5 4 3 2 1

vehicle is pitching down range.

How wind dod chamber pressures are now?

NOL 179 mission. SpaceX's Falcon 9

rocket on June 19 launched NROL 179

classified mission from Space Launch

Complex 4 East at Windenburgg Space

Force Base in California. This was the

third flight for the Falcon 9 first

stage booster supporting this mission

which previously launched two Starlink

missions. Following first a separation,

the first a booster landed on the

landing zone 4 at Wenberg Space Force

Base in California.

Falcon 9 first incorporate nine Merlin

engines and aluminium lithium alloy

tanks containing liquid oxygen and

rocket grade kerosin propellent. Falcon

engine rate more than 1.7 million pounds

of thrust at the sea level. The nine

Marlin engines on the first stage are

gradually throttled near the end of the

first stage flight to limit the launch

vehicle acceleration as the rocket's

mass decreases with the burning of fuel.

These engines are also used to reorient

the first stage prior to re-entry and to

deacelate the vehicle for landing.

Merlin is a family of rocket engines

developed by SpaceX for use on its

Falcon 1, Falcon 9 and Falcon Heavy

launch vehicles. Merlin engines uses a

rocket grade kerosene propellent and

liquid oxygen as a rocket propellent in

a gas genator power cycle. The Merlin

engine was originally designed for

recovery and reuse. Marlin vacuum

features a larger exhaust section and a

significantly larger expansion nozzle to

maximize the engine's efficiency in the

vacuum of space. Its combustion chamber

is regeneratively cooled while the

expansion nozzle is radiatively cooled

at full power. The Merlin vacuum engine

operates with the greatest efficiency

ever for an Americanmade hydrocarbon

rocket engine.

The Falcon 9 first stage is equipped

with four landing legs made of

state-of-the-art carbon fiber with

aluminum honeycomb placed symmetrically

around the base of the rocket. They are

stubbed at the base of the vehicle and

deploy just prior to landing. The

interstage is a composite structure that

connects first and the second stages and

houses the panometric pusher that allow

first and the second stage to separate

during flight. Fol is equipped with four

hypersonic grid fins positioned at the

base of the interstage. They orient the

rocket during re-entry by moving center

of pressure. The second stage powered by

a single Merlin vacuum engine delivers

Falcon 9's payload to the desired orbit.

The second stage engine ignites a few

seconds after the stage separation and

can be restarted multiple times to place

multiple payloads into different orbits.

Made of a carbon composite material. The

fairing protects satellite on their way

to orbit. The fairing is jettisoned

approximately three minutes into flight

and SpaceX continues to recover fairing

for reuse on its future missions.

Let me tell you again that this was the

third flight for the Falcon and first

booster supporting this mission which

previously launched two Starlink

missions. Following first day

separation, the first stage booster

landed on the landing zone 4 at

Windenberg Space Force Base in

California.

>> Stage one landing light deploy.

>> Stage one landing confirmed.

>> And another successful landing of our

Falcon 9 rocket. And as a reminder, this

was the third flight for the booster

supporting tonight's mission. And as

mentioned at the top of the program, we

will not be showing any stage two or

deployment views today at the request of

our customer. So with the successful

recovery of that first stage, we'll be

bringing our live mission coverage to a

close. We'd like to thank the National

Reconnaissance Office for entrusting us

with today's mission, as well as the

Range and FAA for their support. And if

you're interested in more launch

coverage, head on over to

spacex.com/launches

for the most up-to-date information. And

of course, remember to