banner Header Image
NASA Space Shuttle Program Stardust SRC Entry ATV-1 Reentry News

Current projected launch date: 2009 May 11, 2:01 p.m. EDT

In brief:

What: Single aircraft (Gulfstream V) instrumented airborne mission to observe STS-125 Shuttle External Tank (ET) reentry
Where: Just east of Hawaii
Why: Hubble orbit brings ET in close to Hawaii, within reach of California coast. To understand how the tank ruptures during entry
When: May 11, 2009 - 80 minutes after STS-125 launch [keep tuned for possible launch delays]


NASA Space Shuttle Program
STS-125 crew journal
STS-125 mission info

Science team:

Peter Jenniskens (P.I.), SETI Institute, Mountain View, CA

Ron Dantowitz, Clay Center Observatory, MA

Hans Stenbaek-Nielsen, University of Alaska, Fairbanks, AK and Matthew Geoff McHarg, USAF Academy, CO

Ed Schilling, NASA Ames Research Center, CA


NASA Ames Research Center:
- Project management
- Aircraft operations (H211 LLC)
- Education and Public Outreach

NASA Johnson Space Center
- Space Shuttle Program
- Flight planning

SETI Institute
- Coordination research team
- Instrument PI team

Clay Center Observatory
- Instrument PI team
- Daytime tracking

University of Alaska Fairbanks
- Instrument PI team


ET falling away from Shuttle
ET falling away from Shuttle

''Re-entry over Mauna Loa, Hawaii'', by William K. Hartmann, Planetary Science Institute, Tucson (Painting number 212. 16 x 25 inch, Acryclic on 100 percent ragboard). From the ollection of, and photo courtesy of: Robert A. Brown (Space Telescope Science Institute).

Hartmann writes: "That whole elongated cluster of obects was moving across the sky, and among the bright objects many of them or most were changing brightness, sparkling essentially, with different colors among them. So the whole thing had somewhat the appearance of an elliptical mass of sparkly fireworks moving across the sky. And Mauna Loa really was erupting in the mid distance!". When the painting was made, the following notes were provided: "The reentry of the main external tank of space shuttle Challenger, approx 100 mi. south of Hawaii Island. View is at ~5:20 AM, H.S.T., shortly before dawn (glow seen in east (left), April 6, 1984. Painted 9 days after the event, on April 15, 1984 (additional details added in subsequent days), based on my eyewitness view, plus notes and interviews on April 6, 1984. Mauna Loa was in 12th day of its eruption, with fire fountain & flow from ~9000 ft level, and steam clouds at summit & 11,000 ft levels. Smoggy haze from these blew off to the west (right). Tank broke into pieces with prominent, different colors. Magnitude estimates -5 to -10." This image was published in a Sky and Telescope article in July of 1984 (p. 7-8).

Mission statement - An instrumented airborne observing campaign to study the disintegration of the Shuttle External Tank during entry.


May 11 - The STS-125 launched today on schedule at 1:01:56 p.m. Central Time, followed by an ET reentry during daytime just south-east of Hawaii 80 minutes later. Paul Sears at Big Island reports: "Sorry, no one here saw it. Just too cloudy. Aloha."

Footage of STS-125 fuel tank after jettison.

ET tank drop

April 30 - NASA managers completed a review today of space shuttle Atlantis' readiness for flight and selected an official launch date for the STS-125 mission to upgrade the Hubble Space Telescope. Commander Scott Altman and his six crewmates are scheduled to lift off at 2:01 p.m. EDT, May 11, from NASA's Kennedy Space Center in Florida. From: NASA Release 09-093.

If all goes well, the ET will enter during daytime and we will not have an STS-125 "ET" MAC mission. Keep tuned.

April 27 - Atlantis Launch Pushed Up To May 11. Florida Today (4/25, Dean) reported, "NASA on Friday officially moved up its target launch date for shuttle Atlantis by one day, to May 11." This will allow for three launch attempts before the shuttle has to stand down "when the Air Force's Eastern Range is reserved for military use for about a week." The change in schedule was "nearly derailed by an incident Wednesday" when a wrench was dropped, hitting a bay door, but a "detailed inspection Friday morning determined no repairs were necessary, but the incident is under review," NASA spokesperson Allard "Beutel said." Two engineers were also "grazed" by the wrench, but no injuries were reported.

Spaceflight Now (4/24, Harwood) reported, "A NASA spokesman said the only downside to moving launch up one day was a minor reduction in battery charging time. ... But that is still well above the 156-hour requirement for the new batteries and Hubble Program Manager Preston Burch agreed to the request to move launch up one day." Another Spaceflight Now (4/24, Harwood) article described the lack of damage from the wrench as a "lucky break for NASA's shuttle team."

April 24 - Media coverage of Thursday's shuttle-related announcements by NASA focused on the potential launch of Atlantis a day earlier and the uncertainty over whether that plan is viable. Hubble program manager Preston Burch "says he'll know better in a week if his team can make a launch on the 11th. Liftoff has been targeted for May 12th." NASA "wants to have extra time to get the mission off, before having to get in line behind the Air Force. A military operation planned for mid-May would delay the shuttle launch by more than a week." From: AIAA Daily Launch.

April 22 - From Space Shuttle Program Website: On Tuesday, the Space Shuttle Program Flight Readiness Review concluded, setting the stage for the executive-level review at Kennedy, which begins April 30. Following the final review, a firm launch date for the mission to service the Hubble Space Telescope will be set. Launch is currently targeted for May 12 at 1:31 p.m. EDT.

April 20 - Sadly, we were not able to secure the use of a Gulfstream V aircraft for a daytime reentry observing campaign in time to purchase the necessary equipment needed to measure the position of the tank in the daytime sky.

If the STS-125 shuttle launch is delayed to May 22 or later, this will become a night-time reentry, at which time we can use the star background for astrometric measurements (see: ATV-1 "Jules Verne" MAC mission) and we hope our request for use of a Gulfstream V aircraft may be revisited. A decision on the launch date is expected following the STS-125 executive level Flight Readiness Review on April 30th.

April 16 - The mission patch (above) is now in production.

April 13 - Spaceflightnow reports a preferred launch time at about 20 minutes after window open.

The Shuttle External Tank reentry as observed from Hawaii in April of 1985. Photo: Dale P. Cruikshank, NASA Ames Research Center.

April 12 - Dale P. Cruikshank of NASA Ames Research Center witnessed the Shuttle ET entry in 1985 and on request kindly scanned the above images from slides he took at that time. Click on the images for a higher resolution version.

Alt-azimuth camera mount for astrometric measurements. Photo: Brian Lula, PI Nanopositioning and Ron Dantowitz, Clay Center Observatory.

April 08 - Clay Center Observatory has announced the fabrication of two sturdy alt-azimuth mounts for the deployment of cameras onboard a Gulfstream V aircraft. The mounts have a swivel point close to the window and, coupled to an Inertial Measurement Unit, provide for accurate pointing even in daytime conditions.

View from Hilo. Image courtesy Jim Albers

April 03 - If the Shuttle launch occurs on May 12 in the beginning of the 1-hour launch window, as planned, then ground-based observers at Hilo, Hawaii, will see the entry very low on the horizon in a daytime sky, too low for good viewing. This calls for an airborne observing campaign, which provides low extinction near the horizon even if the aircraft is far from the entry area. However, if the Shuttle launch occurs later in the launch window, then viewing conditions will progressively improve for ground-based observers, according to the STS-125 ET MAC mission planners.

Space Shuttle Atlantis being prepared for STS-125. Image: NASA

April 02 - Atlantis stands on the Launch Pad 39A, ready for final preparations for the STS-125 mission to service the Hubble Space Telescope. The mission will be commanded by astronaut Scott Altman. Retired Navy Capt. Gregory C. Johnson will be the pilot. During an 11-day mission, the 7 astronauts will install two new instruments, repair two inactive ones, and perform the component replacements that is expected to keep the telescope functioning until at least 2014. More at NASA's Space Shuttle Program website.

[Image gallery STS-125]

March 28 - NASA Shuttle Program has allocated funding for a Shuttle External Tank reentry observing campaign.

The Shuttle External Tank reentry as observed from Hawaii during deployment of the Hubble Space Telescope on April 24, 1990. Photo: Paul Maley, JSC.

Mission concept:

The External Tank provides the fuel and oxidizer for the Shuttle's main engines during the first 8.5 minutes of the ascent. The tank is separated from the Shuttle and falls back to Earth about 80 minutes after launch, usually over the Pacific Ocean.

Then: In 1990, Paul Maley observed from Mauna Kea in Hawaii the Shuttle's External Tank (ET) reentry from mission STS-31, executed by Discovery, the very flight that deployed the Hubble Space Telescope. Maley posted images of the reentry here. Initially, he noticed from a periodic variation in brightness the tell-tale end over end rotation of the tank, at a rate of some 8 degrees/second. The object was low on the horizon and disappeared briefly from view behind the top of a mountain. He then photographed the disintegration of the tank, with some 50 fragments dispersing along near-parallel trajectories.

Now: Nineteen years later, in May 2009, the Hubble Space Telescope will be serviced by the Space Shuttle. This visit puts the Shuttle in a rare 28 degree inclined orbit, which causes the External Tank to reenter again close to Hawaii. This time, researchers are prepared to observe the reentry with modern imagers and spectroscopic instruments.

If the proposed mission is approved, then the scientists from NASA Ames Research Center, Clay Center Observatory, the SETI Institute, and the USAF Academy, will deploy onboard an H211 LLC operated Gulfstream V aircraft. The aircraft will deploy from NASA Ames Research Center in California on a 10-hour mission, bringing the researchers to the reentry area and back.

The images and spectra recorded during the entry will be used by the Space Shuttle Program to evaluate how the Shuttle External Tank breaks during entry. This knowledge will help design a better tank by helping to control the size of the debris footprint, in an ongoing effort to improve the Space Shuttle in the future.

Contact Us Site Map    Last Modified: w3 April, 2009  
+ NASA Homepage
+ NASA en Español
+ Contact NASA
+ NASA Privacy Statement,
  Disclaimer, and
  Accessibility Certification
Ames Research Center
NASA Ames Research Center Planet Quest Other NASA Missions Johannes Kepler