Delta II
ICESat-2

Live Status

Sept. 13 -- LRR completed

Preparations are underway for the United Launch Alliance Delta II rocket’s sentimental sendoff into retirement after 29 years of service to the U.S. Air Force, NASA, the National Reconnaissance Office and commercial customers.

Saturday’s launch is scheduled for 5:46 a.m. PDT (8:46 a.m. EDT; 1246 UTC) from Space Launch Complex-2 at Vandenberg Air Force Base in California. The mission will deliver NASA’s second Ice, Cloud and land Elevation Satellite, or ICESat-2, environmental spacecraft into a polar orbit to precisely measure the changing height of Earth’s ice sheets in unprecedented detail.

We will provide live updates throughout the countdown and flight on this page starting at 2:30 a.m. PDT (5:30 a.m. EDT; 0930 UTC).

The Launch Readiness Review was completed earlier today. The meeting, chaired by NASA Launch Manager Tim Dunn, confirmed the readiness of the launch vehicle, payload and mission assets for entering the countdown.

The launch weather forecast, according the 30th Weather Squadron at Vandenberg, calls for a deck of low stratus clouds at 1,000 feet and high cirrus at 30,000 feet, visibility of 2-3 miles with fog, northerly winds of 10 to 15 knots and a temperature of 52 degrees F. There is a zero percent chance of a weather rule violation.

This will be the 155th flight by the Delta II rocket since its debut on Feb. 14, 1989. The lasting legacy of the Delta II extends from the Global Positioning System that revolutionized modern navigation on Earth to the exploration of the Martian surface with the Mars rovers Spirit and Opportunity.

The rocket was created in the late 1980s by McDonnell Douglas to serve the Air Force’s need to launch GPS satellites, and the vehicle did just that. Between 1989 and 2009, the dependable Delta II successfully deployed four dozen navigation spacecraft to form the operational constellation and maintain it.

The Delta II rocket also successfully launched eight Mars missions between 1996 and 2007, providing NASA with a reliable launch vehicle that established a campaign of exploration using orbiters, landers and surface rovers. The history includes the launch of Mars Global Surveyor in November 1996, the long-lived orbiter that mapped the red planet, the Mars Pathfinder in December 1996 that demonstrated a novel use of air bags to cushion landings on another planet, the 2001 Mars Odyssey mission that continues to orbit today, the twin Spirit and Opportunity rovers that left Earth a month apart in the summer of 2003 seeking evidence of past water on the surface of Mars and the Phoenix lander, launched in 2007, that went to the north pole of Mars to dig into the soil using a robotic arm to look for subsurface water ice.

Delta II also extended scientific pursuits to the planet Mercury with NASA’s MESSENGER orbiter, to small worlds in our solar system like the NEAR-Shoemaker that landed on the tiny rock called Eros, the Dawn spacecraft that explored Vesta and Ceres and Deep Impact that smashed into comet ¬Tempel 1 to study its interior, the twin STEREO probes to observe the sun, the Stardust and Genesis missions that returned samples of comet dust and the solar wind to Earth, the Kepler observatory to discover exoplanets in the galaxy and the Spitzer Space Telescope with infrared vision to scan the universe.

Evolving market conditions brought about the Delta II’s retirement. GPS satellites became larger and shifted to bigger launch vehicles, NASA now relies on the Atlas V to send its missions to Mars and there are not many payloads in the Delta II market space any longer.

But the beloved rocket will live on in the hearts of the men and women who designed, built and launched it for three decades.

Sept. 14 -- Coverage begins early tomorrow!

Welcome to our Live Launch Updates Blog, bringing you official and timely information during countdowns to liftoff.

Join us early tomorrow morning for live reports throughout the Delta II rocket's countdown to the ICESat-2 launch from Vandenberg Air Force Base in California. Our automatically-refreshing blog -- coming to you from Vandenberg's launch control center -- will begin on this page at 2:30 a.m. PDT (5:30 a.m. EDT; 0930 UTC) prior to the countdown starting.

Liftoff of the final Delta II rocket is scheduled for 5:46 a.m. PDT (8:46 a.m. EDT; 1246 UTC).

For a preview of what to expect after liftoff, see our Mission Profile video.

11:35 p.m. PDT (0635 UTC)

Retraction of the Mobile Service Tower from around the Delta II rocket began at 11:34 p.m. PDT (2:34 a.m. EDT; 0634 UTC).

11:48 p.m. PDT (0648 UTC)

The 177-foot-tall Mobile Service Tower at Space Launch Complex-2 has been retracted to its launch position, revealing the United Launch Alliance Delta II rocket for its morning liftoff to deliver NASA’s ICESat-2 laser altimetry spacecraft into orbit to measure the ebbs and flows of Earth’s polar ice.

The MST is a critical part of the launch complex, proving the primary access and weather protection to the rocket during its stay on the launch pad, and the overhead crane system serves a vital role in vertical integration of the rocket elements and payload.

Rollback of the MST signals a major milestone in the early portion of launch day operations. Configuring launch pad systems and securing equipment will be completed over the next few hours before all personnel clear the site for fueling.

1:00 a.m. PDT (0800 UTC)

See our Flickr page for a collection of beautiful photos of the Delta II rocket taken by United Launch Alliance during rollback of the service tower.

2:30 a.m. PDT (0930 UTC)

From Vandenberg Air Force Base in California, this is Delta Launch Control at T-minus 2 hours, 30 minutes and holding.

We are just over three hours away from liftoff of the final United Launch Alliance Delta II rocket, a venerable industry workhorse for nearly 30 years. This will be the 155th and last flight of the beloved rocket that was developed to launch the Global Positioning System, enabled exploration of Mars and served the medium-class space launch market with distinction.

Today’s liftoff is scheduled for 5:46 a.m. PDT (8:46 a.m. EDT; 1246 UTC) from Space Launch Complex-2 at Vandenberg Air Force Base on a 53-minute ascent to deploy NASA’s ICESat-2 environmental satellite into polar orbit to observe the changes of planet Earth.

The countdown is being orchestrated from the Remote Launch Control Center, located about six miles from the pad, where ULA Launch Conductor Scott Barney and his team will soon initiate the countdown sequence for the Delta II rocket’s bittersweet flight into retirement.

Down the hall in the Mission Director’s Center, senior managers, including ULA Launch Director Tom Heter and NASA Launch Manager Tim Dunn, provide guidance to the team throughout today’s operation.

We are standing by to enter into the count at 2:46 a.m. from the T-minus 2 hour, 30 minute mark. There are two built-in holds at T-minus 15 minutes and T-minus 4 minutes, with durations of 20 minutes and 10 minutes, respectively.

At T-minus 2 hours, 30 minutes and holding, this is Delta Launch Control.

2:46 a.m. PDT (0946 UTC) –Countdown begins

The countdown has been initiated for today’s Delta II rocket launch of NASA's Ice, Cloud and land Elevation Satellite-2 (ICESat-2) mission that will track the changing Earth below.

The next three hours will see the rocket’s guidance system activated and tested, the helium and nitrogen systems on the vehicle pressurized, kerosene and super-cold liquid oxygen loaded into the first stage and engine nozzle steering checks conducted. Those are the key highlights leading to our target liftoff time of 5:46 a.m. PDT (8:46 a.m. EDT; 1246 UTC).

3:01 a.m. PDT (1001 UTC)

The Delta II rocket was created in the late 1980s by McDonnell Douglas to fulfill the Air Force’s need for a medium-performance launch vehicle to carry the Global Positioning System’s first generation of operational satellites into space and create a worldwide precision navigation network. Launching for the first time on Valentine’s Day 1989, the rocket saw several subsequent years filled with rapid-fire missions that successfully deployed an entire fleet of GPS satellites to create a revolutionary utility for the U.S. military and the global civilian population.

Today, GPS is a practical benefit of space to a billion users around the world, offering accurate location data to help with travel directions and exact timing accuracy for financial transactions including credit card purchases and ATMs.

3:10 a.m. PDT (1010 UTC)

Hands-on work to prepare pad systems, put the infrastructure into the proper configuration and arm the vehicle has been completed, leading to a pad-clear status for all personnel at this time.

3:26 a.m. PDT (1026 UTC)

Procedures are underway to turn on RIFCA, the Delta II rocket’s Redundant Inertial Flight Control Assembly computer, that will guide the vehicle to its intended destination in space today.

3:27 a.m. PDT (1027 UTC)

With the launch pad clear of all personnel, hazardous operations are commencing for today’s launch. The helium bottles and nitrogen tanks on the first and second stages are being brought to high-pressure levels, and the second stage fuel and oxidizer tanks, which were loaded earlier this week with storable hypergolic propellants, are being pressurized for flight.

3:40 a.m. PDT (1040 UTC)

Preparations to load the Delta II rocket's first stage with RP-1 fuel are beginning. After verifying valves, sensors, flow meters and equipment are ready, the highly refined kerosene propellant will start flowing into the vehicle.

3:44 a.m. PDT (1044 UTC) -- RP-1 fueling begins

About 10,000 gallons of the kerosene propellant, called RP-1, are pumping into the base of the rocket from a ground storage tank as the fueling of Delta II's first stage begins for today's launch.

3:50 a.m. PDT (1050 UTC)

We are passing the 3,000-gallon level on the rocket. The propellant will feed the RS-27A main engine during the first four-and-a-half minutes of powered flight.

3:52 a.m. PDT (1052 UTC)

The Air Force’s 30th Weather Squadron here at Vandenberg has provided a detailed forecast for today's launch opportunity, predicting a 100 percent chance of favorable conditions at liftoff. This briefing feeds into the decision-making process whether to proceed with liquid oxygen loading operations.

The launch time forecast calls for low clouds at 1,000 feet, visibility of 2-3 miles with fog, northwesterly winds 10-15 knots and a temperature in the mid-to-low 50s.

3:59 a.m. PDT (1059 UTC)

The launch team has computed that the full load for the first stage fuel tank will be 9,881 gallons.

Once the tank is filled to the 98 percent level, or 9,683 gallons, the "rapid load" valve will be closed and the slower "fine load" phase will continue to top off the tank.

4:01 a.m. PDT (1104 UTC)

T-minus 1 hour, 15 minutes (L-1 hour, 45 minutes) and holding. The count has entered a 15-minute hold to give the team time to finish with tasks prior to liquid oxygen loading. These 15 minutes will be borrowed from the T-minus 15 minute planned hold, which will be shortened from 20 minutes to 5 minutes in duration.

4:04 a.m. PDT (1104 UTC) – RP-1 loading is complete

The first stage fuel tank of the Delta II rocket has been fully loaded for today's launch. The tank was filled with a highly refined kerosene during a 20-minute, 23-second process.

4:10 a.m. PDT (1110 UTC)

NASA’s ICESat-2 spacecraft being launched today is the advanced predecessor to the first ICESat mission that was launched from Vandenberg atop a Delta II rocket in 2003 and operated until 2009.

This new bird’s laser-ranging instrument fires its laser 10,000 times per second to take measurements every 28 inches along the satellite’s flight path. The first ICESat pulsed its laser 40 times per second and measured every 558 feet. As a comparison, if measurements were taken by the two satellites over a football field, the first ICESat would have collected data points outside the two end zones, but ICESat-2 would take measurements between each yard line.

4:16 a.m. PDT (1116 UTC)

T-minus 1 hour, 15 minutes (L-1 hour, 30 minutes) and counting. Clocks have resumed ticking toward a liftoff a 5:46 a.m. PDT. A readiness poll for liquid oxygen loading is next.

4:16 a.m. PDT (1116 UTC) -- GO for LOX loading

A successful readiness poll of the launch team by ULA Launch Conductor Scott Barney, with final approval by Launch Director Tom Heter, has given clearance to proceed with liquid oxygen loading into the Delta II rocket's first stage.

4:18 a.m. PDT (1118 UTC)

The launch team has kicked off the early steps to prepare for LOX loading. Tanking should commence momentarily.

4:19 a.m. PDT (1119 UTC)

Confirmation has been received that the rocket's guidance and control system has been powered and brought online.

4:21 a.m. PDT (1121 UTC) -- LOX loading begins

This is Delta Launch Control at T-minus 1 hour, 10 minutes (L-1 hour, 25 minutes) and counting. Flow valves have opened and liquid oxygen is streaming into the base of the Delta II rocket at Vandenberg Air Force Base's Space Launch Complex-2.

4:25 a.m. PDT (1125 UTC) – Launch window update

With LOX load now underway, today’s usable launch window has narrowed from two hours, 34 minutes to a total duration of 69 minutes, extending from 5:46 to 6:55 a.m. PDT (8:46-9:55 a.m. EDT; 1246-1355 UTC).

This narrowing ensures that the kerosene fuel on the first stage remains at an optimal temperature and does not become too cold from the cryogenic liquid oxygen during a prolonged launch window.

The kerosene and LOX are consumed by the Aerojet Rocketdyne RS-27A main eying during the initial four-and-a-half minutes of flight to propel the vehicle to the edge of space before staging.

4:31 a.m. PDT (1131 UTC)

We are 10 minutes into loading minus 298-degree F liquid oxygen into the Delta II launch vehicle, the last of the commodities to be placed aboard the rocket before launch. Tanking should take about 25 minutes.

4:36 a.m. PDT (1136 UTC)

We are now 70 minutes away from liftoff of the final Delta II rocket, a storied launch vehicle that has flown 154 times to date over the last 29 years. The history includes 57 national security launches, 51 NASA science missions and 46 commercial flights. A total of 110 launches originated at Cape Canaveral Air Force Station in Florida and this will be the 45th from Vandenberg. ICESat-2 will be the 231st primary payload put into orbit by the Delta II.

4:46 a.m. PDT (1146 UTC)

This is Delta Launch Control as we enter the final 60 minutes to liftoff. The Delta II rocket will deliver NASA's ICESat-2 environmental spacecraft into orbit to precisely measure the changing height of Earth’s polar ice in unprecedented detail. It will pulse green laser beams at the planet below 10,000 times per second and determine the elevation to an accuracy of 4 millimeters.

The satellite carries one instrument -- the Advanced Topographic Laser Altimeter System, or ATLAS -- that will use a single laser that is split into six beams and arranged in three pairs to better gauge the slope of Earth's surface. ICESat-2 will record the roundtrip time of laser photons as they leave ATLAS, reflect off the ground and return to the receiver telescope. By matching those times with the satellite's location in space, scientists will compute the heights of Earth's surface to track the diminishing ice sheets, estimate the changing mass of glaciers and study sea ice thickness.

Northrop Grumman constructed the satellite at its factory in Gilbert, Arizona, and NASA built the ATLAS instrument at the Goddard Space Flight Center in Greenbelt, Maryland.

4:48 a.m. PDT (1148 UTC)

Liquid oxygen loading has been accomplished for today’s countdown, completing in 26 minutes and 38 seconds. The rocket’s tank will be replenished through the remainder of the count to replace the super-cold LOX that warms and naturally boils away.

4:51 a.m. PDT (1151 UTC)

The Delta II rocket stands 132 feet tall and weighs about 358,000 pounds fully fueled. It will launch on nearly 650,000 pounds of thrust from the RS-27A main engine and four side-mounted solid rocket motors.

The ICESat-2 spacecraft atop the launch vehicle is 12.5 feet tall and has a mass of more than 3,300 pounds. It will have a wingspan of 33 feet once the power-generating solar array is deployed in space.

5:01 a.m. PDT (1201 UTC)

We are just 45 minutes away from liftoff time. The Delta 7420-10C is the official designation of the two-stage launch vehicle flying today. It has a kerosene and liquid oxygen first stage powered by an Aerojet Rocketdyne RS-27A main engine, four ground-lit, side-mounted Northrop Grumman Graphite Epoxy Motors (GEM-40) solid rocket motors and a hypergolic second stage that burns nitrogen tetroxide and a hydrazine blend called Aerozine 50 in its restartable Aerojet Rocketdyne AJ10-118K engine. The payload is protected during atmospheric ascent by a 10-foot-diameter fairing built of composites in two halves.

This particular configuration is flying for the 14th time today. It first flew in 1998 and has performed multiple launches of commercial Globalstar mobile telephone satellites and the constellation of Italian COSMO-SkyMed radar-imaging spacecraft, deployed the GeoEye-1 Earth-imager and performed NASA’s Calipso/CloudSat dual satellite launch.

5:05 a.m. PDT (1205 UTC)

The launch team is setting up for flight slews, the next major milestone in the countdown. This is the steering test patterns that are run on the Delta II rocket nozzles to ensure proper gimbaling during the ascent.

5:08 a.m. PDT (1208 UTC)

NASA’s live coverage and commentary of today’s launch is about to begin in the embedded stream on this page.

5:09 a.m. PDT (1209 UTC)

Steering checks on the second stage AJ10-118K engine nozzle have finished.

5:12 a.m. PDT (1212 UTC)

The first stage RS-27A main engine and twin vernier steering thrusters have completed their slew patterns.

5:16 a.m. PDT (1216 UTC) -- Countdown holding

This is Delta Launch Control at T-minus 15 minutes and holding (L-30 minutes). Clocks have just entered a 5-minute planned, built-in hold. This is the next-to-last pause scheduled into the countdown to give engineers time to address any issues they may be assessing or catch up work running behind schedule. At this moment, however, today’s countdown operation is progressing and we continue to target 5:46 a.m. PDT (8:46 a.m. EDT; 1246 UTC) for liftoff of the final Delta II rocket and NASA’s ICESat-2 environmental spacecraft.

5:18 a.m. PDT (1218 UTC) -- Weather is GO!

Weather is observed and forecast “go” for liftoff of the Delta II rocket from Vandenberg Air Force Base at the opening of today’s launch window, the Air Force launch weather officer just reported in the countdown’s final scheduled briefing.

The outlook now calls for low clouds and unrestricted visibility.,

5:21 a.m. PDT (1221 UTC) -- Countdown resumes

This is Delta Launch Control at T-minus 15 minutes (L-25 minutes) and counting. Countdown clocks are running again after the 5-minute hold and headed to the T-minus 4 minute mark where the final planned hold will occur. We remain on schedule for a liftoff at 5:46 a.m. PDT (8:46 a.m. EDT; 1246 UTC).

5:26 a.m. PDT (1226 UTC)

We are now 20 minutes from the start of today’s launch window.

Ignition sequence start for the RS-27A main engine begins at T-minus 3 seconds when the first stage control console operator in the Launch Control Center presses the engine start switch. The four solid rocket motors then ignite at T-0 to lift the vehicle away from Space Launch Complex-2. A series of pitch, yaw and roll maneuvers will place the Delta II on its southerly heading on a course over the Pacific to obtain a near-circular orbit of 288 statute miles, inclined 92 degrees relative to the equator.

The solids will be jettisoned once clear of the offshore oil rigs, leaving the first stage to continue burning for the first four-and-a-half minutes of flight. After staging, the second stage ignites for a six-and-a-half-minute firing to achieve an elliptical transfer orbit. The payload fairing is separated shortly into the second stage burn.

After a 37-minute coast period, the second stage will restart its engine fir a brief 7-second firing to circularize the orbit. Deployment of ICESat-2 is expected nearly 53 minutes after liftoff.

The second stage will perform a third burn to enter a different orbit for the launch of four educational CubeSats from California Polytechnic University, the University of California at Los Angeles and the University of Central Florida. They well be ejected from dispensers on the rocket at intervals between T+plus 76 and 79 minutes.

A fourth and final burn by the second stage nearly two hours after liftoff will serve as a deorbit burn to remove the spent rocket body from space.

5:28 a.m. PDT (1228 UTC)

Upper level wind conditions are deemed acceptable for flight of the Delta II this morning. A series of weather balloons have been sent aloft over the past several hours to measure the velocity and direction of the winds. A team at ULA’s Denver Operations Support Center received that data and selects the proper flight profile that would ensure a safe climb by the rocket through the atmosphere.

5:32 a.m. PDT (1232 UTC) -- Countdown holding

This is Delta Launch Control at T-minus 4 minutes and holding L-14 minutes). We have just gone into the countdown’s final build-in hold. This is planned to be a 10-minute hold, during which time the final readiness polls of mission managers and the combined launch team will be conducted. We continue to target 5:46 a.m. PDT (8:46 a.m. EDT; 1246 UTC) for liftoff of Delta II and NASA’s ICESat-2 scientific spacecraft.

5:33 a.m. PDT (1233 UTC)

The ICESat-2 spacecraft is transferring to internal power for launch. Confirmation that the satellite is in the proper configuration and go for launch will be announced just prior to resuming the countdown.

5:37 a.m. PDT (1237 UTC)

The hold will be extended a few minutes and launch time has shifted 6:02 a.m. PDT (9:02 a.m. EDT; 1302 UTC) to resolve a temperature issue on the second stage.

5:51 a.m. PDT (1251 UTC)

NASA Launch Manager Tim Dunn has polled his agency team for readiness to proceed into fueling operations. The NASA team is reported GO. That input will be passed to ULA Launch Director Tim Heter during his poll in the next few minutes.

5:54 a.m. PDT (1254 UTC)

We are just 8 minutes away from the final launch of a legendary rocket, the Delta II. All launch commit criteria are "go."

5:56 a.m. PDT (1256 UTC) -- GO for launch!

The ULA Launch Director Tom Heter has given the final approval to resume the countdown for flight of Delta II rocket to send NASA’s ICESat-2 into space. His concurrence was made following a readiness poll of the launch team by Launch Conductor Scott Barney that verified all systems are ready to proceed.

5:57 a.m. PDT (1257 UTC)

The ICESat-2 spacecraft has been declared configured for launch.

5:58 a.m. PDT (1258 UTC) -- Countdown resumes

T-minus 4 minutes and counting. The final phase of today's countdown is underway at Vandenberg Air Force Base in California to launch the last Delta II rocket and NASA’s ICESat-2 spacecraft to precisely measure Earth's ice sheets. The countdown clocks have resumed, leading us to a 6:02 a.m. PDT (9:02 a.m. EDT; 1302 UTC) liftoff.

In the next few seconds, the rocket stages will switch to internal battery power for launch and the pad’s water deluge system will be enabled. The water system will begin flowing at T-minus 60 seconds to suppress the sound intensity at launch.

5:59 a.m. PDT (1259 UTC)

T-minus 2 minutes, 30 seconds, Ordnance aboard the Delta II rocket is armed.

6:00 a.m. PDT (1300 UTC)

T-minus 2 minutes and counting. First stage liquid oxygen tank pressurization has begun. The rocket's vents are being closed so that the tank can be brought up to the proper pressure levels for liftoff. Occasional puffs of white vapor from the LOX tank will be seen through the remainder of the countdown from the center of the Delta II as the tank as the pressure stabilizes.

6:01 a.m. PDT (1301 UTC)

T-minus 55 seconds and counting. The Air Force’s Western Range at Vandenberg has confirmed its "green" condition for launch.

Coming up at T-minus 30 seconds, a final status check will be announced on Delta II and ICESat-2 readiness, followed by the solid rocket booster ignitors being armed at T-minus 11 seconds and the operator at the first stage console in the Launch Control Center manually sending the command to start the RS-27A main engine at T-minus 3 seconds.

6:02 a.m. PDT (1302 UTC)

LIFTOFF! Liftoff of the final Delta II, celebrating the rocket’s legacy by launching NASA's ICESat-2 to monitor Earth’s ever-changing environment. And the vehicle has cleared the tower!

6:02 a.m. PDT (1302 UTC)

T+plus 35 seconds. The Delta II rocket has broken the sound barrier as it accelerates to space on the combined power of its main engine and four strap-on solid motors. The vehicle is flying southward over the Pacific Ocean along a flight azimuth of 196 degrees.

6:03 a.m. PDT (1303 UTC)

T+plus 90 seconds. The four Northrop Grumman-made Graphite Epoxy Motors, or GEM-40s, have burned out and separated from the Delta II rocket. There were 1,003 GEM-40s launched on the Delta II program.

The RS-27A main engine continues to power the rocket into the predawn sky.

6:04 a.m. PDT (1304 UTC)

T+plus 2 minutes. Delta now weighs half of what it did at liftoff two minutes ago.

6:05 a.m. PDT (1305 UTC)

T+plus 3 minutes, 25 seconds. The Aerojet Rocketdyne first stage main engine has about one minute left to go in its burn. The engine is consuming kerosene fuel and liquid oxygen to produce more than 200,000 pounds of thrust.

6:06 a.m. PDT (1306 UTC)

T+plus 4 minutes, 45 seconds. Successful staging and ignition of the Delta II rocket’s second stage is confirmed.

The RS-27A main engine completed its burn and the first stage then separated, allowing the AJ10-118K upper stage engine to begin its first of two burns needed to inject the ICESat-2 spacecraft into the proper polar orbit during the launch.

This marks the 241st and final engine from the RS-27 family to be used by Delta.

6:07 a.m. PDT (1307 UTC)

T+plus 5 minutes, 5 seconds, The 10-foot-diameter, bi-sector composite payload fairing that protected ICESat-2 during ascent through the atmosphere has been jettisoned now that the rocket has ascended above the edge of space.

The Delta II rocket has shed 95 percent of its liftoff weight.

6:09 a.m. PDT (1309 UTC)

T+plus 7 minutes. The hypergolic second stage engine is burning well, consuming nitrogen tetroxide and a hydrazine blend called Aerozine 50 to reach a preliminary orbit around the Earth. The Aerojet Rocketdyne engine produces more than 9,700 pounds of thrust.

6:11 a.m. PDT (1311 UTC)

T+plus 9 minutes. The Delta II rocket remains on course as its Aerojet Rocketdyne second stage engine fires to put the vehicle and payload into orbit. Less than two minutes remain in this initial firing this morning.

6:13 a.m. PDT (1313 UTC)

T+plus 11 minutes, 5 seconds. The first cutoff of the second stage engine, known as SECO-1, has been confirmed. The Delta II rocket has arrived in an elliptical orbit around the Earth where it will coast for about 37 minutes before the engine ignites again to circularize the orbit.

6:16 a.m. PDT (1316 UTC)

T+plus 14 minutes. Data from the Delta II rocket has verified that the second stage achieved the desired orbit following SECO-1.

6:22 a.m. PDT (1322 UTC)

T+plus 20 minutes. The rocket's flight path is taking above the South Pacific, soon to fly over Antarctica and begin a north-bound trajectory. Deployment of ICESat-2 occurs over Madagascar.

6:32 a.m. PDT (1332 UTC)

T+plus 30 minutes. As the rocket coasts in this parking orbit, it performs a "BBQ roll" maneuver to keep the thermal conditions on the vehicle equal.

6:40 a.m. PDT (1340 UTC)

T+plus 38 minutes. We are 10 minutes away from the second stage engine restart. The upcoming circularization burn will last just 7 seconds, but will raise the current elliptical orbit to a near-circular orbit 288 statute miles above Earth, inclined at 92 degrees.

6:50 a.m. PDT (1350 UTC)

T+plus 48 minutes. The second burn of the Delta II rocket’s second stage has occurred to put the vehicle into a near-circular polar orbit. The ICESat-2 spacecraft will be deployed from the launch vehicle in approximately four minutes.

6:53 a.m. PDT (1353 UTC)

T+plus 51 minutes. A good orbit has been achieved by the second stage's second burn, telemetry confirms.

6:54 a.m. PDT (1354 UTC)

T+plus 52 minutes, 45 seconds. SPACECRAFT SEPARATION! NASA’s Ice, Cloud and land Elevation Satellite-2, or ICESat-2, has been released into space from the Delta II rocket's second stage, completing the primary objective of today's launch!

The spacecraft will act like a sophisticated stop-watch, firing its multi-beam laser-ranging instrument 10,000 times per second and measuring the time it takes for photons to reach the Earth’s surface and bounce back to the satellite with a billionth-of-a-second accuracy. That will enable the monitoring of ice elevation changes to the thickness of a No. 2 pencil.

Liftoff of the Delta II rocket! Photo credit: United Launch Alliance

7:00 a.m. PDT (1400 UTC) -- Delta II will stand among giants

United Launch Alliance announced today that the last Delta II rocket will join a lineup of historic rockets in the Rocket Garden on display at NASA's Kennedy Space Center Visitor Complex in Cape Canaveral, Fla.

"The Delta II rocket has been a venerable workhorse for NASA and civilian scientists, the U.S. military, and commercial clients throughout its almost 30 years of service," said Tory Bruno, ULA president and CEO. "This program comes to a close with the final launch of NASA's ICESat-2, but its legacy will continue and the Visitor Complex will help us keep the story of the success of this much-revered rocket in the hearts and minds of the public."

7:13 a.m. PDT (1413 UTC)

T+plus 71 minutes, 55 seconds. The second stage Aerojet Rocketdyne AJ10-118K engine has performed its third burn of the day. This 8-second burn moved the rocket stage into a slightly lower orbit below the ICESat-2 spacecraft in preparation for the upcoming deployment of four CubeSat secondary payloads.

The AJ10 collection of engines is making its 277th and final flight with the Delta family today.

7:18 a.m. PDT (1418 UTC)

T+plus 76 minutes. The CubeSat release window has opened. The first to eject from the rocket was a CubeSat from UCLA.

7:19 a.m. PDT (1419 UTC)

T+plus 77 minutes, 45 seconds. Both CubeSats from the University of California, Los Angeles, called the Electron Losses and Fields Investigation (ELFIN) and the ELFIN-STAR (Spatio-Temporal Ambiguity Resolution), have been deployed.

The twin CubeSats with 75-centimeter unfurlable magnetometer booms will perform in-situ measurements in Earth’s magnetosphere for modeling and predicting the radiation environment.

7:21 a.m. PDT (1421 UTC)

T+plus 79 minutes, 25 seconds. The Damping And Vibrations Experiment CubeSat, or DAVE, from the California Polytechnic University, San Luis Obispo and the Surface charging Satellite (SurfSat) for the University of Central Florida have been deployed from the Delta II rocket.

DAVE will test dampening techniques on a CubeSat for potential incorporation on larger spacecraft in the future and SurfSat will test appropriate surfaces to keep sensitive electronics safe in space.

7:23 a.m. PDT (1423 UTC)

Godspeed, Delta II. A toast to the 30-year legacy of this beloved rocket that made its final flight is being made in the control room.

7:35 a.m. PDT (1435 UTC)

NASA Launch Manager Tim Dunn says that ICESat-2 spacecraft has been delivered on a nominal orbit and the four CubeSats have ejected, declaring that today’s flight by the Delta II rocket has been a success.

This continues 100 percent success for the United Launch Alliance in 130 missions.

”I’m thrilled with mission success and that we were able to close the chapter on Delta II with a huge success of an incredible important science payload. ICESat-2 is going to do cutting-edge scientific data-gathering,” said Dunn. “So to be able to say that we launched this very important scientific mission on the final flight of the industry workhorse is just a huge accomplishment to the entire team.”

The Delta II service career now is complete, flying 155 times since 1989 with 153 successes, a rate of 98.7 percent. Today also marked the 100th consecutive successful Delta II launch dating to 1997.

9:15 a.m. PDT (1615 UTC)

“ULA is proud that the Delta II rocket has been a significant piece of history, launching more than 50 missions for NASA,” said Gary Wentz, ULA vice president of Government and Commercial Programs. “I sincerely thank the entire ULA team, NASA, U.S. Air Force, and all of our partners and suppliers who have worked diligently to launch the final Delta II rocket, as well as the dedication of the teams throughout the past 29 years of the program.”

9:20 a.m. PDT (1620 UTC)

Vandenberg Air Force Base, Calif., (Sept. 15, 2018) – A United Launch Alliance (ULA) Delta II rocket carrying NASA’s Ice, Cloud and land Elevation Satellite-2 (ICESat-2) spacecraft lifted off from Space Launch Complex-2 on Sept. 15 at 6:02 a.m. PDT. This marks the final mission of the Delta II rocket, which first launched on Feb. 14, 1989, and launched 155 times including ICESat-2. Read our news release

Launch photo gallery

See our Flickr page for a collection of beautiful photos of today’s launch of the Delta II rocket taken by United Launch Alliance.