Like the December 2015 landing, there is the possibility that residents of northern and central Brevard County, Florida, may hear one or more sonic booms during tonight’s landing. A sonic boom is a brief thunder-like noise a person on the ground hears when an aircraft or other vehicle flies overhead faster than the speed of sound.
Residents of the communities of Cape Canaveral, Cocoa, Cocoa Beach, Merritt Island, Mims, Port Canaveral, Port St. John, Rockledge, Scottsmoor, Sharpes, and Titusville, Florida, are most likely to hear a sonic boom, although what residents experience will depend on weather conditions and other factors.
Launch Weather 90% ‘GO’
According to the latest weather forecast from the United States Air Force 45th Weather Squadron, there is a 90% percent chance overall of acceptable weather conditions for tonight’s launch. The primary weather concerns for launch are cumulus clouds and flight through precipitation.
Payload
The CRS-9 mission will carry an International Docking Adapter, or IDA, that will provide a vital link between the International Space Station and the new spacecraft in development with NASA’s Commercial Crew Program.
Outfitted with a host of sensors and systems, the IDA is built so spacecraft systems can automatically perform all the steps of rendezvous and dock with the station without input from the astronauts. Manual backup systems will be in place on the spacecraft to allow the crew to take over steering duties, if needed.
“It’s a passive system which means it doesn’t take any action by the crew to allow docking to happen and I think that’s really the key,” said David Clemen Boeing’s director of Development/Modifications for the space station.
The IDA stands about 42 inches tall and is 63 inches in diameter on the inside. Sensors and other fittings ring the perimeter of the adapter and give it an overall diameter of about 94 inches. Spacecraft flying to the station will use the sensors on the IDA to track to and help the spacecraft’s navigation system steer the spacecraft to a safe docking without astronaut involvement.
The adapter also represents the first on-orbit element built to the docking measurements that are standardized for all the spacecraft builders across the world. Its first users are expected to be the Boeing Starliner and SpaceX Crew Dragon spacecraft now in development in partnership with NASA’s Commercial Crew Program. Because the adapter is designed to an international standard, future spacecraft will be able to dock there, too.
“It’s really good we have an international standard now that anybody can build against and come dock to the station or to anything that has the same standard,” Clemen said.
While the crew will be able to move the supplies out of the interior, pressurized compartment of the Dragon without leaving the station, the robotic arm will be called on to pull the IDA from the trunk and maneuver it near the port where it will be connected. NASA astronauts currently living aboard the station will perform a spacewalk later this summer to make the final connection of the IDA to the Harmony module.
This adapter will be one of two at the station. Another already being assembled at NASA’s Kennedy Space Center will be carried into orbit during a future SpaceX cargo resupply mission and attached to another open port on the station, giving the station two docking areas for the new generation of human-rated spacecraft. Both of the IDAs are identical.
With the IDA loaded in the rear trunk of the Dragon, the interior of the spacecraft will hold about 3,800 pounds of material including experiment supplies for dozens of the 250 research projects taking place on the station during Expeditions 48 and 49. The payloads are vital elements for the crew on the station to conduct its research for those on the Earth as well as to help advance the knowledge needed for a future journey to Mars by astronauts.
Photo credit: SpaceX
