Scott Miller wrote:

Let's see. The escape velocity of Mars is about 5 km/s. Relative to
the Sun, an object with that escape speed that is traveling tangent to
the orbit of Mars would either be traveling at 29 km/s if traveling in
the direction of Mars or 19 km/s if traveling in the opposite direction
of Mars. An object traveling radially along the line of the Sun gets
only the 5 km/s value.

Quibble: in the 'radial' case the object still starts out moving with
Mars. Using vector addition on your figures, sqr(24^2 + 5^2) ~= 24.5
km/s, on a heading atn(5/24) ~= 12° sunward of Mars's direction at
that point in its orbit.

--
Odysseus