[Shadowmuse Blown]

Wow.  I did not know this about Apollo 15.  Look at how much of an angle the LM is at in this view.  Not quite sure why NASA didn’t want it known that it wound up on a 10 degree slope once they successfully left the surface.

[TheZookie007]

From July 2013:

Harvard University's Science in the News blog: "The human body in space: Distinguishing fact from fiction"

Since the first two-hour excursion into space by Yuri Gagarin in 1961, the lure of manned space travel has proved irresistible to scientists, entrepreneurs, and entertainers alike. Today, as technology becomes more capable of enabling manned travel to Mars and Hollywood’s imagination runs wild with notions of humanity’s spaceflight-steeped future (with recent blockbusters like Star Trek, Prometheus, Star Wars, and even Wall-E), many fallacies about space have emerged. Outer space is often depicted in film as a cold, inhospitable place, where exposure to the perpetual vacuum will make your blood boil and your body burst; alternatively, if neither of those things happen, you’re bound to instantly freeze into a human-popsicle. Meanwhile, many of these same films conveniently ignore the slightly more subtle, yet highly relevant hazards of prolonged spaceflight even in an enclosed vessel at normal atmospheric pressure.

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. Furthermore, heat transfer cannot occur the same way in space, since two of the three methods of heat transfer (conduction and convection) cannot occur without matter.

What does this mean for a person in space without a spacesuit? Because thermal radiation (the heat of the stove that you can feel from a distance, or from the Sun’s rays) becomes the predominant process for heat transfer, one might feel slightly warm if directly exposed to the Sun’s radiation, or slightly cool if shaded from sunlight, where the person’s own body will radiate away heat. Even if you were dropped off in deep space where a thermometer might read 2.7 Kelvin (-455°F, the temperature of the “cosmic microwave background” leftover from the Big Bang that permeates the Universe), you would not instantly freeze because heat transfer cannot occur as rapidly by radiation alone.

The absence of normal atmospheric pressure (the air pressure found at Earth’s surface) is probably of greater concern than temperature to an individual exposed to the vacuum of space. Upon sudden decompression in vacuum, expansion of air in a person’s lungs is likely to cause lung rupture and death unless that air is immediately exhaled. Decompression can also lead to a possibly fatal condition called ebullism, where reduced pressure of the environment lowers the boiling temperature of body fluids and initiates transition of liquid water in the bloodstream and soft tissues into water vapor. At minimum, ebullism will cause tissue swelling and bruising due to the formation of water vapor under the skin; at worst, it can give rise to an embolism, or blood vessel blockage due to gas bubbles in the bloodstream.

Our dependence on a continuous supply of oxygen is the more limiting factor to the amount of time a human could survive in a full vacuum. Contrary to how the lungs are supposed to function at atmospheric pressure, oxygen diffuses out of the bloodstream when the lungs are exposed to a vacuum. This leads to a condition called hypoxia, or oxygen deprivation. Within 15 seconds, deoxygenated blood begins to be delivered to the brain, whereupon unc onsc iousn ess results. Data from animal experiments and training accidents suggest that an individual could survive at least another minute in a vacuum while unc onscious, but not much longer....

[solvegas]

 

[TheZookie007]

Smithsonian Magazine, 11 January 2023: "NASA Satellite Falls Back to Earth After Almost 40 Years in Space"
The reentry calls attention to the mission’s success and puts a spotlight on the dangers of space debris

After more than 38 years orbiting Earth, NASA’s Earth Radiation Budget Satellite (ERBS) has returned home.

The craft reentered Earth’s atmosphere over the Bering Sea at 11:04 p.m. Eastern time on Sunday, NASA says in a statement. The agency anticipated that most—but not all—of the satellite would burn up as it sped through Earth’s atmosphere. While the return of ERBS calls attention to the mission’s success, its reentry has put a spotlight on the dangers of space debris.


The satellite reentered Earth's atmosphere at 11:04 p.m. Eastern time on Sunday. (NASA)


The 5,400-pound ERBS satellite launched on October 5, 1984, from the space shuttle Challenger. Originally intended to operate for two years, the satellite outlived that goal and gathered data for 21 years, until 2005.

ERBS provided insights into global warming and weather patterns. Two of its instruments measured Earth’s radiation budget—the balance of energy from the sun that’s absorbed by Earth versus reflected or radiated back to space. Data from ERBS revealed how human activities, such as using ozone-eating chemicals called chlorofluorocarbons (CFCs) and burning fossil fuels, impact this delicate balance.

The satellite’s third instrument studied the makeup of the stratosphere, including levels of water vapor, nitrogen dioxide, aerosols and ozone, a gas that protects life on Earth by absorbing ultraviolet radiation from the sun. As a result, ERBS helped confirm that the Earth’s ozone layer was thinning.

In this way, the satellite played a role in shaping the 1987 Montreal Protocol, which phased down the use of close to 100 human-made ozone-depleting chemicals. Nearly 200 countries signed the agreement, and it led to a dramatic decrease in the use of CFCs, writes CNN’s Katie Hunt. A recent United Nations assessment found that the hole in the ozone layer over Antarctica is on track to fully recover by 2066.

[Shadowmuse Blown]

Yes, just look at any color picture of the Sun taken in space

[Shadowmuse Blown]

This is an awesome picture of the recent Falcon Heavy launch.  You can see the main rocket at the bottom of the pic as it heads into space, and it’s two, now ejected, boosters in the upper part of the picture.  Amazing.

[rtpoe]

As seen on today's Astronomy Picture of the Day, a group of amateur astronomers found a new and totally unexpected nebula near the Andromeda Galaxy. A cloud of ionized oxygen (in blue) that very likely isn't part of the Milky Way.

The pros at the huge observatories are looking at tiny things in the distance, and the "all sky surveys" aren't able to do the long hours of observing the same area that you need to bring out this sort of detail. But with digital detectors, filters, and software being priced within the reach of serious amateurs...

https://iopscience.iop.org/article/10.3847/2515-5172/acaf7e/meta

[Shadowmuse Blown]

Getting ready for full wet dress rehearsal for Starship 24 and Booster 7.  The pair will weigh around 5000 tons when fully loaded with fuel and liquid oxygen.  All 33 Raptor engines on Booster 7 have year to be tested together, as well. 

Many don’t think Booster 7 will be launched together with Starship.  I would think they’d want to test the booster by itself before pairing it with Starship, so they may yet decouple this pair and just launch Booster 7 by itself as a first test.  Then, they could use Booster 8 or 9 in conjunction with Starship for the full orbital launch. 

I do know that when the first orbital launch is attempted it will be ridiculously exciting even if something goes wrong at some point.  Look at this thing: it’s like something from Thunderbirds Are Go made real.

[solvegas]

Getting ready for full wet dress rehearsal for Starship 24 and Booster 7.  The pair will weigh around 5000 tons when fully loaded with fuel and liquid oxygen.  All 33 Raptor engines on Booster 7 have year to be tested together, as well. 

Many don’t think Booster 7 will be launched together with Starship.  I would think they’d want to test the booster by itself before pairing it with Starship, so they may yet decouple this pair and just launch Booster 7 by itself as a first test.  Then, they could use Booster 8 or 9 in conjunction with Starship for the full orbital launch. 

I do know that when the first orbital launch is attempted it will be ridiculously exciting even if something goes wrong at some point.  Look at this thing: it’s like something from Thunderbirds Are Go made real.

Exciting times ahead, that's for sure. 

[TheZookie007]

Getting ready for full wet dress rehearsal for Starship 24 and Booster 7.  The pair will weigh around 5000 tons when fully loaded with fuel and liquid oxygen.  All 33 Raptor engines on Booster 7 have year to be tested together, as well. 

Many don’t think Booster 7 will be launched together with Starship.  I would think they’d want to test the booster by itself before pairing it with Starship, so they may yet decouple this pair and just launch Booster 7 by itself as a first test.  Then, they could use Booster 8 or 9 in conjunction with Starship for the full orbital launch. 

I do know that when the first orbital launch is attempted it will be ridiculously exciting even if something goes wrong at some point.  Look at this thing: it’s like something from Thunderbirds Are Go made real.

Gerry Anderson would be proud!

[Shadowmuse Blown]

May 12th, 2009, the SS Atlantis transits the Sun

[solvegas]

 

[Shadowmuse Blown]

One day, people on some distant planet—that probably hasn’t even been formed yet in our time—in the far distant future, will look up into their night sky and the only points of light will be the other planets in their solar system as even the galaxies are eventually torn apart by the expanding universe.

[solvegas]

One day, people on some distant planet—that probably hasn’t even been formed yet in our time—in the far distant future, will look up into their night sky and the only points of light will be the other planets in their solar system as even the galaxies are eventually torn apart by the expanding universe.

Frankly, I'm glad I won't be around to worry about that catastrophe.

[Hiram]

One day, people on some distant planet—that probably hasn’t even been formed yet in our time—in the far distant future, will look up into their night sky and the only points of light will be the other planets in their solar system as even the galaxies are eventually torn apart by the expanding universe.

I think I am right in saying, the only stars you can see with the naked eye from earth are in out solar system.