RECAP: History made as NASA successfully tags asteroid Bennu to collect sample

OSIRIS-REx ’tags’ asteroid Bennu at 6:12 p.m. ET on Oct. 20, making history

A NASA spacecraft booped an asteroid to bring some of it back to Earth, marking a historic first for the U.S. space agency.

After launching from Cape Canaveral in September 2016, the passenger-van-sized spacecraft traveled for two years to catch up with asteroid Bennu, where it has been orbiting since December 2018 and preparing for its big day.

That day finally arrived for OSIRIS-REx, which stands for Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer, a true mouthful even for a NASA acronym. Now, the spacecraft is just hours away from conducting a “touch and go” maneuver using its pogo-stick-like arm to tag the asteroid and collect up to four and a half pounds of space rock and dust.

The 500-meter-wide asteroid was chosen for several reasons, including that it could one day -- in a very long time-- impact Earth, but it’s also thought to hold clues as to how planets formed.

While a live view from Bennu isn’t possible, NASA showed animations of what is happening, play-by-play. NASA aired a live broadcast from Lockheed Martin in Denver of OSIRIS-REx’s descent to the surface of Bennu and attempt at sample collection.

Just before 6:12 p.m. ET OSIRIS-REx successfully conducted the most dangerous part of the mission when it touches the asteroid. Here is a full list of activities leading up to the asteroid “tag” and after to learn how it went.

If the sample collection goes as planned, the spacecraft will drop off the sample to Earth in 2023, where it will then undergo analysis in labs at NASA’s Goddard Flight Center and elsewhere, however, 75% of the sample will be achieved.

See a recap of the events leading up to the asteroid “tag” and for reaction from OSIRIS-REx team members after the main event.

6:30 p.m. TAG event went as planned

OSIRIS-REx teams are now waiting to get more data from the spacecraft to learn how much it collected from Bennu which could be as much as 4.5 pounds. If it didn’t get enough there are two more chances for the spacecraft to go back again to try for more but they won’t know until Saturday at the earliest.

6:11 p.m. OSIRIS-REx ‘go’ to TAG asteroid, sampling happening now

Touchdown is happening and the sampling is in progress, per NASA. The spacecraft arm will fire a bottle of gas to stir up dirt on the asteroid and take it away.

“This is history,” an emotional Principal Investigator Dante Dante Lauretta said.

The spacecraft then backed away from the asteroid.

6 p.m. Matchpoint burn complete

The spacecraft has now conducted the final maneuver called the matchpoint burn to position itself, matching Bennu’s spin rate as it goes in and collects the sample. Because of the time delay, by the time the team knows OSIRIS-REx has made the attempt it will have already happened.

“Whatever has happened has already happened,” OSIRIS-REx Principal Investigator Dante Dante Lauretta said.

To determine if the spacecraft successfully collected a sample, it will place its arm out and conduct a spin to measure the mass of the sample and determine how much it has collected. The minimum they are looking for is 60 grams. That won’t happen until later this week.

5:15 p.m. All looks good

OSIRIS-REx Principal Investigator Dante Dante Lauretta says everything is going well less than an hour before the spacecraft is expected to touch the asteroid Bennu and collect a sample.

“Everything is going exactly according to plan right now, it looks really good," Lauretta said.

Position uncertainty for the spacecraft is .06 meters, according to mission control at Lockheed Martin in Littleton, Colorado.

4: 15 p.m. Spacecraft slowly descends to asteroid

OSIRIS-REx is slowly moving down toward the asteroid’s surface. As it does, its sending back images of Bennu to help navigate around dangerous boulders for the sample collection.

The next major maneuver happens after 6 p.m. ET. slowly but surely.

2:45 p.m. OSIRIS-REx ready to TAG Bennu

At this point the spacecraft’s arm, known as TAGSAM, is out preparing for that five-second tap to the asteroids surface.

Next, the spacecraft will begin to position its navigational cameras toward Bennu to get a good view of the asteroid’s landmarks.

1:20 p.m. virtual animation shows what spacecraft is doing now

The spacecraft team is sharing a virtual play-by-play of what OSIRIS-REx is doing ahead of the “touch-and-go" move later today. Watch the livestream below or on the mission website at

12:45 p.m. Spacecraft science team member sharing experience with his UCF students

OSIRIS-REx science team member and UCF planetary scientist Humberto Campins is teaching a class about asteroids and comets just hours before the mission he has been working on for a decade is set to collect a sample of asteroid Bennu. The sample will be brought back to earth in 2023, a first for NASA.

“I’m actually going to take part of the class today to give them an update on what’s happening with the spacecraft,” Campins said, adding “They have an exam a week from today. So they’re thinking more about the exam.”

OSIRIS-REx will not be on the exam, he says, but it is very timely for his class.

“I just want them to be excited,” he said. “But it is a class on asteroids, comets and meteorites, right? And so this is very relevant.”

Campins is teaching remotely as he is in Tucson, Arizona with the reset of the science team based at the University of Arizona.

After his class, he will have a virtual meeting with the rest of the OSIRIS-REx science team where they will discuss what the spacecraft is doing at that point.

However, the brief tap on the asteroid is all autonomous. “It’s been programmed in a way that it can make its own decisions,” Campins said, adding “because it’s too far away for it to be sending us signals and for us to be responding, it takes about five minutes each way.”

Prior to the big day, the spacecraft rehearsed this touch and go or TAG operation twice and Campins said while it’s risky there is about a 90% chance it will succeed.

While the spacecraft “touch and go” operation lasts about five seconds when it comes into contact with the asteroid, the science already learned from studying Bennu up close is very exciting -- but the sample will tell us so much more once it’s on Earth where it can be analyzed in a laboratory.

“It’s an important step for all of humanity, we’re going to a primitive asteroid is going to answer a lot of questions about how the solar system formed how water and organic molecules were brought to Earth by asteroids and comets, and how life might have formed and evolved here on Earth,” Campins said.

Read more about Campins and the mission here.

9 a.m. Today is ‘tag’ time