At Kennedy Space Center’s Launch Complex 39A, valves are open and propellants are beginning to flow into the SpaceX Falcon 9 rocket. Atop the rocket is the SpaceX Crew Dragon spacecraft, with two NASA astronauts – Robert Behnken and Douglas Hurley – safely strapped inside. Liftoff on NASA’s SpaceX Demo-2 mission to the International Space Station remains planned for an instantaneous launch window at 4:33 p.m. EDT.
Category: International Space Station
Crew Dragon’s Launch Escape System is Armed
The Crew Dragon’s launch escape system (LES), consisting of a set of eight SuperDraco engines integrated into the spacecraft’s body, has been armed in preparation for launch. The LES is designed to separate the spacecraft from the Falcon 9 rocket and carry the crew away to safety in the unlikely event of an emergency.
The system was tested during January’s uncrewed In-Flight Abort Test to show the Crew Dragon’s capability to safely separate from the Falcon 9 rocket. For that test, SpaceX configured Crew Dragon to trigger a launch escape about a minute and a half after liftoff. All major functions were performed, including separation, engine firings, parachute deployment and landing. Crew Dragon splashed down just off the Florida coast in the Atlantic Ocean.
Team ‘Go’ to Load Propellants into the SpaceX Falcon 9 Rocket
SpaceX Launch Director Mike Taylor just verified the launch team is “go” to begin loading the Falcon 9 rocket’s propellants – liquid oxygen and a refined, rocket-grade kerosene called RP-1 – into the rocket’s first and second stages. That should begin in about 10 minutes.
The crew access arm that provided a walkway for the SpaceX Demo-2 crew earlier today is being retracted away from the rocket.
The rocket and Crew Dragon spacecraft are in good shape; the team continues to monitor weather.
Where Will the Station Be at Launch Time?
NASA’s SpaceX Demo-2 mission is targeted to lift off at 4:33 p.m. EDT. At that time, the International Space Station will be flying at an altitude of 256 miles over Iraq, west of Baghdad.
Range Currently ‘Red’ for Weather; Conditions May Improve
The Eastern Range currently is “red,” or no-go, due to rain, cumulus clouds and field mills, which indicate the atmosphere is energized within the launch area. Weather balloons indicate conditions are good at upper altitudes. The launch team continues to monitor weather in hopes that conditions will clear.
Launch of the SpaceX Falcon 9 rocket and Crew Dragon spacecraft carrying NASA astronauts Douglas Hurley and Robert Behnken on NASA’s SpaceX Demo-2 mission is targeted for 4:33 p.m. EDT, just under one hour from now.
Countdown Proceeding as Planned
With about an hour and 15 minutes remaining until today’s 4:33 p.m. EDT launch time, the countdown is proceeding according to schedule. NASA’s SpaceX Demo-2 crew members, Robert Behnken and Douglas Hurley, are buckled into their seats inside the SpaceX Crew Dragon spacecraft, and its side hatch has been closed and checked for leaks. Teams continue to monitor weather conditions.
Here’s a look at some of the major milestones still to come. (Times are shown in “L-time” – minutes and seconds prior to launch time.)
-45:00 SpaceX Launch Director verifies “go” for propellant load
-42:00 Crew access arm retracts
-37:00 Dragon launch escape system is armed
-35:00 RP-1 (rocket grade kerosene) loading begins
-35:00 1st stage LOX (liquid oxygen) loading begins
-16:00 2nd stage LOX loading begins
-07:00 Falcon 9 begins engine chill prior to launch
-05:00 Dragon transitions to internal power
-01:00 Command flight computer to begin final prelaunch checks
-01:00 Propellant tank pressurization to flight pressure begins
-00:45 SpaceX Launch Director verifies “go” for launch
-00:03 Engine controller commands engine ignition sequence to start
-00:00 Falcon 9 liftoff
The Demo-2 mission will serve as an end-to-end flight test to validate the SpaceX crew transportation system, from launch to docking to splashdown. It is the final flight test for the system to be certified for regular crew flights to the station as part of NASA’s Commercial Crew Program.
The Two-Stage SpaceX Falcon 9
The two-stage SpaceX Falcon 9 rocket has flown 83 times for NASA and other customers. The vehicle made history in 2012 when it delivered Dragon into the correct orbit for rendezvous with the International Space Station, making SpaceX the first commercial company to visit the station. Since then, Falcon 9 has made numerous trips to space, delivering satellites to orbit as well as delivering and returning cargo from the space station for NASA. Click here to see a labeled Falcon 9 illustration.
Falcon 9, along with the Dragon spacecraft, was designed from the outset to deliver humans into space, a goal on the cusp of being achieved.
Falcon 9’s first stage incorporates nine Merlin engines and aluminum-lithium alloy tanks containing liquid oxygen (LOX) and rocket-grade kerosene (RP-1) propellant. Falcon 9 generates more than 1.7 million pounds of thrust at sea level but produces over 1.8 million pounds of thrust in the vacuum of space. The first-stage engines are gradually throttled near the end of first-stage flight to limit launch vehicle acceleration as the rocket’s mass decreases with the burning of fuel.
The rocket’s second stage relies on a single Merlin engine that also runs on LOX and RP-1.
Technical Overview
- Height: 70 meters or 229.6 feet
- Mass: 549,054 kilograms or 1,207,920 pounds
- Payload to Low Earth Orbit: 22,800 kilograms or 50,265 pounds
- Diameter: 3.7 meters or 12 feet
The Falcon 9 is the first orbital class rocket capable of reflight, and today, the first-stage booster will aim for a vertical landing on a SpaceX drone ship “Of Course I Still Love You” waiting offshore in the Atlantic.
Air Force One Flies Past Launch Complex 39A
The distinctive blue-and-white Air Force One aircraft just flew near Kennedy Space Center’s Launch Complex 39A, affording U.S. President Trump, onboard the aircraft, a bird’s-eye view of the SpaceX Falcon 9 rocket and Crew Dragon spacecraft on the launch pad. Sealed inside the spacecraft are NASA astronauts Douglas Hurley and Robert Behnken, who are awaiting a 4:33 p.m. EDT liftoff on the agency’s SpaceX Demo-2 mission to the International Space Station – the first launch of American astronauts aboard an American rocket from American soil in nine years.
Crew Dragon’s Hatch Confirmed Closed
The hatch through which NASA’s SpaceX Demo-2 crew members entered the Crew Dragon spacecraft has been closed and a leak check is complete.
Launch of the SpaceX Falcon 9 rocket and Crew Dragon spacecraft carrying NASA astronauts Robert Behnken and Douglas Hurley remains scheduled for 4:33 p.m. EDT from Kennedy Space Center’s Launch Complex 39A. Teams continue to monitor weather conditions throughout the area.
NASA’s SpaceX Demo-2 mission will serve as an end-to-end flight test to validate the SpaceX crew transportation system, from launch to docking to splashdown. It is the final flight test for the system to be certified for regular crew flights to the station as part of NASA’s Commercial Crew Program.
Demo-2 Launch a Cross-Country Effort
Several NASA and SpaceX teams across the country have roles in today’s launch. SpaceX’s launch team is commanding the countdown from Firing Room 4 in Kennedy’s Launch Control Center, then will transfer control to the company’s mission control center in Hawthorne, California. Meanwhile, NASA teams at Kennedy and the agency’s Johnson Space Center in Houston are monitoring today’s activities.