@Mark Ollig
After learning that Artemis II would proceed without an attached lunar lander, I was reminded of Apollo 8.
After learning that Artemis II would proceed without an attached lunar lander, I was reminded of Apollo 8.
In 1968, I wondered what would happen if something went wrong and there was no lunar module (LM) aboard as a lifeboat.
Engineering delays with the LM led Apollo 8 to abandon planned Earth-orbit testing.
NASA sent three Apollo 8 astronauts into lunar orbit in the command and service module (CSM), without an attached LM.
Apollo Spacecraft Program manager George M. Low called the mission “audacious and not without some risk.”
With time running out to meet Kennedy’s goal and the Soviet Union advancing, NASA moved ahead.
NASA chose a free-return trajectory so if the service module engine failed on the way to the moon, the spacecraft would loop around the moon and return safely to Earth, using the moon’s gravity to swing it home.
Apollo 8 launched from Pad 39A Dec. 21, 1968, at Kennedy Space Center.
Apollo 8 astronauts Frank Borman, James Lovell Jr., and William Anders became the first people to leave Earth, reach, and orbit the moon, completing 10 orbits.
It came within 77.6 miles of the lunar surface.
When an oxygen tank exploded in the Apollo 13 service module April 13, 1970, disabling the command module, the astronauts moved into Aquarius, the lunar module, for life support and engine burns.
They later reentered the command module and used its remaining power to return to Earth.
Had that failure occurred on Apollo 8, there would have been no lifeboat.
From Apollo 10 through 17, the LM traveled attached to the CSM as backup.
After two astronauts lifted off in the ascent stage and rejoined the third astronaut in the CSM, the ascent stage was released into lunar orbit, where it later crashed onto the moon.
Apollo 10 was the exception; its ascent stage was sent into orbit around the sun.
NASA’s Artemis II mission launched April 1 from Launch Complex 39B at Kennedy Space Center, using the Space Launch System.
The SLS stands about 322 feet tall and produces more than 8.8 million pounds of thrust, compared with the Apollo-era Saturn V at 363 feet and 7.5 million pounds.
This is the first crewed Artemis flight and the first crewed mission around the moon since Apollo 17.
Commander Reid Wiseman, Victor Glover, Christina Koch, and Jeremy Hansen flew aboard Orion, named Integrity, without a lunar lander.
Rather than entering lunar orbit, Integrity circled the far side of the moon on a free-return path similar to Apollo 8.
The Apollo service module was almost 25 feet tall and housed fuel cells, cryogenic oxygen and hydrogen supplies, propellant tanks, and the Service Propulsion System engine.
Artemis II’s European Service Module (ESM) was built by Airbus Defense and Space under contract to the European Space Agency.
It is about 13 feet tall and houses Orion’s main engine, propellant tanks, water, oxygen, nitrogen, thermal-control hardware, and four solar array wings for onboard power.
Lockheed Martin built the Orion crew module, the capsule where astronauts live and work during the mission.
Together, the crew module and ESM made up the Orion spacecraft for most of the mission.
Apollo 8’s command module was 12 feet 10 inches wide and offered about 210 cubic feet for three astronauts.
Orion’s crew module is 16 feet 6 inches in diameter and has about 316 cubic feet of space for four.
It features a dedicated toilet and a Universal Waste Management System using airflow technology similar to the International Space Station, unlike Apollo crews, who used waste-collection bags and a handheld device.
Apollo 8 astronauts used the DSKY (display and keyboard) with the Apollo Guidance Computer, typing verb and noun codes on a panel with mechanical keys and green electroluminescent numeric readouts.
Verb told the computer what operation to perform; noun told it which data or system to act upon, with the active codes and results shown in three stacked rows of digits.
Orion’s cockpit centers on three large flat-panel glass displays, each reconfigurable for flight data, navigation, systems status, or procedures.
Surrounding the screens are switch panels with guarded and unguarded switches and rotary selectors, plus a cursor control device so astronauts can select on-screen items and still execute critical commands by hard switch if a display or controller fails.
Honeywell Aerospace provides two Vehicle Management Computers, each containing two flight modules, for a total of four.
These modules are connected via a triple-redundant Time-Triggered Gigabit Ethernet network that links sensors, propulsion, and life-support systems while isolating faults if a unit fails.
Honeywell’s navigation technology includes inertial measurement hardware made in Minnesota.
While Apollo’s CSM drew power from three fuel cells and carried backup batteries, Artemis’s Orion module uses lithium-ion batteries and solar array wings.
Orion is equipped with four 120-volt lithium-ion batteries powered by four solar array wings.
The Crew Survival System suits can keep astronauts alive for up to 144 hours in case the cabin loses pressure or becomes contaminated.
Communications advanced from Apollo’s voice transmissions and basic data over the Deep Space Network to Orion’s voice, video, navigation, and science data.
The Artemis II Orion spacecraft also carried the Orion Optical Communications System, which transmitted 4K video at up to 260 megabits per second using infrared light.
After launch, Orion entered a highly elliptical orbit around Earth that extended to about 46,000 miles above the planet.
The trans-lunar injection (TLI) command sent Integrity on a four-day trip to the moon April 2, the first TLI since Apollo 17.
Orion began close lunar observations April 6 at its nearest point to the moon during its flyby.
The spacecraft descended for landing in the Pacific Ocean using two drogue parachutes, three pilot parachutes, and three main parachutes, although it could land safely with two mains.
After splashdown, five airbags righted Orion.
Artemis III, set for 2027, will test docking operations with commercial lunar landers in low Earth orbit, similar to Apollo 9 in 1969.
Artemis IV, scheduled for 2028, will send Orion and its crew to lunar orbit, where they will dock with a lander sent ahead on an uncrewed mission.
Two astronauts will then enter the lunar lander and descend to the surface, making this the first crewed moon landing since Apollo 17 in 1972.
Unlike the Apollo moon-landing missions, the Artemis IV crew will travel 240,000 miles to the moon without a backup vehicle.
In a March 9 audit, the NASA Office of Inspector General warned that NASA lacks the means to rescue stranded astronauts in space or on the lunar surface.
NASA previously developed backup rescue plans for Skylab and the Space Shuttle, including a modified Apollo ready to save a stranded Skylab crew in 1973.
Following the Columbia disaster Feb. 1, 2003, the Columbia Accident Investigation Board concluded Shuttle Atlantis could have been launched on an emergency mission if the tile damage had been identified in time.
Since retiring the shuttle in 2011, NASA has not maintained a dedicated rapid in-space rescue capability for disabled crewed spacecraft, relying instead on each vehicle’s ability to return to Earth safely, including Orion.
Minnesota companies supply important technology for Artemis II.
Stratasys in Eden Prairie made more than 100 3D-printed parts for the Orion spacecraft using specialized thermoplastic.
Honeywell Aerospace Technologies in Plymouth supplied guidance and navigation systems, command-and-data-handling hardware, display and control units, and core flight software.
PaR Systems (Precision Automated Robotics) in Shoreview supplied friction-stir welding technology used to manufacture major Space Launch System and Orion structures for Artemis II.
The Apollo 8 command module is displayed at the Museum of Science and Industry in Chicago.
