NASA’s SpaceX Demo-2: Countdown on Schedule, Eyes on Weather

Clouds move in over Launch Complex 39A at NASA’s Kennedy Space Center in Florida on Saturday, May 30, 2020. A SpaceX Falcon 9 rocket and Crew Dragon spacecraft is scheduled to lift off this afternoon, carrying American NASA astronauts Robert Behnken and Douglas Hurley to the International Space Station. Launch is targeted for 3:22 p.m. EDT. The launch window is instantaneous. Image credit: NASA TV

With about an hour and five minutes remaining until today’s 3:22 p.m. EDT liftoff time, SpaceX Demo-2 launch countdown is proceeding according to schedule at NASA’s Kennedy Space Center in Florida. A weather update is coming up; although rain in the launch area has let up, some conditions are still “no go,” including lightning, cumulus clouds and electric fields.

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

Demo-2 Launch a Cross-Country Effort

A SpaceX Falcon 9 rocket with the company's Crew Dragon spacecraft onboard is seen at Launch Complex 39A through the windows of Firing Room Four of Kennedy's Launch Control Center during a dress rehearsal on May 23, 2020, in preparation for the launch of NASA’s SpaceX Demo-2 mission.
A SpaceX Falcon 9 rocket with the company’s Crew Dragon spacecraft onboard is seen at Launch Complex 39A through the windows of Firing Room 4 of Kennedy’s Launch Control Center during a dress rehearsal on May 23, 2020, in preparation for the launch of NASA’s SpaceX Demo-2 mission. Photo credit: NASA/Joel Kowsky

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.

Liftoff of the SpaceX Falcon 9 rocket and Crew Dragon spacecraft carrying NASA astronauts Robert Behnken and Douglas Hurley remains scheduled for 3:22 p.m. EDT – an instantaneous launch opportunity. The crew is already strapped into the spacecraft at Kennedy’s Launch Complex 39A. The launch team continues to closely monitor the weather, which has a 50-50 chance of cooperating at launch time according to meteorologists with the U.S. Air Force 45th Weather Squadron.

NASA’s SpaceX Demo-2 mission to the International Space Station 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.

Team Continues to Monitor Weather

Clouds move in over Launch Complex 39A at NASA’s Kennedy Space Center in Florida on Saturday, May 30, 2020. A SpaceX Falcon 9 rocket and Crew Dragon spacecraft is scheduled to lift off this afternoon, carrying American NASA astronauts Robert Behnken and Douglas Hurley to the International Space Station. Launch is targeted for 3:22 p.m. EDT. The launch window is instantaneous. Photo credit: NASA TV

Weather is “no go” for now, but meteorologists predict there could be a clearing in the rain later in the countdown. The next decision point for the launch team will be prior to propellant loading operations, which will begin at about 2:47 p.m. EDT or about 35 minutes prior to launch.

Where Will the Station Be at Launch Time?

International Space Station in low-Earth orbit
In this image from October 2018, the fully completed station continues its mission to conduct microgravity research and experiments — ranging from human physiology to astronomy aboard humanity’s only orbital laboratory. Photo credit: NASA

NASA’s SpaceX Demo-2 mission is targeted to launch today at 3:22 p.m. EDT. At that time, the International Space Station will be flying at an altitude of 259 statute miles over the Atlantic off the coast of North Carolina.

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.

Crew Dragon’s Side Hatch Closed; Weather Update

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 3:22 p.m. EDT from Kennedy Space Center’s Launch Complex 39A. Teams continue to monitor weather conditions throughout the area; there are showers popping up in the area, but the team is proceeding with the count. The next decision point will come prior to the loading of the rocket’s propellants.

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.

The SpaceX Falcon 9 Rocket

A SpaceX Falcon 9 rocket with the company's Crew Dragon spacecraft onboard is seen on the launch pad at Launch Complex 39A as preparations continue for the Demo-2 mission, Thursday, May 28, 2020, at NASA’s Kennedy Space Center in Florida.
A SpaceX Falcon 9 rocket with the company’s Crew Dragon spacecraft onboard is seen on the launch pad Thursday, May 28, at Launch Complex 39A as preparations continue for the Demo-2 mission. Photo credit: NASA/Joel Kowsky

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.

An illustration of the SpaceX Falcon 9.
An illustration of the SpaceX Falcon 9. Image credit: SpaceX

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 called “Of Course I Still Love You,” which is waiting offshore in the Atlantic.

Crew, Launch Officials Perform Comm Checks

NASA’s SpaceX Demo-2 astronauts Robert Behnken and Douglas Hurley are performing a series of comm checks – communications checks with key members of the launch and mission teams, including the SpaceX launch director and chief engineer, both in Firing Room 4 in Kennedy’s Launch Control Center; and the SpaceX Crew Operations and Resources Engineer (CORE), located at SpaceX Mission Control in Hawthorne, California.

All Aboard: Astronauts Ingress Crew Dragon

Demo-2 spacecraft commander Douglas Hurley climbed aboard the Crew Dragon first, followed by joint operations commander Robert Behnken, sitting to Hurley’s right. For the boarding process, called “ingress,” the Crew Dragon’s seats are configured in the upright position; later, prior to closure of the spacecraft’s side hatch, the seats will be rotated into a reclined position to give the astronauts easy access to their displays during flight.

Hurley is in Seat 2 and Behnken is to his right in Seat 3. The Crew Dragon can carry up to four astronauts, but Seats 1 and 4 are vacant for this flight.

The SpaceX Crew Dragon

On NASA’s SpaceX Demo-2 flight test, astronauts Robert Behnken and Douglas Hurley will take the SpaceX Crew Dragon for the ultimate test drive to the International Space Station.

The next-generation spacecraft is fully autonomous but also can be controlled manually if needed. During the Demo-2 mission, astronauts Robert Behnken and Douglas Hurley will validate that the spacecraft’s systems operate as expected – both autonomously and manually. Click here to see a labeled Crew Dragon illustration.

An illustration of the SpaceX Crew Dragon.
An illustration of the SpaceX Crew Dragon. Image credit: SpaceX

“We specifically, as part of this test flight, designed in some time in the preflight phase as well as closer to the space station so we can test out actual manual flying capability of the vehicle, just to see and verify that it handles the way we expect it to and the way the simulator shows it to fly,” Hurley said. “It’s a prudent part of our flight test, just like anything else, in case the eventuality happened for a future crew that needed to take over manually and fly spacecraft. So we’re just doing our part to test out all the different capabilities of Crew Dragon.”

The Crew Dragon has several features that set it apart from the company’s Cargo Dragon, which has made several flights to the orbiting laboratory to deliver cargo. Crew Dragon has an integrated launch escape system to carry the astronauts to safety in the unlikely event of an emergency; we’ll discuss that in more detail later in the countdown. SpaceX has completed a series of parachute tests, including several on the Mark III parachutes on today’s Crew Dragon to ensure a safe return to Earth for the crew.

Inside, the spacecraft’s life support system provides air and pressure, and maintains a comfortable temperature and humidity level. Its touchscreens have been tuned to operate with and without the SpaceX spacesuit gloves, and the control system has been thoroughly tested during the hundreds of hours of training and joint simulations with the crew in both suited and non-suited situations to demonstrate full functionality over the entire expected operating range of Crew Dragon.

Behnken and Hurley have been heavily involved in the development of the Crew Dragon and were careful to provide input that would benefit all future crews to fly aboard the spacecraft.

“We’ve tried very hard to not make it a vehicle that just Bob likes, or just Doug likes; this is a vehicle for everybody after us who’s going to fly it,” Behnken said. “You’re trying to make a vehicle that is easy to operate in space, easy to interpret what it’s telling you, easy to get in and get out of, all those things that you need to do that need to be well-oiled for a space vehicle.”