Archive

Posts Tagged ‘Artemis Program’

10/23/2020 – Ephemeris – What is a Near Rectilinear Halo Orbit?

October 23, 2020 Comments off

This is Ephemeris for Friday, October 23rd. Today the Sun will be up for 10 hours and 34 minutes, setting at 6:44, and it will rise tomorrow at 8:10. The Moon, at first quarter today, will set at 12:46 tomorrow morning.

When the astronauts of the Artemis program head for a landing on the Moon is as little as four years from now they will meet their lunar landing craft or Lunar Gateway space station with landing craft docked to it before they descend to the Moon. The orbit of the gateway and/or lander is an odd one. It’s called a near rectilinear halo orbit. And uses the motion and gravitational interaction of the Moon and Earth to create an orbit of the Moon which is nearly face-on to the Earth. The vehicles will never pass behind the Moon. The orbit will pass 1,900 miles (3,000 km) above the Moon’s north pole and out to 43,000 miles (70,000 km) above the south pole. It’s called a halo orbit, because as seen from the Earth it appears to trace a halo around the Moon.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

NASA CAPSTONE pathfinder for gateway orbit

NASA CAPSTONE* pathfinder for gateway orbit is to be launched next year by Rocket Lab to prove out the near rectilinear orbit for the Lunar Gateway. The orbit will always be more or less face on to the Earth, so it and the lunar lander will be always be in contact with the Earth. Credit Advanced Space via Spaceflight Now.

* Yes, CAPSTONE is an acronym: Cislunarˆ Autonomous Positioning System Technology Operations and Navigation Experiment. Aren’t you glad you asked?

ˆ Cislunar: The volume of space between the Earth and Moon’s orbit.

Lunar Gateway NASA

An artist’s rendition of the Lunar Gateway with the Orion spacecraft docked to it. Credit NASA.

For more information

https://spaceflightnow.com/2019/09/26/nasa-to-fly-cubesat-pathfinder-for-gateway-in-unique-lunar-orbit/

https://www.space.com/nasa-capstone-cubesat-moon-gateway.html

 

10/02/2020 – Ephemeris – The rocket that will take NASA crews to the Moon

October 2, 2020 Comments off

This is Ephemeris for Friday, October 2nd. Today the Sun will be up for 11 hours and 37 minutes, setting at 7:20, and it will rise tomorrow at 7:43. The Moon, 1 day past full, will rise at 8:05 this evening.

While we’re looking at the nearly full Moon tonight lets look at the rocket that will take crews to the Moon or as NASA says first woman and next man to the Moon in the Artemis program. It’s called the Space Launch System or SLS, which has been in development for a very long time. The core stage looks the color of the Space Shuttle main tank, because it uses the same insulation. At its bottom are four shuttle main engines. These will not be reused. Strapped to the sides will be two shuttle derived solid rocket boosters or SRBs, with 5 segments, rather than 4, and are upgraded for extra thrust. These will also be discarded, rather than reused. The second stage now is an interim stage to be replaced after a few flights with a more powerful stage. To top it off will be the service module and Orion capsule with an escape tower.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Space Launch System Block 1b

The Block 1b version of the Space Launch System (SLS) which uses elongated Space Shuttle boosters and a core stage with 4 Space Shuttle main engines for the first stage. At lift-off the core stage and the boosters will ignite. The boosters will burn for two minutes and 6 seconds 7,2000,000 pounds  (32,000 kN) of thrust. The core stage contributes 1,670,000 pounds  (7,440 kN) of thrust and will burn for 8 minutes, nearly achieving orbit. The Interim Cryogenic Propulsion Stage and later the Exploration Upper Stage will place the payload first into orbit, and then to send it to the Moon, or interplanetary destination. Credit NASA.

Note that the rocket configuration does not contain a lunar lander craft like the Saturn V of Apollo. The lander, a commercially developed craft will be sent up before the astronauts by a commercial company like SpaceX or Blue Origin and be waiting in lunar orbit or at the Lunar Gateway satellite.

09/04/2020 – Ephemeris – What area of the Moon is the Artemis program interested in?

September 4, 2020 Comments off

This is Ephemeris for Friday, September 4th. Today the Sun will be up for 13 hours and 3 minutes, setting at 8:13, and it will rise tomorrow at 7:10. The Moon, 2 days past full, will rise at 9:40 this evening.

Where will Artemis missions land when they get to the Moon? The Apollo missions mostly landed on the flat lunar seas which were really lava plains. The Artemis missions are headed to the Moon’s south polar regions. The Moon, unlike the Earth has very little axial tilt, so some of the crater floors at the poles are forever in shadow and near absolute zero, so are cold traps for volatile matter like water. Satellites over the years have found hydrogen over the south pole of the moon hinting that there is water ice there from impacting comets. There’s also crater peaks that are always in sunlight where solar panels can be erected to provide power throughout the month long lunar day. On the Moon, water is more precious than gold. There’s water in them thar craters!

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

South pole ice

The south pole of the Moon where the presence of water ice is detected by the absorption of neutrons by the hydrogen atoms in the ice. Credit NASA/GSFC/SVS/Roscosmos. Notice a theme in the crater names here?

09/03/2020 – Ephemeris – Why is the new NASA Moon landing program called Artemis?

September 3, 2020 Comments off

This is Ephemeris for Thursday, September 3rd. Today the Sun will be up for 13 hours and 6 minutes, setting at 8:14, and it will rise tomorrow at 7:09. The Moon, 1 day past full, will rise at 9:20 this evening.

Why is the new NASA crewed Moon landing program called Artemis? And why is it crewed, and not manned? Artemis was a Greek deity and Apollo’s twin sister. He was the god of the Sun and she was goddess, among other things, of the Moon. So she has a greater connection to the Moon than Apollo did. Spacecraft now-a-days are crewed, rather than manned to denote that both sexes are chosen to be astronauts in nearly equal numbers now. Of course that’s crewed spelled c-r-e-w-e-d, not c-r-u-d-e, though they sound the same. Deities of the Moon tend to be female be they Artemis, Cynthia, Luna, Selene, or Chang’e. Astronomers use Cynthia, Luna, and Selene (pronounced Sel-e-nae) in naming various aspects of the Moon and Chang’e is the goddess that the Chinese name their lunar landers after.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

NASA Artemis Logo

The logo chosen by NASA for the Artemis Program. The blue crescent at the bottom represents the earth. The gray ball at the top is the Moon. The curved red path is the stylized return path from the Moon to the Earth of the Orion capsule. Credit: NASA.

Artemis, goddess of the hunt and the Moon.

Artemis, goddess of the hunt and the Moon. Credit: Disney (Fantasia) source Daily Kos.

 

Categories: Mythology, NASA, The Moon Tags: