posted 10-30-2005 10:07 AM               

In December 1966 a Titan 3C would drive a 2450 kg circumlunar Gemini capsule to 11 m/s re-entry velocity to verify the heat shield design. This would be followed by a February 1967 manned qualification flight in earth orbit. A manned Gemini would dock with a Double Transtage and be propelled into a high orbit and re-entry speed.

In April the sequence would be repeated, this time the Gemini being sent by Transtage into a loop around the moon.

The reaction of top NASA management was more categorical. Pete Conrad managed to stir Congressional interest, but NASA administrator James Webb informed them that any extra funds Congress cared to appropriate for such a project would be better spent accelerating the Apollo program.

posted 10-30-2005 11:37 AM            

1. In June 1965, Cooper and Conrad were training for Gemini 5. Slayton said that he had to get the launch slipped a week or two to allow them to finish their training. How did Conrad have time to conspire with Martin and McDonnell if the crew was behind in their training? Or was it just Cooper that was behind?

2. Being contractors, Martin and McDonnell generally did not do feasibility studies for free (or did they?), so how did Conrad have enough clout to get them funding (for somethin that HQ did not want, apparently) even before his first flight?

posted 10-30-2005 07:28 PM               

A Titan 3C would drive a 2450 kg circumlunar Gemini capsule to 11 m/s re-entry velocity to verify the heat shield design. This would be followed by a manned qualification flight in Earth orbit.

A manned Gemini would dock with a Double Transtage and be propelled into a high orbit and re-entry speed. After, the sequence would be repeated, this time the Gemini being sent by Transtage into a loop around the moon.

Gemini Circumlunar Flyby Mission:

1. Titan III-C rocket liftoff: The 140.6-foot-tall rocket places a modified Titan III-C transtage into 100-mile-high LEO. Titan III-C consists of two strap-on solid rocket motors (Stage 0), a liquid-fueled core (Stage I), a liquid-fueled stage II, and a liquid-fueled standard transtage (transtage 1).

   The modified transtage (transtage 2) reaches orbit riding on top of the standard transtage. Transtage 2 modifications include removal of systems to reduce weight and addition of a Gemini docking cone.

2. Gemini liftoff: The two-man Gemini, which consists of capsule, retro, and adapter sections, lifts off four minutes after the Titan III-C. A back-up Gemini launch opportunity occurs 90 minutes later when transtage 2 flies over Cape Canaveral at the end of its first orbit. The study notes that transtage 2 has a 7.5-hour usable lifetime in LEO, so the mission cannot occur if the second Gemini launch opportunity is missed.

   The report states that Martin Marietta is examining transtage 2 modifications permitting a 30-day wait in LEO.

3. Gemini docks with transtage 2: Rendezvous occurs 90 minutes after Gemini launch, at the end of Gemini's first orbit, and docking occurs within three hours of Gemini launch. The astronauts insert their spacecraft's nose into transtage 2's docking cone.

   According to the study, the "interface between the Gemini capsule and transtage 2 is designed for utmost simplicity." The standard Gemini docking umbilical and other spacecraft systems are only lightly modified for this mission; for example, rather than create a new transtage 2 status display panel in the Gemini cockpit, a panel which can be viewed through Gemini's twin windows is added to the transtage 2 docking cone. The Gemini/transtage 2 combination is 36 feet, 8 inches long.

4. Translunar injection (TLI) occurs about six hours after Gemini launch. The astronauts feel 0.6 Earth gravities of acceleration at transtage 2 ignition. They must be certain to secure their seat straps - because they face the front of transtage 2, acceleration pushes them out of their seats.

   During acceleration they feel as though they are falling toward Gemini's nose. Transtage 2 burns for 6 minutes, 40 seconds. As transtage 2 depletes its propellants it becomes lighter. Acceleration thus increases, topping out at five times Earth's gravity at transtage 2 shutdown.

5. Gemini separation and circumlunar flight: The astronauts back away from transtage 2 and turn their spacecraft in the direction of flight. Midcourse corrections using the standard Gemini propulsion system occur between three and 10 hours after TLI and when circumlunar Gemini is 40,000 miles out from the moon. The Gemini spacecraft passes behind the moon 82 hours after TLI.

   The mission is timed so the moon is in last-quarter phase as viewed from Earth - this means that half of the lunar far side is lit by the Sun, making it visible as the astronauts fly over. Additional midcourse maneuvers occur 40,000 miles after leaving the moon and between 5 and 10 hours before Earth atmosphere reentry.

6. Gemini reentry: The Gemini capsule casts off its adapter and retro sections, revealing a heatshield modified to withstand circumlunar speed (36,000 feet per second). The spacecraft passes through the atmosphere and splashes down in the Atlantic off Cape Canaveral. Total flight time is 143 hours.

posted 08-30-2024 11:56 AM            

It would have been grueling I suppose, but Borman and Lovell were able to get a couple weeks out without strangling each other, so it might have been possible? I know they had similar work into a Gemini style service module.

posted 08-30-2024 07:36 PM               

The missions Zond 4 through Zond 8 were test flights for the Soviet Moonshot during the Moon race. The Soyuz 7K-L1 (also mentioned just as L1) spacecraft was used for the Moon-aimed missions, stripped down to make it possible to launch around the Moon from the Earth. They were launched on the Proton rocket which was just powerful enough to send the Zond on a free return trajectory around the Moon without going into lunar orbit (the same kind of path flown by Apollo 13 in its emergency abort). With minor modification, Zond was capable of carrying two cosmonauts.

In the beginning, there were serious reliability problems with both the new Proton rocket and the similarly new Soyuz spacecraft, but the test flights pressed ahead with some glitches. The majority of test flights from 1967 to 1970 (Zond 4 to Zond 8) showed problems during re-entry.

The Zond spacecraft made only uncrewed automatic flights. Four of these suffered malfunctions that would have injured or killed any crew.

posted 09-02-2024 07:53 PM               

For the time period given in Carmelo's second post, in 1967 there were last quarter Moons on April 1, May 1 and May 31. April 1 would have probably been too early as "new" projects generally run late, so that leaves us with May 1 and May 31. It is the May 31st opportunity that is of interest.

To reach the Moon by May 31st, would have meant launching the mission on May 28th. That is the same day that a large solar storm reached the Earth from the infamous May 25-26 solar flares. At the very least, communications with the spacecraft would have been disrupted (as they were on Earth). At the most, spacecraft systems might have been compromised and the crew might have suffered detrimental physical effects. Of course this would depend upon how far Gemini was from Earth.

There was also another significant, but less powerful, solar flare that erupted on May 28th. Its effects reached the Earth-Moon system at midday on May 30th. By then, Gemini would have been about two-thirds of its way to the Moon and the crew essentially unprotected.