Crash Day: A Blow by Blow Account of Deep Impact's Comet Smash

3:15 p.m. EDT July 4, 2005

Less than a day after NASA crashed a probe into a comet, mission scientists are able to draw some conclusions of the resulting crater.

"I don't think it's house-sized, I think it's bigger than that," said Deep Impact co-investigator Peter Schultz during a press conference today.

The press conference, the second mission briefing today, was preceded by the song Rock Around the Clock by Bill Hailey and the Comets.

Deep Impact's Flyby spacecraft has more images of its Impactor's collision with Tempel one, which occurred at 1:52 a.m. EDT (0552 GMT) today and was confirmed by flight controllers five minutes later.

Mission scientists are eager to collect all the data from Flyby, but do not currently have plans for an extended mission.

"Once we get all the data down and finish the look back, we'll consider a mothballing procedure," said Deep Impact project manager Rick Grammier.

Visit's Deep Impact Special Report for complete mission coverage.

4:35 a.m. EDT July 4, 2005

After nearly six months and one long night, the engineering and science team behind NASA's Deep Impact mission has succesfully crashed a probe into a comet to see what lies beneath its surface. Read the entire story, as reported by, here.

"Right now we're minus one spacecraft," said Rick Grammier, Deep Impact project manager at JPL. "It's been totally vaporized as planned."

At about 1:57 a.m. EDT (0557 GMT), flight controllers confirmed that Deep Impact's Impactor probe slammed into Comet Tempel 1. Its Flyby mothership recorded the event as planned and was not harmed flying through the comet's coma.

NASA will hold a mission update at 2:00 p.m. EDT (1800 GMT).

"Flyby is healthy and doing well," said Keyur Patel, Deep Impact's deputy project manager at JPL. "It imaged the impact close to 50 meters to the center."

Deep Impact principal investigator Michael A'Hearn said that, while Flyby and Impactor returned fantastic images, much more spectacular ones will follow the data is relayed back to Earth from Flyby.

"There's still a very good [amount of] ejecta around the comet," A'Hearn said. "It's quite larger that the nucleus."

Researchers said they look forward to the images still locked away aboard Flyby, especially those pertaining to Impactor's crater.

"Presumably, we have a rather large crater there," A'Hearn said.

4:35 a.m. EDT July 4, 2005

Deep Impact researchers have received some data from orbital and ground-based observatories, most of which report an increase in Tempel 1's luminosity after Impactor crashed into it.

"We're getting a lot of results," said Michael A'Hearn, Deep Impact principle scientist from the University of Maryland. "They observed a brightness increase of about two magnitudes, and a few telescopes reported big increases in the emission lines."

Impactor's navigation accuracy was so on target that mission managers were not too worried of a contingency.

"We felt pretty good going in there," project manager Rick Grammier said.

4:20 a.m. EDT July 4, 2005

"There is a comet up in the sky wondering, what in the heck just happened," said JPL director Charles Elachi during today's press conference.

Flyby is reportedly in good health and managed to track Impactor's collision with Comet Tempel 1 perfectly. An animation of Impactor's images show the probe photographing Tempel 1 all the way down to crash time.

3:46 a.m. EDT July 4, 2005

NASA has kick-started the Fourth of July, successfuly slamming its Impactor probe into the comet Tempel 1.'s report of Impactor's successful crash is available here. NASA will hold a post-collision press conference at 4:00 a.m. EDT (0700 GMT).

Both Impactor and its Flyby mothership sent back stunning images of Tempel 1, and flight controllers seemed to have to tear mission managers, engineers and scientists away from display screens and back to their posts.

"We still have a Flyby spacecraft which is still collecting data, so we have to stay focused," JPL director Charles Elachi said. "I think it was worth every cent we spent on it."

Among the well-wishers was actress June Lockhart, who protrayed the mother on the science fiction television show Lost in Space, who along with her granddaughter congratulated the JPL team dropped by with her granddaughter.

2:46 a.m. EDT July 4, 2005

Flyby should have come out of shield mode and swung itself back toward Earth to send images back to eager mission scientists, flight software engineer Anne Elson said.

Don Yeomans, a mission co-investogator, said Flyby's continued observations are just as important as the final shots of Impactor.

Don Yeomans, a mission co-investogator, said Flyby's continued observations are just as important as the final shots of Impactor. The spacecraft's cameras and spectrometers will now look at the ejecta to study Tempel 1's composition.

"The big question is how did we make this big a splash," Yeomans said of the impact. "Now you can look at the material that blasts out onto the surface, and that's what our [infrared] spectroscopy people hope to do."

Mission manager Dave Spencer thanked the Deep Impact team for all their hard work.

From Senior Space Writer Leonard David reporting from Boulder, Colorado:

"I just can't believe it. It's absolutely incredible," said Alice Phinney, Lead Mechanical Design Engineer for the Impactor at Ball Aerospace. She was one of over 600 company colleagues and friends that gathered here at Fiske Planetarium here in Boulder, Colorado. Ball Aerospace is located here.

Phinney told that she worked on the Impactor that smashed into the comet for some two years. One of her key jobs was maximizing the use of copper in the Impactor design.

The task was not as straight-forward as it would seem. "There were a lot of assumptions. Scientists were all over the map," Phinney said regarding the overall composition of Comet Tempel 1.

"That's why I love some point you've got to make a decision." The Impactor "worked like a champ," Phinney said.

2:21 a.m. EDT July 4, 2005

In an initial review of Impactor's final images of Comet Tempel 1, an ecstatic Don Yeomans, Deep Impact mission co-investigator at JPL, said the comet appears to be a treasure trove of geologic features.

"You can see features on the surface here down to a few meters," Yeomans said. "We've got some light features and dark features, what look like's rough terrain. It's unlike anything we've ever seen before."

Deep Impact flight software engineer Anne Elson said Impactor's Flyby mothership is currently in shield mode as it flies through Tempel 1's coma. It will turn its camera eyes back toward Tempel 1 at about 2:28 a.m. EDT.

2:10 a.m. EDT July 4, 2005

From Senior Space Writer Leonard David reporting live from Boulder, Colorado:

Here at the Fiske Planetarium, roof top observers using a 24-inch telescope reported seeing a brightness of the comet at impact.

"This is the biggest thing that's happened for the company," said Roz Brown, a spokeswoman for Ball Aerospace, which built the Deep Impact spacecraft. "This is huge for us."

2:06 a.m. EDT July 4, 2005

Success! NASA's Impactor probe has crashed into Tempel 1.

Cheers rose up as crash images from Impactor's Flyby mothership showed a fantastic plume from the comet collision.a cheer went up when the first images from Impactor were sent back to Earth

"That picture says it all," a NASA spokesperson said.

"Oh yeah...oh yeah!" the flight controllers yelled as the images were displayed.

Impactor's camera snapped images right up until impact, which was confirmed at 1:57 a.m. EDT (0557 GMT).

"I can't believe they pay us to have this much fun," said Don Yeomans.

Impactor was expected to take several images of its final approach to Tempel 1, and its mothership Flyby also was set to image the crash. Those images will help researchers determine the result of their comet crashing mission.

1:45 a.m. EDT July 4, 2005

Impactor is right on target coming out of its third and final targeting burn. The probe is now five minutes away from crashing into Comet Tempel 1. Stand by for confirmation of comet crash.

1:35 a.m. EDT July 4, 2005

Impactor should be minutes away from its final thruster burn.

New images from the probe show Comet Tempel 1 to be "avocado-shaped" rather than resembling a pickle or banana.

1:18 a.m. EDT July 4, 2005

The Impactor probe has successfully completed the second of three navigation burns to finalize its approach to Comet Tempel 1.

A final burn is planned for 1:40 a.m. EDT (0540 GMT).

Impactor is sending home images of Tempel 1 as it approaches the comet, detailing an odd-shaped object bathed in sunlight.

1:05 a.m. EDT July 4, 2005

The Impactor spacecraft is about 15 minutes from executing its second course adjusting thruster burn.

1:02 a.m. EDT July 4, 2005's Senior Space Writer Leonard David reports live from Boulder, Colorado, where Deep Impact builders Ball Aerospace are tracking the mission while a team of astronomers tracks its target, Comet Tempel 1:

High-Tech Hobbyists Prepare for Deep Impact

BOULDER, Colorado - Joining forces with over 50 telescopes and about 200 researchers from around the world, the Deep Space Exploration Society here is at the ready with a finely-tuned radio telescope pointed toward the sky.

And like everybody else watching tonight's Deep Impact mission, nobody knows for sure what they'll observe.

The Deep Space Exploration Society (DSES) is using a restored 60-foot parabolic dish antenna. DSES is an all-volunteer force of high-tech hobbyists that have spent time and limited resources in buffing up the antenna. The group is keen on engaging students, its members and the public in space exploration.

The facility was made available to the group under agreement with the Institute for Telecommunication Sciences, an arm of the U.S. Department of Commerce. It is located in a Federally-mandated radio quiet zone at Table Mountain in Boulder County.

The dish is capable of receiving radio signals over a wide range of frequencies from celestial objects or spacecraft. Now they've turned their attention and upgraded radio dish toward tonight's Deep Impact fireworks.

"This has been the most challenging thing we've done," said Joseph DiVerdi, as he and fellow DSES team members - Paul Berge and Wayne Green -- double-checked newly installed electronic gear for studying Tempel 1's reaction to the impending Impactor. They are hoping to catch a glimpse of any unusual emission of water vapor from the comet at impact time.

"It's uncertain what we're going to get. But we're trying to be prepared for the unexpected," said Tom Meyer, a DSES member.

12:50 a.m. EDT July 4, 2005

With just over an hour before Impactor is due to crash into Comet Tempel 1, flight controllers said the comet is presenting an odd target for the copper-tipped probe.

"We initially thought this thing was something like a pickle," said Rick Grammier, Deep Impact project manager at JPL. "As we get closer we see that it's something like a banana, with a triangular end."

Impactor's collision depends heavily on the face Tempel 1 presents, Grammier added.

12:46 a.m. EDT July 4, 2005

The Impactor probe burned through about three kilograms of fuel in its first navigation burn EDT (0404 GMT), flight controllers reported. The spacecraft has about seven kilograms of propellant remaining for the next two burns. The second burn is slated to occur in about 40 minutes. The final course adjustment is set for 12.5 minutes before Impactor hits Comet Tempel 1 at 1:52 a.m. EDT (0552 GMT).

"We completed the first burn very successful," flight systems engineer Anne Elson said of the navigation adjustment. "We're all very excited to have done as well as we've done."

12:25 a.m. EDT July 4, 2005

Impactor has successfully performed its first orientation maneuver, firing its thrusters for about 21.5 seconds to refine its collision course toward Comet Tempel 1. There are two more burns scheduled before the probe crashes into the icy object, according to its flight plan.

12:11 a.m. EDT July 4, 2005

The Impactor probe is set to make the first of three navigation burns to hit Tempel 1 in about 10 minutes, mission controllers said.

Impactor's autonomous software is designed to home in on a bright, sunlit side of Comet Tempel 1. The probe takes four images per minute to calibrate its impact target. Its Flyby mothership also autonomously points itself at Impactor's target in order to record the collision.

11:55 p.m. EDT July 3, 2005

There is apparently a minor glitch with Deep Impact's Flyby spacecraft.

Mission managers have reported oscillations in the spacecraft's high beam antenna. Flyby is a critical link between the Impactor probe and flight controllers, serving as a relay between the Impactor probe and mission controllers on Earth.

"We are having a small issue with the high beam antenna," explained Anne Elson, a flight software engineer in Deep Impact's mission control center. "They are conferring now."

Flight controllers have passed around a jar of peanuts and each taken a handful for luck, a tradition at NASA's Jet Propulsion Center in Pasadena, California.

11:30 p.m. EDT July 3, 2005

NASA's Deep Impact mission is less than three hours from slamming a probe into Comet Tempel 1.

The mission's Impactor probe is steadily flying toward a 1:52 a.m. EDT (0552 GMT) collision on July 4 while its mothership, Flyby, is keeping its cameras trained on the icy object.

Impactor is scheduled to make a slight course adjustment in just over 20 minutes to hone its cometward path.

Astronomers hope Deep Impact's upcoming comet crash will shed light on the basic composition of comets and the material building blocks that make up the entire solar system.

Originally discovered in 1867, Comet Tempel 1 is whizzing through space at a cool 66,000 miles per hour, though the relative speed of Impactor's crash will be approximately 23,000 miles per hour because both the comet and spacecraft are in motion, mission scientists have said.

8:37 p.m. EDT July 3, 2005

Things are apparently going well for NASA's Deep Impact mission.

In an e-mail update, Monte Henderson, mission program manager for Ball Aerospace and Technologies Corp. - which built the Deep Impact spacecraft - said that the mission has proceeded smoothly since spacecraft separation.

"Everything looks good right now. All planned activities executed successfully. All systems go for impact," Henderson wrote.

The Impactor probe, which is expected to crash into Comet Tempel 1 at 1:52 a.m. EDT (0552 GMT) on July 4, is slated to switch to its autonavigation system at about 11:53 EDT (0353 July 4 GMT).

"Right now it's headed for spot-on for the middle of the comet," said Don Yeomans, a Deep Impact mission co-investigator for JPL. "If we did nothing, it would probably hit. Now when the auto-navigation gets turned on two hours out, it may decide that the comet is not where it should be. Right now it's headed for the center of mass. We don't really want to hit the center of mass, we want to hit the center of brightness closest to the Flyby. So it's going to do a scene analysis and make a slight adjustment to move over to the sunlit side."

Several targeting maneuvers, to better position the spacecraft for impact, are scheduled, the first of which set for 12:22 a.m EDT (0422 GMT).

3:10 p.m. EDT July 3, 2005

NASA has concluded today's pre-comet crash press conference for the Deep Impact mission.

The mission's Flyby and Impactor spacecraft are bearing down on their target, Comet Tempel 1, with less than 225,000 miles (362,102 kilometers) separating them from the icy object. Impactor is set to slam into Tempel 1 at 1:52 a.m. EDT (0552 GMT) on July 4. It successfully separated from Flyby at 2:07 a.m. EDT (0607 GMT) today.

In addition to the cameras aboard Flyby and Impactor, more than 50 telescopes and about 200 researchers from around the world are preparing to make their own observations of the comet collision.

"We have representatives at almost every major observatory in the world," said Deep Impact principal scientist Michael A'Hearn, of the University of Maryland, during today's briefing.

While A'Hearn admitted that mission scientists and engineers do have a pool going to predict Impactor's effect on Tempel 1, he said that at least two extreme cases aren't expected.

Researchers don't expect the 820-pound (371-kilogram) probe to punch a narrow crater deep into Tempel 1's surface, nor to they believe the spacecraft will hit the comet with such force that it is destroyed, A'Hearn said.

With the end of today's press conference, the next live update will begin with mission commentary leading up to tomorrow morning's comet crashing fireworks. Live commentary will begin here at at 11:30 p.m. EDT (0330 July 4 GMT).

2:50 p.m. EDT July 3, 2005

Despite the relative smoothness of Deep Impact's mission to date, there are still challenges ahead, mission managers said.

Chiefly, flight controllers and researchers are crossing their fingers that the geography of Comet Tempel 1 won't prevent Flyby from catching a clear view of Impactor's collision.

"We don't want a mountain between us and the impact, and we have no control over that," said Michael A'Hearn, Deep Impact principal scientist from the University of Maryland.

Mission controllers also hope the autonavigation software performs as expected. Impactor is designed to lock onto a bright patch on Tempel 1 to impact, with Flyby locking onto the same spot to catch the collision.

"Really it's up to the autonavigation software and the comet itself," said Deep Impact project manager Rick Grammier.

2:35 p.m. EDT July 3, 2005

Mission scientists are not worried that a potential outburst from Comet Tempel 1 could cloud the targeting software aboard Flyby or Impactor.

Past outbursts have dissipated quickly enough that the probes' autonavigation software can compensate, they said.

"Three of the last four outbursts have occurred in the same point on the comet," said Deep Impact principal scientist Michael A'Hearn, of the University of Maryland, during the press conference. "If an outburst happens there again, it would be about four hours before impact."

2:25 p.m. EDT July 3, 2005

The autonomous flight software for Flyby and Impactor is ready to go for the upcoming Comet Tempel 1 encounter, a useful capability since it takes light 7.5 minutes to travel the nearly 83 million miles between the them and Earth, mission officials said.

"We anticipate a bit of a rough ride during impact," said Jennifer Rocca, Deep Impact's systems engineer at JPL. "We know there will be a debris field as we near impact."

Flight controllers hope Impactor will be able to photograph Tempel 1 up until three seconds before impact, so long as no comet debris clouds its camera.

"It's an understatement to say we're excited," Rocca said. "We're very confident and very anxious to see the events of the next few hours."

2:10 p.m. EDT July 3, 2005

"Our Flyby spacecraft is ready and the Impactor spacecraft is where it's supposed to be," said Andrew Dansler, NASA's solar system division director, during today's press conference. "Everything looks green."

Both Impactor and Flyby are on target to within one kilometer of accuracy, mission managers said.

"Which is phenomenal," said Rick Grammier, NASA's project manager for Deep Impact at JPL.

2:00 p.m. EDT July 3, 2005

Today's pre-collision Deep Impact press conference has begun at NASA's Jet Propulsion Laboratory in Pasadena, California.

Mission managers appear jubilant despite the late night they pulled to watch over Impactor's separation from Flyby.

1:35 p.m. EDT July 3, 2005

Scientists and flight controllersfor NASA's Deep Impact mission to crash into a comet are celebrating todayafter the mission's Impactor probe successfullyseparated from its Flyby mothership.

Impactor ejected from Flyby less than 12hours ago and is bearing down on its icy target, Comet Tempel 1. TheFlyby craft was able to photographthe probe's departure, and will watch from afar during the impact at 1:52 a.m.EDT July 4.

2:20 a.m. EDT July 3,2005

A cheer rose up at 2:16a.m. EDT (0616 GMT) when a mission controller announced: "We have lock inthe S-band receiver." That means Deep Impact's mission control hasreceived confirmation that the Impactor successfully separatedfrom the Flyby mothership as planned at 2:07 a.m. EDT (0607 GMT),and that Flyby is serving as a relay to ground control.

After the initialseparation, a fault alarm went off onboard Deep Impact's Flyby vehicle. Mission controllers ran through a systemscheck and concluded the spacecraft was on track and the alarm could be ignored.

Click herefor managing editorAnthony Duignan-Cabrera'sreport on Impactor'srelease from Deep Impact mission control at JPL.

1:21 a.m. EDT July 3,2005

"The impactoris officially on its own power," came the announcement and acheer went up in the newsroom here at JPL.

Though still attached toits Flyby mothership,the Impactorprobe went on internal battery power at 1:15 a.m. EDT (0515 GMT). Flybyadjusted itself to the proper Impactor separation angle and ison schedule for separation, which is expected at 2:07 a.m. EDT (0607 GMT).

11:20 p.m. EDT July 2,2005

"We are now in the endgame," Monte Henderson, program manager for Ball Aerospace andTechnologies Corp., the builders of NASA's Deep Impact spacecraft, told a groupof reporters here at the space agency's Jet Propulsion Laboratory in Pasadena,California.

Henderson's announcement followed asuccessful trajectory maneuver of the spacecraft earlier Saturday evening atabout 8:00 p.m. EDT.

The Deep Impact team isexpected to receive verification that the mission's Flyby mothershipreleased its 820-pound (371-kilogram) Impactor probe at about 2:07 a.m. EDT(0607 GMT) July 3, placing the small craft directly in the path of Comet Tempel1. The copper-tipped collider is expected to slaminto Tempel1 on July 4 at 1:52 a.m. EDT (0552 GMT) and open a window into the comet'scomposition and history.

The mission is going well,and only a minor adjustment was made on the spacecraft's trajectory, Hendersonsaid.

"It was a very minor3.15 meters per second burn," Hendersonsaid. "Avery minor update to get it in line with the comet."

Mission managers, however, decided to delaythe activation of the Impactor's battery until 1:10a.m. EDT, almost one-hour prior to spacecraft separation. The decision was madeto ensure the battery remained at peak power. So far, Impactor hasbeen powered by the Flyby mothership.

"Everything that wehaven't tested before today is a risk," Hendersonsaid.

Should the battery fail toperform, mission managers have a 14-hour built-in period to pinpoint theproblem and hopefully correct it. This will not interfere with the Impactor'scollision time window with the comet Tempel 1, Hendersonsaid.

"We have been working onthis program for five-and-a-half years, yet the major milestones are stillahead of us," Henderson said.'s preview of today's Deep Impactcollision is available here,with more mission information available at the Deep Impact Special Report. Refreshthis page to get live updates of Deep Impact's status as they becomeavailable.  

Recent stories

July 1, 2005: PASADENA -- With a little more than two days left in its six-month journey, managers for NASA's Deep Impact mission said the spacecraft is on course to make its historic encounter with a comet late Sunday evening.

Download and go! Grab your telescope or binoculars and with these easy directions and star charts you can begin to hunt Tempel 1.


July 1, 2005: Live webcasts of Deep Impact's collision with Comet Tempel 1 will be provided by NASA and several observatories, large and small, to offer skywatchers a digital view to the cometary collision. Click here to learn where you can watch the event as it happens or submit your own observations.

What's inside Comet Tempel 1 will change what we know about our origins. Learn more in this video look at the Deep Impact mission.  

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