Falcon-9 |
Space Exploration Technologies Corporation
|
The Merlin 1D+ engine now delivers a sea level thrust of 756
kN, representing a 16% increase over the initial Merlin-1D version. In vacuum conditions,
the Merlin 1D+ engine delivers 825 kN of thrust. The improved Merlin 1D+ Vacuum
engine uses an extended nozzle design and achieves a thrust of 935 kN, representing
a 17% increase in thrust.
The Merlin-1D+ engine has an active throttling capability which allows Falcon 9
v1.2 to fly a more flexible mission profile. The previous Merlin engines has
not or no active throttle capability and the Falcon-9 had to shut two Merlin engines
down to limit stress on the vehicle as the launcher approached first stage cutoff.
The tank capacities has been increased by change of the propellant coolings. The
liquid oxygen will now be about 23°C colder than the boiling point. This results
in a density increase of about 9%. Also, the Kerosene is cooled slightly. By a temperature
of about -6°C, its density increases by about 2%.
In addition, the second stage is total of 5 feet longer, the interstage the half
of it.
Moreover, it was the first time decided not to shut down two engines of the first
stage. Therefore, the name FT (Full thrust)
is used.
2018 -- SpaceX will launch its upgraded Falcon 9 rocket
(Block 5 configuration)
on May 04.
The upgraded rocket, known as the “Block 5” iteration, is a brand new vehicle. The
changes include updates to allow SpaceX to recover and reuse first stage boosters
with greater speed.
One of the major changes is the addition of more resilient heat shield material
at the base of the rocket’s first stage. The Block 5 engines can also produce more
power and feature a redesign to make the engines easier to reuse on multiple flights.
Block 5 is the most significant upgrade to the Falcon 9 rocket since SpaceX debuted
the “full thrust” configuration in December 2015, which was the first time the company
used super-chilled, densified RP-1 kerosene and liquid oxygen propellants.
SpaceX engineers also added a permanent fix on the Block 5 upgrade to resolve a
concern with turbine wheel cracks inside the Merlin engine’s turbopump, and new
helium tanks that are not susceptible to pooling frozen liquid oxygen and friction
that led to the explosion of a Falcon 9 rocket on the launch pad in 2016.
Falcon 9 first stage flown on a previous launch with polished engine nozzles, which
are no longer used on SpaceX missions.
Block 5 is the most significant upgrade to the Falcon 9 rocket since SpaceX debuted
the “full thrust” configuration in December 2015, which was the first time the company
used super-chilled, densified RP-1 kerosene and liquid oxygen propellants.
Since then, SpaceX has flown beefed up titanium grid fins to replace the single-use
aluminum steering wings used during the descent of the Falcon 9’s first stage. A
Falcon 9 launch from California in February debuted a slightly larger payload fairing.
Both enhancements are expected to regularly fly on Falcon 9 Block 5 missions.
Components on the Block 5 rocket, such as valves, were planned to be requalified
and redesigned at more extreme operating conditions and for longer durations.
Other changes on the Block 5 upgrade include new landing legs that can be retracted
without the need for recovery teams to remove them from the rocket, and the interstage
structure that connects the first and second stages will be black and unpainted.
The first stage’s engine section, known as the “octaweb,” will be bolted to the
bottom of the booster on the Block 5 configuration. The octaweb arrangement, which
sets the first stage’s nine Merlin engines at the bottom of the rocket and routes
liquid propellants to the powerplants, was welded to the rocket on earlier Falcon
9 designs.