On The Impossibility Of Space Diving – Science 2.0

Since E.E. Doc Smiths 1934 novel, Triplanetary, people have dreamed about performing the first space dive. As we make our first steps toward commercialising space travel, many people have started to wonder if we are any closer to achieving the first space dive.

When Jeff Bezos and Sir Richard Branson were celebrated for travelling to space, some people questioned whether they had actually gone to space, or simply reached the edge of space. This opened up a debate about where space really begins.

According to the Fdration Aronautique Internationale (FAI), which regulates aeronautics, astronautics and related activities, space begins 62 miles above sea level, a line dubbed the Krmn line after Theodore von Krmn, who calculated this altitude level. The region below this line is referred to as the edge of space. Once you cross the Krmn line, you can say that you have reached space, although reaching space doesnt imply being in orbit. However, the United States Air Forces definition of space begins at just 50 miles above sea level, reflecting changes in outer space. To reach orbit, you need to be ~248 miles above sea level, which is where the International Space Station is.

To date, there have been no successful space dives. People have been able to skydive from higher and higher. In 1959, Joseph Kittinger jumped from 74,700 feet, a record which he broke in 1960 when he skydived from 102,800 feet. In 1962, Yevgeni Andreyev set a new record when he skydived from 83,523 feet a record which was only surpassed in 2012 when Felix Baumgartner made skydived on three occasions, from 71,581 feet, 96,640 feet, and 128,000 feet, respectively. The current record for the highest and longest-distance free fall jump is held by Alan Eustace, who, in 2014, jumped from 135,908 feet. However, Kittinger still holds the record for the longest-duration free fall, for his 1960 jump, which lasted 4 minutes, and 36 seconds.

Space diving is a hard problem. Technical challenges have prevented successful jumps from the mesosphere or thermosphere. Orbital Outfitters, which is not defunct, worked unsuccessfully to develop a suit that would allow space diving. Any successful suit would have to be able to deliver larger amounts of oxygen than current suits are capable of, have a carbon dioxide absorber, be able to keep everything cool, and, well, just not melt. At that height, a space diver is at risk of being boiled from their blood outwards. To date, there has been no suit developed to overcome the challenges of space diving.

Its not just about the suit, though. A space diver would need a parachute that could withstand being deployed at the kind of extraordinarily high speeds involved. At the beginning of space, we are talking about reaching velocities of nearly 4,474 miles per hour. At the level of the International Space Station, we are talking about velocities of nearly 17150 miles per hour. With the technology we have, that would kill the space diver.

Scientists have been trying to figure out these equipment problems for decades. Theyre still having to create flowcharts to develop equipment for every single dangerous phase of this audacious feat. Were close, but not very.

Just when you think it couldnt get worse, things get worse, much worse. Re-entry is possibly the single biggest challenge from a technical point of view. Quite simply, any space diver faces the possibility of being burnt alive. No suit in existence can withstand the extreme temperatures that a space diver would be facing. A space diver would have to endure temperatures of as much as 1,370C, whereas the standard spacesuit can only withstand temperatures of about a fifth of that.

Lets make things even harder: if a space diver were hurtling down from the International Space Station, they would be hurtling past satellites and space debris, all of which would be travelling at phenomenal speeds and either of which could instantly kill that space diver upon impact. Basically, it would be like asking someone to race through a firing range and hoping they dont get hit by a bullet.

A final complication is this: if you were space diving from the International Space Station, you wouldnt simply hurtle toward earth, you would orbit for as much as two years, all the while requiring food and water and oxygen, before your orbit started to decay and you fell toward earth.

Space diving is, basically, impossible. From extreme heat, to death by starvation, our intrepid space diver simply faces too many hurdles to ever make it. Perhaps ever is too strong a word. Maybe a century from now we will have resolved all the challenges and space diving will be as common as skydiving.

More here:
On The Impossibility Of Space Diving - Science 2.0