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Updated Information On Columbia Shuttle Tragedy
Thanks to all the readers who have sent links related to today's shuttle disaster. An Associated Press story carried on Salon says that an independent board (with members from the Air Force, Navy, Transportation Department and other federal agencies) has been appointed to investigate the disaster. CNN is carrying official statement from President Bush. Rediff.com has an article on the life of Indian astronaut Kalpana Chawla. borisonanovitch points to "more info on the science aboard Columbia and links to other NASA research." fabel reminds us "Most of the media is focusing on the slight damage that ocurred at takeoff (that NASA discounted at the time) but STS-107 was *delayed* for 6 months (original launch date 19 Jul 2003) Update: 02/01 23:51 GMT by T : [Note, should read "2002."] because of
cracks in the propellant feed lines to the 3 main engines. A defect that could have caused catastrophic failure. Did the fix work or not?"
OMS does have motors and fuel, but the OMS do not use the same lines and fuel as Main Engines.
"orbital maneuvering system provides the thrust for orbit insertion, orbit circularization, orbit transfer, rendezvous, deorbit, abort to orbit and abort once around and can provide up to 1,000 pounds of propellant to the aft reaction control system. The OMS is housed in two independent pods located on each side of the orbiter's aft fuselage. The pods also house the aft RCS and are referred to as the OMS/RCS pods. Each pod contains one OMS engine and the hardware needed to pressurize, store and distribute the propellants to perform the velocity maneuvers. The two pods provide redundancy for the OMS. The vehicle velocity required for orbital adjustments is approximately 2 feet per second for each nautical mile of altitude change."
"Before the deorbit thrusting period, the flight crew maneuvers the spacecraft to the desired deorbit thrusting attitude using the rotational hand controller and RCS thrusters. Upon completion of the OMS thrusting period, the RCS is used to null any residual velocities, if required. The spacecraft is then maneuvered to the proper entry interface attitude using the RCS. The remaining propellants aboard the forward RCS are dumped by burning the propellants through the forward RCS thrusters before the entry interface if it is necessary to control the orbiter's center of gravity.
The aft RCS plus X jets can be used to complete any planned OMS thrusting period in the event of an OMS engine failure. In this case, the OMS-to-aft-RCS interconnect would feed OMS propellants to the aft RCS.
From entry interface at 400,000 feet, the orbiter is controlled in roll, pitch and yaw with the aft RCS thrusters. The orbiter's ailerons become effective at a dynamic pressure of 10 pounds per square foot, and the aft RCS roll jets are deactivated. At a dynamic pressure of 20 pounds per square foot, the orbiter's elevons become effective, and the aft RCS pitch jets are deactivated. The rudder is activated at Mach 3.5, and the aft RCS yaw jets are deactivated at Mach 1 and approximately 45,000 feet.
The OMS in each pod consists of a high-pressure gaseous helium storage tank, helium isolation valves, dual pressure regulation systems, vapor isolation valves for only the oxidizer regulated helium pressure path, quad check valves, a fuel tank, an oxidizer tank, a propellant distribution system consisting of tank isolation valves, crossfeed valves, and an OMS engine. Each OMS engine also has a gaseous nitrogen storage tank, gaseous nitrogen pressure isolation valve, gaseous nitrogen accumulator, bipropellant solenoid control valves and actuators that control bipropellant ball valves, and purge valves.
In each of the OMS pods, gaseous helium pressure is supplied to helium isolation valves and dual pressure regulators, which supply regulated helium pressure to the fuel and oxidizer tanks. The fuel is monomethyl hydrazine and the oxidizer is nitrogen tetroxide. The propellants are Earth-storable liquids at normal temperatures. They are pressure-fed to the propellant distribution system through tank isolation valves to the OMS engines. The OMS engine propellant ball valves are positioned by the gaseous nitrogen system and control the flow of propellants into the engine. The fuel is directed first through the engine combustion chamber walls and provides regenerative cooling of the chamber walls; it then flows into the engine injector. The oxidizer goes directly to the engine injector. The propellants are sprayed into the combustion chamber, where they atomize and ignite upon contact with each other (hypergolic), producing a hot gas and, thus, thrust."
The Apollo 1 fire occurred on January 27, 1967, killing three astronauts on the launchpad. The next flight was Apollo 7, which lifted off on October 11, 1968, a delay of one and a half years. Bear in mind that the US space program was under intense pressure to meet a December 31, 1969, deadline to land a man on the moon.
The Challenger disaster (STS-51L) occurred on January 28, 1986, killing seven astronauts shortly after launch. The next mission (Discovery, STS-26) took off on September 29, 1988, a delay of two and a half years.
At the present time there is pressure to continue construction of the International Space Station. Unless the ISS is to be mothballed, this will probably mean that at least one launch will have to happen within a year or so.
Toronto-area transit rider? Rate your ride.
Not sure of its been posted by anyone on the two threads, but here's a Radar Image of the debris rain being picked up by weather stations.
"But remember, most lynch mobs aren't this nice." (H.Simpson)
-- Joe
Basically it's the same thing you do when you're skiing and want to bleed off speed. It's a pretty common aviation maneuver used to bleed off speed, or in the case of general aviation, to check your blind spots before landing.
Essentially, it's a series of slow, lazy turns from side to side in a sort of half figure eight (resembling and S, ergo: S turns).
-E2
The evil monkey commands you to dance.
Karma: 0 (But I wield a mean +10 Vorpal Apathy)
Shawn Shephard discusses the potential "tire pressure problem". From the video:
Here is a link to the last audio received from Columbia: http://www.canada.com/toronto/globaltv/info/video/ 020103audio.ram
First, this is a tragedy for the astronauts and their families. I extend condolances to all who have been affected.
N ews.Rele ases/Previous.News.Releases/97.News.Releases/97-03 .News.Releases/97-03-28.Shuttles.New.ET.Completes. Testss tsstat/ 1998/sep/9-10-98s.htma ce/updates/sto32.htmle dc/newsreleases/1999/99 -041.htm/ releases/2 002/02-234.html
However, this problem is nothing new. The insulation material on the external fuel tanks was changed in 1997 and immediately caused problems. Lockheed-Martin was recently contracted to provide an external camera to monitor insulation loss. I have not found any documentation of the insulation problems from late 1997 until the cameras were installed.
See:
http://spacelink.nasa.gov/NASA.News/NASA.
http://www-pao.ksc.nasa.gov/kscpao/status/
http://ltp.arc.nasa.gov/sp
http://www.arnold.af.mil/a
http://www1.msfc.nasa.gov/NEWSROOM/news
for details about NASA's work on the problem.
Actually, there's a fairly interesting piece up on the TIME website where they discuss the three most probable (in their opinion) causes for the crash. Their 3 leading suspicions are improper piloting leading to a roll which caused structural breakup, the heat tiles that fell of during launch, and the possibility that what little fuel is reserved for the maneuvering engines ignited somehow.
They also toss some juicy quotes like: "The shuttle was built as a space truck, and then the International Space Station was built to give it something to do. Both programs are likely to suffer as a result of this disaster. " and "it's unlikely that NASA will undertake any further shuttle missions or any other manned space flights for the next two years."
Has anybody explained why they couldn't have done a spacewalk to inspect the damage from the insulation strike?
Yes, they have. It was not possible to inspect the bottom of the shuttle during this flight because (1) the cargo bay was being occupied by the science package and had no remote manipulator, (2) there are no handles or tethers on the bottom of the shuttle, and (3), shuttles are simply not equipped nor is it recommended for spacewalks to occur without tethering or the robotic arm. Thus, no spacewalks to the bottom of the shuttle.
All I've heard is that it wouldn't have made any difference if they had done one, since they weren't equipped to repair it.
I think also that the Columbia is too heavy to make the higher orbit of the ISS, and OMS and RCS thrusters would not have been enough to boost it to that level. The Columbia is heavier because it was overbuilt... the later shuttles are much lighter. This is why the Columbia has *never* gone to the ISS.
Even if they did find the damage, they also have no way to fix it. All of the tens of thousands of tiles on the surface of the shuttle are unique. Each one has different dimensions, and fits in only one place. Obviously, it would be impossible to carry a replacement for every one.
Lastly, if they discovered the problem during reentry maneuvers, it was still too late. The best NASA could have done was say "It was nice knowing you. God be with you." Once the reentry sequence has started, there is no way to abort. Either they make it, or they don't.
"Alcohol, Tobacco, Firearms, and Explosives" should be a convenience store, not a government agency.
Comment removed based on user account deletion
No they weren't. The Orbiter is built largely from very normal aluminium. The thermal protection is provided by tiles. There are two types of tiles: black and white. Only the black ones can stand the full temperature of re-entry, and they are placed over the nose and flat bottom of the craft. The white tiles on the top and sides can only deal with the lesser temeratures that leak around.
The shuttle re-enters "bottom first", not in a glide like an aircraft (that bit comes later). The black tiles on the flat bottom create the same effect as an Apollo or Soyuz capsule, and cause an area of ionisation which actually takes the brunt of the heat like a buffer.
So it requires fairly precise alignment to make the whole thing work. Once a wing rips off, the structure will tumble and rapidly decelerate. If there are organic remains, it is because the temperatures were not very high for very long, not because the crew were encased in something that was designed to withstand that temperature from any orientation.
Here is a better collection of stories than the rediff one on kalpana chawla. Incidentally, chawla was the most experienced of the crew, this being her 2nd trip & she is is the 2nd Indian in space after Rakesh sharma did it with the Russians in 1984.
BTW, this is just in: Columbia crew remains found