Update for 3:11 a.m. EDT: SpaceX postponed the Friday launch Dragon cargo launch to the International Space Station for NASA due to an issue with the drone ship Of Course I Still Love You, where the first stage of the mission's Falcon 9 rocket was to land after this morning's liftoff from Cape Canaveral Air Force Station in Florida. The next launch attempt will be Saturday, May 4, at 2:48 a.m. EDT (0648 GMT).
CAPE CANAVERAL, Fla. — SpaceX is preparing to launch its next resupply mission to the International Space Station (ISS).
At 3:11 a.m. EDT (0711 GMT) on Friday (May 3), a shiny new SpaceX Falcon 9 rocket will take to the skies here from Cape Canaveral Air Force Station, lofting a robotic Dragon cargo capsule carrying more than 5,500 lbs. (2,495 kilograms) of fresh supplies, experiment hardware and other gear for the astronauts aboard the orbiting lab.
You can watch the launch live here at Space.com, courtesy of NASA. You can also watch directly via NASA TV or SpaceX. NASA's webcast will begin Friday at 2:45 a.m. EDT 0645 GMT). SpaceX's webcast will begin about 20 minutes before liftoff.
Related: How SpaceX's Dragon Space Capsule Works (Infographic)
The launch was originally slated to happen on April 26 and has been delayed several times. The latest delay, which saw the launch slip from May 1 to May 3, resulted from a power issue on the space station.
NASA officials explained today (March 2) during a prelaunch news conference that, thanks to some diligent robotic work, the power issues on the ISS have been remedied. "Station is in good shape now to support the CRS-17 launch," said Kenny Todd, NASA's manager of space station operations and integration.
The mission is SpaceX's 17th of 20 commissioned by NASA under the agency's first Commercial Resupply Services contract. The California-based aerospace company also has a commercial-crew deal with NASA, in which the company will transport astronauts to and from the ISS aboard a crewed version of the Dragon spacecraft.
Crew Dragon already has one mission under its belt, acing a test flight to the ISS last month. The mission, dubbed Demo-1, lasted for just six days and demonstrated the capsule's ability to dock to (and undock from) the space station.
The next flight of a Crew Dragon capsule, Demo-2, will carry two NASA astronauts to the space station and back. That mission was originally expected to lift off sometime this summer; however, those plans are on indefinite hold as SpaceX and NASA investigate an April 20 engine-test mishap that destroyed a Crew Dragon capsule.
Twelve days ago, orange smoke was spotted wafting over SpaceX's test facilities at Cape Canaveral Air Force Station. An unofficial video posted to Twitter soon after appeared to show the capsule exploding. Both SpaceX and NASA have remained quiet in the intervening days, but Hans Koenigsmann, vice president of flight reliability for SpaceX, divulged new information during today's prelaunch briefing at Kennedy Space Center.
Koenigsmann explained that it's still very early in the investigation and that there's an abundance of data to review. He said that the smaller Draco thrusters the vehicle relies on powered up just fine. (These are the same thrusters used by Cargo Dragon.) But just before the SuperDracos — special engines embedded in the craft's hull that pull the capsule to safety in the event of a launch emergency — were fired, something went wrong and the vehicle exploded.
Despite both being called "Dragon spacecraft," the Crew and Cargo variants are entirely different vehicles. One major difference is that the cargo spacecraft lacks the SuperDraco abort engines. This aligns with NASA's resupply plans and helps explain why the space agency greenlighted the capsule to fly despite the ongoing investigation with the crewed counterpart.
In addition, the capsule scheduled to fly tomorrow morning has already been to space and back before, previously flying on CRS-12 in August 2017. But the accident has affected where SpaceX plans to land its first-stage Falcon 9 booster.
That first stage was originally supposed to touch down on solid ground at SpaceX's Landing Zone 1 at Cape Canaveral. However, due to that spot's close proximity to the testing facilities that hosted the Crew Dragon two short weeks ago, SpaceX has had to make other arrangements.
The company announced via email on May 2 that it intended to land the booster on one of two SpaceX drone ships, something it has done 24 times before. Only this time, the drone ship will be positioned just 12 miles (20 kilometers) offshore from SpaceX's Cape Canaveral facilities.
This means there's a good chance that watchers on Florida's Space Coast will not only see the landing, but may hear it as well; sonic booms could crackle across the sky when the booster reenters the atmosphere.
The launch could face more delays; the weather forecast for tomorrow's launch attempt does not look favorable. Officials from the Air Force's 45th Space Wing said that an area of disturbed weather over the Bahamas is threatening the Space Coast with rain. If the launch does get delayed, a backup attempt should happen Saturday (May 4) at 2:48 a.m. EDT (0648 GMT). However, if the launch delays past that, the next attempt will be no earlier than May 12 or May 13, Todd said today.
If Dragon launches as planned, it will arrive at the space station on May 5, where it will be captured by the station's robotic arm at 7 a.m. EDT (1100 GMT) and installed 2 hours later. Dragon will remain attached to the station until about May 31. At that time, the craft will journey back to Earth, carrying 2,269 lbs. (1,029 kg) of experiments.
Editor's note: Visit Space.com early Friday, May 3, for complete coverage of the SpaceX CRS-17 Dragon cargo mission.
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