Bodkociarka
-
Upload
marian-such -
Category
Technology
-
view
510 -
download
0
description
Transcript of Bodkociarka
How much is a $emicolon?;or how important bug-free software is
Delta II in 1997
cost
$40 million GPS satellite
$55 million rocket
+ some $$ for launch
~ $100 million
is ; that expensive?
no
that one was cheap
people KILLED
...and besides, crack in the engine was to blame...
6-meter crack
the computer functioned OK
autodestroyed rocket in 1 sec
saving many lives
, but
Nedelin in 1960
80-150 dead
FuelDevil’s venom
nitric acid and hydrazine
extremely efficient
extremely toxic
safety blocks were disabled because of
testing
one switch
The Mariner I space probe was launched from Cape Canaveral on 28 July 1962 towards Venus. After 13 minutes' flight a booster engine would give acceleration up to 25,820 mph; after 44 minutes 9,800 solar cells would unfold; after 80 days a computer would calculate the final course corrections and after 100 days the craft would cirlce the unknown planet, scanning the mysterious cloud in which it is bathed. However, with an efficiency that is truly heartening, Mariner I plunged into the Atlantic Ocean only four minutes after takeoff. Inquiries later revealed that a minus sign had been omitted from the instructions fed into the computer. "It was human error", a launch spokesman said.
This minus sign cost $18.5 million.
"The most expensive hyphen in history"
Phobos 1 & Phobos 2
Co-operation of 14 nations
The failure was traced to an error in the software uploaded,
which had deactivated the attitude thrusters...
...a single character error in an upload sequence resulted
subsequent loss of the spacecraft
Phobos 2
...failure was determined to be a malfunction of the on-board
computer.
Ariane 5$500 million
Ariane 5$500 million
converting 64-bit integer to 16-bit integer
Ariane 5$500 million
converting 64-bit integer to 16-bit integer
priceless
L_M_BV_32 := TBD.T_ENTIER_32S ((1.0/C_M_LSB_BV) * G_M_INFO_DERIVE(T_ALG.E_BV));if L_M_BV_32 > 32767 then" P_M_DERIVE(T_ALG.E_BV) := 16#7FFF#;elsif L_M_BV_32 < -32768 then" P_M_DERIVE(T_ALG.E_BV) := 16#8000#;else" P_M_DERIVE(T_ALG.E_BV) := UC_16S_EN_16NS(TDB.T_ENTIER_16S(L_M_BV_32));end if;P_M_DERIVE(T_ALG.E_BH) := UC_16S_EN_16NS (TDB.T_ENTIER_16S ((1.0/C_M_LSB_BH) * G_M_INFO_DERIVE(T_ALG.E_BH)));
L_M_BV_32 := TBD.T_ENTIER_32S ((1.0/C_M_LSB_BV) * G_M_INFO_DERIVE(T_ALG.E_BV));if L_M_BV_32 > 32767 then" P_M_DERIVE(T_ALG.E_BV) := 16#7FFF#;elsif L_M_BV_32 < -32768 then" P_M_DERIVE(T_ALG.E_BV) := 16#8000#;else" P_M_DERIVE(T_ALG.E_BV) := UC_16S_EN_16NS(TDB.T_ENTIER_16S(L_M_BV_32));end if;P_M_DERIVE(T_ALG.E_BH) := UC_16S_EN_16NS (TDB.T_ENTIER_16S ((1.0/C_M_LSB_BH) * G_M_INFO_DERIVE(T_ALG.E_BH)));
$500 000 000 mistake
meet...
Mars Climate Orbiter $328 million
why do I mention it?
feet meters
Northeast blackout$7 - $10 billion
if (condition); /* statement */
if (condition) if(condition 2) /* statement */ else /*statement */
Solutions?
formally verified error proof
language
ADA!
and
ADA!
450 in 198337 by 1996
1983
1996
# of languages in DoD
Boeing 777
Ariane 4Ariane 5
ATC
TGV
NY metro
Software bugs are costing the U.S.
economy an estimated $60 billion each year
any questions?