LRO in Commisioning Orbit about the Moon

At 8:34am EDT today LRO initiated LOI-5 which was a 230.8 second burn (36 m/s). This placed LRO in a 31x199km 90.2 degree inclination polar orbit. For those interested the orbital position of LRO after we acquired her on the ground when she came into view again is given in the telemetry screen snap. Please note ALL vectors are in the ECI coordinate system. Tomorrow we will transition LRO from solar-inertial pointing to lunar nadir pointing and begin spacecraft commissioning activities.

LOI-4 Successfully Completed

At 8:25am EDT today LRO executed LOI-4. This 10 minute propulsion burn placed LRO in a 200km circular polar orbit about the Moon. Now in this low circular orbit operations will begin to resemble our nominal mission with ground station passes coming and going on a regular frequency as we pass behind the Moon each orbit. During certain days every month the ground can see LRO for her entire orbit of the Moon. This is illustrated in the diagram above.

LRO Status 6/25/2009 8:30pm EST

A nominal day heading into our LOI-4 burn. We are in a 199x740km orbit with an inclination of 89.93 degrees. LOI-4 at 8:25am EDT tomorrow will put us in a 200km circular orbit.

Where's LRO? Available on LROC Homepage

Check it out, and the entire LROC homepage. http://lroc.sese.asu.edu/whereislro/

Links to homepages for all the LRO instruments can be found at the LRO GSFC website.

LOI 3 Burn Successfully Completed

At 06:32 am EDT, the LOI 3 burn was successfully conducted. The burn lasted for 12 minutes and placed LRO in a 2.58 hour orbit. Following the burn, a Delta-H momentum unload was performed.

A Delta-H maneuver is how LRO reduces its system angular momentum (H). Thrusters are fired in a manuver planned to reduce the reaction wheel speeds. At the moon LRO gains angular momentum from torques induced by gravity gradient effects, solar radiation pressure, and from the use of our thrusters for changes in velocity (orbit changes).

LOI 4 burn is scheduled for tomorrow at 8:25am EDT.

LRO Status 6/23/2009 6:35pm EDT

Since the LOI-2 burn the mission has unfolded per our planned timeline without any anomalies. At this point in the day the planning process for the upcoming LOI-3 burn has begun. LOI-3 will be at 6:32am EDT and lasts 13 minutes. This burn is the next in our series of 5 burns to place LRO in the commissioning orbit. The commissioning orbit is 30x216 km and is a quasi-frozen orbit which requires almost no fuel to maintain. In contrast our 50km circular nominal mission orbit requires about 90kg of fuel each year to maintain.

About a week and half after reaching the commissioning orbit we will begin activating the remaining instruments and start calibrating them. These have not been turned on yet for a number of reasons. First, the insertion at the Moon is a critical and time constrained phase of the mission and the prime focus is safely delivering LRO into the right orbit. Secondly, the instruments (except the radiation instruments which are already on) are not designed to yield very useful or interesting data from anywhere except LRO's planned orbits. The cameras in particular are designed to build their images as the lunar surfaces passes through their FOV at ~1.6 km/s as LRO orbits the Moon. They cannot be simply pointed at the moon or earth during our transit to the Moon and snap a photo. To better understand the line-array (NACs) and push-frame (WAC) camera designs an overview paper on LRO's instrument is available at http://lunar.gsfc.nasa.gov/library.html

LOI 2 Burn Successfully Completed

We have successfully completed the LOI 2 burn. All systems remain nominal. The burn lasted 12 minutes and has placed LRO in a 200x1680km above the Moon. 3 more burns remain to lower LRO into its 30x216 km commisioning orbit

LRO Status 5:00pm EDT 6/23/2009

LRO remains in orbit around the Moon. Everything continues to unfold according to our timeline with the exception of a transition to Sun-Safe Mode (safe-mode for LRO) at 11:50 am when AP22 (Action Point for Attitude Error) tripped. This was diagnosed as being caused by a bad Star tracker solution due to partial occultation by the Moon, the valid but incorrect quaternion caused the spacecraft to slew which in turn tripped AP22 due to attitude error. Normally the Kalman Filter would filter this out but at the time we were still checking out the Kalman Filter performance and were not yet controlling with it. By 12:28 pm EDT we were back in Observing Mode and by 2:00pm we had LEND and CRaTER back on. The GN&C team will issue a more complete report when the finish reviewing all the telemetry.

LOI-2 is scheduled for 6:56am on Wednesday 6/24/2009.

We are there!!!

We are in a 220knx3100km polar lunar orbit. Over the next 5 days LRO will execute 4 more burns to eventually place it in our 30km (south pole)x216km (north pole) commissioning orbit.

The LOI-1 was flawless, exactly as planned.

A very happy Team here at the MOC in Greenbelt.

passing 70% point

burn will end 6:26:28am EDT

About halfway, past stable capture (safe) point in burn

this means even if the burn is interrupted now we can make lunar orbit. We are past our zone of greatest danger!

everything going perfect, only 600km above the moon

below 1000 km

now a very long 40 minutes!

Burn in Progress!

final poll completed - all GO

non target for burn attitude, 5 min away

starting slew to burn attitude

LOI-1 will be at 5:47am EDT

We are less than an hour from the start of the LOI-1 burn. This 40 minute burn uses our main thrusters (4x80N) and will place us in a 200x3000km initial orbit. This is the most critical event in the LRO mission after launch itself. Timing is everything as if the burn is delayed or prematurely stopped the window for recovery (via ground intervention) is measured in minutes. The team has practiced our recovery procedures and prepared for this event perhaps more than any other single event in their life.

The spacecraft is ready. My team is ready. GO LRO

See us live: http://www.nasa.gov/multimedia/nasatv/

Latest STK image

here's the latest STK image of where LRO is...

LRO LOI Event Live on NASA TV

Live coverage of our Lunar Orbit Insertion activities begin on NASA TV at 5am EDT. Also check it out at: http://www.nasa.gov/multimedia/nasatv/

Where is LRO now?

from our GNC gurus LRO Cam, here's the latest snapshot of where LRO is....check it out, we are getting closer to the Moon!!

Successful LOI-E Burn!!

We have just successfully completed our Lunar Orbit Insertion Engineering (LOI-E) burn!! All systems continue to perform nominally. Preparations continue for our LOI-1 burn.

LRO Launch from the LRO MOC at GSFC

The LRO Mission Operations Team at the LRO Mission Operations Center (MOC) at Goddard Space Flight Center watching LRO's launch and taking over operations of the LRO Spacecraft as it begins its journey to the moon.

LRO Update

LRO has slowed to a crawl relative to the earth (245 m/s,547 mph) and it at essentially lunar distance (352000km,219000mi) When the moon catches up to us early tomorrow morning we'll execute our LOI-1 burn to capture into our initial orbit.

A note to those leaving comments: This BLOG is updated by the LRO Project Manager and his Deputy at this point. Unfortunately neither of us have time to moderate and reply/respond/post the comments. I do read them as they flow through my inbox but for now that is as far as they go. Sorry.

LRO Status & Upcoming Events

The preliminary work leading to our LOI has begun. All spacecraft systems are healthy. Below is a timeline of key upcoming events:

6/22 10:33pm EDT - Final LOI Maneuver Plan Generation & Verification
6/22 11:05pm EDT - LOI-E (Engineering Burn ~30sec)
6/23 1:05am EDT - Load LOI-1 Maneuver Tables
6/23 4:00am EDT - Shift Handover Briefing
6/23 4:47am EDT - Pre-LOI-1 Configuration Verification Begins
6/23 5:47am EDT - LOI-1 Burn Begins
6/23 6:27am EDT - LOI-1 Burn Complete, LRO in lunar orbit
6/23-6/27 - LOI-2 thru LOI-5 burns, approximately one per day.
6/27 - 30x216km commissioning polar orbit established

B-I-G (Boring is Good)

Our new motto: B.I.G. "Boring is Good"....things continue to go smoothly as LRO cruises towards the moon. LRO is now 339, 838 km from the Earth. We are getting ready for the Lunar Orbit Insertion Engineering (LOI-E) burn which will occur in approximately 23 hours. We are also preparing for the LOI-1 burn which will occur in approximately 29 hours.

White Sands 1 (WS1) has successfully supported S and Ka-Band support for our mission. This is a great milestone with our new ground station enabling clean data transfer from the LRO spacecraft to the MOC at 100 Mbps. Also, solid commanding capability to our spacecraft as it cruises to the moon.

CRaTER, the 1st instrument to be turned on, is reporting good, solid data and has produced their 1st LET spectrum in all 6 detectors from the 1st 10 minutes of data received. LEND is now in their optimal configuration for LOI burns.

LRO Status 6/21/200 10:17am EDT

A calm and boring day thus far (this is good). Gyro mini-cal was completed. Another notable that actually occurred last night was a successful Ka-band file download to WS-1 at 100 Mbps! We are almost at lunar distance and have not yet even calibrated the High Gain Antenna System yet, an activity planned during spacecraft commissioning.

LRO Location

This plot shows the trajectories of LRO and the Moon relative to the Earth (ECI). LRO continues to slow relative to the earth and the moon is gaining on us, as planned.

Quiet Shift & Happy Father's Day!

LRO continues to cruise happily towards the moon. As of 07:30 GMT (3:30 EDT), LRO is 302, 978 km from the Earth.

It was a quiet shift for us, we continue LEND calibration configurations and station handover activities.