Nasa Space Flight – SpaceX and Orbital both fired their new engines. SpaceX’s Merlin 1D rumbled for a full mission duration firing, while Orbital’s AJ-26 continued its testing ahead of its debut on their Antares launch vehicle
The Spacex Merlin D has improved performance. Thrust is increased from 95,000 lbf (sea level) to 140,000 lbf (sea level). Added throttle capability for range from 70-100 percent. Currently, it is necessary to shut off two engines during ascent. The Merlin 1D will make it possible to throttle all engines. Structure was removed from the engine to make it lighter.
The Merlin D has improved manufacturability. A simplified design is used lower cost manufacturing techniques. Reduced touch labor and parts count. Increased in-house production at SpaceX.
The engine firing was for 185 seconds with 147,000 pounds of thrust, the full duration and power required for a Falcon 9 rocket launch.
The extra power and multiple restart elements are major steps towards achieving the highly complex task of making Falcon 9 reusable, a vehicle known as F9r or Grasshopper.
The enhanced design makes the Merlin 1D the most efficient booster engine ever built, with a vacuum thrust-to-weight ratio exceeding 150, while still maintaining the structural and thermal safety margins needed to carry astronauts.
Additionally, as SpaceX continues to fulfil an extensive manifest of launches, the new engine is designed for improved manufacturability by using higher efficiency processes, increased robotic construction and reduced parts count.
SpaceX are expected to be next in action on October 5 of this year, a slightly slipped launch date, pending the approval of SpX-1 – the first Commercial Resupply Services (CRS) mission to the International Space Station (ISS). NASA and SpaceX teams are deep into their review of the COTS 2+ mission, with a view to approve the SpX-1 mission.
Orbital AJ-26 Test
SpaceX are one of two CRS partners for NASA, with Orbital’s Antares set to launch the Cygnus spacecraft on resupply missions from next year.
Orbital have to successfully complete two major milestones prior to their CRS runs, the first being the launch of their new Antares launch vehicle.
The Antares – formerly known as Taurus II – will then followed by a one-off full COTS level demonstration mission, not unlike SpaceX’s C2+ mission, tasking Cygnus with a single flight to prove its ability, prior to starting CRS operations proper.