SpaceX's planned launch of the Deep Space Climate Observatory, or DSCOVR, has been postponed until Tuesday at the earliest due to a problem with the AirForce's tracking radar system in Florida.
That meant an ambitious second attempt to land the Falcon 9 rocket's first stage on an oceangoing platform also had to be delayed.
"Hold, hold, hold," came the call from the launch team, with just two minutes and 26 seconds left in Sunday's countdown toward a sunset launch. The team passed up an opportunity to launch on Monday, due to unfavorable weather, and scheduled the next attempt for 6:05 p.m. ET Tuesday.
Radar tracking is a critical part of operations for a space launch, because range safety officers need to be able to destroy the rocket in case it goes off course during ascent. SpaceX founder Elon Musk said the launch team was also dealing with a problem that affected a transmitter on the rocket's first stage.
The delay means the 17-year-long saga leading up to DSCOVR's launch from Cape Canaveral Air Force Station in Florida would last at least a couple of days longer.
The $340 million mission was first suggested in 1998 by then-Vice President Al Gore, as a way to provide real-time views of Earth's full sunlit disk from a stable gravitational point a million miles away, known as L1. The mission ran into resistance in Congress, however, and the spacecraft was put into storage after President George W. Bush came into office.
Several years ago, NASA, NOAA and the U.S. Air Force got together to formulate a new mission that made use of the old satellite: providing early warnings for potentially hazardous solar outbursts. The Earth-viewing angle turned into a secondary mission, with the aim of studying climate impacts.
Watching for solar storms
DSCOVR will join a constellation of sun-watching probes that watch out for solar storms — blasts of electrically charged particles that could disrupt satellite networks, high-frequency radio communications and power grids. Such geomagnetic storms also can heighten radiation risks for astronauts and airplane passengers flying over the poles.
Satellites such as the Advanced Composition Explorer and Solar and Heliospheric Observatory, which are already located at the L1 point, can provide up to an hour's warning of major storms. Both those satellites are well past their anticipated lifetimes, however, and DSCOVR is designed to provide a much-needed backup.
SpaceX's two-stage Falcon 9 rocket will boost DSCOVR into a preliminary orbit, but it will take 110 days of in-space maneuvers to get the probe into the right position.
This launch would mark the first time that SpaceX has sent a spacecraft so far, and it will be judged a success if DSCOVR reaches its intended orbit. However, SpaceX is hoping for more.
SpaceX's rocket reprise
After the second stage and the satellite separate and head deeper into space, the first stage is programmed to relight its engines to slow down its supersonic descent, and then ease itself down to a vertical landing on an autonomous drone ship stationed in the Atlantic Ocean, about 370 miles from Cape Canaveral.
SpaceX tried this maneuver last month, after sending a Dragon cargo capsule to the International Space Station. But the gambit didn't quite work: A system to control a set of four stabilizing grid fins ran out of hydraulic fluid just before landing, and the rocket hit the 300-by-170-foot deck off-kilter. The rocket stage blew up and broke up in spectacular fashion.
"Close, but no cigar this time," SpaceX's Musk said afterward.
For the DSCOVR launch, SpaceX has added more fluid to the hydraulic system — but the trajectory for the descent is much more challenging, Musk said in a tweet.
If SpaceX can perfect the flyback maneuver, that could reduce the cost of putting payloads into orbit significantly. Musk says such cost savings could eventually make trips to Mars affordable. That would be in keeping with the billionaire's ambition to make humanity a "multiplanet species."
That may sound like science fiction, but Musk has embraced the sci-fi feel of the venture. After last month's nearly successful attempt, he gave the drone ship a name that paid tribute to the sentient starships described in Iain M. Banks' science-fiction novels: "Just Read the Instructions."