Lunar Orbit Rendezvous

The words

1. Bill Michael

   William H. “Bill” Michael Jr. studied parking-orbit ideas at Langley. He shared them with Clint Brown’s group as it considered how to send people to the Moon.

   NASA Langley: Houbolt, Michael and Garrick (opens a new tab)

2. Dark Horse

   Lunar-orbit rendezvous began as an outsider in the mission debate. It gained support because of the smaller landing craft, and NASA announced its selection on July 11, 1962.

   NASA: choosing the lunar mission plan (opens a new tab)

3. Direct Ascent

   Direct ascent would land the Earth-return spacecraft itself on the Moon. Its greater landing mass called for a giant launcher, with Nova studied for that role.

   NASA: choosing the lunar mission plan (opens a new tab)

4. Garrick

   Houbolt’s supervisor Ed Garrick congratulated him when NASA selected lunar-orbit rendezvous. The printed $20 billion savings figure records Garrick’s assessment of Houbolt’s contribution.

   NASA Langley: Houbolt, Michael and Garrick (opens a new tab)

5. Hampton

   NASA’s Langley Research Center in Hampton, Virginia, was a base for lunar-orbit rendezvous studies. Its researchers examined the weight savings and practical problems of a lunar rendezvous.

   NASA: choosing the lunar mission plan (opens a new tab)

6. Holmes

   D. Brainerd Holmes led NASA’s Office of Manned Space Flight. After receiving Houbolt’s arguments from Seamans, he involved Joe Shea in evaluating how Apollo should reach the Moon.

   PDF p. 35 · NASA LOR history: origins and managers (opens a new tab)

7. Houbolt

   John Houbolt persistently argued for lunar-orbit rendezvous within NASA. Several researchers had developed related ideas; his distinctive role was pushing the agency to examine this approach.

   Did you know?

   In 1963, NASA honored Houbolt with its Exceptional Scientific Achievement Medal for his analysis and advocacy of lunar-orbit rendezvous.

   NASA Langley: Houbolt, Michael and Garrick (opens a new tab)

8. Jerome Wiesner

   Jerome Wiesner was Kennedy’s science adviser. He remained opposed to lunar-orbit rendezvous when NASA announced its selection in July 1962, despite growing agreement within the agency.

   PDF p. 40 · NASA LOR history: origins and managers (opens a new tab)

9. Joe Shea

   Joseph F. “Joe” Shea became Holmes’s deputy for spaceflight systems in January 1962. He helped compare the proposed routes to the Moon and build support for a decision.

   PDF p. 35 · NASA LOR history: origins and managers (opens a new tab)

10. Kondratyuk

    Yuri Kondratyuk had expressed early ideas about lunar-orbit rendezvous before Apollo. Langley researchers later said they had not known his work when forming their own proposals.

    PDF pp. 10–11 · NASA LOR history: origins and managers (opens a new tab)

11. Lunar Lander

    Lunar-orbit rendezvous used a small, separate craft to descend to the Moon and return to orbit. It left the heavier Earth-return vehicle above the surface.

    NASA: choosing the lunar mission plan (opens a new tab)

12. Mother Ship

    The Command and Service Modules remained above the Moon while the smaller lander went down. They carried the equipment needed for the astronauts’ journey back to Earth.

    Did you know?

    Choosing lunar-orbit rendezvous required a docking system and an internal crew-transfer tunnel in the Command Module. NASA also needed a separate landing vehicle.

    NASA: redesigning Apollo for rendezvous (opens a new tab)

13. Parking Orbit

    An orbit used as a temporary holding path.

    Michael’s calculations explored leaving Earth-return equipment circling the Moon. Keeping that mass above the surface reduced what the landing portion would need to carry.

    PDF p. 10 · NASA LOR history: origins and managers (opens a new tab)

14. Seamans

    Robert C. Seamans Jr., NASA’s Associate Administrator, received Houbolt’s 1961 appeal. He helped get the competing mission plans reviewed before the 1962 decision.

    NASA: choosing the lunar mission plan (opens a new tab) · NASA: Dryden and Seamans’s leadership roles (opens a new tab)

15. Tanker

    A spacecraft sent up to supply propellant to another vehicle.

    A competing Earth-orbit rendezvous plan would launch a tanker separately from the crewed Moon vehicle. The vehicles would meet near Earth before the lunar journey.

    June 7 briefing, p. 5 (PDF p. 82) · NASA: von Braun’s tanker alternative (opens a new tab)