Paul Marks, senior technology correspondent
(Image: Vandenberg Air Force Base/US air force)
China's space agency took the plaudits for successfully docking its crewed Shenzhou-9 spacecraft with its orbiting lab Tiangong-1 today, but the feat was slightly overshadowed by the weekend landing of the US X-37B spaceplane, which after a record-breaking orbital flight of 469 days showed just how far China has to go to catch up with advanced spacefaring nations.
At around noon local time, the Beijing Aerospace Control Centre relayed live pictures of Shenzhou-9's docking on state broadcaster China Central Television. The space capsule held off at a distance of 62 kilometres from Tiangong-1 before making its docking approach just before 2 pm - and once the crew had manually locked on to the latter's cruciform docking target it took only 8 minutes to latch the spacecraft together safely.
They didn't hang around: shortly afterwards, all three crew - commander Jing Haipeng plus astronaut Liu Wang and China's first woman in space, Liu Yang - were all pictured inside the space laboratory and smiling broadly as they stretched their legs in zero-g. They will spend the rest of their two week mission conducting "scientific experiments and technical tests" - though compared to the ISS (and even the now deorbited Mir) Tiangong-1's bare, padded interior looks surprisingly devoid of instruments.
(Image: Jia Qing/AP/Press Association Images)
Not much is known about Tiangong-1's purpose beyond its claimed role as a testbed for docking systems for larger space station modules that will fly later this decade. That lack of knowledge has fuelled speculation that the US air force's X-37B spaceplane, which was loitering in various orbits after being launched in March 2011, was spying on the space lab.
This Boeing-built spaceplane, roughly one quarter the size of the space shuttle, is equally mysterious. It flies to orbit on a regular rocket and when there deploys a solar array that gives its sensors the power they need for extended missions. It also has enough propellant to fire thrusters that make small changes to its orbit in a bid to foil surveillance. The vehicle re-enters the atmosphere just like the shuttle but lands entirely autonomously, making it a space drone.
At no point has the USAF revealed the craft's purpose: in addition to spacecraft surveillance, it could deploy a robot that repairs (or disables) satellites in orbit, say some, while at the darker end of the spectrum of possibilities - it was a DARPA project in its early days - it could carry a warhead, using its drone homing capability to provide surprise precision strike from orbit.
But whatever it is for, the X-37B seems to be a triumph of spacecraft reusability, the holy grail of latter-day western space flight. In December 2010, the first X-37B (called OTV-1) landed at Vandenberg Air Force Base in California after a 220-day mission, its nose still glowing in infrared footage with the residual heat of its incandescent re-entry. Now that mission time has been more than doubled by the second vehicle which landed on 16 June: OTV-2 managed an astonishing 469 days in orbit (see it landing in the video below).
In geopolitical terms, and at a time of major cost pressures, developing viable reusability like this is key. It is the major technology driver for SpaceX, for example, the first firm to fly a commercial cargo flight to the ISS and which is now converting that technology for crewed missions. Boeing says the X-37B is designed to develop "reusable space vehicle technologies that could become key enablers for future space missions". Its design is scalable, too, so larger versions could be made to carry astronauts.
So while China's achievement today is impressive, it's on the trailing edge of space-flight technology: the US and Russia docked with their own orbital space stations in the early 1970s - and even with each other in Apollo and Soyuz capsules in 1975. Congratulations to the Chinese space agency - but the landing of the X-37B only serves to show them how far they have to go.