Mro On Approach, TCM-3 not required Options

[Redstone]

MRO has shifted from the cruise phase to Approach phase. Apparently, the trajectory is so good that TCM-3 was cancelled. This is good news for the prospects for a long life for MRO supporting future missions. TCM-4 is on Feb 28, and MOI on March 10. Only 5 weeks away!

[RNeuhaus]

Good news. I seems that MRO has started to gain its speed due to Mars gravity tug, has not?

What is MOI? Mars Orbit Insertion.

http://mars.jpl.nasa.gov/mro/gallery/cruis...oach_200602.jpg

"It was a very busy time for the team. Many tests were conducted to ensure that the instruments onboard were functioning properly and our navigators performed trajectory correction maneuvers to keep us on a very precise path to Mars."

Speaking of that precision, the third of four possible course corrections was deemed unnecessary this week.

"The navigation solutions have shown a great consistency since the second trajectory correction maneuver was executed on November 18," said Han You, navigation team chief. "More importantly, the current data indicate that the spacecraft aim for insertion into Mars' orbit is well within the projected target. If the current trend continues, the spacecraft will require only a very small nudge to fine tune the final aim."

Rodolfo

[ugordan]

I seems that MRO has started to gain its speed due to Mars gravity tug, has not?

Where did you hear that? As far as I can see, MRO is sill on the elliptical transfer orbit and too far away to feel Mars' gravity influence. In fact, its heliocentric speed should be decreasing.
MRO won't begin to feel significant pull from Mars probably all the way until around a day or so before MOI.

[jmknapp]

As far as I can see, MRO is sill on the elliptical transfer orbit and too far away to feel Mars' gravity influence. In fact, its heliocentric speed should be decreasing.
MRO won't begin to feel significant pull from Mars probably all the way until around a day or so before MOI.

True--MRO's speed relative to Mars won't start to increase until Feb. 25, & even then only very slightly until the day of MOI (per the SPICE kernel data).

Here's a chart of the speed for the month of March: