"The road to the stars is steep and dangerous, but we're not afraid; space flights can't be stopped."  Yuri Gagarin

The loss of SpaceShipTwo

On Friday, 31 October 2014, Virgin Galactic's SpaceShipTwo crashed during a test flight in California.

Sadly, the co-pilot died and the pilot sustained serious injuries.

The craft was making its first powered flight since January, as part of an ongoing test program to verify the design for flights to space.

SpaceShipTwo is an uprated design from SpaceShipOne, which won the X-Prize challenge in October 2004 by becoming the first privately-funded craft capable of carrying three people to make two flights into space within two weeks.

SpaceShipOne was carried aloft by an aircraft known as White Knight One, before being released and firing its rocket engine. White Knight Two fulfilled a similar function for SpaceShipTwo, and was also constructed with twin fuselages, allowing the spacecraft to be carried between them.

This arrangement effectively allows for a two-stage vehicle which is launched horizontally from a runway, rather than vertically.  This approach requires much less power.

Once released from the carrier aircraft, the rocket engine fires to accelerate the craft upwards.  When the fuel burns out, the craft continues to coast up until it cross the 100 km/62 mile altitude that is regarded as the boundary of space.

The craft's upward velocity continues to fall back to zero, at which point it begins to descend until it is low enough for the atmosphere to have an effect on its control surfaces,  allowing it to glide to a runway landing.

SpaceShipOne in flight
SpaceShipOne in flight

SpaceShipTwo flight profile

SpaceShipOne flight profile.
(Click on the image for a lrger version)

These flights reach a maximum velocity of about 5,500 mph and do not reach orbit, which requires an altitude of at least 200 km/125 miles and a velocity of 17,500 mph.

Once the engine stops firing, the craft and its occupants are in "free fall", somewhat like a roller-coaster as it goes over the top of a climb, and they experience weightlessness.  Although this is often referred to as "zero gravity" this is incorrect, as gravity is still operating; in fact it is the Earth's gravity that pulls the craft back down.  It is also the Earth's gravity that keeps satellites that are in orbit - including the International Space Station - from flying away from the Earth.

This test flight was not intended to reach space; it was planned as another test of the rocket engine.

Virgin Galactic issued reports on Twitter during the flight, and stated that the craft had been released and the engine had ignited.  They then reported that the craft had suffered "a serious anomaly".

SpaceShipTwo was flown by pilot Peter Siebold and co-pilot Michael Alsbury.  Both were employed by Scaled Composites, the company that designed and built the craft.

Siebold received his pilt's licence when he was just 16, and joined Scaled Composites in 1996.

Alsbury had 15 years of flying experience, and first flew SS2 in 2010.  He flew its first rocket-powered flight that took place in April 2013.

It appears that both men were able to eject, but Alsbury was found dead in his seat.  On November 3, Scaled Composites reported that Siebold was alert and talking with his family and doctors.

Co-pilot Peter Siebold and pilot Michael Alsbury
Peter Siebold and Michael Alsbury. Credit: AP

SpaceShipTwo wreckage

Wreckage of SpaceShipTwo, showing part of one of the craft's "feathers"

Initially it was reported that an eye-witness had said the rocket engine fired for just a couple of seconds before cutting out, then the engine re-started and apparently exploded.  However this version of events has since been shown to be incorrect.

Based on that initial report, it was thought that the focus for the investigation into the accident would be the rocket engine.  However on 3 November it was announced that the investigation is actually concerned with the "feathering" system that is designed to slow the craft down on re-entry.  This makes the two wingtips and fins - the 'feathers' - rotate towards the vertical, as shown in the image at the top of the page.  This increases atmospheric drag on the craft and slows it down.

The feathering system was meant to be deployed during the craft's return after completion of the rocket burn, at a speed of Mach 1.4 (1,065 mph / 1,715 kph).  Air safety chief Christopher Hart from the US National Transportation Safety Board gave a briefing in which he explained that the system is controlled by two levers; one unlocks the system and the other deploys it.  Indications are that the system was unlocked, but it deployed without being commanded to do so.  Mr Hart reported;

"About 9 seconds after the engine ignited, the telemetry data showed us that the feather parameters changed from 'Lock' to 'Unlock'.  In order for feathering - this action to be commanded by the pilots - two actions must occur; one is the 'Lock/Unlock' handle must be moved from 'Lock' to 'Unlock' and number 2 is the feathering handle must be moved to the 'Feather' position.  Approximately 2 seconds after the feathering parameters indicated that the 'Lock/Unlock' lever was moved from 'Lock' to 'Unlock' the feathers moved toward the extended position - the deployed position - even though the feather handle had not itself been moved.  This occured just above a speed of Mach 1.0.  Shortly after the feathering occured, the telemetry data terminated and the video data terminated.

"The engine burn was normal up until the extension of the feathers.  There are several cameras in the space vehicle.  There is a camera in the cockpit mounted on the ceiling that looks forward and shows the actions of the pilots, and the instruments, and review of that camera is consistent with the telemetry data and shows that the feather 'Lock/Unlock' lever was moved by the co-pilot from the 'Lock' position to the  'Unlock' position.

'Normal launch procedures are that after the release, the ignition of the rocket and  acceleration, that the feathering devices are not to be moved, the 'Lock/Unlock' lever is not to be moved into the 'Unlock' position until the acceleration up to Mach 1.4"

The question was then how the feathering system could have deployed without being commanded to by the crew.  Mr Hart did add that it was too soon to confirm the reason for the accident.
A video of Mr Hart's briefing was posted on the BBC News website at http://www.bbc.co.uk/news/world-us-canada-29876154

Contrary to initial reports of an explosion, the rocket engine and fuel tanks have been recovered from the desert intact.

How long the investigation might take is impossible to say at the moment; it will involve continuing to gather physical evidence from the crash, reviewing telemetry and video, and conducting interviews in order to help confirm exactly what was wrong.  The next step will be designing a solution to ensure that this cannot be repeated.

The result is that although this will cause a delay in the programme, it is very unlikely that it will prove to be an unsurmountable problem.

I was interviewed by Sky News on November 1 and by Bob FM on November 3.  In both interviews I pointed out that safety is the prime concern, and that this has been proved by the fact that original announcements about commercial operations suggested they might commence in 2007.  It is now 7 years later, clearly showing that Virgin Galactic and Scaled Composites are determined not to rush their development programme, and that safety is clearly more important than commercial profit.

Whenever Man has sought to expand his horizons there have been risks.

Almost exactly 500 years ago, in 1519, Ferdinand Magellan's expedition set out to sail around the world. They started out with 5 ships and 240 men, most of whom did not survive the voyage.  Magellan himself was killed in the Phillipines, and it was his deputy, Juan d'Elcano who took over command of the voyage.  3 years after setting out, just 1 ship and 18 men returned home.

When the American settlers ventured westward from the original colonies on the eastern coast, they faced many dangers and large numbers of them died, but that did not stop the expansion across the US.

Between 1912 and 1913 there was a series of crashes of Wright aeroplanes, with 11 people being killed.  Even now, over 100 years after the first airplanes flew, crashes still occur, and many people are killed.  Yet air travel has not been stopped, and statistically it is one of the safest ways to travel.

In 1967, cosomanut Vladimir Komarov was killed as his spacecraft returned to Earth at the end of the first Soyuz spaceflight.  Speaking about the tragedy, Yuri Gagarin said;

"The road to the stars is steep and dangerous, but we're not afraid; space flights can't be stopped."

A few months earlier, the crew of Apollo 1 died during a ground-based test on the launch-pad when a fire broke out inside their spacecraft.  Mission Commander "Gus" Grissom had previously expressed his views about the risks.

"If we die, we want people to accept it.  We are in a risky business and if anything happens to us we hope it will not delay the program.  The conquest of space is worth the risk of human life."

Speaking about the challenge of sending men to the Moon, President John F Kennedy said;

"We choose to go to the Moon and do these things, not because they are easy, but becuase they are hard!"

Mankind's desire to gain new knowledge and expand our horizons will always involve some risks, but the result of giving up such ventures is not simply to fail to advance, but to stagnate.  There are  those who would say that we should not explore, but I would ask;

"Where do you draw the line? Should we not travel across the oceans?  Should Magellan, Columbus, da Gama and Cook all have stayed in their own countries? Should we stay in our own cities, towns or villages?  Ultimately, instead of being involved in the exploration of space, should we just look at it, sitting around our cave-side fires?"

If we want to progress then we must strive to move forward.  The Greek philosopher Aristotle said:

"Man is a goal-seeking animal.  His life only has meaning if he is reaching out and striving for his goals."

A pro-space slogan from the 1970s put it slightly differently;

"The meek shall inherit the Earth.  The rest of us shall go to the stars!"

Ironically, this accident means that two spacecraft called "Enterprise" have not actually reached space.

SpaceShipTwo was intended to be the first of five craft ordered by Virgin Galactic to be built by Scaled Composites, and there would also be two WhiteKnightTwo carriers. The SS2 craft was named "VSS (Virgin Space Ship) Enterprise" and the carrier was named "VMS (Virgin Mother Ship) Eve", after Richard Branson's mother.

The other spacecraft called "Enterprise" was the very first Space Shuttle orbiter. However Orbiter Vehicle 101 was never actually intended to fly into space; iInstead it was used for a series of Approach and Landing Tests, to verify that after returning from space, a space shuttle could make a landing without any engines.

Like SpaceShipTwo, it was also carried aloft by an aircraft.  In this case it was on top of a modified 747.  It was then released to glide to a runway at Edwards Air Force Base in California.

When it was learned that the craft was due to be named "Constitution", a campaign was started by "Star Trek" fans to have it named "Enterprise" instead.


Shuttle Enterprise gliding from 747

Space shuttle "Enterprise" after release from the Shuttle Carrier Aircraft

It flew without engine power - the three main engines (dummy versions on OV-101) were only used for launch.

If the fans had waited, the name "Enterprise" might have been used for a craft that would actually fly into space.

This photo shows the rollout of "Enterprise" on 17 September, 1976.  In front are NASA Administrator James Fletcher, DeForest Kelly (Dr McCoy), George Takei (Sulu), James Doohan (Scotty), Nichelle Nichols (Uhura), Leonard Nimoy (Spock), Star Trek creator Gene Roddenberry, [unknown NASA official], and Walter Koenig (Chekov).  Partially hidden, with white hair and sunglasses, is Jesco von Putkammer, a NASA "futurist" who was a consultant on "Star Trek - The Motion Picture". Credit: NASA

Rollout of Space Shuttle Enterprise with Star Trek cast members

The one major character of the Star Trek cast who was not present was William Shatner (Captain Kirk).  In another twist, he later signed up to fly with Virgin Galactic, and would probably have flown on VSS Enterprise.

If you are excited by the idea of space exploration then why not book one of my presentations.  I have a range of titles, including "Colonies in Space", "Is Pluto A Planet?", "Would You Believe - We Put a Man on the Moon" and my very popular "The Day They Launched A Woodpecker".

You don't need to know anything about the subject in advance as the presentations are all aimed at a non-specialist audience.  They are extremely visual and easy to follow. They are also entertaining as well as informative.

If you are interested in arranging a presentation on space exploration,
or booking an exciting and inspiring day of space activities at a school

contact me at jstone@spaceflight-uk.com

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