When Nasa’s Atlantis orbiter touched down at the Kennedy Space Centre slightly before sunrise local time on 21 July, it brought the curtain down on a mission that had run for 30 years and spanned more than 130 missions, at an estimated cost of $120bn.

"Nasa is currently developing the new Multipurpose Crew Vehicle, based on the design for the Constellation’s Orion capsule."

It is arguably the most complex machine ever created, as Chris Ferguson, commander of that final mission, said on landing: "The space shuttle changed the way we view the world and it changed the way we view the Universe." But the inevitable question is, what happens next?

From a US perspective at least, although the commitment to sending humans into space remains, with the cancellation of the Constellation program (CxP) which was intended to see a return to the Moon, the route to achieving it in the immediate future is not entirely clear.

Nasa is currently developing the new Multipurpose Crew Vehicle, based on the design for the Constellation’s Orion capsule, along with the Space Launch System – a cheaper, heavy-lift replacement for the project’s more expensive Ares launch vehicle – and beyond that, a mission to Mars still beckons.

In the meantime, however, the US faces the prospect of a five-year gap, with no spacecraft of its own capable of taking American astronauts into space. With the International Space Station (ISS) described by Nasa as "the centerpiece of our human spaceflight activities in low Earth orbit", for the moment, that means hitching a lift on Russian Soyuz spacecraft to get there – but with US grants already supporting the private space industry, that could soon change.

COTS (commercial orbital transportation services) and C3PO

Nasa’s commercial orbital transportation services (COTS) programme is one of three designed to coordinate crew and payload deliveries to the ISS via private companies, with the expectation that the need will remain through to 2017 at least – the earliest date for alternative national capability to be restored.

Along with the related commercial resupply services (CRS) and commercial crew development (CCDev) programmes, COTS is managed by the agency’s Commercial Crew and Cargo Program Office, which delights in the inescapably Star Wars themed acronym of C3PO.

"The next American-flagged vehicle to carry our astronauts into space is going to be a US commercial provider," Commercial Crew Program manager Ed Mungo said in April, as C3PO announced $269 million of funding to make it happen.

Four companies were selected. Boeing and Blue Origin will receive $92.3m and $22m respectively for their capsule designs, while the Sierra Nevada Corporation (SNC) is to get $80m to develop its vertical-takeoff / horizontal-landing Dream Chaser. The fourth, Space Exploration Technologies (SpaceX) – brain child of dot-com millionaire Elon Musk, and already the recipient of a $1.6 billion contract for cargo services to the ISS – has been allocated a further $75m to help make its Dragon space capsule capable of carrying a human crew.

Dragons and Dream Chasers

Outwardly, the Dragon and Dream Chaser designs could scarcely seem more different – the former a conventional, blunt cone, ballistic capsule and the latter a space plane – yet beneath the skin, both share a similar combination of innovative features and well established elements drawn from previous Nasa programme successes.

"India has had its own plans for an eponymously named Orbital Vehicle (OV) since the middle of the last decade."

With a similar body profile to both the earlier Apollo and the moth-balled Orion, the reusable SpaceX capsule has a carrying capacity of three tons of payload, seven people, or a mixture of each and is equipped with a standard ISS common berthing mechanism beneath its hinge-capped nose cone. Even before it begins its scheduled cargo-supply role, the Dragon has already made history.

In November 2010, it became the first-ever commercial spacecraft to be granted a re-entry license by the US Federal Aviation Administration, and a month later, its maiden voyage – forming the inaugural demonstration flight of the COTS programme – established SpaceX as the first non-governmental entity to put a vehicle into low Earth orbit and safely return it.

With COTS-2 tentatively scheduled to launch at the end of November, with ISS-docking planned to follow a few days later, Dragon is fast establishing its credentials as Nasa’s new ‘space taxi.’

The SNC Dream Chaser, by contrast, shares a common ancestry with the shuttle, having evolved from earlier lifting-body concepts, including Orbital Sciences’ X-34 and the Martin Marietta X-24A, which ultimately informed and influenced the development of Atlantis and its kin.

Externally similar to Nasa’s proposed HL-20, and sharing its minimal one-and-a-half G during re-entry, Dream Chaser too is making its presence felt as a serious contender in the sector, having successfully completed four of the 13 project milestones set out in the CCDev Agreement by October 2011.

A wider perspective

However, manned space travel in the post-shuttle era is not all about the ISS, nor is shaping its future destined to be an exclusively American prerogative.

While Nasa’s commercial partnerships are beginning to sort out its short-term need, and allow it to contemplate deep-space exploration missions in the longer term, other players are developing programmes of their own.

In the early hours of 1 November, China launched a Long March 2F rocket from Jiuquan spaceport carrying the unmanned Shenzhou 8 into orbit and towards its rendezvous two days later with the Tiangong-1 lab, itself launched at the end of September – and the country’s first ever docking in space.

"However, manned space travel in the post-shuttle era is not all about the ISS, nor is shaping its future destined to be an exclusively American prerogative."

Beijing has announced its intention to build a space station by 2020. This most recent mission will pave the way for a manned repeat performance with Shenzhou 9 and 10, when Chinese astronauts – ‘yuhangyuans’ – will live onboard for a fortnight. According to local media speculation, one of these flights, scheduled for 2012, could also see the first Chinese woman in space.

Asia’s other rising economy, India, has had its own plans for an eponymously named Orbital Vehicle (OV) since the middle of the last decade, conducting a series of unmanned re-entry trials in 2007 to gain data to design the manned capsule. Funding for the programme was approved in 2009, and the inaugural unmanned flight of the first OV is expected in 2013, with subsequent manned launches to follow sometime towards 2016.

Widening the perspective further, the European Space Agency is working on a possible manned version of its cargo-carrying Automated Transfer Vehicle – the Crew Transport Vehicle – for possible use by around 2020, and Richard Branson’s Virgin Galactic is one of a number of rival commercial ventures seeking to make space tourism a reality by the middle of the decade.

Nonetheless, with the successful completion of the Mars 500 simulation on 4 November, which had seen six men locked inside a ‘spaceship’ in Moscow for a year-and-a-half to investigate the human effects of a mission to the Red Planet, it is perhaps fitting that the final word, for now, should go to Russia. Having started the whole race into space, fifty years on, it seems the supply of Russian ‘right stuff’ is still far from exhausted.