MRO MOI Events Timeline, Time Zone Friendly Options

[djellison]

Z = GMT / UT, P = Pacific
Future, Unconfirmed, Confirmed

NASA TV coverage starts at 2030Z / 1230P

TCM5 was not required.
2049Z / 1249P - Tank Pressurize - nominal pressure reported (@2053Z)
2103Z / 1303P - Switch to LGA ( 2 way doppler @ 2104Z, Lock at 160bps :2105Z)
2107Z / 1307P - Turn to Burn attitude (start of turn confirmed via doppler & telem @2110Z - Slew finished @2119Z via ACS)
2124Z / 1324P - Start of MOI Burn (confirmed via Doppler @2123Z )
(tank pressure about 3psi below predicts but within margins @2131Z )
(307m/sec accumulated delta @2135Z)
(401m/sec accumulated delta @2139Z)
(588m/sec accumualted delta @2144Z)
(telem. indicated eclipse entry @2146Z)
2146Z / 1346P - Loss of signal ( confirmed on doppler @2147Z- actual time 21:46:23Z)
2151Z / 1351P - Nominal End of Burn
2216Z / 1416P - Nominal AOS - (signal aquired - 1 way doppler @2116Z - 22:16:08 actual time)
(2 way doppler @2223Z)
2230Z / 1430p - 1641m/s burn indicated by telementry.

MRO is now orbiting the planet Mars

Status check at 2245Z
Flight Software - Burn done at 20% Utilisation
Prop Nominal
ACS, Earth point on reaction wheels, Star tracker aquisition ( 8 stars ), Burn time 1641 seconds vs 1606 expected. 1000.48 m/s compared to 1000.36m/s expected.
Thermal - all temps nominal. A few alarms due to soak back from the rcs thrusters.
EPS - Nomincal, trickle charging batts ( 110% state of charge ) - 870 Watts being used, 1650 Watts available from arrays.
Telecom - Nominal, on primary equipment, uplink and downlink signals as expected, already got a command in.
Fault Prot - Quicklook, no abnormal responses to the burn, out of go-fast mode.
Nominal termination to the MOI nominal block.






http://mars.jpl.nasa.gov/mro/realtime/mro-doppler_lg.html
Interesting Pre MOI PDF Presentation
http://www.hq.nasa.gov/office/codeq/smadir/hq06/landano.pdf



11th March 0030 Press Conf Update

Usual superlatives from senior management that don't tell us anything.

Jim Graff acknowledged help from NOAA w.r.t. Solar Weather, and the DSN's outstanding job.
Howard Eisan : MRO is safe, stable, on earth point, transmitting at 550kbps. We've earned the 'RO' of MRO. Dippled less than 10% into the batteries, commanded velocity change 2237.6 mph, overshot by 0.4mph, during the burn we underperformed by 2%, burned by 33 seconds longer to make up the difference. First hr of Nav data - orbit 35.5 hrs (predict 35.6) 264 x 28,000 mile orbit.
Rich Zurek : 2 of our 8 investigations were ones lost with MCO, one of those was also lost with Mars Observer. This completes replacement of all the Mars Observer instrumentation. We're going to knock your socks off - it's a good day.

Sally from TPS : Break for 2 weeks, what are you going to be doing (are you going to be celebrating for two weeks) - JG - stand down for w'end for a rest. Then prepare for aerobraking. ORT for Aerobraking, reconfig spacecraft for aerobraking, and some software patches to send up (9 uploaded to date, a few more to go). One other thing - we will take some early images - engineering images not science quality, make sure they work properly, processing that data on the ground to make sure the processing centres can extract the images from the data.

Sally asked when that science will start. RZ mentioned the use of aerobraking (lowest altitude is 60 miles) to understand structure of atmosphere. Sally asked if aerobraking is hard every orbit. RZ said that most of the closest approaches will be over the south pole. They dont expect big dust storms.

That's all the questions- again, kudos to Sally for asking them something. Unarguably the most important moment in Mars exploration since MER landing and potentially more important than anything between then and MSL landing scientifically, and in terms of infrastructure on orbit - $700M's worth of project - and that's three conferences where Sally was almost the only person to ask any questions. Either JPL PAO has furning the media with every single piece of information they could want before the event, or the media seem to be barely taking note of the mission because it's not as sexy as a landing ( there were plenty of spare seats in the V.K. auditorium, at Spirit's landing conf, you couldnt swing a cat in there ). Under-representation of mission rant over.

Doug

Attached File(s)

 doppler_1.mov ( 119.34K ) Number of downloads: 382

 

[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