Satellites Collide in First-Ever Mid-Space Crash

On 15 Feb, 15:31, "
wrote:
On Feb 14, 3:28*pm, Allen Thomson wrote:

On Feb 14, 10:59*am, speedevil wrote:

Has anyone seen anything listing the delta-v of the explosion?

The collision was broadside, so the relative velocity was something
like 8 km/s. Kinetic/chemical break-even is a little under 3 km/s.

Well, orbital velocity at that altitude is about 7.5 km/s, so a
perpendicular collision would give a relative velocity of about 10.6
km/s.

Of the explosion, not of the impact.
Modelling the two satellites as 1m/1000Kg cubes, with a 1kg/m^2 wing
sticking out of them.

There are (ISTM) (broadly) three classes of impacts.

Direct body-body contact.

Plenty of energy to completely vapourise everything, some hard bits
may come out, massive delta-v of several Km/s for the average (largely
vapourised) particle. (~50MJ/Kg)


Body-solar panel contact.

More or less similar to what'd happen if you placed 5mm or so of high
explosive over the area of the body impacted.
Still 50MJ/Kg for the colliding bits, but diluted 1000:1 over the
entire satellite body that's impacting, for 50KJ/Kg or so. A few
hundred meters a second delta-v for the average solid or melted
particle, with lots and lots of shredded stuff, but some largely
intact bits.

Solar panel-solar panel contact.

Say 1m^2 of solar panel impact 2m from the body.
This might be the 'normal' case. (eyeballing the iridium satellite,
maybe 3-4 times more likely than other forms?)

You have a 200MJ explosion 2m from the satellite, resulting in total
vaporisation of the solar panels involved, and production of a gas
cloud expanding at 5Km-s.

This may even - if everything goes just right - completely miss the
main body of the satellite.
If it hits, it's probably broadly similar to the above case, but with
maybe poorer coupling to the satellite, as some may expand and miss
the body, perhaps impacting the solar panels.

Rather similar to the above case, but with lower velocities due to the
poorer coupling.