Posted on 05/20/2015 7:22:45 AM PDT by Jack Hydrazine
The countdown is beginning for today’s launch of the Atlas 5 rocket to haul the Air Force’s X-37B reusable spaceplane back into orbit.
Clocks are picking up the seven-hour sequence of work that will prepare the booster, payload and ground systems for blastoff at 11:05 a.m. EDT (1505 GMT).
Soon the launch team will begin powering up the rocket to commence standard pre-flight tests. Over the subsequent few hours, final preps for the Centaur's liquid oxygen and liquid hydrogen systems will be performed, along with a test of the rocket's guidance system and the first stage propulsion and hydraulic preps, internal battery checks and testing of the GPS metric tracking system used to follow the rocket as it flies downrange, plus a test of the S-band telemetry relay system.
A planned hold begins when the count reaches T-minus 120 minutes. Near the end of the hold, the team will be polled to verify all is in readiness to start fueling the rocket for launch.
Supercold liquid oxygen begins flowing into the Centaur upper stage, followed by the first stage filling. Liquid hydrogen fuel loading for Centaur will be completed a short time later.
A final hold is scheduled at the T-minus 4 minute mark. That pause will give everyone a chance to finish any late work and assess the status of the rocket, payload, Range and weather before proceeding into the last moments of the countdown.
The unclassified launch period extends to 2:45 p.m. EDT (1845 GMT).
In today's first weather briefing to mission managers, all current conditions are observed GO for launch of the Atlas 5 rocket and odds for the launch period stand at 60 percent favorable. The main concern that meteorologists are watching are cumulus and anvil clouds and lightning potential.
The outlook predicts scattered clouds at 3,000 and 30,000 feet, isolated showers, good visibility, southwesterly winds of 10 gusting to 13 knots, a temperature in the low 80s degrees F.
The Atlas-Centaur rocket has been powered up at Complex 41 and guidance system testing is getting started for today's launch, as the countdown progresses as planned.
LAUNCH TIME. A pair of 10-minute launch windows will be avaialble for the X-37B to take flight aboard the Atlas 5 rocket today. Liftoff is targeted for 11:05 a.m. EDT (1505 GMT). A backup opportunity begins at 12:42 p.m. EDT (1642 GMT).
Atlas 5 represents the culmination of evolution stretching back several decades to America's first intercontinental ballistic missile. At the dawn of the space age, boosters named Atlas launched men into orbit during Project Mercury and became a frequent vehicle of choice to haul civil, military and commercial spacecraft to orbit. Topped with the high-energy Centaur upper stage, Atlas rockets have been used since the 1960s to dispatch ground-breaking missions for NASA, including the Surveyors to the Moon, Mariner flights to Mars, Venus and Mercury, and the Pioneers that were the first to visit Jupiter and beyond.
In its newest era, the Atlas 5 rocket sent the Mars Reconnaissance Orbiter to the red planet in 2005, propelled the New Horizons probe toward Pluto and the solar system's outer fringes in 2006, doubled up with the dual Lunar Reconnaissance Orbiter and LCROSS impactor to the Moon in 2009, hurled Juno to Jupiter in August 2011 and dispatched the car-sized Curiosity rover on the Mars Science Lab mission in November 2013.
Today marks the 54th flight for Atlas 5, born of the Air Force's competition to develop next-generation Evolved Expendable Launch Vehicles. In its previous 53 missions since debuting in August 2002, the Atlas 5 has flown 19 flights dedicated to the Defense Department, 12 for NASA, 11 with spy satellites for the National Reconnaissance Office. and 11 commercial missions with communications and Earth-observing spacecraft.
bttt
looks like a tampon.
On the side it should say “Sponsored by: Tampax”
Sometimes a rocket is just a rocket.
Did he just say that Bill Nye, the “Science” “Guy” will be there? How embarrassing.
launch in Florida?????
I miss the Saturn V. It looked like a real space going ship.
Hopefully the Atlas will launch before Bill Lie comes on.
Would you rather it be at Vandenberg, AFB in CA?
You can also watch it here.
http://www.ulalaunch.com/webcast.aspx
Couldn't he do a simulcast from the blast pit?
*
You want him to be a Geraldo of science?
Five minutes to liftoff!
LOL. Excellent.
Did anyone see that giant insect go by the rocket? I, for one, welcome our new fly overlords.
Top secret X-37B space plane to blast off this morning - and we still don’t know what it will do in orbit or when it will be back
X-37B drone will blast off on its fourth secret mission at 11:05 am ET
Theories range from it being a space bomber to destroying satellites
Flight will also test a system that makes satellites easy to manoeuvre
This is probably a small part of the vehicle’s true mission, say experts
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.