perigee and set course for a docking at the ISS late Sunday morning. And a little over 90 minutes into the flight, Commander Hurley took control of his ship for the “Far Field Manual Flight Test”, the first of two manual evaluations of Crew Dragon. Following a meal, Hurley and Behnken oversaw their final “burn” of the day.
This so-called Coelliptic Burn served to circularize Crew Dragon’s orbit about 6 miles (10 km) “below” the space station. Coming up on Sunday morning, following a few snatched hours of rest, Hurley and Behnken will push into the final stages of rendezvous and docking. Current plans call for Demo-2 to dock at International Docking Adapter (IDA)-2 at the forward end of the station’s Harmony node at 10:29 a.m. EDT.