Hubble Space Telescope Failsgreenspun.com : LUSENET : TimeBomb 2000 (Y2000) : One Thread
From CBS Marketwatch.
"15:26 HUBBLE SPACE TELESCOPE HALTS OBSERVATIONS; POINTING SYSTEMS FAILS"
What does a pointing system use to point? Can you spell ephemeris?
Here's some ephemeris data.
February 99 Ephemeris Mo/Dy/Yr Sun Moon Merc Venu Mars Jupi Satu Uran Nept Plut 2/ 1/99 12Aq10 22Le29 10Aq14 4Pi45 2Sc21 27Pi33 27Ar48 12Aq43 2Aq14 10Sg03 2/ 2/99 13Aq11 5Vi40 11Aq57 6Pi00 2Sc44 27Pi45 27Ar51 12Aq47 2Aq16 10Sg04 2/ 3/99 14Aq12..
Satellites are located, flown and communicated with ephemeris data too. Lots of ephemeris data is now compliant. Some still isn't.
-- ng (firstname.lastname@example.org), November 15, 1999
Did this happen today? Could have been the CME that was supposed to hit the earth today?
-- FLAME AWAY (BLehman202@aol.com), November 15, 1999.
My understanding is that if the earth goes through the CME of the other day, it will be tomorrow.
I'd say this pointing system is a ground based computer and communications system that computes the location of a object in space from ephemeris data and tells the Hubble where to orient and focus.
-- ng (email@example.com), November 15, 1999.
The next Shuttle mission is scheduled to replace all the gyroscopes on Hubble.
From this NASA site:"Gyroscopes/Rate Sensor Unit (RSUs)-The gyroscopes help Hubble point and move by continuously reporting the telescope's position and any small movement it makes. This information is sent to a computer that commands Hubble to stay stable or move at a desired rate.
"Each gyro contains a spinning wheel inside a sealed container. Hubble's movement is constantly compared to the position of these spinning wheels. By keeping Hubble steady with respect to these wheels, the telescope stays stable.
"Hubble has six gyroscopes. They are grouped in pairs inside three Rate Sensor Units (RSUs). Any three gyroscopes can keep Hubble fully operating. In 1997, at the end of Servicing Mission 2, all six gyroscopes were working normally. By January 1999, three had broken, though this did not affect Hubble's mission. NASA wants to restore Hubble's spares, leaving it with six healthy gyros. Without the three spares, if any other gyros break, Hubble must stop its science mission and park in orbit until astronauts can bring it fresh gyros."Apparently that next gyroscope has now failed, leaving only two operating. So the rig puts itself to sleep and waits for help.
-- Tom Carey (firstname.lastname@example.org), November 15, 1999.
1) Ephemeris data is data which gives the precise position of astronomical bodies (or satellites).
2) The (solar) Corona Mass Ejection (CME) was supposed to hit (or miss) the earth today (15th) according to the solar flare site that I visit most often. Of course, it's already the 16th on about half of the planet... I checked earlier today, but couldn't find anything about the effects...yet.
-- Mad Monk (email@example.com), November 15, 1999.
The article I read at Marketwatch said a fourth gyro had failed. Has six, needs three to stabilize. Like the ephemeris stuff tho. Gonna try out my old DOS program and see what it looks like. Cheers, AGF
-- drac (firstname.lastname@example.org), November 15, 1999.
my brother in law and i use 2 different on line broker services and today of all the days ( it was a fairly quiet tradign day) our systems were down for about 1 hour just frozen could that have been related>
-- rena (email@example.com), November 15, 1999.
The failure on the Hubble (a keyhole series sat FYI) was not unexpected. Hubble was a real blunder in many respects maybe the worst being they put a lot of used parts on Hubble as a cost cutting measure. Problems are well outlined in the book "The Hubble Wars". I heard a lot about Hubble when I was working on Chandra (Hubbles "younger bro" in the "Great Observatories" program, the Wolter grazing incidence X-Ray telescope) from various folks in the field. It's actually amazing it works so well based on what I hear.
-- Don Kulha (firstname.lastname@example.org), November 15, 1999.
My Mom was a keypunch operator on a Univac in 1954... She says the things that are going to get us are "the ones we did not think of."
Reckon she is right, as usual.
Mom's being what they are and all that.
-- (...@.......), November 15, 1999.
Anyone have any information on other possible CME related problems today?
-- Donna (email@example.com), November 16, 1999.
Are you refering to the spy sats pointed at Earth?
-- Bill P (firstname.lastname@example.org), November 16, 1999.
-- g (email@example.com), December 13, 1999.
-- o (firstname.lastname@example.org), December 13, 1999.
Hubble is "like" the Keyhole satellites, only pointed out, not in.
Similar design, optics, controls, launch mode, etc.....that's why NASA thought they could build it and launch it cheaply - didn't work out.
The company, for example, that did the grinding and the optics used several NASA contracts to make equipment and expensive tools so they could work on future contracts for the CIA Keyholes (and other satellites) rather than re-use the existing CIA-paid eqpt at other companies for NASA. Bigger furnaces, deposting machines for the Al, vacuum systems, that kind of stuff.
Similar design though: and they can be used either way. At least one Keyhole, for example, was used to "look up" at the Shuttle one time to inspect for missing tiles when NASA thought it had lost some during launch.
-- Robert A. Cook, PE (Marietta, GA) (email@example.com), December 13, 1999.