1. The problem statement, all variables and given/known data A 2700 kg spacecraft is in a circular orbit 1000 km above the surface of Mars. How much work must the spacecraft engines perform to move the spacecraft to a circular orbit that is 4000 km above the surface? mars: Mass=6.4185*10^23 KG, radius=3397000 m 2. Relevant equations TME=U+KE U=Gm1m2/R KE=.5Gm1m2/r (this doesn't seem right for some reason) 3. The attempt at a solution U1+k1+work=U2+k2 work=U2+k2-(u1+k1) u1=2.630*10^10 ke1=1.315*10^10 U2=2.891*10^10 Ke2=1.446*10^10 TME1=3.945*10^10 TME2=4.337*10^10 Work= TME2-TME1=3.92*10^9 webassign says I'm wrong. Is my equation for either KE or potential energy incorrrect? Any help is appreciated.