MRO MOI Events Timeline, Time Zone Friendly Options

[Marz]

2225 GMT (5:25 p.m. EST)

IN ORBIT! The Mars Reconnaissance Orbiter is truly an orbiter now after successfully swooping into orbit around the Red Planet today, mission control confirms!
WAW MRO IS ALREADY IN ORBIT

Rodolfo

Wahoo! I guess it's better to slightly underburn than overburn, since the aerobraking seems to have more variables to it, and it's always better to have more fuel than less fuel to correct the orbit. I'd imagine this won't add any extra time to the 6 month trim manuvers?

Time to celebrate another great day on mars! At this rate, JPL will need to add traffic control operations for mars.

[Joffan]

Time to celebrate another great day on mars! At this rate, JPL will need to add traffic control operations for mars.

mental image of 3 or 4 rovers jostling to take pictures of an interesting rock...

[MERovingien]

I can breathe again!

Congratulations to the JPL for another amazing mission!! 3 orbiters! 2 rovers!! Bravo!

[djellison]

Burn time 1641 seconds vs 1606 expected. 1000.48 m/s compared to 1000.36m/s expected.

So burn performance 97.87% of nominal, but actual Delta V 100.012% of predicted.

i.e. yes - the burn was a little under the mark, but the onboard sequence saw this, worked off the Delta V, and terminated the burn according to the accumulated Delta V hitting the right mark.

Doug

[lyford]

M-R-O-O-O-o-o-o-o!

[SFJCody]

Would be nice to have a Mars visualisation thingy that shows the locations of all four orbiters and two rovers.

[Marz]

Burn time 1641 seconds vs 1606 expected. 1000.48 m/s compared to 1000.36m/s expected.

So burn performance 97.87% of nominal, but actual Delta V 100.012% of predicted.

i.e. yes - the burn was a little under the mark, but the onboard sequence saw this, worked off the Delta V, and terminated the burn according to the accumulated Delta V hitting the right mark.

Doug

Excellent update! Thanks, Doug. I suppose this implies the aerobraking experienced less friction than anticipated, since the burn went longer than expected?

[djellison]

MOI and aerobraking are very seperate. The difference wasnt anything to do with aerobraking, I think it was simply a slight underperformance by the engines, and the sort of underperformance you only notice if you have a really long burn ( i.e. much bigger than TCM1 was).

First post in this thread updated with all the info from the 0030 conf.

We now have 6 spacecraft at work at Mars, that is a great thing.

Doug

[Redstone]

MRO isn't aerobraking yet. MOI took place outside the atmosphere (although Mars atmosphere does extend a long way, but very tenuously. The longer burn was due to the engines underperforming very slightly. Whether that was because of less thrust per unit of fuel or less fuel per unit of time is not clear yet.

EDIT: heh, knew someone would answer before me.

Zurek made a poignant point at the press conference, I thought. MRO has now completed the recovery of the loss of Mars Observer, whose instruments have been reflown on MGS, MCO (whose lost instruments have also been recovered), MODY and now MRO.

Space science teaches patience.

[Guest_Sunspot_*]

How many journalists attended the press conference lol ?. Hmmmm we really need to send someone from this forum to ask questions.

[RNeuhaus]

4 orbiters and 2 landers operating at mars at the same time !
What a pleasant day !

-- Rakhir

Maybe there are 6 orbiters including two Vikings are still looping on Mars, aren't they?

Rodolfo

Post-edit
Viking I is still orbiting around Mars at 320 x 56,000 km and it will crash on 2019.
Viking II is still orbiting around Mars at 302 x 33,176.
The other present orbiter is Mariner 9 until the year 2022.

[odave]

Sounds good to me - how would UMSF go about getting press credentials so we can dispatch "cub reporters" to various events? Much ado was made about the presence of bloggers at the political conventions during the 2004 US presidential campaign, and how this "Internet" thing was the wave of the future for journalism.

Anyhow, congratulations to all on the MRO team for a successful MOI. I can't wait for the images to start coming down!

[The Messenger]

From JPL Horizons, I prefer Orbiter UTC, so no Earth-received, no time zones, longitudes are areocentric:

2006-03-10 21:21:14, alt = 1000 km, lat = 73° S, lon = 285° E
2006-03-10 21:22:03, alt = 900 km, lat = 76° S, lon = 282° E
2006-03-10 21:22:57, alt = 800 km, lat = 80° S, lon = 278° E
2006-03-10 21:23:55, alt = 700 km, lat = 83° S, lon = 268° E
2006-03-10 21:25:02, alt = 600 km, lat = 86° S, lon = 232° E
2006-03-10 21:26:21, alt = 500 km, lat = 85° S, lon = 155° E
2006-03-10 21:28:09, alt = 400 km, lat = 78° S, lon = 130° E
2006-03-10 21:31:20, alt = 329 km, lat = 63° S, lon = 120° E

This was a braking manauver, the engine underperformed by 2%, but the approach was 71 km closer than the nominal target (400 km)? The delta V was returned to almost exactly nominal by burning longer, but I do not understand why this would result in a lower-than-expected altitude. (?) What am I missing this time?

[mcaplinger]

What am I missing this time?

1) The post you referenced was made before MOI even happened.
2) Horizons is using a trajectory that is weeks old.
3) I have no idea if "Orbiter" is propagating the elements from Horizons correctly anyway.

[Bob Shaw]

Maybe there are 6 orbiters including two Vikings are still looping on Mars, aren't they?

Rodolfo

Post-edit
Viking I is still orbiting around Mars at 320 x 56,000 km and it will crash on 2019.
Viking II is still orbiting around Mars at 302 x 33,176.
The other present orbiter is Mariner 9 until the year 2022.

Rodolfo:

There may be some Soviet vehicles still there, too. I doubt if they've all decayed so soon!

Bob Shaw