MESSENGER Is In Orbit Around Mercury “NASA’s MESSENGER probe has become the first spacecraft to enter orbit about Mercury. At 9:10 p.m. EDT, engineers in the MESSENGER Mission Operations Center at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., received radiometric signals confirming nominal burn shutdown and successful insertion of the MESSENGER probe into orbit around the planet Mercury.” Keith’s note: Updates on Twitter at MercuryToday