Expert: Jayendra Upadhye - 2/27/2008

Question
I saw the shoot down of the ailing spy satellite with a missile.   There was an explosion.   I was always told that an explosion in space is impossible.   Am I interpreting what I saw incorrectly or can explosions actually happen in space (assuming that there is an explosive and an oxidizer in the missile/ warhead …or space ship if your into scifi)?

Answer
Hi,
Kurt, i am very much into sci fi!
if you are in a hurry go directly to the end, else read on!

By default all missiles have to have high explosive warheads!!
That is why they are built in the first place!
(not bult to approach a target at supersonic speed only to say hi, bye or hello). :)

Explosives could range from conventional TNT to nuclear to thermonuclear.
Von Braun used 1 ton in his V2 (german A4), ordered by hitler, if memory serves me right.

Nowadays may be they use C4 or some such ultra high explosiove.

The fuses vary from proximity fuses (in sams / aams as one need not "exactly hit", but needs to be just in vicinity of target for this high explosive to destroy target with its flying debtis.
(prefragmented warheads may be used. (the deep groves in hand grenades are part of the pre-fragmentation technique).

Explosions in space are different from explosions on earth.
On earth, the greater part of the energy of the explosion is lost quickly in overcomingh air resistance, and as sound!
That is why aerial views of bomb explosions show a rapidly expanding circular area of opacity around the exploding center.
That is the shock wave as the blast sound travels across the ground.
It is powerful enough to shatter glass a few 100 meters away!

The vertical rising mushroom also tells us the horizontal and vertical limits of the explosion. (beyond this, only the shock wave and radio-active fallout cause secondary damage).
In very large ( multi megaton thermonuclear) explosions, radiative damage from ultra hot explosion center, can burn objects a 100 km away!
In space, the destructive kinetic energy of the blast travels in all directions equally. Only, the density of the debri decreases inversely with distance!
thus a fragment of the warhead released at 3000 met/sec would travel indefinitely in space ..until captured by a gravitating body.
imagine howmuch damage such explosions can have on other satellites near by!

In case of nuclear thermonuclear warheads, the main killer in space would be the EMP (electromagnetci pulse) generated by lenzes law as the explosion sets up a large flux of charged particles in an instant.
the di/dt (rate of change of current) is very large in small area of space. This gets coupled with existing powergrids and is transported over continental distance by the grid! killing all electrical appliances along the way!

Conclusion:-
Explosions happen in space (chemical / nuclear) and are more deadly.

please do rate the answer if you find it interesting.
Hope that suffices.
Jayen