SpaceX takes another step

SpaceX plans to send its Dragon spacecraft to dock with the space station, perhaps as soon as Monday 7th May. If successful this will be a major step forward for the comapny.

I've been following the development of SpaceX's launcher and spacecraft hardware with great interest. On Monday 7th May, unless there's a further schedule change, the privately owned company will make its first attempt to fly a Dragon spacecraft to dock at the International Space Station (ISS).

The launcher - Falcon 9 has flown only twice so far, both launches were successful. On its first flight the rocket carried a dummy Dragon to orbit. On the second flight a fully functioning Dragon was orbited and made a successful splashdown and recovery off the Californian coast.

Two successes out of two attempts is a great performance, but tells us almost nothing about levels of reliability. A third success would boost confidence, a failure would be a serious setback.

TECHNOLOGY - Reusable rockets

SpaceX is an innovative space launch company with a number of impressive 'firsts' to their name and a large order book of reservations for satellite launches on their Falcon 1 and Falcon 9 vehicles.

The company was founded by Elon Musk using capital earned by his earlier IT businesses, particularly PayPal which was sold in 2002 for $1.5 billion. Musk's share was more than 10% enabling him to start SpaceX as well as the electric car company, Tesla.

In September 2008 Falcon 1 achieved earth orbit, the first time a privately owned company had orbited a liquid fuelled rocket. All previous successes were by the government programs of a variety of nations.

In June 2010 Falcon 9, a much larger vehicle, also flew successfully to orbit. And in December 2010 Falcon 9 flew again, this time carrying a Dragon capsule which completed two orbits, successfully re-entered, splashed down and was recovered. This was another first for a private company.

Messenger in orbit

The Mercury Messenger probe is intended to make a long burn to decelerate into Mercury orbit tomorrow (Thursday 17th March). If successful this should be the start of a year of detailed observations of the innermost planet.

It's taken the spaceprobe six and a half years to get to the right place at the right time and at the right velocity to make a major 15 minute engine burn for capture into Mercurian orbit.

This is, frankly, an astonishing achievement. Hopefully all will go well and the prime mission will return very large amounts of new and detailed knowledge about the innermost planet.

Read more on these web pages...

• NASA's MESSENGER website
• MESSENGER - the spacecraft (Wikipedia)
• Mercury - the planet (Wikipedia)
• APL information on the orbit insertion burn

TECHNOLOGY - SpaceX, another first

It was a privilege to be able to watch SpaceX's live webcast of the launch of their first Dragon capsule. This is a unique achievement, it's the first time a private company has put a spacecraft into orbit and safely returned it to earth.

The icing on the cake is that they also manoevered Dragon while in orbit, testing some of the moves that will be required to dock with the International Space Station (ISS). But why is all this such a great thing?

Let me explain. The human race undoubtedly has a built-in urge to explore and try out new things. We might have different views on the reason for this, and some might argue that space exploration is far too expensive to justify. But for whatever reason people have a built-in desire to explore beyond the boundaries, to go further than before, to see and understand new things.

TECHNOLOGY - Dragon readies for launch

Most people are aware that the American Space Shuttle fleet is being retired. The last flight is currently scheduled for next year, 2011. After that, the only way Americans will be able to travel to orbit and dock at the International Space Station (ISS) will be to buy seats from the Russians.

The Constellation Program that was intended to replace the Shuttle has been cut and modified several times and is unlikely to provide a crewed launch facility soon or, perhaps, ever. China has a crewed vehicle, and Europe and Japan both have operational cargo craft from which crewed vehicles might be developed. India is planning and building a crewed launch system.

What the USA does have however is something quite unique. It has several businesses designing and building crewed spacecraft as commercial ventures.

One of these is SpaceX, based in California. They launched the first of their Falcon 9 rockets carrying a dummy Dragon capsule in June 2010. In November they plan to launch another Falcon 9 with a fully functioning Dragon cargo capsule to test the re-entry and landing systems. If all goes well, next year they will be in a position to begin carrying and returning cargo for the ISS - and they already have a full order book from NASA and other clients around the world.

Dragon was designed from the ground up to be capable of carrying seven astronauts in place of cargo. SpaceX is hoping that once Dragon is proven as a reliable cargo system NASA will decide to fund its upgrade and testing as a crewed vehicle.

I wish SpaceX well and hope the mission in November will be a complete success.

(For full details and more photos visit the SpaceX Updates page.)

See also: Up, up, and away

Awesome video, great music, astonishing machine

Here's a fine video beautifully put together with excellent music and sound effects. Mike Interbartalo edited imagery of the Space Shuttle launch process from beginning to end. It really is an experience to watch and listen, even if you're not much interested in space or rockets.

It's strange to think that next year the Space Shuttle will fly for the very last time and there is nothing in place to take over. The USA will no longer be able to launch crewed vehicles into orbit.


STS-129 Ascent Video Highlights from mike interbartolo on Vimeo.

For anyone wanting a bit more detail, you will see the Shuttle stack on the giant tracked platform arriving at the launch pad. There are some details of the engine ignition sequence, the three main engines first, then the solid rocket boosters. You will see the solid boosters fall away and splash down under their parachutes ready to be collected by boat and returned for re-use. You will see the giant external tank released to return to a fiery destruction in the atmosphere. And then finally the shuttle itself heads on into Earth orbit.

There are shots from many angles here. Some from the ground or from the air, some from cameras mounted on the solid boosters, the external tank, and the shuttle itself.

Fomalhaut b

What, you may ask, is 'Fomalhaut b'? If you are interested in astronomy you will already know. Fomalhaut b is a planet circling one of our Sun's nearest neighbour stars.

Fomalhaut b has been imaged twice by the Hubble Space Telescope, once in 2004 and again in 2006. This is important because it's the first time a planet outside our own Solar System has been seen to have moved in its orbit around its central star.

This is extraordinary news indeed. It's the same scale of forward step as Galileo seeing craters on the Moon for the first time, or discovering the rings of Saturn, Halley predicting the return of his eponymous comet, or the Apollo 11 Moon landing in 1969.

Why is it so important? It's a milestone because astronomers have long assumed that other stars have planets. In recent years the presence of such planets has been indirectly detected, but this is the first time we can claim to have seen the light reflected by an exoplanet. You may not have realised it, but you have just lived through a truly historic moment.

The difficulty of making these images is difficult to grasp. Look at the picture again (you can click the image to see the full-size version).

The star - In the middle of the full image (but near the upper left in the article's thumbnail picture) is a small white circle. This is not part of the image, it was added later, but it marks the position of the star (Fomalhaut). In reality the star would be far smaller, just the tiniest speck, it's shown much larger to make it easy to see.

The obscuring disk - if the Hubble telescope had just been pointed at the star, the overpowering brightness would have flooded the image with light so that nothing but glare would be visible.

To see details really close to the star, it's essential to block the direct starlight. This was done by moving an obscuring disk in front of the star, and this is seen in the image as the irregular black area around the central white dot.

The halo of diffracted light - Outside the black zone, some starlight is still diffracted into the surrounding area. This is the circular zone that looks like the iris of an eye, close inspection of the large version of the image reveals that it's made up of lines of light radiating out from the position of the star. This not a real, distant object, it's created by subtle interactions between the starlight and the structure of the telecope.

The debris disk - The oval shape (clearly visible only in the full-size version) is a band of dust, gas, and orbiting rock and ice particles. It's part of a disk of material which is in the process of condensing into planets. Fomalhaut is a young star and is still developing a planetary system.

The planet - Just inside the inner edge of the dusty band is where astronomers thought there might be a planet, and sure enough when they looked they found one! This is a gas giant, probably much like Jupiter though something like twice as large, and it is so bright that many astronomers suspect it must have a ring similar to Saturn's (but larger).

The real clincher is that the planet appears in two Hubble photos of Fomalhaut, taken two years apart. It has moved, as expected, in its orbit around the star.

For more information see

• Wikipedia article - on Fomalhaut b
• BBC news article - about the discovery
• Astronomy Picture of the Day - the Keck Telescope's observations
• Gemini Observatory - details on exoplanet observations in infra-red light

Up, up and away!

Yesterday was a very special day. Elon Musk's company, SPACEX, launched a small rocket and carried a dummy payload into Earth orbit. So why is that special? Here's why - it's a major change from government funded space programmes to private spaceflight. SPACEX is a privately owned company, and they achieved this all by themselves.

I was so excited that I mailed a congratulatory message to the company, here's what I wrote...

To everyone at SPACEX and Elon in particular. Well done everybody, this is a great day for spaceflight and space exploration. In fact it's a major turning point that will go down in history. On Sunday 28th September 2008 private individuals running a private business have a space programme!

From this day forward, spaceflight is no longer the domain of governments and big business alone. Cheaper orbital access is coming with the Falcon family and in a few years with Dragon - first for cargo, then for astronauts. This is fundamentally different from major aerospace companies launching communications and weather satellites. Why? Because they are in it to use expensive technology developed by or for government programmes. The days of cutting edge at high price are coming to an end, to be replaced by routine at budget prices.

SPACEX - you have changed the world... er, I mean space!

Congratulations!

The company - Elon Musk had already run several highly successful startup ventures including PayPal. He has spent some of the proceeds on innovative technology startups like Tesla Motors and Space Exploration Technologies (SpaceX).

SpaceX has designed and built Falcon 1 from scratch, it is intended to be cheap to operate, mainly reusable (the first stage is designed for recovery, the second stage is expendable), and simple. Simplicity is really the key, a simple design is likely to be both cheaper and more reliable than a complex design.

The successful flight - After three launch failures, the fourth attempt resulted in a smooth ride to orbit. Falcon 1 has shown it can do the job and the next flight in early 2009 is expected to loft a Malaysian satellite.

This will begin a revenue stream for SpaceX and put the company on track for eventual growth. Meanwhile, 2009 should also see the first flight of Falcon 9, a much larger and more powerful launcher.

Meanwhile, although the first success placed only a dummy payload into orbit, it did so accurately and without incident. The icing on the cake was that the second stage engine was successfully restarted while in orbit, something SpaceX hoped to achieve, but not necessarily on such an early flight.

The future - Falcon 1, Falcon 9, and perhaps Falcon 9 Heavy will meet the same requirements as other launchers already in the market place, but they'll do it at perhaps a third of the price. This suggests that SpaceX may be a name to watch, they might be able to clean up, taking over a large part of the space launch business.

Not only that, the company is building a cargo delivery craft, Dragon, which will launch on Falcon 9 and is also expected to fly in 2009. And a passenger version is already under development and may fly in 2010, carrying up to seven astronauts to the International Space Station (ISS).

As if even that is not enough, the launch manifest for 2011 has a Falcon 9 booked for Bigelow Aerospace who plan to orbit their third inflatable habitat, Sundancer. It will be the first privately developed and launched craft capable of use as a manned space outpost. Bigelow already have two development systems in orbit, Genesis I and Genesis II, both are still in operation and returning images and other data at the time of writing.

In other words, SpaceX and Bigelow taken together represent the beginnings of private, manned, orbital spaceflight. Now that really is exciting!

See also: Dragon readies for launch

Who moved our spacecraft?

Some spacecraft have trajectories that are slightly unexpected. Something has speeded them up or slowed them down - but what? Current methods of analysing and predicting spacecraft behaviour involve many factors, but the figures just don't add up. Something strange and unexpected is going on.

The major factors that affect spacecraft motion are gravity and rocket propulsion. Spacecraft and indeed all bodies in the solar system, from dust grains right up to the the largest planet Jupiter, move through a complex gravity field. Each body is tugged upon by every other, and the strength of pull depends on the masses involved. The mathematics is very complex and for more than two bodies involves iteration.

The second major factor comes into play whenever a manoevering engine is fired, this clearly changes the trajectory (which is the purpose of the engine of course).

The velocity of a spacecraft can be measured very accurately by examining its radio signals. Changes in velocity cause a change in frequency. But the calculated trajectories don't always match up with the measured ones.

There are many other subtle factors that affect a spacecraft. Pressure from solar radiation, loss of gas from the spacecraft's systems, impact by small particles, relativity effects, loss of speed due to passing through the outermost fringes of a planetary atmosphere, magnetic and electrostatic fields, and more.

But effects such as these are quite well known and can be allowed for. Yet the figures still don't quite add up. And nobody knows why.

The effect was first noticed decades ago as the Pioneer probes passed into the outer Solar System. They were travelling ever so slightly slower than they should have been. At the time this didn't cause much surprise, it was put down to some minor effect that nobody could identify and, like all these effects, it was far too small to affect the mission. Several possibilities were discussed at the time, none of them were accepted enthusiastically.

But it's happened again, and again, and again with other spacecraft.

At last a pattern is beginning to emerge. All the affected spacecraft have made close planetary passes to help shape their trajectory (gravity assists), while other spacecraft have not been affected. John D Anderson, Curator of Aerodynamics at the National Air and Space Museum in the USA, has been looking very carefully at the evidence. Anderson and others working with him have now come up with a mathematical formula which may enable them to predict the size and direction of the effect, it seems to work for all the effects seen in past spaceflights and they're waiting with bated breath to see if it accurately predicts the effect for Rosetta as it made its second fly-by of Earth last November (they haven't seen the data yet). There's another opportunity in November 2009. (John Anderson's scientific paper is "Anomolous orbital-energy changes observed during spaceflight fly-bys of Earth", John Anderson et al., Physical Review Letters, Vol 100, p 091102. There's also a report in New Scientist, 20th September 2008, pp 38-41).

All of this is quite fascinating, both to spacecraft engineers and to physicists; it really does seem as if something may be slightly wrong with our theory of gravity or there's some other effect at work that we are not yet aware of. Either way, prepare for a major new discovery in physics. But either way, don't hold your breath. Finding the underlying mechanism could take quite some time (years or decades, perhaps even longer).

Earth and Moon movie

NASA has done something amazing. One of their spacecraft has made a movie of the Moon passing in front of the Earth as it orbits our planet.

This was not a simple achievement! To see things from a suitable distance you need to have a camera position many times further away than the Moon.

A hundred and twenty times as far as the Moon would be fine, and this is what NASA has done.

Just think, the Moon circles the Earth once every 28 days, drawing out a circle half a million miles across. From our perspective the Moon glides past the starry constellations of the night sky.

But if we could travel far enough away we'd see the Moon sometimes one side of the Earth, sometimes the other, but never straying very far.

First, sit back and watch the movie. Then come back and read more of this blog post to find out how it was done.

In the year 1610 Galileo saw four points of light changing position night by night when he turned his telecope on the bright planet Jupiter. He realised that these points of light were circling Jupiter. It was final proof that not all celestial bodies orbit the Earth and therefore our planet cannot be the centre of the universe as was supposed by the mediaeval church.

This is exactly how the Moon would be seen to behave from a camera 31 million miles away, and this is what the video shows.

Here's how this amazing video was made. The Deep Impact spacecraft successfully investigated a comet in July 2005, but with its primary mission completed NASA decided it could usefully perform two further tasks. The Deep Impact team realised that they could also use the spacecraft to take images of the Earth and Moon, and they commanded the craft to take a series of images through four different colour filters at 15 minute intervals. Afterwards, the images were combined to make full colour versions and a series of the colour images were put together to make the video.

Learn more about Deep Impact (now renamed EPOXI) and the Earth/Moon video from NASA's website.