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EDITOR’S NOTE: Updated at 11 p.m. EST Jan. 16 (0400 GMT Jan. 17) after Falcon 9 was raised vertical.

A SpaceX Falcon 9 rocket and Crew Dragon capsule were raised vertical at launch pad 39A in Florida late Thursday, setting the stage for a launch day dress rehearsal Friday with NASA astronauts Doug Hurley and Bob Behnken — the veteran space fliers assigned to the Crew Dragon’s first piloted mission later this year — before a critical in-flight test of the ship’s emergency escape system Saturday.

NASA and SpaceX officials convened a launch readiness review Thursday and gave approval for SpaceX to proceed with final preparations for the Crew Dragon In-Flight Abort Test Saturday.

The test flight is set for liftoff from pad 39A during a four-hour window Saturday opening at 8 a.m. EST (1300 GMT). There is a 90 percent chance of favorable weather for the test flight Saturday, according to the official launch weather forecast.

The launch escape demonstration will verify the SuperDraco abort engines on the Crew Dragon capsule can safely push the spacecraft away from a Falcon 9 rocket in flight. If the test goes well, the abort demonstration will be the final planned test flight for SpaceX’s Crew Dragon program — managed under contract with NASA’s commercial crew program — before astronauts Doug Hurley and Bob Behnken are cleared to fly the next Crew Dragon mission to the International Space Station.

Hurley and Behnken, both veterans of multiple space shuttle missions, are expected to put on their SpaceX-designed spacesuits early Friday to go through the procedures they will execute on launch day.

The two veteran NASA astronauts will not actually board the Crew Dragon spacecraft, but will practice their suit-up activities inside the Neil Armstrong Operations and Checkout Building at the Kennedy Space Center, the same facility where Apollo and space shuttle crews prepared for launch.

SpaceX’s spacesuits are fabricated in the company’s factory in Hawthorne, California. Made of a single garment, with built-in gloves and boots, the pressure suits have a black and white motif, matching the colors of the Falcon 9 rocket and the launch tower and crew access arm at pad 39A.

Once in their launch and entry space suits, Behnken and Hurley are expected to travel to pad 39A from Kennedy’s Operations and Checkout Building. The crew will take the same 8-mile (13-kilometer) trip by road on launch day.

Ground teams will also perform final inspections on the Crew Dragon capsule and close the ship’s side hatch as they will before a crewed mission, according to NASA.

“Additionally, SpaceX and NASA flight controllers along with support teams will be staged as they will for future Crew Dragon missions, helping the integrated launch team gain additional experience beyond existing simulations and training events,” NASA said in a statement.

The crew access arm will back away from the Crew Dragon spacecraft in the final hour of the countdown, and the spaceship’s abort engines will be armed for flight.

The modified Falcon 9 rocket and Crew Dragon vehicle rolled out of SpaceX’s hangar and up the ramp to pad 39A Thursday. After completing the quarter-mile trip on SpaceX’s transporter-erector, the rocket was raised vertical at the launch pad shortly before 11 p.m. EST Thursday (0400 GMT Friday).

The Falcon 9 rocket will fire off pad 39A Saturday with 1.7 million pounds of thrust from its nine Merlin 1D engines, following a standard launch trajectory to mimic a crew flight to the space station.

Arcing toward the east over the Atlantic Ocean, the Falcon 9 will accelerate the Crew Dragon faster than the speed of sound before reaching a predetermined supersonic velocity threshold. Once the Falcon 9 hits that velocity — expected around 84 seconds after liftoff — the rocket will shut down its nine main engines to simulate a launch failure.

Then eight SuperDraco thrusters fixed to the circumference of the Crew Dragon spacecraft will ignite to quickly propel the spaceship away from the top of the Falcon 9 at an altitude of more than 60,000 (about 19 kilometers).

The SuperDraco engines, burning a high-pressure mix of hydrazine and nitrogen tetroxide propellants, will fire for less than 10 seconds to push the capsule away from its crippled booster.

Engineers expect the Falcon 9 itself, which is powered by a reused first stage booster, to break apart from aerodynamic forces after the Crew Dragon’s escape maneuver, either immediately after the abort command or during its uncontrolled descent back through the atmosphere.

The SuperDraco engines would be used on a piloted flight to save astronauts from a catastrophic launch failure.

Launch abort systems have been used during emergencies on other rockets, most recently in October 2018, when a Russian Soyuz booster failed two minutes after liftoff. The Soyuz abort rockets fired to safely carry Russian cosmonaut Alexey Ovchinin and NASA flight engineer Nick Hague away from the Soyuz booster as it tumbled out of control.

After shutting down the SuperDraco engines, smaller Draco thrusters on the Crew Dragon will re-orient the craft for descent. The capsule will coast to an apogee of about 138,000 feet (42 kilometers), then jettison its no-longer-needed trunk section. The capsule will deploy parachutes to slow for splashdown in the Atlantic Ocean around 20 miles (32 kilometers) east of the Florida coast, where teams from SpaceX and the U.S. Air Force will practice search-and-rescue techniques before retrieving the Crew Dragon for return to port.

Personnel with the Air Force’s Detachment 3, part of the 45th Space Wing at Patrick Air Force Base, will work with SpaceX’s recovery team downrange in the Atlantic Ocean to observe the Crew Dragon’s splashdown. The military rescue team, working in coordination with SpaceX recovery vessels, will practice their approach to the spacecraft in the ocean, rehearsing a real-life astronaut rescue operation.

SpaceX teams will eventually pull the capsule from the sea and return it to port for inspections.

The Detachment 3 teams from Patrick Air Force Base include an HC-130 transport and refueling plane, and two HH-60 Pave Hawk helicopters with search and rescue teams on-board, according to NASA officials.

The military pararescue specialists will parachute from the aircraft into the Atlantic with inflatable boats.

SpaceX and Boeing, NASA’s other commercial crew contractor, are responsible for recovering their spacecraft after a normal landing. The Crew Dragon splashes down at sea, with a primary zone in the Atlantic Ocean east of Florida and a backup zone in the Gulf of Mexico, and Boeng’s Starliner capsule returns to a touchdown on land at one of several possible sites in the Western United States.

But like SpaceX’s vehicle, the Boeing Starliner is designed for a water landing in case of a launch abort.

“We requested from (the military), if something goes awry, such as a pad abort or an ascent abort — which is what we’re talking about with this In-Flight Abort Test — then they typically would go out and deploy their teams and provide for rescuing the crew, picking them up,” said Ted Mosteller, NASA’s commercial crew launch and landing lead, in an interview with CBS News.

“SpaceX, they’re really specifically for the nominal landing site and nominal landing in most cases,” he told CBS News. “And then the DoD, specifically Detachment Three down at Patrick, coordinates with the Air Force the assets that we use for rescue.”

For a crewed mission, the search and rescue team at Patrick Air Force Base will have primary responsibility for retrieving the astronauts from the Crew Dragon spacecraft after a pad abort or launch emergency in the first few minutes of the flight, a scenario that would lead to a splashdown within about a 230-mile (370-kilometer) radius from Cape Canaveral.

Launch trajectories toward the space station head to the northeast from the Kennedy Space Center, following a path roughly parallel to the U.S. East Coast. NASA required SpaceX and Boeing, which launches its Starliner capsule on United Launch Alliance Atlas 5 rockets, to design their crew capsules to avoid splashing down in the middle of the North Atlantic Ocean in the event of an in-flight abort late in the ascent sequence.

If required, thrusters on the Crew Dragon or Starliner spacecraft would fire after an abort to ensure the capsule lands within about 300 miles of eastern Canada or Ireland, NASA officials told CBS News.

“Once you detach from a failing rocket, you will either have enough propellant to slow down and land before you get there, or to boost you to the other side of that zone,” said Steve Payne, NASA’s launch integration manager for the commercial crew program.

NASA and contractor teams will also assess sea states in the Atlantic Ocean before giving final approval for a crew launch.

On future commercial crew flights with astronauts on-board, a C-17 cargo plane from Charleston Air Force Base in South Carolina will be on standby to respond for a sea rescue farther away from the launch site in Florida. A C-17 aircraft with a similar search and rescue team would deploy from Hickam Air Force Base, Hawaii, for an emergency landing in the Pacific Ocean or neighboring seas.

During a crew launch, the rescue teams at Patrick Air Force Base could be airborne in 10 or 15 minutes, Mosteller told CBS News, and will aim to retrieve the astronauts and transport them to a local hospital within six hours. The C-17s are on a one-hour alert from the time of a SpaceX or Boeing crew launch until docking with the space station, with a goal of getting to the astronauts within 24 hours after an emergency landing anywhere in the world.

Mosteller told CBS News that the SpaceX and Boeing crew capsules both carry radio beacons to help the military search and rescue team locate the spacecraft. The Crew Dragon and Starliner both have flashing lights, and crews will carry handheld radios and personal locator beacons to communicate with search and rescue teams if the astronauts have to leave the spacecraft after splashdown.

The SpaceX and Boeing crew capsules both have a raft on-board, plus a survival kit with medications, food and fresh water, signaling mirrors, blankets and other equipment, Mosteller told CBS News.

Military rescue teams are also equipped with a larger life raft that can accommodate the search and rescue forces, along with the astronaut crews, and carries provisions for up to three days.

SpaceX developed the Crew Dragon under a $2.6 billion contract with NASA signed in 2014. NASA also awarded a contract to Boeing, which is also awaiting its first crewed mission — giving the agency two vehicles to help end U.S. reliance on Russian Soyuz spacecraft for crew transportation to the station.

SpaceX conducted the first Crew Dragon test flight to the space station last March, but engineers ran into trouble in April, when the capsule exploded during a ground test. The accident occurred moments before a ground test-firing of the Crew Dragon’s SuperDraco abort engines and resulted in no injuries, but it destroyed the spaceship that just returned from the space station.

Engineers say they resolved the problem that led to the explosion, and SpaceX performed a similar ground firing of the SuperDraco engines on a new Crew Dragon vehicle in November, paving the way for the In-Flight Abort Test.

Assuming the launch escape test goes well Saturday, SpaceX could be on pace to launch astronauts Hurley and Behnken on the next Crew Dragon test flight in the next few months. That mission, designated Demo-2, is a precursor to the start of SpaceX’s operational crew rotation service, with missions ferrying up to four astronauts to and from the space station for stays of up to 210 days.

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Follow Stephen Clark on Twitter: @StephenClark1.