Weather threatens U.S. astronauts' SpaceX launch from Florida

Weather has become a major concern for the planned launch of two American astronauts Wednesday from Kennedy Space Center in Florida in the first crewed mission from U.S. soil in nine years. The projected liftoff has a 60 percent of violating weather constraints because of a thick cloud cover and the likelihood that their SpaceX Falcon 9 rocket would fly through rain, Air Force meteorologists at nearly Patrick Air Force Base said Sunday. "On launch day, remnant moisture" from a tropical wave will remain in the area, according to the Launch Mission Execution Forecast. "The primary launch weather concerns remain flight through precipitation, the thick cloud layer rule and the cumulus cloud rule associated with the remnant tropical moisture and proximity of [a] developing low." A launch cannot occur if precipitation is occurring at the launch pad or within the flight path. Similarly a launch generally cannot occur if any part of the planned flight path is through a layer of clouds within 5 nautical miles and is 4,500 feet thick or thicker. Other parameters have to be met, as well. If the launch is scrubbed, NASA has said, the next attempt to send the Crew Dragon capsule to the International Space Station would come Saturday. Both President Donald Trump and Vice President Mike Pence have announced they would attend the launch Wednesday, and it was not clear whether a postponement would change those plans to attend. Despite the dire weather forecast, astronauts Doug Hurley and Bob Behnken -- and the mission team -- participated in a "dry dress' rehearsal Saturday in which they donned their black and white spacesuits and made a 20-minute drive in a Tesla Model X to Launch Complex 39A.

Elon Musk, who operates SpaceX, also is the chief executive officer of Tesla.

Hurley and Behnken then took a service tower elevator to the spacecraft access arm gantry and climbed into the capsule. They checked out communication systems, and the hatch was closed. They then went through a run-through with all launch personnel.

According to the space agency, "the rehearsal concluded with the go/no-go poll for Falcon 9 propellant loading, which normally occurs 45 minutes before launch."

A day before the rehearsal, engineers successfully fired the rocket's nine Merlin first-stage engines for seven seconds in what NASA describes as a "critical but routine test."

The liftoff, should it occur Wednesday, is planned for 4:33 p.m. EDT. The Dragon capsule would dock with the International Space Station on Thursday at 11:29 a.m. EDT.

SpaceX rocket prepared for Demo-2 Mission

A SpaceX Falcon 9 rocket with the company's Crew Dragon spacecraft onboard is seen as it is raised into a vertical position on the launch pad at Launch Complex 39A as preparations continue for the Demo-2 mission, Thursday, May 21, 2020, at NASA's Kennedy Space Center in Florida. NASA's SpaceX Demo-2 mission is the first launch with astronauts of the SpaceX Crew Dragon spacecraft and Falcon 9 rocket to the International Space Station as part of the agency's Commercial Crew Program. The flight test will serve as an end-to-end demonstration of SpaceX's crew transportation system. Behnken and Hurley are scheduled to launch at 4:33 p.m. EDT on Wednesday, May 27, from Launch Complex 39A at the Kennedy Space Center. A new era of human spaceflight is set to begin as American astronauts once again launch on an American rocket from American soil to low-Earth orbit for the first time since the conclusion of the Space Shuttle Program in 2011.

Marshall team prepares for upcoming Commercial Crew Launch

A new era of human spaceflight is set to begin as American astronauts Robert Behnken and Douglas Hurley once again launch on an American rocket from American soil to the International Space Station as part of NASA's Commercial Crew Program - the first time since the end of the Space Shuttle Program in 2011.? The Commercial Crew Program was formed to facilitate the development of a U.S. commercial crew space transportation capability with the goal of achieving safe, reliable and cost-effective access to and from the International Space Station and low-Earth orbit. The mission, known as Demo-2, is currently targeted for May 27 at 4:32 p.m. EDT from Launch Complex 39A at NASA's Kennedy Space Center. Behnken and Hurley will launch atop a Falcon 9 rocket, en route to an extended stay on the station. "The Commercial Crew Program has challenged the traditional way of developing human spaceflight launch vehicles by shifting the way we think," said Bobby Watkins, manager of the Human Exploration Development and Operations Office at NASA's Marshall Space Flight Center. "This is a huge moment for NASA and its partners, and we are proud at Marshall to be a small part of this monumental mission." The Human Exploration Development and Operations Office at Marshall supports the Commercial Crew Program with engineers that have helped review critical design and development documentation. The team also helps provide oversight to safety standards for the spacecraft and verifies data. For the launch, members of the team will be present in the Huntsville Operations Support Center (HOSC) at Marshall and will work closely with teams at SpaceX in Hawthorne, California, Kennedy Space Center in Cape Canaveral, Florida and Johnson Space Center in Houston, Texas to monitor launch conditions.

The team has already conducted several simulations in the HOSC, and will continue to do so in preparation for launch. During the simulations, participants use headsets and voice loops to communicate with flight control teams at Kennedy and Johnson Space Center as well as SpaceX. Marshall team members help analyze data for the simulations in real time,

"Using the HOSC for the simulations protected our employees by not having to travel during the COVID-19 pandemic," said Steve Gaddis, launch vehicle deputy manager for the Commercial Crew Program. "This recent sim makes the excitement all the more tangible - especially for the team here at Marshall."

For almost 20 years, humans have continuously lived and worked aboard the International Space Station, advancing scientific knowledge and demonstrating new technologies that enable us to prepare for human exploration to the Moon and Mars.

The station's design requires humans living aboard to maintain it, operate it, and upgrade it; thus, International Space Station operations, including commercial resupply and commercial crew, are essential to the mission. Marshall also supports the station by operating the Payload Operations Integration Center, which operates, plans and coordinates the science experiments onboard 365 days a year, 24 hours a day.