SpaceX postponed the launch of its Falcon 9 rocket with the Deep Space Climate Observatory once more on Tuesday because upper-level winds were too high.
The rocket was geared up to send the observatory, also known as DSCOVR, on its trek to a vantage point a million miles from Earth — and then make a second try to land the rocket's first stage on an oceangoing platform.
But with 12 minutes left on the countdown clock, the upper-level winds were judged to be too strong for the rocket to handle.
DSCOVR's liftoff was scheduled for Sunday, but a problem with the Air Force's radar tracking system and a stretch of unfavorable weather forced a two-day delay. With Tuesday's scrub, liftoff was rescheduled for 6:03 p.m. ET Wednesday. The weather outlook called for a 90 percent chance of acceptable weather.
Even before the launch was postponed, SpaceX founder Elon Musk expressed concern about Tuesday's conditions. "Extreme wind shear over Cape Canaveral," Musk said in a tweet. "Feels like a sledgehammer when supersonic in the vertical. Hoping it changes..."
Falcon 9: Recovering the rocket
Strong winds would have added to the challenge of landing the first stage on what Musk calls an "autonomous spaceport drone ship," currently stationed in the Atlantic Ocean about 370 miles (600 kilometers) off the Florida coast.
SpaceX tried a similar maneuver last month, after launching a Dragon cargo ship to the International Space Station, but it didn't quite work. A system of stabilizing grid fins ran out of hydraulic fluid just before landing. As a result, the rocket hit the deck off-kilter and exploded.
This time around, the planned trajectory is more challenging. In a tweet, Musk said the rocket stage would encounter two times the force and four times the heat as it makes its descent. "Plenty of hydraulic fluid, though," he added.
It's not as if Musk didn't have enough on his mind: At the same time that SpaceX was counting down to the DSCOVR launch, it was also preparing for the splashdown of the returning Dragon spaceship, about an hour and a half later off the coast of Baja California in the Pacific.
DSCOVR: 17 years in the making
Meanwhile, the scientists behind DSCOVR were looking forward to the start of a $340 million deep-space mission that has been 17 years in the making. The mission started out in 1998 as an idea of Vice President Al Gore's — to send a probe with a camera out to a stable gravitational point known as L1 to capture inspirational full-color, full-disk views of Earth.
After Gore lost the 2000 presidential election, the mission was canceled and the spacecraft was put in storage. Over the years, the mission morphed into a project to detect potentially hazardous solar storms as they sweep toward Earth, with backing from NASA, the National Oceanic and Atmospheric Administration and the U.S. Air Force.
Like NASA's aging Advanced Composition Explorer satellite, DSCOVR will provide up to an hour's advance warning of geomagnetic disturbances — which would be enough time to protect satellites, power grids and other systems that are vulnerable to solar storms.
DSCOVR's Earth-facing instruments will be looking at our planet as well, not only for pretty pictures but also for radiation data that could lead to better climate prediction models. DSCOVR's price tag, for the spacecraft and its refurbishment as well as for its launch and two years of operation, is $340 million.
In a Tuesday tweet, Gore said the satellite was beginning a "critical observational mission." After launch, it will take about 110 days for the spacecraft to reach the L1 point, and another 40 days or so to gear up for observations.