SpaceX plans to launch a robotic space capsule, fly it around the world two times, then order the craft back home Wednesday in a whirlwind test flight to demonstrate the ship’s readiness to NASA.
The Falcon 9 rocket fired its nine Merlin first stage engines Saturday during a preflight countdown rehearsal and health check. Credit: NASA/KSC
The mission is scheduled to last three-and-a-half hours after originating from Cape Canaveral, Fla. Splashdown of the Dragon spacecraft will occur in the Pacific Ocean several hundred miles off the west coast of northern Mexico and California.
Liftoff from Cape Canaveral’s Complex 40 is scheduled for a launch window opening at 9 a.m. EST and closing at 12:22 p.m. EST (1400-1722 GMT) Wednesday.
Launch was delayed 24 hours as SpaceX engineers inspected and repaired cracks in the Falcon 9 second stage’s Merlin engine nozzle.
The nozzle features a 9-foot-long extension made of ultra-thin niobium alloy. Officials discovered cracks in the material in a review of close-out photos Monday, and SpaceX repaired the problem.
The flight is sponsored by NASA’s Commercial Orbital Transportation Services, or COTS, program, an initiative to develop private spacecraft to ferry cargo to and from the International Space Station.
The federal government has invested $253 million in SpaceX’s Falcon and Dragon programs so far. The awards are based on milestones in design, development and flight testing of the company’s Falcon 9 rocket and Dragon capsule.
Described as a public-private partnership, SpaceX is utilizing NASA know-how and resources for the flight, but the company holds ultimate responsbility for the mission.
“We’ve spent well over $600 million at SpaceX getting to this point,” said Gwynne Shotwell, SpaceX president.
“NASA took on the role as the lead investor (and) also a technical consultant to SpaceX to offer assistance when needed and requested,” said Alan Lindenmoyer, manager of the commercial crew and cargo program at NASA’s Johnson Space Center in Houston.
Elon Musk, SpaceX’s founder and CEO, said the flight is supposed to last two orbits, but managers could issue a re-entry “at any time” from the company’s new Mission Control Center in Hawthorne, Calif.
Photo of SpaceX’s mission control facility in Hawthorne, Calif. Credit: SpaceX
The two-stage Falcon 9 rocket will deliver the 11,500-pound Dragon spacecraft to orbit 10 minutes after liftoff. Then the capsule will pull away from the Falcon’s second stage, leaving behind its trunk compartment that will ultimately house unpressurized cargo and experiments on future flights.
The mission will operate entirely on battery power, Musk said. The next flight will feature twin panels of solar arrays for electricity.
“Then it’s going to basically turn on all its systems and engines and start flying around the sky,” Musk said in an interview Sunday. “Then something could go wrong in the propulsion system, electronics, software, pressure vessel integrity, we could lose telemetry. I’m taking this pessimistic view and naming everything that could go wrong. It’s important to let the public know there’s so much that can go wrong. This really is rocket science.”
The Dragon will communicate through a fleet of NASA tracking satellites and a network of ground stations scattered across the globe, ensuring mission controllers in Hawthorne are in regular contact with the spacecraft.
Eighteen Draco thrusters on the craft’s exterior will provide impulses to change its orientation in space and alter its orbit. Several of the miniature rocket engines will fire at the end of the flight to slow the ship’s velocity and drop from orbit.
Engineers have programmed portions of the Dragon’s rendezvous sequence with the space station into the craft’s computer for this mission. The flight testing will verify the capsule’s ability to accomplish tightly-choreographed maneuvers.
“The intent is the Dragon will execute a regimented series of maneuvers, and once its done that, we will command it to return to Earth,” Musk said.
The maneuvers will test “the elements that matter to determine whether our guidance and navigation hardware is doing what it should and that our inertial navigation system is correctly reporting where it is in the sky,” Musk said.
Controllers will have the ability to intervene if necessary, but most of the tests are automated. Mission control will issue the command for the Dragon’s de-orbit burn and re-entry, according to Musk.
The plunge back into the atmosphere will be expertly guided by the craft’s Draco thrusters. The capsule’s blunt shape, designed to help steer the vehicle in the atmosphere, can also be exploited for precision landings, Musk said.
The crack in the second stage engine nozzle is in the niobium flange and probably won’t pose a problem in real-time flight, although notice hasn’t been released about what kind of repair was enacted, if any.
The launch window is three hours, 9 am to around noon until tomorrow. No word has been given about whether the weekend is a possibility or not, or if it’s needed.
Good luck and God’s speed Dragon!