WASHINGTON — NASA’s next mission to the moon might solve a puzzle from the Apollo flights of the 1960s and 1970s — if all goes well.
Astronauts on Apollo missions 8, 10, 15 and 17 noticed mysterious pale and luminous twilight rays about 10 seconds before lunar sunrise and sunset. Scientists then were at a loss as to what they could be.
On Friday, NASA’s spacecraft, the Lunar Atmosphere and Dust Environment Explorer, or LADEE, is scheduled for launch at 11:27 p.m. EDT, and the mission is poised to answer decades-old questions about the mystifying twilight rays using a new spacecraft building design and testing new technology.
The nighttime launch will be visible over a wide area with millions of people throughout the Northeast potentially able to watch.
Robert Reed Park on Chincoteague Island in Virginia
Beach Road between Chicoteague and Assateague islands
The Apollo astronauts discovered dust permeates everything on the lunar surface. It is thought that interaction between lunar dust and the intense energy from the sun may play a part in the moon’s atmosphere and the twilight rays reported by Apollo crews.
You may be asking why probe the “atmosphere and dust” aspects of the LADEE mission? A good question, indeed. Believe it or not, the moon has an atmosphere and plenty of dust for LADEE to observe and accumulate data on during its 160 day mission.
The moon’s atmosphere is what scientists call “a surface boundary exosphere,” which means that there isn’t much to the moon’s atmosphere.
NASA’s LADEE (Courtesy NASA.gov)
As stated by NASA, “… on earth, each cubic centimeter contains 10,000,000,000,000,000,000 molecules; by comparison, the lunar atmosphere has less than 1,000,000 molecules in the same volume. That still sounds like a lot, but it is what we consider to be a very good vacuum on earth. In fact, the density of the atmosphere at the moon’s surface is comparable to the density of the outermost fringes of earth’s atmosphere where the International Space Station orbits.”
Additionally,”The Apollo 17 mission deployed an instrument called the Lunar Atmospheric Composition Experiment (LACE) on the moon’s surface. It detected small amounts of a number of atoms and molecules including helium, argon, and possibly neon, ammonia, methane and carbon dioxide. From here on earth, researchers using special telescopes that block light from the moon’s surface have been able to make images of the glow from sodium and potassium atoms in the moon’s atmosphere as they are energized by the sun. Still, we only have a partial list of what makes up the lunar atmosphere. Many other species are expected.”
The scientific instruments carried by LADEE should help scientists learn more about the lunar atmosphere, dust and their interactions on, and around, the moon. Knowledge gained can be applied to other planets and moons in the solar system which are also thought to have exospheres.
LADEE is carrying a lunar laser communications system which will demonstrate the use of lasers instead of radio waves for broadband speeds to communicate with earth. This will be the first time such a communication system is used in space and will mark a significant advance in space technology if it works as planned.
LADEE is also breaking new ground by utilizing a Modular Common Spacecraft Bus, or body, instead of a customized, one-time-only spacecraft design. Having this capability allows for cheaper and more efficient building of spacecraft.