Friday, September 8, 2017

SpaceX Beats Odds, Hurricane Irma to Launch Falcon 9 with X-37B

SpaceX launches the secretive X-37B spaceplane just days before Hurricane Irma is forecast to approach the Space Coast. Photo Credit: Tom Cross / SpaceFlight Insider

With weather iffy at best and Hurricane Irma on the approach, SpaceX managed to launch its 13th Falcon 9 rocket this year. The flight sent the U.S. Air Force’s secretive robotic X-37B spaceplane into orbit. Despite the 50-50 weather chances, the Falcon 9 soared into clear skies at 10 a.m. EDT (14:00 GMT) Sept. 7, 2017, from Launch Complex 39A – 10 minutes into the 5-hour, 5-minute launch window. The countdown, while mostly silent, appeared to have gone smoothly.

Loading of rocket-grade kerosene, otherwise known as RP-1, started at about 1 hour before liftoff, while the liquid oxygen was loaded some 35 minutes before liftoff. Within a few minutes of the planned launch, the vehicle was fully fueled and computers began final preflight checks.

At 45 seconds before launch, SpaceX’s launch director verified all was go for launch. Three seconds before lifting skyward, the nine first stage Merlin 1D engines ignited and spooled up to full power.

Once the flight computers verified the engines were healthy, the launch clamps released the Falcon 9 to let it fly toward the black of space with the fifth Orbital Test Vehicle (OTV-5) mission and its classified X-37B payload.

A few seconds later, the Falcon 9 began pitching over toward its designated orbit. One minute, 19 seconds after leaving Florida, the vehicle reached the moment of peak mechanical stress while pressing through the atmosphere – Max Q.

Some 2 minutes, 23 seconds after launching, the nine first stage Merlin 1D engines cut off, as planned. Three seconds later, the first and second stages separated.

In a span of 13 seconds after stage separation, the second stage started its lone vacuum Merlin 1D engine to begin powering toward orbit while the first stage restarted three of its engines for a one-minute boostback burn to return toward Cape Canaveral.

Brig. Gen. Wayne Monteith, 45th Space Wing commander, thanked the entire OTV-5 mission team for their efforts in ensuring a successful launch.

“I’m incredibly proud of the 45th Space Wing’s contributions to the X-37B program,” Monteith said. “This marks the fifth successful launch of the OTV and its first [on board] a Falcon 9. A strong relationship with our mission partners, such as the Air Force Rapid Capabilities Office, is vital toward maintaining the Eastern Range as the World’s Premier Gateway to Space.”

Because this was a classified mission, there was no coverage of the second stage flight and subsequent separation of the X-37B. SpaceX did, however, continue to follow the first stage all the way back to the ground.

After the boostback burn, the first stage again pitched around to point its engines toward the direction of travel. Meanwhile, four grid fins on the interstage of the rocket deployed. These fins help steer the booster in while traveling through the atmosphere.

Six minutes, 34 seconds after leaving Florida, the first stage performed an entry burn to ease itself back into the atmosphere over Florida. This lasted just under a minute.

About a minute later, the center Merlin 1D engine ignited to begin slowing the first stage down just above Landing Zone 1 at Cape Canaveral Air Force Station, just several miles south of where it launched from.

Seconds before touchdown, four landing legs deployed to allow for a safe landing, which occurred 8 minutes, 14 seconds after initially taking off.

This was the seventh successful ground landing and the 16th successful since December 2015. Today’s launch was the 41st launch of a Falcon 9 since 2010, the 36th from Cape Canaveral. Additionally, this was the 15th launch of any rocket from Cape Canaveral in 2017.

SpaceX hopes to launch at least seven more rockets before the end of 2017, including the maiden flight of the years-delayed Falcon Heavy. The latter is currently slated for liftoff in November.

The Boeing-built robotic OTV-5 mission was the fifth launch of an X-37B and the first to launch atop a Falcon 9. The decision to launch with SpaceX was only announced in June 2017. The previous four flights launched atop United Launch Alliance Atlas V rockets.

This particular spaceplane was used during the OTV-1 and OTV-3 missions in 2010 and 2012–14, respectively.

Not much is known about the X-37B program. The two spaceplanes are each about 11,000 pounds (4,990 kilograms) and measure about 29 feet (8.8 meters) long with a 15-foot (4.5-meter) wingspan.

The vehicle sports a small cargo bay about the size of the bed of a pickup truck. Inside, there is classified payload as well as a solar panel with gallium arsenide solar cells for power. Additionally, the spacecraft has a single maneuvering engine that burns hydrazine and nitrogen tetroxide.

While the orbit for OTV-5 is classified, the X-37B typically operates between 200 and 250 miles (320 and 400 kilometers).

Per the U.S. Air Force, the X-37B is an experimental test program to demonstrate technologies for a reliable, reusable, unmanned space test platform. The primary objective is to develop reusable spacecraft technologies for America’s future in space and operate experiments that can be returned to and examined on Earth.

There are two X-37B spacecraft. The second one launched on the OTV-2 and OTV-4 missions, the latter landing in May 2017.

In total, the two vehicles have racked up a combined 2,085 days in orbit during the previous four missions. How long OTV-5 will spend in orbit is also classified.

In the near term, the Space Coast is now in the process of preparing for Hurricane Irma. As 11 a.m. EDT (15:00 GMT), Sept. 7, the storm is still a Category 5 with maximum sustained winds of 175 mph (282 km/h).

On Sept. 5, in preparation for the OTV-5 launch, Cape Canaveral Air Force Station entered into hurricane condition (HURCON) 5. Additionally, on Sept. 7, the Brevard County Office of Emergency Management announced a mandatory evacuation order starting at 3 p.m. EDT (19:00 GMT) Friday, Sept. 8.

The order includes the barrier islands, Merritt Island and some mainland low-lying areas along the Indian River Lagoon. Those that live in mobile or manufactured homes, or in flood-prone areas, are also asked to evacuate regardless of their location.

Tropical storm-force winds are expected to begin overnight on Saturday, Sept. 9. Should the storm track on its current heading (as of Sept. 7), the worst of the storm is expected to occur late Sunday night, Sept. 10, into Monday morning, Sept. 11. Maximum sustained winds could be as high as 120–145 mph (193–233 km/h) – a Category 3 or Category 4 storm.

So far, the storm has caused catastrophic damage in its wake. The storm is the strongest ever recorded in the Atlantic. About 95 percent of homes and properties were destroyed on tropical islands Barbuda and St. Martin. Some 900,000 people are without power in Puerto Rico.

Written by: Derek Richardson
Original source: spaceflightinsider.com

No comments:

Post a Comment