NASA set to launch first-ever solar probe

NASA set to launch first-ever solar probe
© Rebecca Kheel

CAPE CANAVERAL, Fla. — NASA is on track for a Saturday morning launch of the first-ever probe to the sun, a mission officials described as 60 years in the making.

The launch window for the Parker Solar Probe opens at 3:33 a.m. on Saturday, and the probe is expected to set a record as the fastest object to leave the earth, reaching 43,000 mph during the launch. It will also become the fastest human-made object ever when it travels at about 430,000 mph when it passes by Venus.


The probe is named after Gene Parker, who in 1958 wrote a paper theorizing the expansion of the solar atmosphere and solar wind. The mission will seek to answer some of the questions Parker first raised in that paper that can only come from “touching” the sun, according to Nicky Fox, the project scientist for the mission at Johns Hopkins University Applied Physics Laboratory.

The probe is expected to get as close as 3.83 million miles to the sun’s surface, in the atmosphere known as the corona.

“We’ve had to wait so long for our technology to catch up with our dreams,” Fox told reporters this week. “The sun is full of mysteries. One of those mysteries is that the corona, that lovely atmosphere that we all saw during the total solar eclipse last year, that is about 300 times hotter than the surface of the sun, and that just doesn’t make sense. So we need to go up there and figure out why that’s happening."

“The other thing of course is we really need to understand why, as Gene predicted, why this atmosphere is continually expanding and continually accelerating away from the star," she added.

The probe is equipped with a 4 1/2–inch thick carbon-carbon heat shield designed to withstand temperatures of about 2,500 degrees Fahrenheit. The shield took more than a decade to develop and 18 months to build, said Andy Driesman, project manager for the mission at the Applied Physics Laboratory.

The probe will make at least 24 passes around the sun, with gravity assists from Venus for seven of them, and continue going after that as long as it has propellant. When it runs of fuel, it will stay in the sun’s orbit in perpetuity.

In the lead-up to the launch, NASA collected 1.1 million names from members of the public who wanted their names to orbit the sun at close range. The names were uploaded to a memory drive that is being carried by the probe.

“Your names will continue to orbit with the spacecraft even after we have no fuel,” Fox said. “The spacecraft will break up into large pieces and then smaller and smaller until it becomes part of the dust cloud, so your name is going to orbit the sun forever.”

The probe is being carried on a Delta IV Heavy rocket from United Launch Alliance (ULA), giving the defense contractor an opportunity to tout its product’s role in a high-profile mission at a time that it’s facing increasing competition from Elon Musk’s SpaceX.

ULA previously had a monopoly on the U.S. Air Force's Evolved Expendable Launch Vehicle program for launching sensitive payloads into space. In February, SpaceX successfully launched its Falcon Heavy rocket.

At more than double the power of the ULA rocket, the one from SpaceX is the world’s most powerful commercial rocket and makes Musk’s company a competitor for contracts to launch larger spy satellites.

But ULA argues its rocket is more reliable.

Company CEO Tory Bruno downplayed the importance of the Parker mission to the ULA-SpaceX competition when speaking to a small group of reporters Friday at Cape Canaveral Air Force Station.

"It's really no different for us," Bruno said. "All the launches are high-profile — this one's a little extra high. They're all, every one of them is important. I mean, we fly one-of-a-kind missions very often."

Still, Bruno took the opportunity to detail why the Delta IV Heavy was better for the mission than the Falcon Heavy.

"Delta IV is the only rocket in the world, still today, that can both give it the energy necessary as well as deliver it with sufficient accuracy to make it work," he said.