New Mars Forums

The repair kit for the next shuttle mission might not fix a problem the size of Columbia's.Months before NASA resumes space shuttle missions, program managers concluded Thursday that Discovery astronauts will have to rely on an experimental repair kit that may not fix the kind of damage that doomed Columbia.

Shuttle engineers acknowledged difficulties late last year with a caulk-like substance used to fill in gouges in the shuttle's soft silica tiles. The substance produced air pockets in simulated flight conditions.

Columbia was downed by a breach of six to 10 inches in the carbon composite material lining a vulnerable region of the wing. At best, Discovery astronauts could fill cracks or patch holes no larger than four inches.

The small blaze began atop one of the building's low bays, where roofers were doing work with a blowtorch and tar

NASA’s Opportunity Mars rover has come across an interesting object -- perhaps a meteorite sitting out in the open at Meridiani Planum. Initial data taken by the robot’s Mini-Thermal Emission Spectrometer (Mini-TES) is suggestive that the odd-looking “rock” is made of metal.

Endeavour Maintenance Slips
Editor's note: According to NASA sources, tomorrow (13 Jan) the PRCB will be told that OV-105 (Endeavour) maintenance will not be completed in time to support the STS-117 launch. A schedule slip of approximately 4 months will be identified.  KSC has adjusted its resources to support preparation of OV-103 (Discovery) and OV-104 (Atlantis) for flight and is going to go a 24/7 schedule to support the STS-114/STS-300 Rescue missions and STS-121.  In addition, charts will be presented at the PRCB suggesting a waiver of the 3 year period between major maintenance overhauls for OV-104 so as to allow more flights to compensate for the lack of a flight-ready OV-105.

The Trifid Nebula is a giant star-forming cloud of gas and dust located 5,400 light-years away in the constellation Sagittarius.

"With Spitzer, it's like having an ultrasound for stars. We can see into dust cocoons and visualize how many embryos are in each of them."

For the first time, astronomers have been able to combine the deepest optical images of the universe, obtained by the Hubble Space Telescope, with equally sharp images in the near-infrared part of the spectrum using a sophisticated new laser guide star system for adaptive optics at the W. M. Keck Observatory in Hawaii. The new observations, presented at the American Astronomical Society (AAS) meeting in San Diego this week, reveal unprecedented details of colliding galaxies with massive black holes at their cores, seen at a distance of around 5 billion light-years.

"The advent of the laser guide star at Keck has opened up the sky for adaptive optics observations, and we can now use Keck to focus on those fields where we already have wonderful, deep optical images from the Hubble Space Telescope," Koo said.

Because the diameter of the Keck Telescope's mirror is four times larger than Hubble's, it can obtain images four times sharper than Hubble in the near infrared now that the laser guide star adaptive optics system is available to overcome the blurring effects of the atmosphere.

Adaptive optics (AO) corrects for the blurring effect of the atmosphere, which seriously degrades images seen by ground-based telescopes. An AO system precisely measures this blurring and corrects the image using a deformable mirror, applying corrections hundreds of times per second. To measure the blurring, AO requires a bright point-source of light in the telescope's field of view, which can be created artificially by using a laser to excite sodium atoms in the upper atmosphere, causing them to glow. Without such a laser guide star, astronomers have had to rely on bright stars ("natural guide stars"), which drastically limits where AO can be used in the sky. Furthermore, natural guide stars are too bright to allow observations of very faint, distant galaxies in the same part of the sky, Koo said.

Radiation exposure - from the sun and other solar systems - is among the biggest risks astronauts face as they explore space.

The particles can make the astronauts sick on their journey, rendering them unable to finish their mission, or they can leave astronauts cancer stricken soon after their glory years.

The old Apollo spacecraft, she said, used aluminum shielding. Newer spacecraft use shielding made of various materials.

Liquid hydrogen is an excellent radiation shield, Simonsen said, but it's flammability makes it a poor bet for the new space vehicles.

One shielding method uses magnetism to control the radioactive particles. But because of health concerns arising from the magnetism, NASA has decided those active systems - as opposed to more passive shields - are not worth the risk.

"Every 10,000 years or so, we should get a tsunami from an asteroid, and we haven't had one in about that amount of time," Galen Gisler said. "It's a hard thing to calculate, because we don't know how many asteroids are out there, but some international groups are starting to do surveys to quantify that."

A half-mile-wide asteroid hitting the Atlantic near Florida could cause a 10-foot tsunami that could kill thousands and leave massive destruction.