Mercury's mass is 3.285 × 10^23 kg, so if we assume each satellite is 328.5 kg and there are 1,000 of them, then that's 1/10^18 of Mercury's mass. So, if each

Mercury's mass is 3.285 × 10^23 kg, so if we assume each satellite is 328.5 kg and there are 1,000 of them, then that's 1/10^18 of Mercury's mass. So, if each satellite changes speed by 10 km/s, then Mercury's orbital speed will change by 10^-14 m/s, or about 0.03mm/century. Doesn't seem like we'll notice it.