41 votes

Why was the Friendship 7 Mercury heat shield detachable?

To reduce the force of the impact on landing the heat shield was designed to separate and be held on by a skirt that acted as an airbag. From the NASA list of Mercury illustrations: Figure 46: ...
1337joe's user avatar
  • 7,206
34 votes
Accepted

What is this pin on John Glenn's suit jacket?

It's the Project Mercury / Mercury Seven emblem. The astronauts went under the name Mercury Seven, and the program design includes the number seven. The symbol represented around the seven is the ...
Organic Marble's user avatar
31 votes
Accepted

Why were seven astronauts selected when there were only six crewed Mercury flights?

It wasn’t originally intended for the astronauts to be matched 1-to-1 with the flights; four additional crewed Mercury-Redstone (suborbital) and three more Mercury-Atlas (orbital) flights were planned ...
Russell Borogove's user avatar
26 votes
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Did Ham the Chimp follow commands, or did he just randomly push levers?

I'll preface my answer with the comment that it was a different time and the way that experimental animals, even primates, were treated was different than today. tl;dr the chimpanzee was trained to ...
Organic Marble's user avatar
23 votes
Accepted

Did any "washouts" of the Mercury program eventually become astronauts?

To my knowledge, only two of the candidates that failed the tests did later become astronauts and flew on missions for NASA: Jim Lovell According to the Wikipedia article on Project Mercury: ...
Cendolt's user avatar
  • 346
21 votes
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Tracking of spacecrafts of the Mercury project

NASA report SP-6, chapter 2 describes the tracking network in detail. It provides this overview schematic explaining how the various stations communicated with each other: (source: NASA SP-6, chapter ...
Ludo's user avatar
  • 14.4k
20 votes

What would have happened if an Apollo/Gemini/Mercury splashdown hit a ship?

In the Apollo era, landing guidance had gotten quite precise and there wasn't a "huge flotilla" waiting; Apollo 8's recovery force was the largest, with 6 ships waiting for it in each of two ...
Russell Borogove's user avatar
19 votes

How did the Mercury Seven compare in military seniority?

The Mercury selection process started on February 2, 1959 with the first meeting at the Pentagon, so I will keep 1959 as the rank evaluation year, which results in the following ranks. (*) denotes ...
Ludo's user avatar
  • 14.4k
19 votes
Accepted

How did astronauts tie the laces on their gloves?

There was no need for astronauts to adjust the laces. Laces were for sizing parts of the suit, not for putting them on or taking them off. Unpressurized, the Mark IV was considered comfortable, and ...
DrSheldon's user avatar
  • 48k
14 votes
Accepted

Why did the cones of the Mercury and Gemini capsules have a neck?

Understanding of re-entry heating at the time led to that decision. Around the time that Mercury was being designed, there was a huge problem in the field of ballistic missile design (which had a ...
Michael Stachowsky's user avatar
12 votes
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How did Shepard's and Grissom's speeds compare with orbital velocity?

The Post Flight Mission Report for Grissom's flight compares key parameters for the two manned suborbital missions (Shepard's MR-3 and Grissom's MR-4): The corresponding document for John Glenn's ...
Organic Marble's user avatar
12 votes
Accepted

What are some specific examples of the calculations human "computers" did for the Mercury space program?

(This is adapted from my question/answer at Day-to-day tasks of human computers, ala Hidden Figures movie - History of Science and Mathematics Stack Exchange) I was also fascinated by the film Hidden ...
nealmcb's user avatar
  • 711
12 votes
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What caused the bruises when the Mercury capsule was opened by the astronauts?

The hatch had an explosive charge to open it. From This New Ocean, an outline of how it worked: Among other innovations in No. 11 for MR-4 was an explosive side hatch, whose evolution, encouraged by ...
Andrew is gone's user avatar
11 votes
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How many earth stations had astronauts on-site during John Glenn's orbit in Friendship-7?

According to NASA's mission report on Mercury-Atlas 6, the following ground stations in the Mercury network offered voice communication and spacecraft telemetry (in order of eastward travel): ...
Russell Borogove's user avatar
10 votes
Accepted

What are the thrusters present on the side of the Mercury-Atlas launch vehicle?

These are vernier thrusters! They're small (relative to the main engine) rocket engines used to finely control the heading and alignment and form part of the Mercury-Atlas' attitude & roll control ...
marked-down's user avatar
  • 8,941
10 votes
Accepted

Why did Ham the Chimp push levers?

This was to test the change in the chimp's reaction time from the ground to space. It was a human analog experiment--i.e. the results of the test were used to make estimations of how human reaction ...
called2voyage's user avatar
  • 23.7k
10 votes
Accepted

Which spacecraft are models in this Astronaut Group 1+2 photo?

On the left in front of Cooper & Grissom is, I believe, a model of an Agena rocket stage, used as the basis for the Gemini-Agena Target Vehicle, which was the uncrewed rendezvous-docking target ...
Russell Borogove's user avatar
9 votes

When did Chevrolet stop giving astronauts Corvettes?

Al Worden’s 1971 Corvette and Alan Bean’s 1969 Corvette When it comes to information on Corvette, it's best to take a gander at the Corvette Museum has to say. Starting with Alan Shepard and the ...
gwally's user avatar
  • 1,074
9 votes

How did astronauts tie the laces on their gloves?

For project Mercury, the astronauts wore the pressure suit for the entire flight. There was therefore no need for astronauts to tie laces, as that can done by ground crew before launch, and then ...
SE - stop firing the good guys's user avatar
8 votes
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Why did Mercury use multiple CAPCOMs while Apollo did not?

During Project Mercury, NASA's communication network was new, and many of the ground stations did not have dedicated voice communications links back to Houston, so each site needed its own CAPCOM, as ...
Russell Borogove's user avatar
8 votes
Accepted

What was the point of the Redstone rocket when there was the X-15 rocketplane?

The goal of Project Mercury as stated in 1958 was to put a man into orbit safely. In order to do that, NASA wanted to send animals, first. The Russians had done exactly that, and NASA preferred using ...
Polygnome's user avatar
  • 6,936
8 votes

Selection of booster for Mercury capsule

I understand Redstone was selected just because it was the most powerful and dependable rocket in those times The primary driver for the selection of both the Atlas and the Redstone for Mercury was ...
Russell Borogove's user avatar
8 votes
Accepted

Escape tower details of Mercury spacecraft

They "...ensure(d) that exhaust from the combustion chamber was distributed equally within these three nozzles." by test and redesign. The first test on March 8, 1959 of a three-nozzle ...
Organic Marble's user avatar
7 votes

Are Mercury/Apollo/Gemini capsules visible in any museum?

All of the Apollo Command Modules are on display as follows: Apollo 6 - Fernbank Science Center, Atlanta, Georgia Apollo 7 - Frontiers of Flight Museum, Dallas, Texas Apollo 8 - Chicago ...
Richard S's user avatar
7 votes

Did any "washouts" of the Mercury program eventually become astronauts?

He was not exactly a Mercury washout, but Deke Slayton was selected as one of the original Mercury 7, and was scheduled to take the fourth Mercury flight (second orbital, following John Glenn) but was ...
Russell Borogove's user avatar
7 votes
Accepted

Did astronaut candidates have a lung capacity test, as portrayed in the movie The Right Stuff?

This article on health concerns for space tourists includes a photo of Wally Schirra performing the lung capacity test: . He appears to be blowing into a tube but it's unclear if there's a ball ...
Russell Borogove's user avatar
7 votes

Why did the manned Mercury-Redstone flights carry and use retrorockets?

They did slow the capsules down, and, thereby, cause the thermal loads on their heatshields to be lower and their splashdown points to be closer to the Cape, but the Mercury heatshield could easily ...
Russell Borogove's user avatar
6 votes
Accepted

Why didn't Project Mercury advance to an orbital flight on their second mission?

You have to remember that during Project Mercury, not only crewed spaceflight was in its infancy, but spaceflight itself was. The Mercury-Redstone rocket could not achieve orbit, it wasn't powerful ...
Polygnome's user avatar
  • 6,936
6 votes
Accepted

How was time kept on board early manned spaceflights?

Apollo had an onboard guidance computer, with its own clock. From Wikipedia: The AGC timing reference came from a 2.048 MHz crystal clock. The clock was divided by two to produce a four-phase 1.024 ...
Phiteros's user avatar
  • 5,626
6 votes

Size of Apollo era astronauts

NASA probably learned a lot of lessons following the development of Gemini. Astronaut Gus Grissom (170cm) was instrumental in the cockpit layout and design, and they even nicknamed the spacecraft the ...
Innovine's user avatar
  • 4,625

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