Still covered in soot from a previous supply run to the International Space Station, a SpaceX Falcon 9 took to the skies over Florida’s Cape Canaveral Monday afternoon – lifting a flight-proven Dragon spacecraft into orbit for a critical delivery of science gear, supplies and maintenance hardware to the orbiting laboratory as the first of at least six cargo ships inbound to the U.S. Segment of ISS this year.
The fourteenth operational Dragon is packed with over two and a half metric tons of cargo, including equipment for over 50 scientific studies and two new science facilities for the Station’s exterior, studying the energetic processes ongoing where Earth’s atmosphere meets space and offering a new state-of-the-art exposure facility for commercial materials science. Dragon is also carrying the largest satellite to be deployed from ISS to date, setting sail on an innovative demonstration of active space debris removal technology.
The 65-meter tall Falcon 9 rose from its sea-side launch pad at 20:30 UTC, 4:30 p.m. local time and swung to the north east under the power of its nine Merlin 1D engines, propelling the rocket to a speed of over two Kilometers per second when the first stage dropped away. SpaceX decided against recovering the booster and instead used it for experimenting with extreme flight envelopes to help fine-tune future recoveries of flight-worthy stages.
As the first stage used its remaining life for a data-gathering exercise, it was up to Falcon’s factory-new second stage to boost Dragon into orbit via a six-minute engine burn. The once-flown Dragon was set free a second time ten minutes after blastoff and successfully spread its wings by deploying its power-generating solar arrays. Dragon is expected to begin breathing fire around five hours after launch for a major orbit-raising maneuver on its climb up to the Space Station, en-route to a robotic capture on Wednesday to kick off a month-long stay.
Monday’s launch was SpaceX’s seventh mission of the year, the sixth with Falcon 9 and the fourth to ride into orbit on used hardware – a major step toward the routine re-use of rocket parts that SpaceX envisions will slash launch prices. Another re-use element involved in this mission is the Dragon capsule itself, having spent 33 days in orbit back in 2016 when it supported the Dragon SpX-8 mission that delivered the BEAM expandable module to ISS.
Only a year ago, on March 30, 2017, did SpaceX re-fly its first Falcon 9 booster on the SES-10 mission. Now, seven of the last ten Falcon 9 missions relied on first stages with one prior flight – an impressive demonstration of re-use finding its way into regular spaceflight operations at SpaceX, so far with a spotless success record.
The company’s spacecraft branch is also enjoying the early successes of re-use as Dragon C110 is the third Dragon cargo vehicle to make a second trip into orbit, following up on the SpX-11 and 13 missions of 2017 that also flew used capsules. SpaceX and NASA plan to fly out the remaining six missions under the extended Commercial Resupply Services-1 contract with flight-proven Dragons, allowing SpaceX to focus all resources on ramping up production of Dragon 2 vehicles that will handle crew and cargo missions in the future.
Monday’s launch marked the first of at least three cargo Dragons headed to the ISS this year, to be joined by two Cygnus, three Progress and one HTV mission to keep up a steady chain of supplies for the six crew members living and working off the planet. Additional traffic is expected to arrive in the form of the uncrewed test flights of SpaceX’s Dragon 2 and Boeing’s Starliner which will also ferry some cargo items before the two spacecraft upgrade to crewed transport either late this year or early 2019.
The 14th operational Dragon mission is carrying a total cargo upmass of 2,647 Kilograms, including 1,721 kg of pressurized cargo packed into the Dragon and 926 Kilograms between the three eternal payloads bolted into the Trunk Section of the craft. Cargo items loaded into Dragon range from the seemingly mundane like everyday-life supplies for the crew and a new printer for the Station to state-of-the art experiment facilities, a German time capsule, numerous human research and materials science experiments, as well as live specimens like cell cultures and a group of Japanese lab mice.
The three trunk payloads comprise a pair of external research facilities and a potentially critical spare part for the Station’s thermal control system.
ASIM, the Atmosphere and Space Interactions Monitor, is a 314-Kilogram package taking up residence on the exterior of ESA’s Columbus module to employ a series of cameras, high-speed radiometers and specialized X- and Gamma-ray sensors to capture the ultra-fast signatures of Transient Luminous Events like Blue Jets shooting up from thunderstorms or Red Sprites flashing up in the ionosphere. Data from the Danish-led experiment is hoped to provide insights into the energy exchange processes between the dense gaseous atmosphere and the Mesosphere/Thermosphere where charged particles roam.
MISSE-FF, the second utilization payload riding in the Trunk, will open new possibilities for Materials Science outside the Space Station. A product of Alpha Space, the MISSE Flight Facility takes the original MISSE concept as a basis which had a successful run of over a decade starting in 2001 and exposed over 1,500 samples to the space environment.
While the original MISSE required spacewalking astronauts to deploy & remove the samples, MISSE-FF re-packages the experiment onto a central module hosting up to 14 exchangeable sample carries that can be transferred robotically, no-longer taking up precious crew time. Additionally, MISSE-FF can support powered payloads and offers regular image collection of deployed samples to permit an in-detail study of how different materials degrade in the challenging space environment.
The third Trunk Payload is a spare Pump Flow Control Subassembly to be pre-staged outside ISS in case one of the Station’s eight operating PFCS units encounters a failure and requires replacement. These units are tasked with circulating ammonia coolant through the photovoltaic power-generation system and build an integral part of the Station’s functionality as a world-class laboratory.
While the Station’s external robots will be dealing with moving the trunk payloads, the four U.S. Segment crew members will enter a busy sprint to empty out the Dragon, perform dozens of experiments, and then re-pack the craft with items for return to Earth – penciled in for May 2nd if all goes according to plan.
Research heading up on this mission includes a study exploring how gravity affects the process of hardening materials through heat treatment, how prolonged exposure to microgravity changes bone marrow production in humans, and whether luminous cells can be used as a tracer for tracking metabolic activity for future drug development studies.
Also riding up on the Dragon is new equipment for the Station’s Veggie facility to test out new watering and nutrient delivery hardware in a bid to increase the harvests of lettuce and other vegetables grown on ISS for crew consumption and a learning curve for future missions actively relying on plant growth as a food source.
Taking up a large portion of Dragon’s internal volume is the RemoveDebris satellite, the largest and heaviest to be deployed from ISS via the Japanese Airlock. After deployment some weeks after arriving on ISS, the SSTL-built satellite will be setting out on a mission testing tools for active space debris removal including a net capture demonstration, a harpoon mechanism and a vision-based navigation system for approaching uncooperative targets in space.
Getting this precious cargo on the way toward ISS fell to a flight-proven Falcon 9 rocket, employing Booster 1039 that first flew in August 2017 on the SpX-12 mission and was paired with a factory-new Block 4 second stage. Processing the sooty booster after its successful Return-to-launch-site landing half a year ago was smooth and the second stage was shipped to Cape Canaveral on March 1st to begin the build-up for the mission.
Falcon 9 completed its Static Fire Test on Wednesday and received its payload on Friday and Saturday before returning to the launch pad for the customary late cargo load – a feature of Dragon that permits time-critical items to be loaded inside 24 hours to launch. Late-load items for the SpX-14 mission included one JAXA Rodent Module, a pair on InVitroBone modules and various time-critical experiment samples riding to ISS in a Polar freezer or double cold bags.
Taking its vertical position atop SLC-40 before dawn, Falcon 9 started its countdown with a multi-hour checkout campaign before computers took over at the T-70-minute mark to load over 500 metric tons of sub-cooled Liquid Oxygen and chilled Rocket Propellant 1 into the two-stage rocket. Operations continued like clockwork as Falcon 9 headed into the tail-end of the count, comprising the fast-paced sequence of chilling down the nine Merlin 1D engines, exercising actuators and engine valves one last time, switching the rocket to internal power and closing out the process of loading propellant and pressurization gas onto the vehicle inside T-120 seconds to liftoff.
Falcon 9 came to life at the T-3-second mark when its redundant engine controllers commanded the nine powerplants to fire up and throttle to a collective launch thrust near 700 metric-ton-force. Hold-down systems released the vehicle at precisely 20:30:38 UTC and Falcon 9 thundered away from its Atlantic-side launch pad, balancing in a vertical posture before pitching to the north-east to deliver Dragon into the orbital plane of the Space Station.
Burning 2,500 Kilograms of propellant per second, Falcon 9 accelerated beyond the speed of sound in less than 66 seconds and encountered Maximum Dynamic Pressure only moments later, placing the used airframe of the core stage through peak stress on the way out of the atmosphere.
The nine Merlins revved back up to full thrust after passing MaxQ and continued pushing Falcon 9 until T+2 minutes and 42 seconds – employing a slightly extended burn profile (likely in an effort to set the proper separation energy of the 1st stage to create the desired starting conditions for its descent test).
MECO, Main Engine Cutoff, occurred after the seasoned booster accelerated the vehicle to a speed of 2,191 meters per second followed four seconds later by the separation of the stages at an altitude of 78 Kilometers. Four pneumatic pushers sent the two stages on separate ways with B1039.2 headed into a data-gathering exercise toward a mock landing target in the Atlantic while Stage 2 was tasked with lifting Dragon into orbit.
Monday’s mission was SpaceX’s fifth Falcon 9 launch in a row that flew the first stage in throw-away mode. Of those, four were by choice while one was by necessity due to rough seas preventing a Drone Ship Recovery attempt on the Hispasat mission.
This recent streak of expendable missions is due to SpaceX shifting gears toward the inauguration of the finalized Falcon 9 Block 5 version later this month – allowing Block 3 and 4 first stage that are deemed unsuitable for a third mission to be expended to clear storage room for what is expected to be a flood of recovered boosters once Block 5 gets going at full speed.
Opting for a string of expendable missions with leftover performance also afforded SpaceX some opportunities for data collection not possible on operational recovery missions. Going through the motions of a mimicked sea-based return, the boosters of recent Falcon 9 missions were flown in different profiles – testing out alterations to the boost-back and entry burn profiles, though particular focus was on the atmospheric leg of the booster’s return.
Flight dynamics assessments looked at different angle-of-attack profiles that may allow for additional reduction of fuel needed for the final deceleration maneuver toward landing.
According to SpaceX, Booster 1039 was to continue exploring the bounds of what will be considered acceptable angle-of-attack profiles during atmospheric descent and collect data on the more-aggressive landing burns needed for fuel-constrained drone ship landings. Signals from the first stage were lost around eight minutes into the mission and SpaceX is not expected to comment on the of the planned data collection.
While the booster found its watery grave, Falcon’s second stage was tasked with earning the money – firing up its 95,000-Kilogram-force MVac engine two minutes and 53 seconds into the flight on a planned burn of six minutes and 11 seconds to lift Dragon into orbit. The protective nose cone separated at T+3:25 when the vehicle had crossed 115 Kilometers in altitude, continuing to push toward an injection speed of 7.7 Kilometers per second.
Propulsive flight ended at T+9 minutes and ten seconds and SpaceX confirmed a good orbit was achieved by the Falcon 9 rocket. The Dragon was released on its chase of the Space Station at the T+10:12-mark and successfully primed its propulsion system shortly after separation followed by the deployment of the power-generating solar arrays.
Embarking on a 25-orbit, 38-hour rendezvous with the Space Station, Dragon will be tasked with its first and largest orbit-raising maneuver around five and a half hours after launch. Another pair of engine burns around mid-day on Tuesday (UTC) will place the Dragon in a position to slowly catch up with ISS from behind and below before initiating its rendezvous in the overnight hours to Wednesday.
If all goes well, Dragon will arrive in the Station’s vicinity at 9 UTC for a straight-up approach to the planned capture point just ten meters from ISS. JAXA Astronaut Norishige Kanai will be at the controls of the Station’s robotic arm for the planned 11 UTC capture on Wednesday to mark the start of Dragon’s month-long stay.