History is full of decisions that if I had gone a different way could have
given us quite a different outcome today and space history certainly has its fair
share of those. As part of NASA's quest for a replacement Space Shuttle it
embarked on a project that looked as if it could bring a groundbreaking
combination of technologies that would make the original Space Shuttle look
like a 1970s trim phone compared to an iPhone X. But in a decision that was as
dogmatic as it was controversial the project was cancelled when 95% of the
components had been fabricated, tested, delivered and even a new launch facility
had been built. The project was the x-33 and was revolutionary on many fronts, it
was designed to be fully reusable like a plane, it would be much cleaner than the
shuttle as it would only use hydrogen and oxygen for both for the main engines as
well as the thrusters and wouldn't use any solid rocket boosters. It could be
remotely controlled and take off vertically and land on a normal runway
much like the space shuttle but unlike the shuttle it was designed to be easy
to maintain and dramatically cut the amount of time, resources and people
required to launch and then turn it around for the next flight and thus cut
the cost of getting each kilogram of payload into space from $20,000 to
$2,000. The roots of this design would come from a previous x-plane project
called the national space plane or the X-30 which itself can be traced back to
the X-20 dinosaur in the early 1960s. When Ronald Reagan was elected in 1980
his administration was looking at the Soviet nuclear threat and what they
could do to counter it. In 1983 Reagan announced the Star Wars initiative but
what soon became clear was in order to build a space shield hundreds of new
satellites would need to be placed into orbit. The problem was fast becoming
clear to the US Air Force was of the maintenance schedule of the Shuttle
would not be able to keep up with the amount of hardware that will be needed
to be placed in orbit so they were looking at additional ways to deploy
their hardware. From 1982 to 1985 a secret DARPA project called 'Copper Canyon'
was set up to look into the viability of a single-stage-to-orbit
reusable space plane that would use an air-breathing engine, be able to take off
fly to space, deliver its payload and then land back on a normal runway much
more like an airplane than a rocket based to shuttle. In 1990 this eventually
became the x30 project however this was cancelled just three years later in 1993
before a single prototype was ever built because the technology required to make
it work was found to be many more years away than expected. NASA however
continued its research into a replacement for the shuttle and in 1994
it requested proposals from the aerospace industry to come up with
designs for a single-stage-to-orbit vehicle. There would also be a change as
to how NASA would operate the new system. Instead of owning and operating the new
spacecraft like a shuttle, NASA would purchase flights from the company that
developed the winning system, this meant that the commercial companies they
would be renting the craft rather than just selling it to NASA. Three companies
replied McDonnell Douglas, Rockwell aerospace and Lockheed Martin. Of the three
designs for Rockwell one was pretty conservative and was basically an
updated remake of the Space Shuttle. The McDonnell Douglas design the DC-X looked
like has come from the set of Buck Rogers with a vertical takeoff, a lifting
body design and vertical landing with four legs that dropped from the corner
of the vehicles base. It was a strange-looking beast but it worked and
it had been flight tested it would also go on to serve as the inspiration for
the Blue Origin New Shepard and several of the key engineers that worked on the
DC X would go on to work for Blue Origin. The most ambitious design was that from
Lockheed Martin, this pushed the envelope not only in its design but also its chosen
propulsion and also construction. Lockheed Martin won the contract which
was worth about $1 billion to produce a 53% scale flight demonstrator
something but commentators of the time said was an incredibly low price to
bring together an all-new vehicle, however if it was successful it would
then be made into a full-scale commercial version called the 'VentureStar'
The Lockheed design would use aerospike engines first developed by
Rocketdyne in the 1970s but as yet still not flight tested. It would not use any
boosters or external fuel tanks like the shuttle so it would have to be very
light with the empty weight being no more than 10% of the fully laden weight.
This would mean on landing it would be able to use a runway as short as 8000ft
much shorter than required for the shuttle and increasing the
possible number of landing sites. It would also have a lifting body, that
means that the body of the spacecraft can generate his own lift without the
need for wings like the Space Shuttle. Because of the greater surface area of
the body it would re-enter the atmosphere more gently and generate less
heat allowing for the use of an all-new thermal protection system made up of
metallic tiles. These were developed by BF Goodrich and made from Inconel, a
heat-resistant nickel-chromium based of superalloy which was first developed
for the SR-71 blackbird. These will be screwed to the body structure using
mounting brackets, this change alone would save an estimated 17,000 men hours
of checking and replacing the ceramic tiles on each flight of a space shuttle.
But the most controversial element of the design was that of the main fuel
tanks which would also be the structure of the body, it was almost like a giant
flying fuel tank and this would be its Achilles heel. The fuel tanks one for
the liquid oxygen in the front and the two liquid hydrogen ones on either side
at the rear would be made from a carbon composite
material which was meant to be lighter and stronger than the aluminium tanks and
this is where things started to unravel. The choice of composite instead of metal
was meant to be cheaper to make but engineers and designers knew that it was
going to be a big problem. They were trying to make a new fuel tank to hold
pressurized liquid hydrogen with hollow honeycomb walls. There was in fact so
much resistance from the engineers that they forced the management to allow them
to build Aluminium Lithium tanks in the same way as they did for the space
shuttle. When it came to the testing of the first composite tank, it failed the
pressure test as the material De bonded. air was getting into the honeycomb walls
and was liquefying, forcing the composite to break apart. Engineers had anticipated
this and had a solution to fill the honeycomb with closed cell foam but this
would add an additional 500kg of weight to the rear of a craft. Then
another problem showed up the aerospike engines needed to have larger than
expected exhaust ramps to allow them to cool correctly. These ramps were made
from a heat-resistant heavy copper alloy called Narloy-Z, so now the engines would
also be adding extra weight to the rear of a craft. This extra weight at the rear
would make the lifting body unstable without a major redesign something that
would cost a lot in both time and money. The problems with the composite fuel
tanks were in danger of stopping the whole project so the engineer's asked to
fit a standby aluminium fuel tanks. These had passed the pressure testing and
ironically turned out to be slightly lighter than the composite ones so
things were looking OK as this would also help offset the engine weight issue.
NASA had chosen for Lockheed designed because it was A) a very low bid and B) it
was to introduce a range of new and untested technologies in one project.
This was a high risk approach but if it worked it would be a game-changer for
launch vehicles. However there was one more problem that
would prove to be the killer blow to the entire project. In 2001 the NASA director
at the time Ivan Bekey was to appear in front of a
Subcommittee on space and Aeronautics at the US House of Representatives for a
funding round. In a speech that stunned the workers on the project, he said that
the X-33 project must use the composite fuel tanks as this was key to testing
the interaction of all the new technologies in real-world flight tests.
To use the aluminium tanks instead of the composite ones which would be the
structure of a craft and where the new thermal protection system will be
mounted to would make the whole point of real-world testing invalid he said. With
this the X-33 was effectively doomed without extra funding for the
development of the composite fuel tanks something both NASA and Lockheed Martin
disagreed about who should pay.Now some might say why not take a more pragmatic
approach and build with aluminium tanks to test it and then change over to the
composite when the technology had advanced enough, the reply to this was
that because the VentureStar was to be privately funded, if it were to go ahead
with the aluminium tanks it would be confirming that the technology was
simply too difficult to do and maybe the whole project was overreaching itself on
the technology front and that would make funding almost impossible to find. With
this impasse on the side of the management the project was canceled in
2001 and all the new technologies and hopes of a brave new future for reusable
vehicles went with it. In 2004 Northrop Grumman who have been
working with NASA announced that they had solved the problem of the composite
fuel tanks after they had used a new manufacturing technique and they had
successfully been tested over 40 times over a nine-month period and they made
them 25% lighter than the aluminium ones. There were several attempts by the US
Air Force take on the project and make the VentureStar
their own, they had plans to have it fully usable by 2012 but each
time they tried it was denied at the highest levels of government leading
some to say that it was a political decision and that Dick Cheney was not
going to let a project set up by Al Gore back on the books. No part of the X-33
technology would be used for the new upcoming SLS system which was to use
traditional disposable rockets in much the same way as Apollo had done 50 years
earlier. NASA has acknowledged that it made fundamental mistakes and was simply
trying to do too much with too little funding on a high-risk project, which
with a little greater forthought and funding could have given us a
revolutionary new space shuttle and probably changed the way we access space.
If you're interested in finding out more about the aerospike engines, we have
a video about those and I'd also like to thank our patrons for their ongoing
support and please check out some of our other videos. So for now I'd like to say
thanks watching and please subscribe, rate and share.