NASA’s historic mission to “touch the Sun” just reached two important milestones: It now holds the record for the closest approach to the Sun by a human-built object—and also the record for the fastest spacecraft ever sent into space.
Launched on August 12, 2018, the Parker Solar Probe is now entering into the first stages of its mission.
At 1:04 pm ET on October 29, the spacecraft got closer than 42.7 million kilometers (26.55 million miles) from the Sun’s surface—a new record for a human-built object. The old record was held by the German-American Helios 2 spacecraft, which achieved the feat in April 1976. From here on in, every inch closer that the probe gets to the Sun will be a new distance record, with a closest approach of 6.16 million kilometers (3.83 million miles) expected in 2024.
“It’s been just 78 days since Parker Solar Probe launched, and we’ve now come closer to our star than any other spacecraft in history,” Parker Solar Probe Project Manager Andy Driesman said in a NASA statement. “It’s a proud moment for the team, though we remain focused on our first solar encounter.”
Less than 10 hours later, the probe set yet another record. Attaining and then surpassing a speed of 246,960 kilometers per hour (153,454 miles per hour), the Parker probe became the fastest-ever human-built object relative to the Sun. The previous record was also held by the Helios 2 mission. By 2024, the spacecraft is expected reach speeds in excess of 692,000 kilometers per hour (430,000 miles per hour, or 0.064 percent the speed of light).
To calculate the speed and distance of the Parker Solar Probe, the space agency utilizes its Deep Space Network, or DSN. NASA explains:
The DSN sends a signal to the spacecraft, which then retransmits it back to the DSN, allowing the team to determine the spacecraft’s speed and position based on the timing and characteristics of the signal. Parker Solar Probe’s speed and position were calculated using DSN measurements made on Oct. 24, and the team used that information along with known orbital forces to calculate the spacecraft’s speed and position from that point on.
At its current distance to the Sun, the probe requires 150 days to make a complete orbit. It will achieve the first of 26 perihelion events (the point closest to the Sun) on November 6, 2018. Over the next six years, the probe’s orbital length will gradually shrink, allowing it to get closer to the Sun. As it gets nearer to the star’s surface, the probe will face formidable heat and radiation, which it will fend off with a maneuverable shield always pointed toward the flaming ball of fire at the center of our Solar System.
The Parker Solar Probe’s onboard sensors will take measurements, providing unprecedented new data for scientists. By learning more about the Sun, we will have a better understanding of how it affects Earth and other planets, and possibly improve our space weather forecasting. Knowing how and when the Sun produces massive solar storms, for example, could go a long way in reducing damage on Earth.
Correction: An earlier version of this post had an incorrect conversion of mph to speed of light.