Soyuz – What next?

Many of my readers will be aware the Soyuz MS-10 spacecraft failed to get into orbit on Thursday 11 October. It was on a mission to take fresh crew to the International Space Station (ISS).

Mission patch for Soyuz MS-10

A major fault occurred at an altitude of about 50 km when the booster rocket failed, causing the spacecraft to start falling back to Earth. Fortunately, the space capsule containing the crew separated successfully from the faulty rocket and the astronauts landed unharmed.

The Russian Space agency is now investigating the cause of the failure. The next mission to rotate the ISS crew,  Soyuz MS-11,  was  scheduled to take place on 20 December, but this has now been put on hold. Hopefully the cause of the failure will be identified and rectified, enabling the launch to happen as originally planned. However, if Soyuz is grounded for a longer period then the existing crew will have to abandon the ISS (using a Soyuz spacecraft which is attached to the station) until Soyuz is allowed to fly again or American missions start. This would be the first time that the ISS has been unoccupied since Nov 2000, when the first crew arrived.

This failure underlies how dependent America and the other nations are on Soyuz, a spacecraft first flown more than 50 years ago. For the rest of this post I’ll talk about this spacecraft which has effectively become the space station ‘taxi’.

The First Mission

On 23 April 1967, six years after Yuri Gagarin had became the first man to go into space, a Soviet Soyuz spacecraft was launched carrying cosmonaut Vladimir Komorov. He completed 18 orbits and then returned to Earth.

Mission patch for the first Soyuz mission

Sadly, during reentry the parachute failed to open properly and the spacecraft was destroyed when it hit the Earth at high speed and burst into flames – killing Komorov and giving him the unfortunate distinction of being the first person to die in space flight.

Despite this initial setback, the Soyuz spacecraft was successfully flown back into space the following year, when cosmonaut Georgy Beregovoy, a decorated World War 2 hero, completed 81 orbits and landed safely.

A Soviet 10 kopek stamp showing  Georgy Beregovoy. The Soyuz rocket is in the background – image from Wikimedia commons

Since Beregovoy’s mission, Soyuz has been launched into space a further 137 times, and has proved to be a great success, outliving the vastly more expensive  technologically advanced Space Shuttle. It has established itself to be a reliable and safe way of getting into Earth orbit.  In fact, since the retirement of the Space Shuttle in 2011, it has been the only way of getting astronauts to and from the ISS.  A fact worth bearing in mind given the somewhat tense relationship between Russia and the West.

The spacecraft

The Soyuz spacecraft was designed in the Soviet Union in the early 1960s. The chief designer was a man called Sergei Korolev (1907-1966), who was the driving force behind many of the early successes in the Soviet space programme.

Korolev in 1956 – image from Wikimedia Commons

Korolev had a chequered career. In 1938 he fell foul of the authorities and was arrested by the Soviet secret police, tried and sentenced to death. The sentence was reduced to imprisonment and he spent number of months in a Soviet gulag – a hard labour camp – in a remote part of Siberia. Conditions were extremely harsh and many prisoners died from cold, disease and sheer exhaustion.  Towards the end of the Second World War he was rehabilitated by the Soviet government and rose up the ranks in the 1950s to head the space programme. He died in Jan 1966 at the age of 59, his final years plagued by ill health caused by his time in the gulag.  In the 1950s and 1960s  the Soviet space programme was kept under intense secrecy and, unlike his American counterparts,  Korolev was unknown outside a small elite. His achievements were only made public after his death.

 

The Soyuz spacecraft, shown above, consists of three modules:

  • The first part of the spacecraft is the service module (labelled A). This contains the main engines, fuel, oxygen, computers, communications equipment and the solar panels used to generate electricity
  • The reentry capsule (labelled B) is shaped like a hemisphere and is the only part of the spacecraft which returns to Earth. The cosmonauts enter the capsule just before reentry. It is very cramped and is only designed for the crew to stay in for a short period of time. It does not, for instance, have a toilet.
  • The spherical-shaped orbital module (labelled C) is where the crew live during a mission, although  because all Soyuz missions  are at the moment to and from the ISS, astronauts only spend a short time there.

At launch the spacecraft sits on top of a 45 metre (150 feet) tall Soyuz rocket. The solar panels are folded away, and are unfolded when the spacecraft is in orbit.

Image from Wikimedia commons

As mentioned above, conditions in the reentry capsule are very cramped. It carries a crew of three squeezed into only 2.5 cubic metres of usable space. This is the volume of a cube measuring 1.36 by 1.36 by 1.36 metres. These cramped conditions meant that, in the early Soyuz spaceflights, the cosmonauts couldn’t wear bulky spacesuits and the associated life support equipment. This unfortunately lead to the deaths of the cosmonauts in the Soyuz 11 mission in 1971 who suffocated when a faulty valve caused all the air to escape from their capsule. Had they been wearing spacesuits they would have survived. After this accident Soyuz was redesigned to carry only two cosmonauts, both wearing spacesuits, although this was later increased back to three. The redesigned spacecraft was known as the Soyuz Ferry because its mission was to transport cosmonauts to and from the Salyut space station.

Over the last 50 years Soyuz has gone through several further updates and the latest version, known as Soyuz MS, was first launched in July 2016. The upgrades are mainly to computers, electronics and navigational systems and the internal layout of the spacecraft. The fundamental design hasn’t changed since Kamorov’s first flight back in 1967.

A safe and reliable way of getting into space.

Since 1971 there have been no fatalities on a Soyuz mission and the spacecraft has proven itself to be a safe, relatively cheap and reliable way of getting people to and from the International Space Station (ISS).  The recent failure was the first for 43 years and it important to emphasise that the  astronauts escaped unharmed.

In 2011 the cost of a flying a Space Shuttle mission to the ISS worked out at about $500 million in today’s money (NASA 2011). In contrast, the cost of using the older Soviet-era Soyuz technology worked out more than eight times cheaper at the equivalent of $60 million per mission (Wade 2016).

The table below shows the number of missions flown by the Apollo, Soyuz, Space Shuttle and Shenzou spacecraft.

Only manned missions are included. So, although the Shenzou spacecraft has gone into orbit 11 times only 6 of these missions had humans aboard.

 

NASA and Soyuz

NASA pays Russia $70 million per seat for each astronaut who flies in Soyuz (Wall 2013). This figure, which is roughly the same as the per seat cost of the Space Shuttle ($500 million for a crew of seven), enables the Russian space agency to make a significant profit.

However, NASA won’t be entirely reliant on buying seats on Soyuz for much longer.  As readers of my blog will know, rather than designing and building new craft to fly crew to and from the ISS, NASA administers a US-government funded programme called Commercial Crew Development (CCDev). After a lengthy evaluation process NASA announced on 16 September 2014 that Boeing and SpaceX had received contracts to provide crewed launch services to the ISS.

When the final decision was made, NASA hoped that the winning companies would be able to launch manned missions to the ISS by 2017. However, perhaps unsurprisingly, there have been numerous delays in the development of both spacecraft and the launch dates have slipped.

According to the current launch schedule (https://www.nasa.gov/launchschedule/ ), the target dates for unmanned test flights are:

  • ‘March 2019′  for Boeing CT100
  • ‘January 2019’ for SpaceX Dragon v2

However, it must be be pointed out that they are only target dates and it is possible that they will slip further.

If there are no further delays and these test flights do take place as planned and are successful, then in June 2019 the SpaceX Dragon v2 spacecraft will be the first American spacecraft to carry astronauts into orbit since the retirement of the Space Shuttle. This will be followed by the Boeing CT100, shown below, in August 2019.

DragonV2

 The Dragon V2 spacecraft – image from NASA 

Replacement of Soyuz

In the longer term Soyuz is due to be replaced in 2023 by a new spacecraft called Federation.  The design of Federation is still at the early stages but it will be capable of both low Earth orbit missions such as ferrying astronauts to and from the ISS and also missions deeper into space, such as orbiting the Moon (Nowakowski 2016).

Artist’s concept of the Federation spacecraft. image from  Roscosmos


I hope you have enjoyed this post. To find out more about the Science Geek’s blog, click here or at the Science Geek Home link at the top of this page.


Notes

1 The total includes all Soyuz missions which were launched with humans on board, including the two missions where the spacecraft failed to get into orbit.

2 After the last spaceflight to the Moon, there were 4 further Apollo spaceflights:

  • 3 to the Skylab space station in 1973 and 1974.
  • 1 joint mission with the Soviet Union known as Apollo-Soyuz in 1975.

3 The total of 135 Space Shuttle missions includes the ill fated Challenger mission in 1986 when the spacecraft broke apart 73 seconds after take off.

References

NASA (2011) How much does it cost to launch a Space Shuttle?, Available at:http://www.nasa.gov/centers/kennedy/about/information/shuttle_faq.html#1 (Accessed: 15 October 2017).

Nowakowski, T (2016) Russia runs first tests of its next-generation “Federation” manned spacecraft, Available at: http://www.spaceflightinsider.com/organizations/roscosmos/russia-runs-first-tests-of-its-next-generation-federation-manned-spacecraft/ (Accessed: 15 October 2018).

Wade, M. (2016) Cost, Price, and the Whole Darn Thing, Available at:http://www.astronautix.com/c/costpriceanholedarnthing.html (Accessed: 15 October 2018).

Wall, M (2013) NASA to pay $70 Million a seat to fly astronauts on Russian spacecraft,Available at: http://www.space.com/20897-nasa-russia-astronaut-launches-2017.html(Accessed: 25 April 2016).

Space stations past and present

The International Space Station (ISS) is now 20 years old. In this post I’ll talk about the history of the ISS and other space stations, and I’ll also touch on some of the politics involved.

Image from NASA

 

Early space stations

 

Although America was the first country to put a man on the Moon, the Soviet Union led the way in long duration spaceflights and was the first country to launch a space station, where humans could  live and work for longer periods of time. Before the advent of space stations, astronauts were confined to cramped space capsules.  Continue reading “Space stations past and present”

The International Space Station updated

Since the publication of the original post on 2 August 2018, NASA have delayed the planned launch dates for the American spacecraft to carry astronauts to and from the International Space Station. In my original post I referred to the Boeing and SpaceX spacecraft taking astronauts this year, which was an ambitious target, bearing in mind that it was already August and neither spacecraft had flown an unmanned mission! Perhaps unsurprisingly the planned launch dates have slipped into 2019 and I have updated my post to reflect this.

Original post below——

This year marks the 20th anniversary of the International Space Station (ISS).

Image from NASA.

The first module of the ISS, called Zarya, was launched by a Russian rocket back in November 1998. Zarya was not an inhabitable module and its function was to provide electrical power, storage and propulsion to the ISS during the initial stages of assembly. Interesting the word ‘Zarya’ is Russian for sunrise and Zarya, being the first step in building the ISS, was to signify a new dawn in international cooperation.

The first module of the ISS called Zarya – Image from NASA  Note: the solar panels shown are no longer used and have been retracted.

The ISS has a modular design and in the twenty years since Zarya numerous modules have been added, gradually growing it into the structure we see today.  A key milestone was achieved on 2 November 2000 when a Russian Soyuz spacecraft bought the first crew to the ISS. The ISS has been manned ever since that date, providing a permanent human presence in space. The current crew of the ISS is known as Expedition 56 and consists of: three Americans, two Russians and one German.

Mission patch for Expedition 56 – Image from NASA

Key role of the Space Shuttle

Image from NASA

The American Space Shuttle, which flew between 1981 and 2011, was key to building the ISS. The Shuttle had the capacity to take large modules in its cargo bay and crews of up to six astronauts on assembly missions. Many of these missions involved extended spacewalks. Indeed, without the Space Shuttle it would not have been possible to build the ISS. In fact, post 1998, construction of the ISS became the almost the entire focus of the shuttle programme. This is illustrated by the statistic that of the 43 space Shuttle Missions flown after the launch of Zarya, 38 (89%) of them went to the ISS to deliver a new module and components to the station, bring fresh supplies or to bring fresh crew to the ISS and return the old crew to Earth.

The ISS today

The ISS is shown in the image at the top of this post. Although some minor construction missions are planned later this year and in 2019, the components to be added are relatively small and construction is essentially complete. The ISS is a very flat structure. It is 73 metres long and a maximum of 109 meters wide, but its maximum depth is only a few metres. It has a mass of 420 tons. Its most noticeable feature are the eight separate sets of solar panels, which look like giant wings and in total generate up to 90 kilowatts of electric power (NASA 2018).

The orbit of the ISS 

The ISS orbit is almost perfectly circular, just over 400 km above the Earth’s surface. At this altitude, although it is classified as being in space, which begins at an altitude of 100 km, (see my previous post), here are sufficient traces of the Earth’s atmosphere to cause the ISS to lose energy as it moves against the air resistance caused by this very thin gas. This causes the ISS to very gradually spiral down to Earth as it loses a small amount of energy on each orbit. The distance a satellite drops in altitude is known as its orbital decay and for the ISS is 2 km per month, which works out at about 70 metres per day. If nothing were done the ISS would gradually return to Earth within a few years and as it hit the thicker atmosphere it would disintegrate. To prevent this happening the ISS has a set of thrusters, which are fired periodically to boost it into a higher orbit. Visiting spacecraft also fire their rocket motors to the same effect.

Because it is both large and travels in a low orbit, the ISS can be easily seen from Earth. It is visible to the naked eye as a slow-moving, bright white dot. Its brightness is due to sunlight reflecting off its solar panels. The best time to see it is either after sunset or before sunrise, when the station remains sunlit, but the sky is dark.  This is shown in the diagram below.

The ISS takes about 90 minutes to complete an orbit. As it moves around its orbit:

  • the ISS is visible at night between sunset, point A, and when it disappears behind the Earth’s shadow, point B;
  • between points B and C the ISS is in the Earth’s shadow it receives no direct sunlight and cannot be seen;
  • between point C, when it emerges from the Earth’s shadow, and point D, sunrise, the ISS is visible;
  • between points D and A, the ISS cannot be easily seen against the brightness of the daytime sky.

Because of its size, the ISS is the brightest artificial object in the sky and has a similar brightness when overhead to the planet Venus.

 

Research at the ISS

A good deal of research is carried out at the ISS. This is described in more detail at the following website  https://www.nasa.gov/mission_pages/station/research/overview.html.  Much of this research is based upon the fact that that the strength of gravity is very close to zero in the ISS. This is known as micro-gravity and the only place it is possible to create a micro-gravity environment, for longer than a few minutes, is in space. Some examples of this research are given below.

  • Fluids can be almost completely combined in micro-gravity, so physicists can investigate fluids that do not mix well on Earth.
  • In micro-gravity environment combustion occurs differently. Flames have a spherical shape. In the diagram below, the candle on the left is in normal gravity, whereas the candle on the right is in micro-gravity.

Image from NASA

  • Research has been carried out as to how plants develop in micro-gravity. Interestingly, results have shown that plants use light rather than gravity to determine which direction is ‘up’.

But perhaps the most interesting area of research are the effects on the human body of spending long periods on time in near weightlessness. This area is important, because in the next few decades when astronauts travel to Mars they will have to spend at least six months in zero gravity when travelling to the red planet and a further six months on the return journey. Some of the effects which have been found are.

  1. Without any weight to work against, muscles gradually will get smaller and lose their strength. This includes the heart muscle.
  2. Fluid shifts around the body causing fluid pressure in the brain to increase.
  3. One of the most serious problems is that, without gravity, a strong skeleton is not needed to support the body. Studies have shown that astronauts lose 1-2 % of their bone mass for each month of weightlessness; the calcium from their bones is excreted in their urine. So much calcium may be lost that it can cause kidney stones.

Research on the ISS has shown that to retain their muscle mass, and ensure their heart stays in good condition, astronauts need to spend many hours a day exercising.  Because there is no weight for their muscles to work against, astronauts often spend a large fraction of the day running on a treadmill, using elastic harnesses to provide resistance.

However, nothing has been discovered which can prevent the loss of bone density. The rate of bone loss continues at 1-2% per month and does not level off after long durations in space. After more than two years in low gravity, astronauts’ bones would be so weak they would easily fracture and would be unable to support their weight then they returned to Earth. This may be a limiting factor for how long humans can spend in zero gravity environments, especially since it takes a significant time for the bone density to return to normal.

A further limiting factor is that on long duration spaceflights astronauts will be exposed to high doses of radiation. This can cause genetic damage making the astronauts more prone to cancer in later life.

Taller Astronauts

Spending time in a microgravity environment causes the spine to elongate. On Earth, gravity keeps the vertebrae in place by constantly pushing them together. But without gravity, the vertebrae will naturally expand slightly, causing a person to become taller.

 

Typically, astronauts in space can grow up to three percent of their original height. For example, in 2016 when Scott Kelly came to Earth after spending nearly a year in space he was 2 inches (5 cm) taller. However, this gain in height is only temporary. When under the effects of gravity again astronauts return to their original height.

Scott Kelly – Image from NASA

Getting to and from the ISS

Since the end of the Shuttle programme the only way astronauts can get to and from the ISS is by the Russian Soyuz spacecraft, a point worth remembering now that relations between the US and Russia are rather strained.  Soyuz was first flown in 1967 and its design has changed little since then. Like the Apollo spacecraft which took astronauts to the Moon, it is a single use spacecraft.  Currently NASA pay $70 million for each astronaut who flies in the Soyuz spacecraft (Wall 2013), which enables the Russian space agency to make a significant profit.

In the next few years US spacecraft should return to space.  Rather than build a new craft to fly crew to and from the ISS, NASA administer a US-government funded programme called Commercial Crew Development (CCDev). After a lengthy evaluation process NASA announced in September 2014 that Boeing and SpaceX had received contracts to provide crewed launch services to the ISS.

When the final decision was made, NASA hoped that the winning companies would be able to launch manned missions to the ISS by 2017. However, perhaps unsurprisingly, there have been numerous delays in the development of both spacecraft and the launch dates have slipped.

According to the current launch schedule (https://www.nasa.gov/launchschedule/ ), the target dates for unmanned test flights are:

  • ‘late 2018 / early 2019’ for the Boeing spacecraft
  • ‘November 2018’ for SpaceX.

However, it must be be pointed out that they are only target dates and may slip further.

If there are no further delays and these test flights do take place as planned and are successful, then in April 2019 the SpaceX Dragon v2 spacecraft will be the first American spacecraft to carry astronauts into orbit since the retirement of the Space Shuttle. This will be followed by the Boeing CT100, shown below, in the middle of the year.

The Boeing CT-100 Starliner Space Capsule – image from NASA. In lmid 2019 this spacecraft may take astronauts to and from the ISS.

Next post

I hope you’ve enjoyed this post. In my next post I’ll talk about the costs of the space station, international cooperation in space and how I see the future of the ISS.

 

 

NASA (2018) International Space Station facts and figures, Available at: https://www.nasa.gov/feature/facts-and-figures (Accessed: 30 July 2018).

 

Wall, M (2013) NASA to pay $70 Million a seat to fly astronauts on Russian spacecraft,Available at: http://www.space.com/20897-nasa-russia-astronaut-launches-2017.html(Accessed: 30 July 2018)

 

 

The International Space Station

Note 10 September 2018.  The information in the section ‘Getting to and from the ISS’ has been superseded by information in the updated version of this post.

This year marks the 20th anniversary of the International Space Station (ISS).

Image from NASA.

The first module of the ISS, called Zarya, was launched by a Russian rocket back in November 1998. Zarya was not an inhabitable module and its function was to provide electrical power, storage and propulsion to the ISS during the initial stages of assembly. Interesting the word ‘Zarya’ is Russian for sunrise and Zarya, being the first step in building the ISS, was to signify a new dawn in international cooperation.

The first module of the ISS called Zarya – Image from NASA  Note: the solar panels shown are no longer used and have been retracted.

The ISS has a modular design and in the twenty years since Zarya numerous modules have been added, gradually growing it into the structure we see today.  A key milestone was achieved on 2 November 2000 when a Russian Soyuz spacecraft bought the first crew to the ISS. The ISS has been manned ever since that date, providing a permanent human presence in space. The current crew of the ISS is known as Expedition 56 and consists of three Americans, two Russians and one German.

Mission patch for Expedition 56 – Image from NASA

Key role of the Space Shuttle

Image from NASA

The American Space Shuttle, which flew between 1981 and 2011, was key to building the ISS. The Shuttle had the capacity to take large modules in its cargo bay and crews of up to six astronauts on assembly missions. Many of these missions involved extended spacewalks. Indeed, without the Space Shuttle it would not have be possible to build the ISS. In fact, post 1998, construction of the ISS became the focus of the shuttle programme. This is illustrated by the statistic that of the 43 space Shuttle Missions flown after the launch of Zarya, 38 (89%) of them went to the ISS to deliver a new module and components to the station, bring fresh supplies or to rotate crew.

The ISS today

The ISS is shown in the image at the top of this post. Although a few more construction missions are planned later this year and in 2019, the components to be added are relatively small and construction is essentially complete. The ISS is a very flat structure. It is 73 metres long and a maximum of 109 meters wide, but its maximum depth is only a few metres. It has a mass of 420 tons. Its most noticeable feature are the eight separate sets of solar panels, which look like giant wings and in total generate up to 90 kilowatts of electric power (NASA 2018).

The orbit of the ISS 

The ISS orbit is almost perfectly circular, just over 400 km above the Earth’s surface. At this altitude, although it is classified as space (which begins at an altitude of 100 km, see my previous post ), there are sufficient traces of the Earth’s atmosphere to cause the ISS to lose energy as it moves against the air resistance caused by this very thin gas. This causes the ISS to very gradually spiral down to Earth as it loses a small amount of energy on each orbit. The distance a satellite drops in altitude is known as its orbital decay and for the ISS is 2 km per month, which works out at about 70 metres per day. If nothing were done the ISS would gradually return to Earth within a few years and as it hit the thicker atmosphere it would disintegrate. To prevent this happening the ISS has a set of thrusters, which are fired periodically to boost it into a higher orbit. Visiting spacecraft also fire their rocket motors to the same effect.

Because it is both large and travels in a low orbit, the ISS can be easily seen from Earth. It is visible to the naked eye as a slow-moving, bright white dot. Its brightness is due to sunlight reflecting off its solar panels. The best time to see it is either after sunset or before sunrise, when the station remains sunlit, but the sky is dark.  This is shown in the diagram below.

The ISS takes about 90 minutes to complete an orbit. As it moves around its orbit:

  • the ISS is visible at night between sunset, point A, and when it disappears behind the Earth’s shadow, point B;
  • between points B and C the ISS is in the Earth’s shadow it receives no direct sunlight and cannot be seen;
  • between point C, when it emerges from the Earth’s shadow, and point D, sunrise, the ISS is visible;
  • between points D and A, the ISS cannot be easily seen against the brightness of the daytime sky.

Because of its size, the ISS is the brightest artificial object in the sky and has a similar brightness when overhead to the planet Venus.

 

Research at the ISS

A good deal of research is carried out at the ISS. This is described in more detail at the following website  https://www.nasa.gov/mission_pages/station/research/overview.html.  Much of this research is based upon the fact that that the strength of gravity is very close to zero in the ISS. This is known as microgravity and the only place it is possible to create a microgravity environment for longer than a few minutes is in space. Some examples of this research are given below.

  • Fluids can be almost completely combined in microgravity, so physicists can investigate fluids that do not mix well on Earth.
  • In microgravity environment combustion occurs differently. Flames have a spherical shape. In the diagram below, the candle on the left is in normal gravity, whereas the candle on the right is in microgravity.

Image from NASA

  • Research has been carried out as to how plants develop in microgravity. Interestingly, results have shown that plants use light rather than gravity to determine which direction is ‘up’.

But perhaps the most interesting area of research are the effects on the human body of spending long periods on time in weightlessness. This area is important, because in the next few decades when astronauts travel to Mars they will have to spend at least six months in zero gravity when travelling to the red planet and a further six months on the return journey.

  • Without any weight to work against, muscles gradually will get smaller and lose their strength. This includes the heart muscle.
  • Fluid shifts around the body causing fluid pressure in the brain to increase.
  • One of the most serious problems is that, without gravity, a strong skeleton is not needed to support the body. Studies have shown that astronauts lose 1-2 % of their bone mass for each month of weightlessness; the calcium from their bones is excreted in their urine. So much calcium may be lost that it can cause kidney stones

Research on the ISS has shown that to retain their muscle mass, and ensure their heart stays in good condition, astronauts need to spend many hours a day exercising.  Because there is no weight for their muscles to work against, astronauts often spend a large fraction of the day running on a treadmill, using elastic harnesses to provide resistance.

However, nothing has been discovered which can prevent the loss of bone density. The rate of bone loss continues at 1-2% per month and does not level off after long durations in space. After more than two years in low gravity, astronauts’ bones would be so weak they would easily fracture and would be unable to support their weight then they returned to Earth. This may be a limiting factor for how long humans can spend in zero gravity environments, especially since it takes a significant time for the bone density to return to normal.

A further limiting factor is that on long duration spaceflights astronaut would be exposed to high doses of radiation. This can cause genetic damage making the astronauts more prone to cancer in later life.

Taller Astronauts

Spending time in a microgravity environment causes the spine to elongate. On Earth, gravity keeps the vertebrae in place by constantly pushing them together. But without gravity, the vertebrae will naturally expand slightly, causing a person to become taller.

 

Typically, astronauts in space can grow up to three percent of their original height. For example, in 2016 when Scott Kelly came to Earth after spending nearly a year in space he was 2 inches (5 cm) taller. However, this gain in height is only temporary. When under the effects of gravity again astronauts return to their original height.

Scott Kelly – Image from NASA

Getting to and from the ISS

Since the end of the Shuttle programme the only way astronauts can get to and from the ISS is by the Russian Soyuz spacecraft, a point worth remembering now that relations between the US and Russia are rather strained.  Soyuz was first flown in 1967 and its design has changed little since then. Like the Apollo spacecraft which took astronauts to the Moon, it is a single use spacecraft. The astronauts return to Earth in a small capsule which has a heat shield to protect it during the most dangerous part of the mission, re-entry into the Earth’s atmosphere. Currently NASA pay $70 million for each astronaut who flies in the Soyuz spacecraft (Wall 2013), which enables the Russian space agency to make a significant profit.

In the next few years US spacecraft should return to space.  Rather than build a new craft to fly crew to and from the ISS, NASA administer a US-government funded programme called Commercial Crew Development (CCDev). After a lengthy evaluation process NASA announced in September 2014 that Boeing and SpaceX had received contracts to provide crewed launch services to the ISS.

When the final decision was made, NASA hoped that the winning companies would be able to launch manned missions to the ISS by 2017. However, perhaps unsurprisingly, there have been numerous delays in the development of both spacecraft and the launch dates have slipped.

According to the current launch schedule (https://www.nasa.gov/launchschedule/ ), the target dates for unmanned test flight of both spacecraft are actually this month, August 2018, although precise date haven’t been specified. If there are no further delays and these test flights do take place this month and are successful, then in November 2018 the Boeing CT 100 spacecraft will be the first American spacecraft to carry astronauts into orbit since the retirement of the Space Shuttle. This will be followed by the SpaceX Dragon v2 the following month.

 

Next post

I hope you’ve enjoyed this post. In my next post I’ll talk about the costs of the space station, international cooperation in space and how I see the future of the ISS.

 

 

NASA (2018) International Space Station facts and figures, Available at: https://www.nasa.gov/feature/facts-and-figures (Accessed: 30 July 2018).

 

Wall, M (2013) NASA to pay $70 Million a seat to fly astronauts on Russian spacecraft,Available at: http://www.space.com/20897-nasa-russia-astronaut-launches-2017.html(Accessed: 30 July 2018)

 

 

Soyuz 50 years on

On 23 April 1967, six years after Yuri Gagarin had became the first man to go into space, a Soviet Soyuz spacecraft was launched carrying cosmonaut Vladimir Komorov. It completed 18 orbits and then returned to Earth.

Mission patch for the first Soyuz mission

Sadly, during its reentry the parachute failed to open properly and the spacecraft was destroyed when it hit the Earth at high speed and burst into flames – killing Komorov and giving him the unfortunate distinction of being the first person to die in space flight.

Despite this initial setback, the Soyuz spacecraft was successfully flown back into space the following year, when cosmonaut Georgy Beregovoy, a decorated World War 2 hero, completed 81 orbits and landed safely.

A Soviet 10 kopek stamp showing  Georgy Beregovoy. The Soyuz rocket is in the background – image from Wikimedia commons

Since Beregovoy’s mission, Soyuz has been launched into space a further 131 times, and has proved to be a great success, outliving the much more expensive and more technologically advanced Space Shuttle. It has established itself to be a reliable and safe way of getting into Earth orbit.  In fact, since the retirement of the Space Shuttle in 2011, it has been the only way of getting astronauts to and from the International Space Station. This is a fact worth bearing in mind given the somewhat tense relationship between Russia and the West.

The spacecraft

The Soyuz spacecraft was designed in the Soviet Union in the early 1960s. The chief designer was a man called Sergei Korolev (1907-1966), who was the driving force behind many of the early successes in the Soviet space programme.

Korolev in 1956 – image from Wikimedia Commons

Korolev had a chequered career. In 1938 he fell foul of the authorities and was arrested by the Soviet secret police, tried and sentenced to death. The sentence was reduced to imprisonment and he spent number of months in a Soviet gulag – a hard labour camp – in a remote part of Siberia. Conditions were extremely harsh and many prisoners died from cold, disease and sheer exhaustion.  Towards the end of the Second World War he was rehabilitated by the Soviet government and later rose up the ranks in the 1950s to head the space programme. He died in Jan 1966 at the age of 59, his final years plagued by ill health caused by his time in the gulag. The 1950s and 1960s were during the Cold War and the Soviet space programme was kept under intense secrecy and, unlike his American counterparts,  Korolev was unknown outside a small elite. His achievements were only made public after his death.

 

The Soyuz spacecraft, shown above, consists of three modules:

  • The first part of the spacecraft is the service module (labelled A). This contains the main engines, fuel, oxygen, computers, communications equipment and the solar panels used to generate electricity
  • The reentry capsule (labelled B) is shaped like a hemisphere and is the only part of the spacecraft which returns to Earth. The cosmonauts enter the capsule just before reentry. It is very cramped and is only designed for the crew to stay in for a short period of time. It does not, for instance, have a toilet.
  • The spherical-shaped orbital module (labelled C) is where the crew live during a mission, although all Soyuz missions at the moment are to and from the International Space Station.

At launch the spacecraft sits on top of a 45 metre (150 feet) tall Soyuz rocket. The solar panels are folded away, and are unfolded when the spacecraft is in orbit.

Image from Wikimedia commons

As mentioned above, conditions in the reentry capsule are very cramped. It carries a crew of three squeezed into only 2.5 cubic metres of usable space. This is the volume of a cube measuring 1.36 by 1.36 by 1.36 metres. These cramped conditions meant that, in the early Soyuz spaceflights, the cosmonauts couldn’t wear bulky spacesuits and the associated life support equipment. This unfortunately lead to the deaths of the cosmonauts in the Soyuz 11 mission in 1971 who suffocated when a faulty valve caused all the air to escape from their capsule. Had they been wearing spacesuits they would have survived. After this accident Soyuz was redesigned to carry two cosmonauts, both wearing spacesuits, although this was later increased to three. The redesigned spacecraft was known as the Soyuz Ferry because its mission was to transport cosmonauts to and from the Salyut space station.

Over the last 50 years Soyuz has gone through several further updates and the latest version, known as Soyuz MS, was first launched in July 2016. The upgrades are mainly to computers, electronics and navigational systems and the internal layout of the spacecraft. The fundamental design hasn’t changed since Kamorov’s first flight back in 1967.

A cheap and reliable way of getting into space.

Since the accident in 1971 there have been no fatalities aboard a Soyuz and the spacecraft has proven itself to be a relatively cheap and reliable way of getting people to and from the International Space Station (ISS). In 2011 the cost of a flying a Space Shuttle mission to the ISS worked out at about $500 million in today’s money (NASA 2011). In contrast, the cost of using the older Soviet-era Soyuz technology worked out more than eight times cheaper at the equivalent of $60 million per mission (Wade 2016).

The table below shows the number of missions flown by the Apollo, Soyuz, Space Shuttle and Shenzou spacecraft. Only manned missions are included. So, although the Shenzou spacecraft has gone into orbit 11 times only 6 of these missions had humans aboard.

The table below lists the launch dates of the next four Soyuz missions:

Data from http://spaceflight101.com/iss/iss-calendar/

When Soyuz MS-07 is launched in the coming October, it will have flown more manned missions than the Space Shuttle.

The Future

NASA pays Russia $70 million per seat for each astronaut who flies in Soyuz (Wall 2013). This figure, which is roughly the same as the per seat cost of the Space Shuttle ($500 million for a crew of seven) enables the Russian space agency to make a significant profit.

However, NASA won’t be entirely reliant on buying seats on Soyuz for much longer. Rather than itself building a new craft to fly crew to and from the ISS, NASA administers a US-government funded programme called Commercial Crew Development (CCDev). After a lengthy evaluation process NASA announced on 16 September 2014 that Boeing and SpaceX had received contracts to provide crewed launch services to the ISS.

At the moment there is no confirmed date when these companies will send their spacecraft to the ISS. The SpaceX website states that the first crewed flight by their Dragon V2 spacecraft will be in the second quarter of 2018, although this date seems somewhat ambitious given that the spacecraft has not yet flown and that an unmanned test flight is only due to be carried out in November 2017.

DragonV2

 The Dragon V2 spacecraft – image from NASA 

In the longer term Soyuz is due to be replaced in 2023 by a new spacecraft called Federation.  The design of Federation is still at the early stages but it will be capable of both low Earth orbit missions such as ferrying astronauts to and from the ISS and also missions deeper into space, such as orbiting the Moon (Nowakowski 2016).

Artist’s concept of the Federation spacecraft. image from  Roscosmos

 

Notes

1 The total of 133 spaceflights includes all Soyuz missions which were launched with humans on board, whether or not the spacecraft went into orbit. The number of spaceflights by each version of the spacecraft are as follows:

  • First generation Soyuz  launched 10 times between Apr 1967 and Jun 1971.
  • Soyuz Ferry launched 30 times between Sep 1973 and May 1981. This number includes one launch where the spacecraft failed to get into orbit.
  • Soyuz T launched 14 times between Jun 1980 and Mar 1986.  This figure excludes an attempted launch where the rocket exploded just before it should have taken off and from which the cosmonauts safely escaped.
  • Soyuz TM launched 33 times between Feb 1987 and April 2002.
  • Soyuz TMA launched 22 times between Oct 2002 and Nov 2011.
  • Soyuz TMA-M launched 20 times between Oct 2010 and Mar 2016.
  • The latest incarnation of the spacecraft, Soyuz MS, was first launched in July 2016 and has been launched 4 times so far.

2 After the last spaceflight to the Moon, there were 4 further Apollo spaceflights:

  • 3 to the Skylab space station in 1973 and 1974.
  • 1 joint mission with the Soviet Union known as Apollo-Soyuz in 1975.

3 The total of 135 Space Shuttle missions includes the ill fated Challenger mission in 1986 when the spacecraft broke apart 73 seconds after take off.

References

NASA (2011) How much does it cost to launch a Space Shuttle?, Available at:http://www.nasa.gov/centers/kennedy/about/information/shuttle_faq.html#1 (Accessed: 9 Apr 2017).

Nowakowski, T (2016) Russia runs first tests of its next-generation “Federation” manned spacecraft, Available at: http://www.spaceflightinsider.com/organizations/roscosmos/russia-runs-first-tests-of-its-next-generation-federation-manned-spacecraft/ (Accessed: 26 April 2017).

Wade, M. (2016) Cost, Price, and the Whole Darn Thing, Available at:http://www.astronautix.com/c/costpriceanholedarnthing.html (Accessed: 10 Apr 2017).

Wall, M (2013) NASA to pay $70 Million a seat to fly astronauts on Russian spacecraft,Available at: http://www.space.com/20897-nasa-russia-astronaut-launches-2017.html(Accessed: 25 April 2016).

July 8 2011- The Final Mission

On 8 July 2011 Atlantis took off for the final 13 day mission of the Space Shuttle programme and it remains to this day the last American spacecraft to carry humans into orbit.

Space shuttle Atlantis (STS-135) touches down at NASA's Kennedy Space Center Shuttle Landing Facility (SLF), completing its 13-day mission to the International Space Station (ISS) and the final flight of the Space Shuttle Program, early Thursday morning, July 21, 2011, in Cape Canaveral, Fla. Overall, Atlantis spent 307 days in space and traveled nearly 126 million miles during its 33 flights. Atlantis, the fourth orbiter built, launched on its first mission on Oct. 3, 1985. Photo Credit: (NASA/Bill Ingalls)

The landing of Atlantis on 21 July 2011, which brought the Space Shuttle programme to a close – Image from NASA.

Development of the Space Shuttle

Prior to the Space Shuttle, all astronauts were launched into space in a small capsule which was stacked on top of a tower of one or more large rockets. It took months to build each launcher and space capsule, which could only be used for a single mission. This way of getting into space was very expensive and access to space had been restricted to a very small number of people. In today’s money each launch would cost hundreds of millions of dollars.

In the early 1970s, as the Apollo programme to put a man on the Moon was drawing to a close, the next stage of manned space exploration was logically seen as widening it out so that many more people would be able to go into space at a much lower cost. At the time many people thought that, with continual improvements in technology, travelling into space would become commonplace by the 2020s –  just like flying in a plane.

The Space Shuttle was announced by president Richard Nixon in 1972 as the first step in this process, saying it would be “…designed to to help transform the space frontier of the 1970s into familiar territory easily accessible to human endeavor in the 1980s and 1990s … It will revolutionize the transportation into space by routinizing it.” (Gehrman et al 2003:22)

Richard Nixon

Image from Wikimedia Commons

It was planned that there would  initially be a fleet of four Space Shuttles. Each would be launched like a traditional rocket into Earth orbit and after it had completed its mission would land like a conventional airplane on a runway. After it had landed, the shuttle would be refueled and serviced and could be launched again within 10 days. In 1972, when Nixon announced the approval of the Shuttle programme, NASA expected that they would be launching 50 shuttle missions a year by the time the shuttle was fully operational.  They estimated that it would cost $5.15 billion (equivalent to $30 billion in 2016 dollars) to design, develop and build the Shuttle fleet and each launch would cost $7.7 million ($45  million in 2016 dollars). At that time it was expected that the Shuttle would have a lifetime of 10-15 years and in the early 1990s the shuttle would be replaced by a new generation of more advanced spacecraft.

However, the development of the Space Shuttle was more complex and took much longer than expected.  By 1979 the programme was already three years late, with the date of the first planned launch having slipped from 1978 to 1981, and it was the equivalent of $5 billion (in 2016 dollars) over budget.  President Jimmy Carter wanted to ensure that the programme was still worth continuing with and subjected it to an intensive review. The decision was taken to continue – a key factor being that it was needed to launch military surveillance satellites.

Space Shuttle missions

The Space Shuttle was first launched into Earth orbit in April 1981 and was the first, and so far the only, manned spacecraft which could take off like a rocket from a launch pad, go into orbit and then glide back to Earth to land like a plane on a runway. A total of 5 shuttles were built and between them they flew a total of 135 times between 1981 and 2011.  Sadly it never achieved anywhere near the frequency of flights originally planned. Over its 30 year lifetime there were, on average, only 4.5 Shuttle flights per year.

STS_1_launch

The first launch of the space shuttle on April 12 1981- Image from NASA

The much lower number of flights per year was for a number of reasons. One was that the minimum time interval between a Shuttle landing and it being ready for its next launch was much longer than the ten days originally planned. The three main engines needed to be removed from the Shuttle and carefully inspected before each flight for signs of any damage. Each Shuttle was covered by 30,000 protective insulating tiles to protect the spacecraft from damage due to the high temperatures when it re-entered the Earth’s atmosphere. Each of these tiles needed to be individually checked for damage and replaced if necessary. This was a time consuming task. Each tile was was designed to fit a particular place on the Shuttle and so was a slightly different shape from the others.

But the biggest reason for the lower frequency of flights were perhaps the two fatal accidents in 1986 and 2003, both of which stopped all Shuttle flights for a period of time.

In the first of these, on 28 January 1986, the Space Shuttle Challenger broke apart 73 seconds after take off, killing all the crew.

Challenger Breakup

Space Shuttle Challenger – 15 seconds before its destruction – Image from NASA

Space Shuttle flights were suspended for nearly three years, while a commission under the chairmanship of former Secretary of State Williams Rogers investigated the cause of the accident and NASA put into place its recommendations.

After the accident one of the observations was that because NASA wanted to have as many Shuttle flights as possible, they had cut corners when it came to checking that a Shuttle was safe to launch. When Shuttle flights resumed in late 1988 there were fewer launches per year with a larger gap between them, to allow for additional safety checks. Before the accident, the Shuttle was intended to be the main vehicle to get NASA’s spacecraft into orbit, but after the accident NASA moved away from relying mainly on the Shuttle and went back to traditional non-reusable launchers as an alternative, which turned out to be a cheaper way of getting satellites into orbit. Prior to the accident, the Shuttle generated revenue, because private companies could pay NASA to launch their satellites on the Shuttle – indeed many of the early Shuttle flights carried such satellites. However, in August 1986, President Reagan made an announcement that the Shuttle would no longer carry any commercial satellites in order to focus on scientific and military objectives only. Although this might sound like good news for science, the problem was that the Shuttle was no longer generating any money, which in turn weakened the economic case for ongoing investment in it.

The second accident occurred on 1 February 2003 when the Space Shuttle Columbia broke apart during its re-entry into the Earth’s atmosphere.  The Columbia Accident Investigation Board (CAIB) was set up to investigate the cause of the accident and found it to be the result of damage to a wing of the Shuttle caused by foam debris hitting it at very high speed shortly after launch.  The CAIB found that there had been many similar “foam strikes” which had caused damage to the Shuttle over the years. However, because there had never been a serious accident NASA had become complacent and ignored the warnings which had previously been given by scientists from within the organisation.

The STS-107 crew includes, from the left, Mission Specialist David Brown, Commander Rick Husband, Mission Specialists Laurel Clark, Kalpana Chawla and Michael Anderson, Pilot William McCool and Payload Specialist Ilan Ramon. (NASA photo)

The Space Shuttle Columbia crew tragically killed in February 2003 – Image from NASA

After the second accident, Space Shuttle flights were suspended for two and half years. When they did resume, only 20 more shuttle flights took place and all but one of these missions used the Shuttle to carry components to the International Space Station (ISS) which was being constructed in space and which NASA were committed to finishing. Flying to the ISS had the advantage that if the Shuttle were damaged on take off and couldn’t safely return to Earth then the crew could stay on the ISS until they could return to Earth on another spacecraft.

A remarkable machine

The Space Shuttle was one of the most complex machines ever built. Each Shuttle was assembled from over 2.5 million parts and had 370 km of wire in its electrical circuits. Weighing 4.5 millions pounds (2,000 tonnes) at launch, it could take a crew of seven astronauts up to an orbital velocity of 28,500 km/h, which is 25 times the speed of sound, in just over 8 minutes. The Shuttle could carry into orbit a payload the size of a small bus and weighing up to 26 tonnes (Gehrman et al 2003:14).

Although it never achieved its original objective of frequent flights into space, over its 30 year lifetime the shuttle launched numerous satellites, interplanetary probes (including the Galileo mission to Jupiter and its moons), and the Hubble Space Telescope.

HST

The Hubble Space Telescope – launched by the Shuttle in 1990 – Image from NASA

Shuttle astronauts also conducted numerous science experiments in orbit, such as studying the affects of zero gravity on plant and animal life. It would not have been possible to construct the ISS without the shuttle, as it played a key role in ferrying components, supplies and crew there.

Costs of the programme.

One of the key failures of the programme is that both the development of the Shuttle and each Shuttle mission cost far more than the original estimates. According to NASA (2012), the total cost of the Space Shuttle from 1972 until the end of the programme in 2011 was $113.7 billion. However, this figure is misleading because it is not adjusted for inflation. If we do this, the cost (in 2016 dollars) is around $220 billion. This compares with a cost of $175 billion in today’s money of the Apollo programme to put a man on the Moon (NASA 2014).

It we divide $220 billion by the number of missions (135), The average cost of each Shuttle missiion works out at $1.6 billion.  This is a very high figure and it would perhaps be fairer to ignore the upfront design and build costs and use the figure of how much it cost to launch a single Shuttle mission.  In NASA (2011) the figure given is around $500 million in today’s money. This compares with a figure of only $60 million to launch a Russian Soyuz spacecraft (Wade 2016)

The final mission

The final mission had a crew of four and the purpose of the mission was to deliver supplies and equipment to the ISS. The astronauts spent seven days aboard the ISS, joining the six astronauts who were already there.

STS-135 meal

The four members of the shuttle crew having a meal with the six astronauts already aboard the space station – Image from NASA

Inside the ISS the Space Shuttle crew presented the ISS crew with a US flag, which was then mounted on the hatch leading to Atlantis.  This particular flag is special because it was flown on the first Shuttle mission. It will remain on board the ISS until the next crew launched from the US retrieve it and bring it back to Earth.  It is still unclear when this will be.

STS135

Image from NASA

The future

Since the end of the Shuttle programme the only way astronauts can get to and from the ISS is by the Russian Soyuz spacecraft, a point worth remembering now that relations between the US and Russia are rather cool.  Soyuz was first flown in 1967 and its design has changed little since then. Like Apollo, it is a single use spacecraft. The astronauts return to Earth in a small capsule which has a heat shield to protect it during the most dangerous part of the mission re-entry. Currently NASA pay $70 million per seat for each astronaut who flies in the Soyuz spacecraft (Wall 2013), which enables the Russian space agency to make a significant profit.

In the next few years US  spacecraft should return to space.  Rather than build a new craft to fly crew to and from the ISS, NASA administer a US-government funded programme called Commercial Crew Development (CCDev). After a lengthy evaluation process NASA announced on 16 September 2014 that Boeing and SpaceX had received contracts to provide crewed launch services to the ISS. At the moment there is no confirmed date when these companies will send their spacecraft to the ISS. Although both companies have ambitious pans to send crewed spacecraft in 2017, significant development and testing is still needed, so I expect it won’t be until 2018 at the earliest when the US crew will retrieve the flag.

In the medium term NASA are developing a spacecraft which will be able to take a crew to beyond low Earth orbit. However, this is not expected to carry crew until 2023. I will write about this spacecraft, which is called Orion, in a future post.

 

Further reading

I hope you have enjoyed this post. While researching it I found the information in the Columbia Accident Investigation Board report a useful source. It gives a lot more background to the Space Shuttle programme than I could mention here. If you want to view the report I have created a references page on my blog where the it can be viewed or downloaded. To do this click here.

References

Gehrman, H.W., Barry,J. L., Deal, D. W., Hallock, J. N., Hess, K. W., Hubbard, G.S, Logsdon, J. M., Osberon, Ride, S. K., Tetrault, R. E., Turcotte, S. A., Wallace, S.B, Widnall, S. E. (2003) Columbia Accident Investigation Board -Report Volume I, Available at: www.thesciencegeek.org(Accessed: 15 July 2016).

NASA (2011) How much does it cost to launch a Space Shuttle?, Available at:http://www.nasa.gov/centers/kennedy/about/information/shuttle_faq.html#1 (Accessed: 9 July 2016).

NASA (2012) Space Shuttle era facts, Available at:https://www.nasa.gov/pdf/566250main_SHUTTLE%20ERA%20FACTS_040412.pdf(Accessed: 9 July 2016).

NASA (2014) Project Apollo: A Retrospective Analysis, Available at:http://history.nasa.gov/Apollomon/Apollo.html (Accessed: 15 July 2016).

Wade, M. (2016) Cost, Price, and the Whole Darn Thing, Available at:http://www.astronautix.com/c/costpriceanholedarnthing.html (Accessed: 10 July 2016).

Wall, M (2013) NASA to pay $70 Million a seat to fly astronauts on Russian spacecraft,Available at: http://www.space.com/20897-nasa-russia-astronaut-launches-2017.html(Accessed: 10 July 2016).

Space Tourism

This post is about  space tourism, which means ordinary people travelling into space for leisure purposes and paying to do so.  This is a subject which has always been of great interest to me and although the market is very small at the moment I think it will grow over the coming decades. With the proposed launch of Virgin Galactic’s SpaceShip Two later this year, it is a topic which is likely to be in the headlines.

The stuff of science fiction

Even since as a child I read the the novels of British author Arthur C Clarke (1917-2008)  I have been fascinated by the idea of space tourism.

As I mentioned in my post on 27 June, “Living on the Moon”, I am particularly fond of  “A Fall of Moondust” . It was written in 1961, but set in the 2050s. In the novel the Moon has been already been colonised, and it is visited by tourists from Earth. One of its attractions is a cruise, in a specially designed boat, across one of the maria, or lunar seas, which is filled with an extremely fine and very dry dust which flows like water.

Arthur C Clarke

Arthur C Clarke author of “A  Fall of Moondust”

Sadly, I think that the chances of frequent tourist visits to the Moon by the 2050s are zero. However,  I think that in the future there will be a large growth in space tourism and in the next few decades more ordinary people will be venturing into space.

What do we mean by ‘going into space’ ?

One question we need to think about what talking about space tourism is: what do we actually mean by ‘going into space’? Where does the Earth’s atmosphere end and space begin? This is a question to which there are no hard and fast answers. As we get higher up, the atmosphere gets gradually thinner and thinner and very gradually merges into interplanetary space, but there is no clear line where the Earth’s atmosphere ends and space begins. Most people would agree that:

  • a jet airliner flying at 35,000 feet in altitude (10.6 km) is not in space, even though a human would be dead at that altitude without supplemental oxygen, and
  • the International Space Station (ISS) which orbits around 400 km above the Earth’s surface is in space.

The diagram below shows a number of key altitudes above the surface of the Earth.

 

altitudes

 

Various Key Altitudes

  • The summit of Mount Everest -8.8 km. At this point the air pressure is only one third of that at sea level and even a fit young person acclimatised to altitude could not survive for more than 30 minutes without extra oxygen.
  • A jet airliner -10.6 km. This is the height at which a jet airliner flies on a long journey. The air pressure at this height is around 27% of that at sea level and a human would be dead within minutes from lack of oxygen.
  • Concorde -18.3 km. This is maximum altitude at which the supersonic aeroplane Concorde could travel. Indeed Concorde, which is sadly is no longer in service, could travel at twice the speed of sound and was advertised as travelling ‘on the edge of space’. At this altitude the air pressure is around 6% that of sea level and the air is so thin the the sky is dark blue in daytime. At this pressure the boiling point of water is around body temperature so that any exposed liquids in the eyes, mouth throat and the lining of the lungs will literally boil away. To prevent this happening, a human would need to be enclosed in a pressurised space suit  to survive.
  • The manned balloon flight record -39 km. This the altitude record set by the Austrian skydiver Felix Baumgartner in August 2012.  When the balloon reached this altitude, he jumped out wearing a space suit. On his descent he reached a speed faster than the speed of sound in free fall before his parachutes opened to slow him down – hence his nickname name Fearless Felix.
  • Aurora 100 km to 200 km. Aurora are caused by high speed electrically charged particles from the Sun hitting the Earth’s upper atmosphere, at altitudes of 100 km upwards, causing it to glow.  Incidentally, Mrs Geek and I are hoping for a sight of the Aurora Borealis, more commonly known as the Northern Lights, when we visit Finland in September, as they are rarely visible in England.  The chance of this is actually pretty low, as we will be in Helsinki and they are seen more often further north, but we live in hope.
  • Low Earth orbit -160 km to 2000 km. 160 km is the lowest altitude at which a satellite can remain in orbit. At this altitude, a satellite would be slowed by air resistance, caused by traces of the Earth’s atmosphere, which means it would lose energy and spiral down to Earth within a day. As we get higher than this the atmosphere continues to get thinner and thinner and satellites are slowed less and less by air resistance, enabling them to stay in orbit longer. The International Space Station, which orbits at an altitude of 400 km, loses altitude at the rate of around 2 km per month and rocket motors attached to the station or on visiting spacecraft need to be used a few times a year to lift it higher up, thus maintaining its orbit and preventing it from crashing down to Earth.
  • Medium Earth orbit -above 2000 km. Above 2000 km the traces of the Earth’s atmosphere are negligible and a satellite will remain in orbit indefinitely.

So where exactly does space begin?

The Fédération Aéronautique Internationale (FAI), the international body setting standards and keeping records in the field of aeronautics and astronautics defines space as starting 100 km above the surface of the Earth.  As you can see, this is a very conveniently rounded number, which strongly suggests that it is somewhat arbitrary.  At this altitude the air pressure is around 0.00003% of that at sea level, which is too low for a conventional aeroplane to fly.  Although this pressure is very low, it is still high enough to cause so much air resistance that a satellite could not orbit. The thin air would cause it to burn up like a meteorite.

Space Tourists

So, space travel means travel to beyond 100 km above the earth.  So far, the only space tourists are the few who have been carried into space in the Russian Soyuz spacecraft. The first of these was the American investment manager Dennis Tito who in 2001 traveled on a Soyuz to the ISS and returned 7 days later.

dennis tito

Dennis Tito (left) with his fellow crewmates in his Soyuz capsule- Image in public domain

He paid $20 million for his trip and had to undergo months of tough cosmonaut training in Russia. He was followed by six other space tourists. The last of them, Guy Laliberté, the Canadian founder of Cirque du Soleil,  paid $40 million for a 11 day stay in space in 2009.

At the moment, because of the high cost and physical demands of getting into orbit, space tourism is only open to those who are super-rich and able to undergo the necessary training and preparation.  Not only is true demand therefore very small, but supply is also very limited indeed. The Russian space agency is – so far – the only organisation with the capacity and willingness to put space tourists into orbit.

NASA never allowed paying space tourists on the space shuttle and, following the retirement of the space shuttle in 2011, America has no capability of putting a human into space. Rather than NASA developing their own spacecraft to do so, the contract to ferry astronauts to and from the ISS will be put out to private corporations. The Dragon 2 spacecraft developed by the SpaceX company is the leading contender to win the contact.

Although initially its primary purpose will be to ferry astronauts to and from the space station, removing the reliance on Russia, it is likely that SpaceX will eventually sell seats on a Dragon 2 orbital flight to space tourists.  SpaceX plan to charge NASA  $140,000,000, or $20,000,000 per seat if the maximum crew of 7 is aboard.

Virgin Galactic

For a number of years the Virgin Galactic group have been developing the suborbital space plane called SpaceShip Two. This is planned to offers space tourists a much cheaper “taster” of space tourism. Launched from an aeroplane, it is a small plane with a rocket motor rather than a jet engine, which will take eight people up to just beyond the 100 km line thus – just about – qualifying as travel into space. During the flight the passengers will experience weightlessness for around 5 minutes and will be above the 100 km boundary for a couple of minutes.  Virgin Galactic eventually plan to have a fleet of five SpaceShip Twos, each seating six passengers, which will fly multiple times a day. Although a definite date for the first flight has not yet been released, it is likely to be later this year or early next year. There is a waiting list of over 500 people for SpaceShip Two flights, each of whom has already paid a $20,000 deposit.  At $250,000 for a seat it is hardly cheap, and is well beyond the budget of most ordinary people -including Mr and Mrs Geek. This works out at around $ 7.5 million for for each hour spent in in space!  Nevertheless, as competitors emerge and Virgin Galactic build more spacecraft the price may come down – but I doubt it will be within the reach of ordinary people.

space ship two

Virgin Galactic Space Ship Two in testing -Image provided by Jeff Foust

 

Next Post

In my next post I will say more about SpaceShip Two and discuss what being a space tourist would really be like.