Following 18 successful launches since June 2010, the heart was torn from SpaceX earlier today (Sunday, 28 June), following the disintegration of a Falcon 9 v1.1 booster during its flight to deliver the CRS-7 Dragon cargo ship to the International Space Station (ISS). Launched on time at 10:21:00 a.m. EDT, the mission carried 4,116 pounds (1,867 kg) of pressurized cargo for the incumbent Expedition 44 crew of Commander Gennadi Padalka and One-Year crewmen Scott Kelly and Mikhail Kornienko, as well as NASA’s first International Docking Adapter (IDA-1) for Commercial Crew support. The vehicle appeared to enjoy a largely flawless first-stage flight, but at T+139 seconds—seemingly from nowhere—the plumes of the nine Merlin 1D engines flared and the vehicle disintegrated, depositing debris across a huge area on the Melbourne Weather Radar. Speaking at a press conference, hosted at the Kennedy Space Center (KSC) on Sunday afternoon, key SpaceX, NASA and FAA officials expressed sorrow at the failure and declared their determination to identify the root cause and return to flight within months. At the same time, AmericaSpace understands that both SpaceX and NASA were aware of an issue associated with liner cracking, close to the liquid oxygen tank “dome” on the Falcon 9 v1.1’s second stage, although it remains to be seen if this was a factor in today’s accident.
Following a nominal Static Fire Test of the Merlin 1D first stage engines last week, efforts to prepare for this flight proceeded with similar smoothness. Meteorological conditions for an on-time launch at 10:21:00 a.m. Sunday were highly favorable, with Patrick Air Force Base 45th Weather Squadron predicting a 90-percent likelihood of acceptable weather, tempered by a possible violation of the Cumulus Cloud Rule. “A surface boundary will continue to move slightly southward and into northern Florida by Sunday morning,” it was noted at 8 a.m. EDT Saturday. “Although lightning chances remain high in the afternoon and evening, given the time of launch, weather violation threat is low. The primary weather concern is early cumulus development. Max winds will be southwest at 25 knots at 30,000 feet (10,000 meters).” However, the 45th cautioned that a 24-hour delay until Monday—whose “launch window” was timed to open slightly earlier, at 9:58 a.m. EDT—would be more problematic. “On Monday, conditions worsen slightly as the surface boundary pushes further south into Central Florida,” it was explained. “The added instability could create unsettled weather even in the morning hours.” The result for Monday was an added risk of violating the Flight Through Precipitation Rule and a slightly lower 70-percent probability of acceptable conditions at T-0.
Shortly after midnight Sunday, efforts to power up the Falcon 9 v1.1—a two-stage vehicle, first trialed back in September 2013, which drew upon the heritage of its predecessor, the Falcon 9 v1.0—got underway at the darkened SLC-40. A few hours later, as the first glimmers of dawn reached the Cape, fueling of the booster with liquid oxygen and a highly refined form of rocket-grade kerosene, known as “RP-1”, commenced. The cryogenic nature of the oxygen required the fuel lines of the engines to be chilled down, in order to avoid thermally shocking and potentially fracturing them. According to AmericaSpace’s Launch Tracker, liquid oxygen tanking began at 7:46 a.m. and was complete about 65 minutes later. All stations declared themselves “Green” (“Go for Launch”), with the weather holding steady at 90-percent favorable.
At 10:08 a.m., the countdown reached its final “Go/No-Go” polling point of all stations at T-13 minutes and passed smoothly through the poll of flight controllers, allowing the Launch Director to issue a definitive “Go for Launch” and authorize the initiation of the Terminal Countdown at T-10 minutes. Passing into Autosequence Start, the nine Merlin 1D engines of the first stage were chilled, ahead of their ignition sequence. All external power utilities from the Ground Support Equipment (GSE) were disconnected and the CRS-7 Dragon spacecraft was transferred to internal power at 10:14:50 a.m. Less than a minute later, as planned, SLC-40’s strongback began its roughly 90-second retraction from the Falcon 9 v1.1 stack and the Flight Termination System (FTS)—tasked with destroying the vehicle in the event of a major accident during ascent—was placed onto internal power and armed.
During the final minutes, liquid oxygen topping ended, propellant tanks attained flight pressure and the Merlin 1Ds were purged with inert gaseous nitrogen. At T-60 seconds, the SLC-40 complex’s “Niagara” deluge system of 53 nozzles was activated, flooding the pad surface and flame trench with 30,000 gallons (113,500 liters) of water, per minute, to suppress acoustic energy radiating from the engine exhausts.
At T-3 seconds, the nine Merlin 1Ds roared to life, ramping up to a combined thrust of 1.3 million pounds (590,000 kg). Following computer-commanded health checks, the Falcon 9 v1.1 was released from SLC-40 at 10:21:00 a.m. Immediately after clearing the tower, the vehicle executed a combined pitch, roll and yaw program maneuver to establish itself onto the proper flight azimuth to inject the CRS-7 Dragon into low-Earth orbit. Eighty seconds into the uphill climb, the Falcon 9 v1.1 exceeded the speed of sound and experienced a period of maximum aerodynamic turbulence—colloquially known as “Max Q”—on its airframe. Shortly afterwards, as expected, the second stage’s Merlin 1D Vacuum engine began its chill-down protocol, ahead of its ignition later in the ascent, following the separation of the first stage at about T+3 minutes.
It was during this latter phase of first-stage flight that the flight began to go catastrophically awry and the vehicle broke up at 10:23 a.m., with the final telemetry received at T+2 minutes and 19 seconds. “There appears to have been a problem with the Falcon 9 rocket,” noted AmericaSpace’s Launch Tracker. “The Range Operations has confirmed the malfunction.” It was initially believed that the FTS had been activated to destroy the vehicle, although at Sunday afternoon’s press conference SpaceX President Gwynne Shotwell explained that she had “heard no indication that there was a destruct signal” issued to the Falcon 9 v1.1, prior to breakup. In the minutes after the accident, SpaceX CEO Elon Musk—whose 44th birthday, today, has been overshadowed by what is undeniably the worst day in the Hawthorne, Calif.-based launch services provider’s 13-year history—tweeted that “There was an overpressure event in the upper stage liquid oxygen tank”. He added that “data suggests counterintuitive cause” and AmericaSpace’s Launch Tracker stressed that Mr. Musk’s words tied in “with slow-motion footage of the explosion where a plume of vapor can be seen streaming down the sides of the booster immediately before the explosion”.
Within two hours of the accident, NASA Administrator Charlie Bolden issued a preliminary statement. “We are disappointed in the loss of the latest SpaceX cargo resupply mission to the International Space Station,” he said. “However, the astronauts are safe aboard the station and have sufficient supplies for the next several months. We will work closely with SpaceX to understand what happened, fix the problem and return to flight. The Commercial Cargo Program was designed to accommodate loss of cargo vehicles. We will continue operation of the station in a safe and effective way as we continue to use it as our test bed for preparing for longer-duration missions farther into the Solar System.”
A post-anomaly press conference was initially expected to convene at KSC at 12:30 p.m. EDT, but was repeatedly postponed and eventually commenced shortly after 1 p.m. Present both in person and via telephone were Ms. Shotwell, together with NASA Associate Administrator for Human Exploration and Operations Bill Gerstenmaier, ISS Program Manager Mike Suffredini and Deputy Division Manager for the FAA Office of Commercial Space Transportation Pam Underwood. In her opening comments, Ms. Shotwell remarked that “first-stage flight was successful”, up until 139 seconds, whereupon “we experienced an anomaly which led to the failure of the mission”. However, she stressed that “first-stage flight remained nominal” and that she did not expect the cause of the failure to be specifically rooted in the first stage hardware. Ms. Shotwell also pointed out that telemetry continued to be received from the CRS-7 Dragon cargo ship in the seconds after the anomaly.
“A tough day” was Mr. Gerstenmaier’s summary, and “not where I’d like to be on a Sunday afternoon”. Of obvious significance was the fact that three ISS cargo providers—Russia’s Progress, Orbital Sciences’ Cygnus and now SpaceX’s Dragon—have succumbed to catastrophic failures, within the course of just a single year. Orbital lost its ORB-3 mission, seconds after liftoff atop an Antares booster, back in October 2014, after which Russia’s Progress M-27M experienced a third-stage failure during its April 2015 ascent and re-entered the atmosphere to destruction last month. “I didn’t think we’d lose them all in a one-year timeframe,” he admitted. “Having three this close together is not what we’d hoped for,” agreed Mr. Suffredini. In his comments, Mr. Gerstenmaier said that there exists “no commonality” between the three accidents, with the exception that space is a difficult, demanding and unforgiving environment in which to operate. He added that the ISS remains in “good shape from a food standpoint and water standpoint” and saw no reason to delay the planned launch of Progress M-28M from the Baikonur Cosmodrome in Kazakhstan on 3 July or the launch of Soyuz TMA-17M and its crew of Russian cosmonaut Oleg Kononenko, U.S. astronaut Kjell Lindgren and Japan’s Kimiya Yui on 22-23 July.
Nonetheless, as well as being SpaceX’s worst day, the loss of this particular mission carries profound consequences for Commercial Crew, in view of the presence of the critical IDA-1. This docking interface—described in an earlier AmericaSpace article—was to be installed onto Pressurized Mating Adapter (PMA)-2 on the forward end of the station’s Harmony node in early August by spacewalkers Scott Kelly (EV1) and Kjell Lindgren (EV2). In doing so, it would provide the primary docking interface for SpaceX’s Dragon V-2 and Boeing’s CST-100 crewed vehicles, which are expected to undertake their first unpiloted missions within two years. Mr. Gerstenmaier and Mr. Suffredini also pointed out that a significant amount of research hardware, including a substantial number of student experiments, and a U.S. Extravehicular Mobility Unit (EMU) space suit, had also been lost. A second IDA was tentatively scheduled to fly aboard the CRS-9 mission in December 2015, to be installed onto PMA-3 at the space-facing (or “zenith”) port of Harmony, in order to offer a backup Commercial Crew location. Mr. Suffredini hinted that this mission may be brought forward, dependent upon the findings of the mishap investigation, and that he expects the ISS cargo manifest across all of the International Partners to be adjusted in the coming months to ensure that the station remains adequately stocked.
steps for SpaceX are the investigation process, which Ms. Shotwell expects to be completed within a matter of months, and not the year of downtime which has characterized Orbital Sciences’ recovery in the aftermath of the ORB-3 loss. In offering her perspective on the FAA’s position, Ms. Underwood pointed out that the CRS-7 mission was flown under an FAA Launch License and that today’s accident has been formally classified as a “Mishap”, which will generate an investigation, undertaken in-house by SpaceX, with FAA oversight. Ms. Shotwell told the assembled media that, since all of the Falcon 9 v1.1 and Dragon hardware belonged to SpaceX, this would improve the process of investigating what went wrong. She expects to leverage the help and support of the FAA and will submit documentation prior to the next launch attempt. Summing up, Ms. Shotwell was philosophical in her insistence that SpaceX’s launch provision was a “tough business” and that today’s events served as “a reminder of how difficult this is”.
It remains to be seen where the investigation will lead, although there are clear indications that the Falcon 9 v1.1’s second stage hardware was a contributor in today’s anomaly. AmericaSpace understands from sources that both NASA and SpaceX were well aware of an issue on the vehicle, pertaining to cracking of the liner on the second stage’s liquid oxygen tank dome. Until recently, SpaceX’s solution has been to utilize sprayed-on Teflon lubricant, in the hope that it would alleviate the stresses which caused the problem and AmericaSpace has reached out for additional comment. Senior sources at SpaceX told AmericaSpace that “We are always worried about our Helium pressurant tanks, but we don’t have data yet that says it was them”. Meetings will continue this evening and over the coming days to review the early data and enable a piecing-together of what is known.
Responses on Twitter have offered support to SpaceX and acknowledgement of the difficulty of delivering vehicles into orbit. Veteran NASA astronaut Rick Mastracchio—who spent more than 187 days aboard the ISS between November 2013 and May 2014, spanning Expeditions 38 and 39—remarked that today’s accident was “more proof launching into space is difficult and dangerous. I’m sure they will come back strong.” Former shuttle commander Chris Ferguson added that it had been a “tough day in space”, a sentiment shared by fellow astronaut Mark Kelly, who tweeted that he had recently spoken to his twin brother, Scott, aboard the ISS. “He’s paying close attention to sit[uation] w/the catastrophic failure of the @SpaceX resupply vehicle.” And from aboard the ISS, Scott Kelly himself tweeted that he had “Watched #Dragon launch from @space_station. Sadly failed. Space is hard.”
In spite of today’s accident, one other point of significance is that Expedition 44 Commander Gennadi Padalka will today surpass fellow Russian cosmonaut Sergei Krikalev to become the most experienced spacefarer. At 6:58 p.m. EDT Sunday, Padalka will exceed Krikalev’s cumulative achievement of 803 days, nine hours and 39 minutes, which he established across six space missions between November 1988 and October 2005. Krikalev flew four long-duration voyages—two to Russia’s Mir space station and two to the ISS—as well as becoming the first cosmonaut to fly aboard the shuttle in February 1994 and joining the crew of the first ISS construction mission in December 1998. By contrast, Padalka has flown five long-duration missions and, with Expedition 44, becomes the first human being to command the ISS on four discrete occasions. Last month, on 25 May, Padalka surpassed the 769-day career total of fellow Russian cosmonaut Aleksandr Kaleri and moved into second place on the list of the world’s most experienced spacefarers, having also exceeded another cosmonaut, Sergei Avdeyev, and positioned himself in third place, back on 3 May. By the time Padalka returns to Earth on 11 September, he will have accrued a career total of 878 days in orbit, which represents approximately 2.4 years of his 57 years of life.
ADDITIONAL PHOTOS: Alan Walters, Matt Gaetjens and Talia Landman / AmericaSpace, all rights reserved.
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