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STS-48: Atmosphere research satellite
With launch of the Upper Atmosphere Research Satellite from space shuttle Discovery in September 1991, a new era in studying Earth's environment from space began. The crew of STS-48 describes the mission in this post-flight film, which includes an beautiful nighttime flyover of the United States.

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STS-40: Medical lab
Astronauts, rodents and jellyfish were the subjects during extensive medical tests performed aboard the first Spacelab Life Sciences mission launched in June 1991 aboard shuttle Columbia. A space laboratory module riding in the payload bay housed the experiment facilities. The crew of STS-40 explain the mission in this post-flight film.

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Exploration update
A progress report on development of the Orion crew exploration spacecraft and the Ares launch vehicle is given during this briefing held October 18 at the Glenn Research Center in Cleveland.


MRO early images
Some of the initial pictures and data from NASA's Mars Reconnaissance Orbiter since the craft entered its mapping orbit around the Red Planet are presented in this news briefing held October 16 from the Jet Propulsion Laboratory.


Soyuz moves ports
The three-man Expedition 14 crew of the International Space Station complete a short trip, flying their Soyuz capsule to another docking port in preparation for receiving a resupply ship.

 Undock | Re-dock

STS-39: Military maneuvers
Space shuttle Discovery's STS-39 flight, launched in April 1991, served as a research mission for the U.S. Department of Defense. An instrument-laden spacecraft for the Strategic Defense Initiative Organization was released to watch Discovery perform countless rocket firings and maneuvers, as well as canisters releasing clouds of gas. The crew tells the story of the mission in this post-flight film presentation.

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STS-37: Spacewalkers help Gamma Ray Observatory
Seeking to study explosive forces across the universe, the Gamma Ray Observatory was launched aboard shuttle Atlantis in April 1991. But when the craft's communications antenna failed to unfold, spacewalking astronauts ventured outside the shuttle to save the day. The rescue EVA was followed by a planned spacewalk to test new equipment and techniques. The crew of STS-37 narrate this post-flight mission film.

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Mars rover seen by orbiter
Dazzling images from Mars are revealed by scientists. The robotic rover Opportunity has reached the massive Victoria crater with its steep cliffs and layers of rock exposing the planet's geologic history. Meanwhile, the new Mars Reconnaissance Orbiter has photographed the rover and its surroundings from high above.


Hubble discovery
n this news conference from NASA Headquarters, scientists announce the Hubble Space Telescope's discovery of 16 extrasolar planet candidates orbiting a variety of distant stars in the central region of our Milky Way galaxy. Five of the newly found planets represent a new extreme type of planet not found in any nearby searches.

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NASA chief to reveal decision on Hubble mission Tuesday
Posted: October 27, 2006

Editor's note...Portions of this story first ran last December.

Another Hubble service call could be performed by a shuttle crew in 2008. Credit: NASA
NASA Administrator Michael Griffin today heard engineering briefings on the risks and requirements of a final shuttle mission to service the Hubble Space Telescope in 2008, a flight that was deemed too risky by previous Administrator Sean O'Keefe in the wake of the Columbia disaster.

Griffin will announce a decision on whether to reinstate a Hubble servicing mission during a news conference Tuesday at the Goddard Space Flight Center in Greenbelt, Md. If he approves the flight, another briefing will be held at the Johnson Space Center in Houston to introduce the astronauts who will fly the mission.

O'Keefe's much-criticized January 2004 decision to call off Servicing Mission 4 (SM-4) was based in large part on recognition that a Hubble repair crew could not seek "safe haven" aboard the international space station in case of major problems with the shuttle that might prevent a safe re-entry. The two spacecraft circle the globe in very different orbits and shuttles cannot carry enough fuel to move from one to the other.

But Griffin has made no secret of his desire to reverse O'Keefe's decision.

"For any given single mission, I would say that the Hubble servicing represents the highest priority utilization of a single shuttle mission that I can conceive," Griffin said in an interview late last year. "Because servicing the Hubble is something only the shuttle can do, it's only one flight and is, therefore, I think a very high agency priority if we can do it technically."

Without a servicing mission to replace Hubble's aging batteries and stabilizing gyroscopes, one of the most scientifically significant satellites ever launched will die in the next few years. Given that two new instruments are already built that will extend Hubble's scientific reach, supporters are urging Griffin to reinstate the mission.

They argue the success of three post-Columbia missions proves NASA has dramatically lowered the risk of external tank foam insulation problems like those blamed for Columbia's demise.

Carrying the same heat shield inspection boom and sensors that station flights carry, Discovery's crew will be able to inspect all critical areas on the shuttle before rendezvousing with Hubble and again, after Hubble is released. If impact damage is found, the crew will have improved repair materials and techniques at their disposal.

But flying in Hubble's orbit, the servicing crew would be exposed to a greater chance of micrometeoroid impacts. During a shuttle flight in September, a small object hit a payload bay door radiator and while it didn't cause any problems for the mission, it illustrated the threat posed by space debris.

That threat, while higher for a Hubble mission, is offset somewhat by reduced risk in other areas. But what if non-repairable damage is discovered? One of the options Griffin will consider is whether to process a second shuttle in parallel to serve as a "launch-on-need" rescue ship that would eliminate concern about the lack of safe haven aboard the station.

To provide enough time for a rescue mission to be launched, the Hubble crew would take off with additional supplies of lithium hydroxide, a chemical used to scrub carbon dioxide form the shuttle's air supply. Those additional supplies would permit a Hubble crew to remain in orbit aboard a damaged ship for 25 days or more.

If two shuttle pads are available, planners believe a rescue flight could be launched with a week of the Hubble launch. If only one pad is available - and NASA currently plans to turn pad 39B over to the Constellation moon-Mars program next year - the best-case turnaround time is about 15 days.

In one scenario, sources say, the rescue shuttle would be moved to the launch pad, loaded with internal rocket fuel and then moved back to the Vehicle Assembly Building to make way for the Hubble launch. If a problem developed in orbit, the rescue shuttle then could be moved back out to the pad and quickly launched.

But any launch-on-need capability would effectively take two space shuttles out of the space station assembly flow, delaying downstream flights from one to several months.

In addition, manpower and hardware processing issues at the Kennedy Space Center make the current April 2008 target date unlikely, engineers say. A more realistic target is the summer of 2008.

In any case, Griffin must balance the threat of delays, additional costs and increased risk with the high value of servicing a telescope that is arguably the most significant scientific satellite ever launched.

When Columbia blasted off on Jan. 16, 2003, Servicing Mission 4 was scheduled for takeoff in early 2005. The major objectives of the flight were to install two new scientific instruments, to replace the observatory's batteries and to install a fresh set of gyroscopes.

O'Keefe's cancellation of SM-4 in January 2004 touched off a storm on protest, prompting NASA to look into the feasibility of an robotic servicing mission.

The goals of the unmanned mission included the attachment of a propulsion module that could drive Hubble to a safe, targeted re-entry at the end of its useful life. But such a robotic flight ultimately was deemed too technically risky and too expensive.

With relatively minor exceptions, the goals of the currently envisioned shuttle mission are virtually unchanged from the flight O'Keefe cancelled:

  • Installation of three new rate sensing units, or RSUs, containing two gyroscopes each to restore full redundancy in the telescope's pointing control system

  • Installation of six new nickel-hydrogen batteries to replace the power packs launched with Hubble in 1990

  • Installation of the Wide Field Camera 3 (in place of the current Wide Field Planetary Camera 2), providing high-resolution optical coverage from the near-infrared region of the spectrum to the ultraviolet

  • Installation of the Cosmic Origins Spectrograph, sensitive to ultraviolet wavelengths. COS will take the place of a no-longer-used instrument known as COSTAR that once was used to correct for the spherical aberration of Hubble's primary mirror. All current Hubble instruments are equipped with their own corrective optics

  • Installation of a refurbished fine guidance sensor, one of three used to lock onto and track astronomical targets (two of Hubble's three sensors suffer degraded performance). The refurbished FGS, removed from Hubble during a 1999 servicing mission, will replace FGS-2R, which has a problem with an LED sensor in a star selector subsystem

  • Attachment of new outer blanket layer - NOBL - insulation to replace degrading panels
Even though O'Keefe cancelled SM-4, money was put in NASA's budget later to keep mission planning active. Engineers ultimately added a repair job to restore the Space Telescope Imaging Spectrograph to operation. The instrument was shut down in 2004 when a power supply failed. As part of the fix, a passive radiator will be installed to help lower operating temperatures in the telescope's instrument section.

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