TAMPA • US space agency Nasa has postponed until today the launch of its US$1.5 billion (S$2 billion) unmanned Parker Solar Probe, to allow engineers more time to investigate a red flag that was raised in the last moment before lift-off.
The problem had to do with the gaseous helium pressure alarm on the spacecraft, officials said early yesterday. The next launch window opens at 3.31am (3.31pm Singapore time) today.
The first spacecraft to fly directly towards the Sun was poised to blast off yesterday, on a mission to plunge into our star's sizzling atmosphere and unlock the mysteries of the centre of the solar system.
Nasa's car-sized probe had been scheduled to launch on a Delta IV Heavy rocket from Cape Canaveral, Florida, during a 65-minute launch window that opened at 3.33am (3.33pm Singapore time) yesterday.
By coming closer to the Sun than any spacecraft in history, the unmanned probe's main goal is to unveil the secrets of the corona, the unusual atmosphere around the Sun.
"We are going to be in an area that is so exciting, where solar wind - we believe - will be accelerating," said Nasa planetary science division director Jim Green.
PARKER SOLAR PROBE
6.16 million km
Closest Parker mission will get to the Sun.
1,370 deg C
Expected temperature on the protective front heatshield.
"Where we see huge magnetic fields that are passing by us, as coronal mass ejections make their way out into the solar system."
Not only is the corona about 300 times hotter than the Sun's surface, but it also hurls powerful plasma and energetic particles that can unleash geomagnetic space storms, wreaking havoc on Earth by disrupting the power grid.
"The Parker Solar Probe will help us do a much better job of predicting when a disturbance in the solar wind could hit Earth," said Dr Justin Kasper, a project scientist and professor at the University of Michigan.
A 11.43cm-thick, ultra-powerful heat shield should protect the spacecraft as it comes within 6.16 million km of the Sun's surface.
Even in a region where temperatures can reach more than a million degrees Celsius, the sunlight is expected to heat the shield to just around 1,371 deg C.
But if all works as planned, the inside of the spacecraft should stay at just 30 deg C.
The goal for the Parker Solar Probe is to make 24 passes through the corona during its seven-year mission.