As NASA’s MESSENGER spacecraft gets closer to Mercury, it’s also flying closer to the Sun. And temperatures are rising. The spacecraft rotated 180-degrees on June 21, pointing its sunshade towards the Sun. This will keep temperatures to safe levels within the spacecraft. MESSENGER will keep this shade between itself and the Sun for the remainder of its mission. The spacecraft’s next big event will be its flyby with Venus on October 24.
The MESSENGER spacecraft performed its final “flip” maneuver for the mission on June 21. Responding to commands sent from the MESSENGER Mission Operations Center at The Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., through NASA’s Deep Space Network antenna station near Goldstone, Calif., the spacecraft rotated 180°, pointing its sunshade toward the Sun.
The 16-minute maneuver, designed to keep MESSENGER operating at safe temperatures as it moves closer to the Sun, wrapped up at 9:34 a.m. EDT, with successful reacquisition of signal from MESSENGER’s front-side antenna. The spacecraft was 196.5 million kilometers (122.1 million miles) from Earth and 144.6 million kilometers (89.8 million miles) from the Sun when the maneuver occurred.
MESSENGER had been flying with its back to the Sun since a March 8 “flop,” allowing it to maintain temperatures within safe operating ranges at Sun distances greater than 0.95 astronomical units (1 AU is Earth’s distance from the Sun). Mission plans call for the spacecraft to keep its sunshade facing the Sun for the remainder of its cruise and science orbital operations around Mercury.
“Initial indications look very good” says MESSENGER Mission Operations Manager Mark Holdridge, of APL. “Spacecraft temperatures are coming down as expected and all systems and instruments are nominal.”
The team will now turn its attention to preparing for the first Venus flyby on October 24. “We have mission simulations and flight tests coming up to test particular operations that will have to occur during the Venus flyby,” Holdridge says. “There will be a 57-minute solar eclipse during the October operation, so we will be testing the flight systems in the flyby configuration to verify they will behave properly during the eclipse period.”
On August 11, for instance, the team will conduct a flight test of the new autonomy that will power off components prior to the solar eclipse, allow the battery to discharge by approximately the same amount as during the real eclipse, and then power on components again once the battery is recharged, all in a more controlled setting with real-time visibility. This test will be combined with a battery reconditioning.
Later in August and through September, during the approach to Venus, MESSENGER’s navigation team will use the Mercury Dual Imaging System cameras onboard the spacecraft to take a series of optical navigation pictures. These images are not required for the Venus flyby but will be used by the MESSENGER navigation team for calibration and as practice for the optical navigation imaging to be utilized at Mercury.
Original Source: JHUAPL News Release