LADEE

Spacecraft nº:

US spacecraft nº:

Launch data: Designation  39246 / 13047A Launch date  07 Sept 2013 - 03:27 UT (06 Sept 2013 at 11:27 EDT) Launch site  WI, LA0B Launch vehicle  Minotaur 5 Mission  Lunar orbiter Highly elliptical Earth orbit: Perigee / Apogee   km Eccentricity   Inclination   deg Period   min

Spacecraft data: Prime manufacturer  NASA's Ames Research Center Platform  Modular Common Spacecraft Bus (MCSB) Operator  NASA's Ames Research Center Mass at launch  383 kg (includes 135 kg of fuel) Dry Mass  248.2 kg Basic shape  cylinder Dimension (m)  dia: 1.85m - height: 2.37m Equipment  UVLS, NMS, LDE, LLCD Solar array  none, Solar cells covering the outside surface Stabilization   Propulsion  R-4D-15 HiPAT DC power  295 W

End of live: Impact date on the moon:  18 April 2014 Lifetime:

Description:

• A U.S. Air Force Minotaur 5 rocket will launch the Lunar Atmosphere and Dust Experiment, or LADEE, mission for NASA. LADEE will study the moon's tenuous atmosphere and dust from lunar orbit.
• LADEE is a strategic mission that will address science goals 8a and 8b from the 2007 National Research Council Study "The Scientific Context for Exploration of the Moon" to the extent that is possible within the limitations imposed by mass, cost, and duration of the proposed mission.
• The objectives of the LADEE mission are:
  • Determine the global density, composition, and time variability of the fragile lunar atmosphere before it is perturbed by further human activity;
  • Determine if the Apollo astronaut sightings of diffuse emission at 10s of km above the surface were Na glow or dust and;
  • Document the dust impactor environment (size-frequency) to help guide design engineering for the outpost and also future robotic missions.
• NASA expects to place this orbiter into a low orbit (tentatively about 50 km) for at least four months (one month of check-out, and three months of data collection). The mission will be small; it is expected that the total available mass for all two or even three payload instruments will be approximately 20 kg. The available payload power is approximately 60W, but can peak to 100W depending on spacecraft orientation and thermal constraints
• Onboard, LADEE will include three science instruments and a technology demonstration:
  • Ultraviolet and Visible Light Spectrometer: will determine the composition of the lunar atmosphere by analyzing light signatures of materials it finds.
  • Neutral Mass Spectrometer: will measure variations in the lunar atmosphere over multiple lunar orbits with the moon in different space environments.
  • Lunar Dust Experiment: will collect and analyze samples of any lunar dust particles in the tenuous atmosphere.
  • Lunar Laser Communications Demonstration: will demonstrate the use of lasers instead of radio waves to achieve broadband speeds to communicate with Earth.
• LADEE was originally planned to be launched as a secondary payload with NASA's GRAIL mission, but was later transferred to a dedicated Minotaur-5 launch vehicle.
• Minotaur-5 will boost the LADEE Spacecraft into a highly elliptical orbit of 200 km × 278,000 km around the Earth. Over the next 23 days, as LADEE orbits Earth 3.5 times, the Moon's gravitational field will increase the perigee of its orbit. The spacecraft will fire its on-board thrusters to alter its trajectory to allow it to enter orbit around the Moon. LADEE will spend about 2.5 months reaching the Moon, getting into its science orbit, and checking out systems before its 100 day science mission starts. The nominal science orbit will be a near-circular retrograde (clockwise) equatorial orbit with a period of 113 minutes at about 50 km above the surface. The periselene (closest approach) will be over the sunrise terminator. After the science mission is complete the orbiter will impact the lunar surface. It has an Aerojet Rocketdyne/Redmond R-4D-15 HiPAT 455N thruster for lunar orbit insertion and orbit manoeuvers.

Mission details:

• Launch delayed from Aug. 12, 2013.
• The Lunar Atmosphere and Dust Enviroment Explorer mission was launched on Sep 7, 2013. Despite the Explorer in the name, the mission is the first of the new Lunar Quest series rather than part of the long standing Explorer program. The spacecraft is 383 kg full 248 kg dry, and is developed and operated by NASA's Ames Research Center near San Jose, California. The Minotaur V rocket took off from the Mid Atlantic Regional Spaceport on Wallops Island and inserted LADEE into highly elliptical Earth orbit.
• The Minotaur V consisted of the first three stages of the MX Peacekeeper missile, and a guidance and control section, with ATK Star 48V and Star 37FM solid motors as fourth and fifth stages. The addition of the fifth stage distinguishes it from the Minotaur IV+ used to launch Tacsat 4.
  The third stage flew a suborbital trajectory with the fourth stage reaching orbit at 0335 UTC, probably around 200 x 800 km. After a coast in this parking orbit until 0343 UTC, the Star 37FM fired to reach an orbit expected to be about 200 x 274600 km x 37.7 deg. Two despin weights were released at 0348 UTC and LADEE separated at 0350 UTC. After several days the orbit will naturally evolve to raise the perigee to more than 1000 km.
• Following the first perigee burn on Sep 13, 2013 at 1641 UTC, LADEE's orbit changed from 2059 x 289461 km x 33.9deg to 2063 x 325450 km x 35.4 deg.
  LADEE's second perigee burn was on Sep 21 at 1153 UTC. It was expected to raise the orbit to 1352 x 373000 km x 38.2 deg, reaching apogee around Sep 26, and perigee on Oct 1.
• LADEE is in a 1460 x 375352 km x 38.6 deg Earth orbit. It passes its third and final Earth perigee of 1453 km altitude at 1056 UTC on Oct 1, 2013; on Oct 6 at 1802 UTC it entered the lunar gravitational sphere of influence. The orbit insertion burn at 1057 UTC on Oct 6, which placed LADEE in a 24-hour-period 269 x 15772 km selenocentric orbit inclined 157 deg to the lunar equator.
• The LOI-2 burn at 1038 UTC Oct 9, 2013 lowered the orbit to 227 x 2200 km. A further burn on Oct 13 at 0333 UTC circularized the orbit at 235 x 250 km and LADEE is now in its commissioning phase, and breaking records with its laser communication system.
• NASA's LADEE spacecraft was lowered into an orbit with a 2 km perilune in early April 2014, and it impacted the lunar farside at 6:59 UT (2:59 a.m. EDT) on Apr 18, 2014 possibly on the east rim of the crater Sundman V at 12N 93W, north of Mare Orientale. LADEE studied the thin lunar atmosphere.