The threat of lightning could thwart plans to launch an Atlas 5 rocket from Cape Canaveral Friday with a Boeing commercial crew capsule on an unpiloted test flight to the International Space Station, according to the forecasters on the Space Coast.
There is a 60% chance that weather could prevent liftoff at 2:53 p.m. EDT (1853 GMT) Friday, when the Atlas 5 has an instantaneous opportunity to launch on a trajectory to allow the Starliner spacecraft to intercept the space station Saturday.
If launch occurs on time, the Starliner spacecraft is set to dock with the station at 3:06 p.m. EDT (1906 GMT) Saturday. The capsule is scheduled to undock and return to Earth for a parachute-assisted landing in New Mexico on Aug. 5.
But that assumes weather cooperates for Friday’s launch attempt.
“It kind of feels like all eyes are on weather at this point,” said Will Ulrich, launch weather officer at the U.S. Space Force’s 45th Weather Squadron. “Anytime me and my colleagues see a launch being put on the schedule or on the calendar during the summer months from Kennedy Space Center or Cape Canaveral Space Force Station, we always have to be prepared for a challenge. And this particular launch is no different, especially given the time of the instantaneous launch window just before 3 p.m.”
The sea breeze pattern over Central Florida this week favors afternoon thunderstorms on the eastern half of the peninsula, putting Cape Canaveral at risk of lightning each day.
“We’re a little bit pessimistic going into week’s end, but we do have to be realistic with that,” Ulrich said Tuesday.
The primary weather concerns are with cumulus clouds, electric fields at the surface, and with lightning in the area, according to the forecast team.
Those rules are “designed to protect from both natural and rocket-triggered lightning,” Ulrich said. “In addition, we’ll be monitoring winds and other user constraints. But overall, outside of any thunderstorms, we are expecting favorable winds and temperatures temperatures in the middle 80s (Fahrenheit), not atypical for this time of year, and southerly winds up to about 15 miles per hour.
“With that said, we have to be realistic going into late week, and we can hope that we’ll find a gap in the shower and thunderstorm activity that we’re anticipating,” Ulrich said.
The Starliner team will also assess wind and sea conditions along the Atlas 5’s flight corridor northeast from Cape Canaveral. The capsule could splash down in the Atlantic Ocean along the offshore flight path if an emergency triggers a launch abort, in which the Starliner’s abort engines would propel the ship away from the Atlas 5 rocket.
The capsule’s launch abort system will be active for the first time on the OFT-2 mission. It operated in a “shadow” mode on the OFT-1 launch in 2019, collecting data for analysis by engineers after the flight.
For a Starliner mission with astronauts on-board, the abort weather constraints would factor in to the decision on whether to proceed for a launch. On this unpiloted test flight, teams will monitor the conditions but would not hold the launch if they were out of limits.
If the OFT-2 mission doesn’t take off Friday, the next opportunity to launch would be Tuesday, Aug. 3, at 1:20 p.m. EDT (1720 GMT). Another launch opportunity is available at 12:57 p.m. EDT (1657 GMT) on Aug. 4.
The launch times are determined by when Earth’s rotation brings the launch pad at Cape Canaveral under the space station’s flight path.
NASA says a “classified” operation on the Space Force’s Eastern Range will tie up ground assets Saturday, preventing the OFT-2 mission from launching that day. The position of the space station in its orbit precludes launch opportunities on Sunday and Monday.
The Atlas 5 rocket will deploy the Starliner spacecraft about 15 minutes after launch, then the Boeing crew capsule will use its on-board maneuvering thrusters to climb into a stable orbit and begin the pursuit of the space station. The demonstration flight, called Orbital Flight Test-2, is a redo of a Boeing test mission in December 2019 plagued by software problems.
The Starliner suffered from a mission timer error, causing it to burn too much fuel after arriving in space. The excess fuel consumption left too little propellant to rendezvous and dock with the space station, and the capsule landed in New Mexico two days after launch.
Boeing engineers, working with NASA, rewrote portions of the Starliner software code and performed additional simulations to ensure the same problems don’t recur on the OFT-2 mission, which managers added to the program after the early end to the OFT-1 mission.
If all goes well, NASA could clear Boeing to launch astronauts on the next Starliner mission, giving the U.S. space agency two independent vehicles capable of ferrying crews to and from the space station. SpaceX’s Crew Dragon capsule, also developed under contract with NASA, successfully flew astronauts for the first time last year.
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