Sunday's scheduled liftoff of the DSCOVR satellite could mark the realization of a dream as old as Al Gore's vice presidency and as new as SpaceX founder Elon Musk's vision of rocket reusability.
A SpaceX Falcon 9 rocket is due to launch DSCOVR — that is, the Deep Space Climate ObserVatoRy — from Cape Canaveral Air Force Base at 6:10 p.m. ET Sunday.
The satellite will eventually settle into a stable position known as L1, where the sun's gravitational pull is precisely balanced by our own planet's gravity field. From that vantage point, a million miles out in space, DSCOVR will watch for the sun's outbursts and keep an eye on Earth as well.
DSCOVR's history has been almost as tortuous as the spacecraft's acronym. Gore suggested the mission in 1998 as an inspirational way to capture continuous imagery of Earth's full disk from deep space. The then-vice president talked up the satellite so much that it became known unofficially as "GoreSat." (Its official name, Triana, paid tribute to Rodrigo de Triana — the sailor who is said to have been the first to spot America during Christopher Columbus' famous voyage in 1492.)
The Bush administration mothballed the $100 million-plus Triana satellite in 2001, but the mission was revived in 2009 as part of the U.S. early warning system for potentially damaging space weather. DSCOVR is now a joint project involving NASA and the National Oceanic and Atmospheric Administration as well as the Air Force.
DSCOVR is equipped with an instrument known as the Earth Polychromatic Imaging Camera, or EPIC, which will take multispectral pictures of Earth's disk continually, if not continuously. Another instrument called the National Institute of Standards and Technology Advanced Radiometer, or NISTAR, will measure the radiation coming off Earth's surface. Those instruments should help scientists get a better fix on our planet's inflow and outflow of radiant energy — and lead to the development of better climate prediction models.
Another suite of instruments will be pointed toward the sun to watch for solar flares, fluctuations in the solar wind of electrically charged particles, and disturbances in the sun's magnetic field. In this capacity, DSCOVR will expand upon the roles played by sun-watching satellites such as the Advanced Composition Explorer and the Solar and Heliospheric Observatory (ACE and SOHO).
The original idea was to deploy Triana from a space shuttle — but since that's no longer an option, the Air Force went for SpaceX's Falcon 9 instead. The cost of refurbishing and launching the satellite is about $150 million.
SpaceX tries again
This launch is a second chance for SpaceX as well: Last month, the California-based company made an unprecedented attempt to land the Falcon 9 rocket's first stage on an oceangoing platform — also known as an autonomous spaceport drone ship, or ASDS.
The ambitious gambit almost worked. After launching a Dragon cargo capsule toward the International Space Station, the stage separated and relit its rocket engines to slow itself down during a supersonic descent. The onboard guidance system successfully steered the stage down to the 300-foot-long, 170-foot-wide, thruster-stabilized platform. But instead of coming in for a graceful, vertical landing, the 14-story-tall stage hit the deck and blew up.
Afterward, SpaceX's Elon Musk said the hydraulic fluid ran out in the stage's stabilizing grid fin control system just before landing. The Falcon 9's rocket engines couldn't compensate for the off-kilter final approach. "Close, but no cigar this time," Musk said in a tweet.
Musk said the Falcon 9 that's being used for the DSCOVR launch would have 50 percent more hydraulic fluid in the grid fin control system. "At least it should explode for a different reason," he quipped.
Recovering the rocket's first stage has no relation to the success or failure of the DSCOVR mission, since the second stage and the satellite have already separated and headed for outer space by the time the retro firing takes place. But if the recovery maneuver works consistently, that could lead to a significant reduction in launch costs — and further Musk's dream of making spaceflight so affordable that a million colonists could eventually fly to Mars.
Last month, Musk said during an Ask Me Anything chat on Reddit that he would unveil his grand plan for future Mars missions by the end of this year.
Musk has given in to his science-fiction sentiments even more since last month's rocket landing attempt: The patched-up autonomous spaceport drone ship, which is now standing by in the Atlantic Ocean hundreds of miles off the coast of Florida, has been dubbed "Just Read the Instructions." That happens to be the name of one of the sentient starships described in Iain M. Banks' sci-fi novels.
You can watch the DSCOVR mission's pre-launch briefing online at 1 p.m. ET Saturday via NASA TV. NASA TV will also provide live coverage of the DSCOVR launch starting at 3:30 p.m. ET Sunday.