/sci/ - Science & Math

The Galileo Entry Probe was moving over 21,000 m/s when it first touched the upper atmosphere. Two minutes later the probe had slowed to less than 1000 m/s. It only used up 80kg of its heat shield ablator.
20 km/s of delta V from 80 kg of propellant. Given a starting mass of 340 kg, this means Galileo's heat shield provided delta V with an effective Isp of about 7750 seconds. Goes to show the extreme advantage of aerobraking and why we should be using it wherever possible.