This Week in Space: DART Spacecraft Crashed Successfully

Hello, readers, and welcome back to This Week in Space, your Friday escape from terrestrial news. This week, NASA finally crashed its DART spacecraft into its target asteroid. Three cosmonauts also came home from the International Space Station. And despite the center of Hurricane Ian passing directly over the Kennedy Space Center, and despite a “fire” in the Vehicle Assembly Building, as far as we know the Artemis rocket is doing fine.

DART Spacecraft Finally Crashes Into Asteroid

Monday evening, NASA’s Double Asteroid Redirect Test (DART) smashed into its target asteroid: Dimorphos, AKA “Didymoon.” Dimorphos is a moonlet, an asteroid orbiting another, slightly larger asteroid called Didymos. Neither poses a threat to Earth, so NASA chose the smaller of the two for a low-stakes field test of their ability to defend the planet from an inbound asteroid.

In the weeks preceding the launch, concern mounted among scientists poring over data from observations of Dimorphos. One report characterized it as a “rubble pile,” more akin to a pile of rocky snowballs than a snow-covered rock. The moonlet’s low density suggested that DART would leave a much larger crater in Dimorphos than NASA expected — or even destroy it altogether.

The video below compiles data from DART’s final two minutes before impact into a 4K60 (interpolated) video. While it’s not exactly Stanley Kubrick, it’s mesmerizing to watch, especially the last few frames. We recommend slowing the video to 1/4 speed around the 40-second mark to enjoy the final approach. Pause on the final shots and you can even see the texture of the ice. YouTube can also be advanced or rewound frame-by-frame by using the “” keys.

As you can see here, the “rubble pile” hypothesis holds true. In fact, we’re pretty sure DART did blow a gigantic crater in Didymoon, and it may have disrupted the moonlet entirely. However, DART mission control reported the time of impact by reporting when telemetry cut off. That means we don’t have much direct data about the innards of the asteroid yet.

Other telescopes were watching Didymoon for signs of impact. While we don’t yet have anything else in the same exquisite focus as the impact video, Webb and Hubble were both watching.

Webb, Hubble, and other observatories captured “plumes” or “tendrils” of debris, streaming away from the asteroid after the impact. You can check out full-res versions of these images, along with animated versions of both, at the Space Telescope Science Institute.

Webb Calibration Puts Observations in Jeopardy

Speaking of the JWST, Nature reports on the space telescope’s calibration sent a frisson of alarm through the astronomy community this week. Webb officially opened for science on July 12 of this year. Booked solid for its entire first year, the telescope immediately went to work full-time gathering data and taking pictures. However, calibration procedures from July 14-15 cast initial doubt on observations performed during that period.

Nature assured astronomers in an editorial that after “a bit of panic,” so far nobody has found any problems in any of the studies published in their journals. Thankfully, that includes several candidates for the universe’s first galaxies, including the blurry red splotch you see here. However, many studies of Webb images are self-published by their authors on arXiv, sacrificing peer review to get the information out there faster. One scientist called the process “peer review via Twitter.”

One Mission Ends, Another Begins Aboard International Space Station

Three cosmonauts landed safely in Kazakhstan Thursday evening at about 5 p.m. local time, as they returned from the International Space Station this week. Denis Matveev, Sergey Korsakov, and former space station commander Oleg Artemyev came back planetside in a Soyuz-21 capsule.

Samantha Cristoforetti Assumes Command of the ISS

Already a decorated pilot and a spaceflight veteran, ESA astronaut Samantha Cristoforetti made history this week as she took over command of the International Space Station. During a formal ceremony on Wednesday, Artemyev handed over control of the station. Cristoforetti is the first European female to step into the role.

Cristoforetti herself is nearing the end of her stay on the station. Consequently, one of her principal responsibilities is now ensuring a smooth handoff of the station to her successor.

Wind Speeds, and Blood Pressure, Dropping After Ian

Hurricane Ian cut a broad swathe across Florida this week, and despite being all the way over on the state’s Atlantic coast, NASA’s Kennedy Space Center was no exception. In fact, the hurricane’s eye passed directly over the KSC. Afterward, Ian yawed back out to sea, where it resumed its hurricane status before taking aim at the Carolinas.

As you may imagine, it’s been a very busy week for NASA. Here are the highlights:

There was a “fire” in the VAB, but Artemis wasn’t involved. NASA officials reported Tuesday that fire alarms in the VAB had gone off around noon, local time. As fires go, though, this one was a nothingburger. We’re using scare quotes for a reason. Later in the day, the agency gave more detail:

“The notification came,” said NASA spokesperson Patti Bielling, “when an arc flash event occurred at a connector on an electrical panel in High Bay 3. A spark landed on a rope marking the boundary of the work area. The rope began to smolder, workers pulled the alarm, and employees evacuated the building safely.”

Nobody was injured, and the agency later said bluntly, “The Artemis I rocket and spacecraft were never in any danger.”

Kennedy Space Center’s “ride-out” team weathered the storm onsite. It’s kind of bananas to put this many billions of dollars worth of space equipment in one of the places most likely to get hit by a hurricane. Thankfully, NASA has a plan in place to batten down its very expensive hatches. Like the armed forces’ DEFCON (defense readiness condition) levels of alert, there’s a HURCON specifically for impending hurricanes. “As of 6 p.m. Wednesday, Sept. 28,” the agency said in a blog update, “Kennedy Space Center declared HURCON I status with the ride-out team sheltered in place at their designated locations until the storm passes.”

To prepare for the storm, NASA decided to roll the Space Launch System back from pad 39B to the VAB, where the rocket hung out beside Psyche. Meanwhile, SpaceX mission techs secured the Dragon Endurance spacecraft and its Falcon 9 rocket in their hangar at Launch Complex 39A.

Crew-5 should launch on October 5. As late as the 27th, NASA and SpaceX were targeting October 4 to launch Crew-5 to the ISS. However, the agency has since updated the Crew-5 launch window to reflect atmospheric conditions and hurricane cleanup. Undocking of the current Crew-4 mission from the ISS “will move day-for-day along with the Crew-5 launch.”

Crew-5 will include NASA astronauts Nicole Mann and Josh Cassada, who will serve as mission commander and pilot, respectively. Astronaut Koichi Wakata of JAXA (Japan Aerospace Exploration Agency) and cosmonaut Anna Kikina will serve as mission specialists.

Artemis 1, however, won’t launch until November. During a Wednesday briefing, NASA officials confirmed that while they do have another launch window in October, Artemis will be delayed for at least one more launch period. Janet Petro, director of the KSC, explained that hurricane cleanup, along with some necessary attention to “some of the rocket’s more delicate components,” would take longer than the remaining October launch window permits.

Instead, Petro confirmed that the agency will wait for the next lunar launch window, which opens on Nov. 12.

Skywatchers Corner

Last week, six planets went into retrograde: Mercury, Venus, Jupiter, Saturn, Uranus, and Pluto. All six will remain in retrograde until Mercury resumes its “proper” motion on Oct. 2. At the time, I wrote:

Not only did it confound their equations, retrograde motion confounded the horoscopes drawn up by more spiritually-inclined [classical] astronomers. During periods when the planets were in retrograde, astrologers then and now forecast that the characteristics associated with each planet could turn on their heads, changing the horoscope like an inverted tarot card changes a reading. The gamut ran from stubbed-toe inconveniences, à la Mercury in retrograde, to celestial omens that swayed the hand of Alexander the Great in his march across the Mediterranean and the Near East.
Imagine what he would have thought to hear that NASA means to launch a moon rocket with six planets in retrograde.

To be clear, what I half-suspected would happen was some glitch on Artemis’ umpteenth rescheduled launch date, Oct. 3. Then, over the weekend, the hurricane blew in, scuttling the launch date entirely.

Do you think NASA will have time to hire some sort of paranormal professional to remove the obvious curse before Nov. 12? Failing that, how much of the ocean has to be holy water, by volume, to confer some kind of protection in time for the next auspicious launch date? Inquiring minds demand to know.

Elsewhere in the night sky, the waxing crescent moon is visible shortly before dawn. You’ll see it framed by the triangle between Mars, Betelgeuse, and Aldebaran if you look to the south. All three are big, bright points of reddish light, with Mars highest in the sky.