Back in December 2009, with great fanfare, space tourism company Virgin Galactic unveiled the vehicles their fare-paying passengers will ride in as they ascend into space. Built by the Spaceship Company (a coventure of Virgin and that supremely adventurous aircraft manufacturer Scaled Composites), the pair are engineering marvels. The huge yet elegant White Knight Two jet aircraft has a 43 m (141 ft) wingspan. Its payload is the SpaceShipTwo spaceplane, a considerably larger offspring of the SpaceShipOne which won the Ansari X-Prize in 2004. Since then progress has been much slower than Virgin Galactic anticipated (the enterprise was announced in 2004; flights to space were to begin in 2007).
NASAòÀÙs X-15s were superb research aircraft. On 9 November 1962, an engine failure forced pilot Jack McKay to make an emergency landing in the second X-15. The aircraftòÀÙs landing gear collapsed flipping the X-15 on its back. McKayòÀÙs injuries eventually forced his retirement from NASA. The X-15 was repaired to fly again. (Image credit: NASA)
If all goes well, in the near future (next year at the very earliest) a White Knight Two will carry a SpaceShipTwo spaceplane to an altitude of 15 km (9.3 miles) and release it. The SpaceShipTwo will fire its rocket and blaze upwards, reaching a peak altitude of between 50 miles to 110 km (68 miles) before gliding home. The six passengers will have the time of their lives, enjoying a few minutes of micro-gravity and stunning views of the Earth. The age of routine spaceflight will finally have arrived. Hopefully.
(UPDATE: in 2014 Virgin Galactic quietly admitted the SpaceShip Two craft will probably only be able to carry passengers to 50 mile altitudes, missing the internationally accepted boundary of space. However in the 1960s, the US armed services awarded Astronaut Badges to pilots who flew about 50 miles and based on this Virgin Galactic intends to define space as starting 50 miles up.)
Just to clear up a common misconception, SpaceShipTwo will not fly into orbit, nor can it dock with the ISS or any future orbital hotel. Limited to a maximum speed of 4000 km/h (2500 mph), it simply cannot reach the velocity of 28 000 km/h (17 400 mph) needed for a Low Earth Orbit (as one wit has pointed out Virgin Galactic passengers will not reach LEO, never mind LIBRA, VIRGO or any other constellation). An orbital vehicle could be designed to fit under White Knight Two, but to meet the weight considerations it would be of necessity a tiny, one-person pod, not unlike an early space capsule. Rather than holidays in space, Virgin Galactic is selling the ultimate in exciting but brief stunt flights in a rocket plane.
My main reason for being sceptical about the claims of Virgin Galactic (and its rather insubstantial competitors) is the possible safety of rocket planes (or lack thereof). Burt Rutan, founder of Scaled Composites, has said that Virgin’s vehicle “is designed to be at least as safe as the early airliners in the 1920s”. To anyone aware of the history of aviation, this statement is not particularly reassuring.
A dying Komet: a sequence of photographs shows the demise of a Luftwaffe Me163 in a rare non-fatal accident . (Image via http://robdebie.home.xs4all.nl/me163/kelb.htm)
There once was a vogue for rocket-powered aircraft. Their speed, rate of climb and ability to attain great altitudes was superior to even jet aircraft. The major aircraft-building nations between 1940 and 1975 spent a lot of money researching rocket planes, including flying a series of experimental prototypes. Nazi Germany even put one into mass production. More than 400 bat-like Me 163 Komets were built to defend the Third Reich from Allied bombers (although only a few dozen were used operationally). Yet SpaceShipTwo is the first production rocket plane in decades. Why? Part of the answer is that developments in jet engine technology side-lined the rocket as an aviation powerplant. However there was another important reason: rocket planes crashed very often. A liquid-fuelled rocket engine is a very complex piece of engineering with many components capable of potential (and often catastrophic) failure. This was tragically demonstrated in July 2009 when three engineers were killed when a prototype of SpaceShipTwoòÀÙs rocket motor exploded as it was being fuelled. A rocket plane is full of very explosive propellants and flies at high speeds where any structural failure will bring disaster so quickly no pilot could react. The Me 163 referred to above is said to have killed more German pilots in accidents than Allied aircrew in combat.
In 1956 Mel Apt became the first man to fly at Mach 3 in a Bell X-2 rocket plane, sadly the flight ended in a fatal crash. (Image credit: USAF)
Here are some numbers. They cover only rocket planes belonging to the UK and USA as those of other nations are not well-documented. In a thirty year period starting in 1947, just 16 rocket planes of seven basic types (Bell X-1 and X-2, Douglas Skyrocket, NAA X-15, Northrop HL-10, SARO SR53 and Martin X-24) made 846 flights (compared to thousands of jet aircraft making hundreds of thousands of flights in the same period). Ten of these aircraft were lost in crashes, five of them fatal. Two of these crashes can be attributed to pilot error and can be ignored. The rest were the result of technical problems with the rocket plane itself. These figures indicate an accident rate of about 1 in 105! This risk may be acceptable for volunteer test pilots, but are fare paying passengers prepared to face it? The Space Shuttle in comparison suffered two fatal crashes in 135 flights. (NB after publishing this, I looked at these figures and discovered that I had not actually counted the flights of the Skyrocket and SR53 in the total, I have now fixed that error, making the accident rate much better. Mea culpa! Further note, I have not counted aircraft fitted with RATO gear to assist their take-off either as they are not at all comparable to aircraft which rely on liquid-fuelled rocket motors for propulsion.)
The beautiful HL-10 rocket plane and its pilots survived to a peaceful retirement (Image credit: NASA)
Perhaps this does not mean there are grounds for concern. Travel by conventional aircraft was once very dangerous, but nowadays by several yardsticks it is among the safest modes of transport. If a similar improvement to rocket-propelled aircraft has occurred – and I have no doubts that this is achievable – the safety of space tourists will be assured. However it is unclear if such improvement has happened. Sad to say, but the safety of modern Boeings and Airbuses is based in part on the lessons learned through thousands of air accidents. Some of the historical rocket plane accidents could have been avoided thanks to lessons learned, but they were very specific to the designs of the vehicles involved. We do not have enough experience of rocket-powered craft operating at the edge of space. SpaceShipOne was (controversially) retired after only three flights above 100km. Passenger aircraft must make thousands of test flights before they are certified. I am not sure that the Spaceship Company can afford to do this with SpaceShipTwo.
NASA’s X-24 also had a long and successful career with no fatal accidents (Image credit: NASA)
I am sorry to say this but sooner or later a space tourism craft will be lost and almost certainly passengers will be killed. What happens next? Our society is very safety conscious and the vehicleòÀÙs owner will find themselves in court (remember only the very wealthy will be able to afford space tourism tickets òÀÓ their relatives may be able to afford the sharpest lawyers). Rather as fear of being sued for malpractice has allegedly forced some doctors out of medicine, we may find space tourism companies shutting shop to avoid litigation.
I very much hope that I am wrong but I suspect space tourism in the Virgin Galactic mode is a false dawn. I fear the first crash of a space tourism vehicle will do as much harm to commercial spaceflight as the Hindenburg crash did for travel by airship.
(UPDATE: On 31 October 2014 I was distressed to hear that a Virgin Galactic SpaceShipTwo under test had been lost. One crew member perished while the second survived. The thoughts of all of us at Armagh Planetarium are with the families of both crew members and we hope the survivor makes a speedy and complete recovery from his injuries.)
(Article by Colin Johnston, Science Education Director)
This week a tourist helicopter in NYC crashed and killed a woman who was taking a ride for her birthday. Despite such a tragedy, it is extremely unlikely that tourist helicopter services are going to end in NYC or anywhere else.
In January the U.S. Parachute Association (USPA) put out a news release hailing the fact that only 21 parachutists died in 2010. Commercial parachuting has stayed in business and will continue to do so despite fatal accidents.
Every so often there is a video on the news of a hot air balloon going up in flames in some horrific accident in which people are killed. Yet hot air balloon businesses continue on.
In 2007 an explosion occurred during the setting up of equipment at a Scaled Composites engine test facility that killed three workers. I remember on the homepage of a Bakersfield newspaper website reporting on the incident that there was an article at the bottom of the page about a local person who had died in a commercial river rafting incident. No one is surprised that commercial river rafting survives such accidents.
For various historical reasons, there is a double standard in attitudes towards the risks in space travel versus other types of adventure activities. A good sociology thesis could be written on why that happened. Nevertheless, it is very likely that the space tourism industry will survive its first fatal accident. There is a regulatory regime in place that requires that “commercial spaceflight participants” be fully informed of the risks and that they sign off to that. States like Virginia and Florida have passed liability protection for space tourism services. A lawsuit will have to overcome such barriers as well as convince a jury that someone taking a spaceflight somehow did not know that spaceflight is at least as risky as riding a helicopter or hot air balloon.
There is unfortunately sure to be a first “bad day” in commercial spaceflight. However, I expect space travel services will continue on regardless.
Surely one must take into account the successes of the EZ-Rocket and the Rocket Racing League vehicles.
Is it right to denegrate anyone else who has happened to build and routinely fly rocket planes in the last decade? Or is it “insubstantial?”
This does not suppose risk exists. Losses will occur. The people who are paying for the risk are aware of that.
To be brutally honest I didn’t include the Rocket Racing aircraft because they seem more like toys than proper research or transport aircraft. Given that the extreme delay in starting the Rocket Racing League (announced in 2005, races to begin in 2006, still no racing events as of now), it seems building even a low-speed rocket-powered stunt ‘plane is rather tricky.
They are anything but toys. The Lynx engines derive directly from the X-Racer vehicle program. Similarly Armadillo’s tourist vehicle builds on their rocket racer program.
You seem unaware that (1) XCOR flew their X-Racer at Oshkosh in 2008 in front of a large crowd. They did it repeatedly and on time for each exhibition flight. (2) Armadillo’s rocket racers flew at the Tulsa Air Show in April 2010. Again, they flew repeatedly and reliably.
The RRL program was a great way to start to prove that liquid fueled rocket powered vehicles can be operated as reliably and safely as a jet powered vehicles.
(XCOR has test fired their Lynx engine hundreds of times with no sign of any wear. They expect they will last for many thousands of firings. There is no inherent reason rocket engines cannot be as reliable as jet engines.)
The RRL difficulties have nothing to do with the hardware. The problem is trying to build a brand new entertainment business in the middle of a terrific recession.
Hi Clark, thanks for your comment. You clearly know more about rocket racing than I do. I agree that as you say that “There is no inherent reason rocket engines cannot be as reliable as jet engines”, my own quibble is will take decades to get to that point. I believe that the development of sub-orbital vehicles is being rushed and truncated, and this could cause problems. I can’t really see how experience building slow altitude vehicles like the rocket racers will assist with the structure and aerodynamics of suborbital vehicles.
The lawyers will be a problem, but early commercial aviation was hardly risk free – now it’s safer than driving.
You’re right, but commercial aviation met a real need whereas launching people to this altitude doesn’t. (Note: human access to orbit is also a real need but this isn’t what we’re talking about here.)
Economics teaches us that demand is demand. Considering that, what makes something a “real” need?
“The meek shall inherit the Earth. The rest of us shall have left for the stars.” is a simple way of saying that the cowardly will remain on the ground.
Further, the examples of rocket planes you use are ancient tech. The X15 was designed over 60 years ago; the German plane was perhaps near 80 years ago. My friends at XCOR light and relight rocket engines time after time after time with narry a burp.
This is not to say there will not be tragedies. There will be. In this business we are all prepared to lose friends at some point. We are at the equivalent of commercial aviation in 1920 or earlier. If that scares you, then stay on the ground and watch the rest of us live our lives to the max.
Thanks for your comments, people should be free to risk their own lives as they wish, I never said otherwise. My points behind this article were that developing and operating vehicles with this kind of performance is very difficult – Richard Branson clearly didn’t realise just how hard it would be when he involved himself with Scaled Composites – and in today’s culture legal and public safety concerns can limit technological development (see the under-exploitation of nuclear power and GM crops).
I wish XCOR best of luck in developing rocket motors, their proposed upper stage sounds like it could be useful for real space travel.
It bears mention that the pressure-fed rocket engines being built for these private suborbital spacecraft are substantially simpler mechanically than a jet engine. One key innovation of companies like XCOR, Armadillo and Masten is the development of very simple and robust rocket engines.
It should also be noted that many of the early rocket plane failures were due to the fact that supersonic flight was highly experimental at the time. Vastly more is now known about how to design safe and controllable airframes.
Actually you may have confused companies. XCOR is doing suborbital spaceplanes and will be use the experience to move into more challenging operational environments; SpaceX is the one which has already begun to dominate the launch industry and who have recently announced they will attempt to develop fully recoverable 1st and second stages to go with their manned Dragon capsule. Even with just the Falcon 9 they are sucking up launch contracts right and left; with the Falcon Heavy not even the Chinese can compete. If they succeed in their reusability development, everyone else might as well close up shop and go to the beach.
btw, when I am not travelling (which I am most of the year) I reside in Belfast.
Hi Dale, yes I knew that, I was at that talk about a commercial moonbase you gave to the IAA some time ago.
Yes, and the Falcon Heavy, Dragon and the Bigelow Habs will make all of what I spoke of in that talk feasible.
One of my rocket scientist friends (who builds these things) said the following on my ‘Wall’:
Randall Clague
“Fact is, in more than 120 rocketplane flights in this century, there has yet to be an injury accident. Even the single mishap (Brian Binnie has a talk he calls Get A Little Dirt On A Plastic Spaceship…) didn’t damage the ship, which was flying again four months later.
The last rocketplane accident? 1980, Credible Sport, a C-130 flight test mishap, no injuries. Before that? 1971, LC-130 JATO accident, no injuries. Before that? 1971, NF-104A, hard start not even technically an accident because Thompson landed the plane after the explosion. All military aircraft.
Last non-military rocketplane accident? 1930. Maybe the problem isn’t the rocket.”
One can add to his list of military machines the Me163, which was often built with slave labour who had an interest in them blowing up, plus the fairly nasty C-Stoff and T-Stoff selection and the care and cleanliness required in its use, something that did not always happen in wartime, particularly at the time he went into use as a point defender as the war was coming to and end.
The X-15 did have a number of misadventures, but as opposed to the number of streets of Vandenberg named after Century Series test pilots, it only killed one pilot. The crash landing was not a rocket issue; nor was the fatal landing that ended the program. But, hey, this was an X program, absolutely meant to push the boundaries of aviation to the breaking point.
Er, fatal landing is not exactly the right word for that last event. You can get details on all of the flights here:
http://www.sierrafoot.org/x-15/adventures/adventures.html
I feel the author is more right than most people want to admit, to include the MBA’s at Virgin.
I have flown above Armstrong’s line in a full pressure space suit for a living and logged more time in one than most NASA astronauts. As an aerospace physiologist and pilot I can tell you that flights in this regime are brutal on the body and if there is a decompression at that altitude and the occupants are not wearing one, its death in a very violent way in less than 3 seconds. Add to that,, if they are wearingone, that most of the passengers have likely not ridden even a roller-coaster in the last 30 years, they can possibly vomit in their helmets and aspirate emisis (drown in their own vomit) or go into cardiac arrest and there would be no treatment options until they got back to earth. The hundreds of hours of training NASA personnel go though to desensitize them from these effects are not being adequately addressed. Add to the whole package that the executives in charge have more business experience than flight experience and I feel that the risks are far greater than anyone wants to admit.
Lastly, the passengers are going to be wealthy and important individuals and if there is an accident, it will be very public and very graphic. One accident and the government may decide to pull all civil space certificates and it will be over before it began because it was about th e bottom line, not safety.
Hi Colin,
An international group of propulsion professionals have obtained and commented on the Cal/OSHA investigation report on the scaled composites accident.
Please see: http://knightsarrow.com/rockets/scaled-composites-findings/
what are the things that space
tourists expect
I don’t know really, to see the Earth from high up, float around the cabin for a few minutes and boast about it for years afterwards I guess.