Spacecraft reentry Gemini 2, for example, endured such a blackout for four minutes, beginning at 9 minutes 5 seconds into the descent. For
When a spacecraft travels through the atmosphere at speeds much faster than the speed of sound – say, during reentry – the friction between its surface and the surrounding air forms a plasma sheath, leading to a communication blackout lasting up to 10 minutes.
What is this? Astronauts often describe re-entry with ballistic capsules as a series of car crashes as opposed to the smooth glider-like landing of the space shuttle. The journey back to Earth aboard a Soyuz vehicle takes about 3.5 hours.
Why was the communication blackout during the Apollo 13 reentry a minute longer than expected? Because they were on a shallower (longer) than normal re-entry path due to the dynamics of bringing the LM all the way home with them, and having limited maneuverability for course corrections.
During re-entry, the shuttle is going so fast, it compresses the air ahead of it. The compression of the air layers near the leading edges of the shuttle is quick, causing the temperature of the air to rise to as high as 3000 degrees Fahrenheit! Being in contact with the shuttle, it heats the shuttle's surface.
The unit g denotes the acceleration due to gravity, where 1 g is the ordinary pull of gravity. Early astronauts were subjected to launch and re-entry forces of up to 6 g or more; in the space shuttle, more than 3 g is experienced on lift-off.
But, remember, energy is conserved, so where does all the “lost” energy go? It converts to heat (from friction) caused by the atmosphere's molecules striking its leading edges. This heat makes the Shuttle's surfaces reach temperatures of up to 1477° C (2691° F).
3.5 Apollo 13
During the second period, the Commander, Command Module Pilot, and Lunar Module Pilot slept 5, 6, and 9 hours, respectively. The third sleep period was scheduled for 61 hours, but the orygen tank incident at 56 hours precluded sleep by any of the crew until approximately 80 hours.
According to the mission log maintained by Gene Kranz, the Apollo 13 re-entry blackout lasted around 6 minutes, beginning at 142:39 and ending at 142:45, and was 1 minute 27 seconds longer than had been predicted. Communications blackouts for re-entry are not solely confined to entry into Earth's atmosphere.
Five minutes to go now for reentry into the Earths atmosphere. Now reading a velocity of 34,335 feet per second [10,465 m/s]. Range to go 2,921 nautical miles [5,410 km].
There's no detectable change in sensation, but once you strike the atmosphere at Mach 25, the ship will experience drag and start to decelerate.
The human body is designed to work in Earth's gravity, which means that when astronauts return to Earth, their bodies have to readjust to the planet's gravitational force. Astronauts may experience a reduced sense of balance, mobility, and coordination after landing on earth.
Space exploration usually includes two different kinds of spacesuits, both of which protect astronauts from the dangers of their mission. One kind is worn inside a spacecraft during launch and ascent to space, and again on the way home during re-entry into Earth's atmosphere as well as during landing.
It would take a very large amount of rocket fuel to slow its speed before reentry. And, that rocket fuel must be launched into orbit too. In order to lift and accelerate that huge fuel tank into orbit the shuttle would require even greater amounts of fuel at liftoff.
When a person is blacked out, the brain continues to process information but is incapable of forming new memories due to this reaction. All blackouts are not the same and can be distinguished by the severity of amnesia experienced.
Alcohol-related blackouts are gaps in a person's memory for events that occurred while they were intoxicated. These gaps happen when a person drinks enough alcohol to temporarily block the transfer of memories from short-term to long-term storage—known as memory consolidation—in a brain area called the hippocampus.
During the Apollo 13 mission, the LM environmental control system provided a habitable environment for about 83 hours (57:45 to 141:05 GET). Cabin temperature remained low due to low electrical power levels. This caused crew discomfort during much of this period, with cabin temperatures ranging between 49°F and 55 °F.
In fact, there is enough energy at reentry to melt and vaporize all the material in the command module several times over, so the spacecraft had to be protected by an ablative heat shield that charred and slowly burned away, thereby protecting all that it surrounded.
When the Apollo 11 flight crew returned from the historic Moon expedition on July 24, 1969, their command module pierced the Earth's atmosphere traveling at 36,237 feet per second and became engulfed in a fireball burning at 5,000 degrees Fahrenheit. This NASA rendering depicts the Apollo 11 capsule during re-entry.
The command module of Apollo 13 entered Earth's atmosphere and splashed down on target on April 17 at 1:07 PM Eastern Standard Time. The mission has been referred to as a successful failure, in that all the crew members survived a catastrophic accident.
Two of the three astronauts (Lovell and Haise) are still alive today. Sadly, Swigert died in 1982 due to complications from cancer in 1982.
The astronauts sleep in small sleeping compartments by using sleeping bags. They strap their bodies loosely so that their bodies will not float around. In the zero-gravity world, there are no "ups" or "downs".
The Stardust sample-return capsule was the fastest man-made object ever to reenter Earth's atmosphere, at 28,000 mph (ca. 12.5 km/s) at 135 km altitude. This was faster than the Apollo mission capsules and 70% faster than the Shuttle.
Acute exposure to the vacuum of space: No, you won't freeze (or explode) One common misconception is that outer space is cold, but in truth, space itself has no temperature. In thermodynamic terms, temperature is a function of heat energy in a given amount of matter, and space by definition has no mass.
Things “burn up” on reentry only because they are entering the upper atmosphere at orbital speed, on the order of Mach 20 or more. They compress the air as it rushes to get out of the way, and that compression heats the air to incandescence. Contrary to popular belief, there is comparatively little friction involved.